CN120824408A

CN120824408A - Sulfide solid electrolyte and preparation method thereof, solid electrolyte membrane, electrode plate, solid-state battery and electrical device

Info

Publication number: CN120824408A
Application number: CN202410437620.5A
Authority: CN
Inventors: 翁伟; 胡波兵; 宁子杨; 令月霞; 邵期农; 阳敦杰; 杨武; 王延涛; 钟成斌; 钟泞宽; 张宏图
Original assignee: Contemporary Amperex Technology Co Ltd
Current assignee: Contemporary Amperex Technology Co Ltd
Priority date: 2024-04-11
Filing date: 2024-04-11
Publication date: 2025-10-21
Also published as: WO2025213780A1

Abstract

The present application relates to a sulfide solid electrolyte and its preparation method, solid electrolyte membrane, electrode plate, solid-state battery, and electrical device. The sulfide solid electrolyte comprises an argyrodite-type crystal phase; the argyrodite-type crystal phase comprises Li, P, S, M, and T; wherein M is selected from one or both of Se and Te, and T is selected from one or both of Cl and Br; in the argyrodite-type crystal phase, the atomic ratio of T to P is 1+x, with x >0; in the argyrodite-type crystal phase, the atomic ratio of M to P is y, with y > 0. The sulfide solid electrolyte has high ionic conductivity and can effectively improve the rate performance of solid-state batteries.

Description

Sulfide solid electrolyte, preparation method thereof, solid electrolyte membrane, electrode plate, solid battery and electricity utilization device

Technical Field

The application relates to the technical field of secondary batteries, further relates to the technical field of solid batteries, and further relates to sulfide solid electrolyte, a preparation method of sulfide solid electrolyte, a solid electrolyte membrane, an electrode plate, a solid battery and an electric device.

Background

The statements herein merely provide background information related to the present disclosure and may not necessarily constitute prior art.

The solid-state battery introduces nonflammable solid electrolyte to replace organic electrolyte in the traditional liquid secondary battery, so that the safety of the battery is greatly improved. Among the numerous solid electrolyte materials, sulfide solid electrolyte is one of the most promising solid electrolyte materials for practical use and industrialization due to its extremely high ionic conductivity and excellent mechanical properties. As a sulfide solid electrolyte, the ion conductivity of the sintered product of the sulfur silver germanium ore type sulfide solid electrolyte often cannot be expected, resulting in unsatisfactory discharge capacity and rate performance of the solid-state battery.

Disclosure of Invention

In view of the above, the present application provides a sulfide solid electrolyte and a method of manufacturing the same, a solid electrolyte membrane, an electrode tab, a solid battery, and an electric device according to various embodiments and various examples of the present application. The sulfide solid electrolyte has higher ionic conductivity and can effectively improve the multiplying power performance of the solid-state battery.

In a first aspect of the present application, there is provided a sulfide solid electrolyte comprising a sulfur silver germanium ore-type crystal phase;

The sulfur silver germanium ore type crystal phase comprises Li element, P element, S element, M element and T element, wherein the M element is selected from one or two of Se element and Te element, and the T element is selected from one or two of Cl element and Br element;

in the sulfur silver germanium ore type crystal phase, the atomic number ratio of the T element to the P element is recorded as 1+x, and x >0;

In the sulfur silver germanium ore-type crystal phase, the atomic number ratio of the M element to the P element is denoted as y, and y >0.

The sulfide solid electrolyte provided in the first aspect of the application is a sulfide solid electrolyte comprising a sulfide silver germanium ore type crystal phase, wherein the sulfide silver germanium ore type crystal phase contains Li element, P element, S element and T element (the T element is one or two of Cl element and Br element), under the condition that the atomic number ratio (1+x) of the T element to the P element is more than 1 (at the moment, x > 0), more lithium vacancies can be generated by introducing M element (one or two selected from Se element and Te element), on one hand, the ionic radius of the M element is more than that of the S element, the ionic transmission structure of the M element can be widened, the ionic conductivity of the sulfide solid electrolyte can be improved by utilizing the smaller coulomb binding force of the T element to lithium ions, the migration of lithium ions can be promoted more easily, the ionic conductivity of the solid electrolyte can be promoted, on the other hand, the sulfur (S) loss of sulfide raw materials in the sintering process can be restrained, the heterogeneous phase generation of LiT and the ionic conductivity of the solid electrolyte can be promoted, on the other hand, the ionic radius of the M element is more than that of the S element can be widened, the ionic transmission structure of the S element can be widened, and the ionic conductivity of the sulfide solid electrolyte can be improved, and the ionic conductivity of the sulfide solid electrolyte can be remarkably improved.

When the sulfide solid electrolyte is used as a solid electrolyte material in a solid-state battery, the sulfide solid electrolyte can be used as the solid electrolyte material in one or more structural layers of the solid electrolyte layer, the positive electrode layer and the negative electrode layer, so that the resistance of the solid-state battery can be effectively reduced, the multiplying power performance of the solid-state battery can be improved, and the solid-state battery can have better electrochemical performance under high multiplying power.

When the sulfide solid electrolyte is used as the positive electrode electrolyte particles in the positive electrode layer, the capacity exertion of the positive electrode active material in the positive electrode layer can also be promoted.

When the sulfide solid electrolyte is used as the positive electrode electrolyte particles in the negative electrode layer, the capacity exertion of the positive electrode active material in the negative electrode layer can also be promoted.

In some embodiments, 0< x≤0.8 in the sulfur silver germanium ore type crystal phase.

By controlling x in the above range, the T element can be controlled in a better range, which is beneficial to better improving the ionic conductivity of sulfide solid electrolyte, and the impurity phase content can be controlled in a lower proportion.

In some embodiments, 0< y≤0.1 in the sulfur silver germanium ore type crystal phase.

By controlling y in the above range, the M element can be controlled in a more preferable range, which is more advantageous in suppressing the impurity phase and improving the ion conductivity of the sulfide solid electrolyte.

In some embodiments, in the sulfur silver germanium ore type crystal phase, the atomic number ratio of Li element, P element, S element, M element and T element is (6-x): 1 (5-x-y): y (1+x), wherein 0< x≤0.8, 0< y≤0.1.

In some embodiments, the sulfur silver germanium ore type crystalline phase has the chemical formula Li _6-xPS_5-x-yM_yT_1+x.

When the sulfur silver germanium ore type crystal phase has the chemical formula, the mixed phase is better inhibited and the ion conductivity of the sulfide solid electrolyte is better improved.

In some embodiments, the sulfur silver germanium ore type crystalline phase has the chemical formula Li _6-xPS_5-x-ySe_yCl_1+x.

When the M element includes Se element and the T element includes Cl element, the sulfide solid electrolyte is advantageous in having better ionic conductivity.

In some embodiments, the sulfur silver germanium ore-type crystalline phase satisfies one or more of the following characteristics:

In the sulfur silver germanium ore type crystal phase, x is more than or equal to 0.05 and less than or equal to 0.8, alternatively, x is more than or equal to 0.1 and less than or equal to 0.8, and further alternatively, x is more than or equal to 0.3 and less than or equal to 0.8;

in the sulfur silver germanium ore type crystal phase, y is more than or equal to 0.02 and less than or equal to 0.1, alternatively, y is more than or equal to 0.02 and less than or equal to 0.09.

In some embodiments of the present invention, in some embodiments, x is more than or equal to 0.3 and less than or equal to 0.8,0.02 y is more than or equal to 0.09.

By controlling one or two parameters of x and y in the range, the T element and the M element can be adjusted to have more proper contents, which is beneficial to better improving the ion conductivity of the sulfide solid electrolyte. Wherein, by controlling y in the above range, the M element can be controlled in a more preferable range, which is more advantageous in suppressing the impurity phase and improving the ionic conductivity of the sulfide solid electrolyte.

In some embodiments, the atomic number ratio of S element to P element in the S-Ag-Ge ore type crystal phase is recorded as 5-x-y, and 4.1≤5-x-y <5.0.

In some embodiments, 4.1< (5-x-y) <4.7.

When the atomic number ratio (5-x-y) of the S element to the P element is controlled within the range, the impurity phase is more favorably inhibited and the ionic conductivity of the sulfide solid electrolyte is more favorably improved by controlling the content of x and y.

In some embodiments, the sulfur silver germanium ore-type crystalline phase satisfies one or both of the following characteristics:

In the sulfur silver germanium ore type crystal phase, the T element includes Cl element;

in the sulfur silver germanium ore type crystal phase, the M element includes a Se element.

When the M element includes a Se element, it is advantageous for the sulfide solid electrolyte to have a better ion conductivity.

When the T element includes Cl element, it is advantageous for the sulfide solid electrolyte to have better ion conductivity.

in the sulfur silver germanium ore type crystal phase, the atomic number ratio of Cl element to Br element is more than or equal to 1;

in the sulfur silver germanium ore type crystal phase, the atomic number ratio of Se element and Te element is greater than or equal to 1.

By setting one or two characteristics of the atomic number ratio of Cl element and Br element being more than 1 and the atomic number ratio of Se element and Te element being more than 1, the ionic conductivity of the sulfide solid electrolyte is more beneficial to improvement.

In some embodiments, the sulfur silver germanium ore type crystalline phase has any one of the following formulas ：Li_5.7PS_4.65Se_0.05Cl_1.3、Li_5.5PS_4.44Se_0.06Cl₁Br_0.5、Li_5.5PS_4.44Se_0.05Te_0.01Cl₁Br_0.5 and Li _5.5PS_4.44Se_0.06Cl_1.5.

By disposing one or more of the foregoing sulfur silver germanium ore-type crystalline phases in the sulfide solid electrolyte, it is more advantageous to reduce the impurity phase and to enhance the ion conductivity.

In some embodiments, the 2 θ (°) diffraction angle in the X-ray diffraction pattern of the sulfide solid electrolyte has a characteristic peak that conforms to the sulfur silver germanium ore type crystalline phase.

In some embodiments, the sulfide solid electrolyte satisfies at least one of the following characteristics:

Diffraction angles of 2θ (°) in an X-ray diffraction pattern of the sulfide solid electrolyte have peaks at 15.5±δ°, 18.1±δ°, 25.6±δ°, 30.1±δ°, 31.4±δ°, 39.8±δ°, 45.1±δ°, 47.9±δ° and 52.5±δ°, wherein δ is 0.2 or 0.1;

The sulfide solid electrolyte has no LiT hetero-phase peak in an X-ray diffraction diagram;

the sulfide solid electrolyte has no diffraction peaks at the diffraction angles of 2 theta (°) of the X-ray diffraction pattern of 34.9±0.2°, 29.2±0.2° and 33.9±0.2°;

An X-ray diffraction pattern of the sulfide solid electrolyte is obtained by using Cu kα rays;

the X-ray diffraction pattern of the sulfide solid electrolyte was obtained by a powder X-ray diffraction test.

The chemical composition and the amount of the impurity phase in the sulfide solid electrolyte can be confirmed by X-ray diffraction (XRD) detection.

In a second aspect of the present application, there is provided a method for producing a sulfide solid electrolyte which can be used for producing the sulfide solid electrolyte according to the first aspect of the present application.

In some embodiments, the method for preparing a sulfide solid electrolyte includes the steps of:

providing a precursor mixture comprising Li ₂S、P₂S₅, an optional elemental sulfur, an elemental M and LiT according to the required stoichiometric ratio of raw materials, wherein the elemental M is selected from one or two of an elemental Se and an elemental Te, T is halogen, and LiT is selected from one or two of an elemental LiCl and an elemental LiBr;

And sintering the precursor mixture in an inert atmosphere to prepare a sulfide solid electrolyte comprising a sulfur silver germanium ore type crystal phase, wherein in the sulfur silver germanium ore type crystal phase, the atomic number ratio of the T element to the P element is recorded as 1+x, the atomic number ratio of the M element to the P element is recorded as y, and the sulfur silver germanium ore type crystal phase satisfies x >0 and y >0.

In some embodiments, the method of preparing a sulfide solid electrolyte satisfies one or more of the following characteristics:

In the step of sintering the precursor mixture in an inert atmosphere, the sintering temperature is 450-530 ℃;

the sulfide solid electrolyte prepared is the sulfide solid electrolyte according to the first aspect of the application.

In a third aspect of the present application, there is provided a solid electrolyte membrane comprising at least one of the sulfide solid electrolyte according to the first aspect of the present application and the sulfide solid electrolyte produced by the production method according to the second aspect of the present application.

The solid electrolyte membrane provided with the sulfide solid electrolyte can effectively reduce the resistance, can endow the corresponding solid battery with better multiplying power performance, and can enable the solid battery to have better electrochemical performance under high multiplying power.

In a fourth aspect of the present application, there is provided an electrode sheet comprising an electrode active material layer comprising an electrode active material, and further comprising at least one of the sulfide solid electrolyte according to the first aspect of the present application and the sulfide solid electrolyte prepared by the preparation method according to the second aspect of the present application.

In some embodiments, the electrode sheet is a positive electrode sheet, the electrode active material layer is referred to as a positive electrode active material layer, and the electrode active material layer is referred to as a positive electrode active material;

or the electrode plate is a negative electrode plate, the electrode active material layer is marked as a negative electrode active material layer, and the electrode active material is marked as a negative electrode active material.

The electrode pole piece provided with the sulfide solid electrolyte can reduce the internal resistance of the pole piece, promote the capacity exertion of active substances in the pole piece, and endow the corresponding solid battery with better multiplying power performance.

The electrode sheet can be a positive electrode sheet or a negative electrode sheet.

In a fifth aspect of the present application, there is provided a solid-state battery comprising at least one of the sulfide solid electrolyte according to the first aspect of the present application, the sulfide solid electrolyte prepared by the preparation method according to the second aspect of the present application, the solid electrolyte membrane according to the third aspect of the present application, and the electrode sheet according to the fourth aspect of the present application.

In some embodiments, the solid state battery is a sulfide all-solid state battery.

For the solid-state battery provided with the aforementioned sulfide solid electrolyte, the sulfide solid electrolyte may be provided at one or more of the positive electrode layer, the negative electrode layer, and the solid electrolyte layer.

In a sixth aspect of the present application, there is provided an electric device comprising at least one of the sulfide solid electrolyte according to the first aspect of the present application, the sulfide solid electrolyte prepared by the preparation method according to the second aspect of the present application, the solid electrolyte membrane according to the third aspect of the present application, the electrode tab according to the fourth aspect of the present application, and the solid-state battery according to the fifth aspect of the present application.

The details of one or more implementations or embodiments of the application are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the application will be apparent from the description and drawings, and from the claims.

Drawings

For a better description and illustration of embodiments, examples, or examples provided herein, reference may be made to one or more of the accompanying drawings. Additional details or examples used to describe the drawings should not be construed as limiting the scope of any of the disclosed applications, the presently described implementations, examples or illustrations, and the best mode of carrying out these applications presently understood. It should be further noted that the drawings are drawn in a simplified form and serve only to facilitate a convenient and clear illustration of the application. The various dimensions of each of the components shown in the figures are arbitrarily, may be exact or may not be drawn to scale. For example, the dimensions of the elements are exaggerated in some places in the drawings for clarity of illustration. Unless otherwise indicated, the various elements in the drawings are not drawn to scale. The drawings of the present application are not intended to limit each size of each component. Also, like reference numerals are used to designate like parts throughout the accompanying drawings. In the drawings:

Fig. 1 is a schematic structural diagram of a solid-state battery cell according to an embodiment of the present application, where the solid-state battery cell includes a positive electrode layer, a solid electrolyte layer, and a negative electrode layer that are sequentially stacked.

Fig. 2 is a schematic view of a solid-state battery cell according to an embodiment of the present application.

Fig. 3 is an exploded view of the solid-state battery cell according to an embodiment of the present application shown in fig. 2.

Fig. 4 is a schematic view of a battery module according to an embodiment of the present application.

Fig. 5 is a schematic view of a battery pack according to an embodiment of the present application.

Fig. 6 is an exploded view of the battery pack of the embodiment of the present application shown in fig. 5.

Fig. 7 is a schematic view of an electric device in which a solid-state battery according to an embodiment of the present application is used as a power source.

Fig. 8 is an X-ray diffraction (XRD) pattern of sulfide solid electrolyte prepared in example 8 and comparative example 3 in the present application, with the abscissa axis being 2θ (unit is degree may be expressed as °), and the ordinate axis being intensity.

Reference numerals indicate 100, a solid electrolyte layer, 200, a positive electrode layer, 300, a negative electrode layer, 1, a battery pack, 2, an upper box, 3, a lower box, 4, a battery module, 5, a solid-state battery cell, 51, a shell, 52, a solid-state battery cell, 53, a cover plate and 6, and an electric device.

Detailed Description

Hereinafter, some embodiments of the sulfide solid electrolyte of the present application, a method of producing the same, a solid electrolyte membrane, an electrode tab, a solid battery, an electric device, and the like are described in detail with reference to the drawings as appropriate. However, unnecessary detailed description may be omitted. For example, detailed descriptions of well-known matters and repeated descriptions of the actual same structure may be omitted. This is to avoid that the following description becomes unnecessarily lengthy, facilitating the understanding of those skilled in the art. Furthermore, the drawings and the following description are provided for a full understanding of the present application by those skilled in the art, and are not intended to limit the subject matter recited in the claims.

The "range" disclosed herein may be defined in terms of lower and upper limits, with a given range being defined by the selection of a lower limit and an upper limit, the selected lower and upper limits defining the boundaries of the particular range. Ranges may be defined in this way as either inclusive or exclusive of the endpoints, any of which may be independently inclusive or exclusive, and any combination may be made, i.e., any lower limit may be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a particular parameter, it is understood that ranges of 60-110 and 80-120 are also contemplated. Furthermore, if minimum range values 1 and 2 are listed, and if maximum range values 3,4, and 5 are also listed, the following ranges are all contemplated as 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In the present application, unless otherwise indicated, the numerical range "a-b" represents a shorthand representation of any combination of real numbers between a and b, where a and b are both real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" have been listed throughout, and "0-5" is simply a shorthand representation of a combination of these values. When a certain parameter is expressed as an integer of 2 or more, it is equivalent to the list of the parameter as, for example, integers of 2,3, 4,5, 6, 7, 8, 9, 10, 11, 12, etc. For example, when a parameter is expressed as an integer selected from "2-10", the integers 2,3, 4,5, 6, 7, 8, 9 and 10 are listed.

In the present application, unless otherwise specified, "about" means that the fluctuation range may vary depending on the type and the numerical value of the present number within a range of a reasonable amplitude above and below the present number. For example, it may be allowed to range in a range of ±10%, ±5%, ±2%, ±1% or the like. For example, taking "about 20 ℃ and its divisor of ±1 ℃, about 19 ℃, 19.5 ℃ and the like within the divisor range indicated by" about 20 ℃ should also be included within the range indicated by "about 20 ℃.

In the present application, as referred to "plural", "a plurality", and the like, the terms "a" and "an" are not particularly limited, and are greater than or equal to 2 in number. For example, "one or more" means one or two or more. It is understood that when referring to "any plurality" of items, it is intended to refer to any suitable combination of items, i.e., combinations of items in a manner that is not conflicting and capable of carrying out the application.

All embodiments of the application and alternative embodiments may be combined with each other to form new solutions, unless otherwise specified.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment or implementation of the application. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those of skill in the art will explicitly and implicitly appreciate that the embodiments described herein may be combined with other embodiments. Reference herein to "embodiments" is intended to have a similar understanding.

It will be appreciated by those skilled in the art that in the methods of the embodiments or examples, the order of writing the steps is not meant to be a strict order of execution and the detailed order of execution of the steps should be determined by their functions and possible inherent logic. All the steps of the present application may be performed sequentially or randomly, and may preferably be performed sequentially, unless otherwise specified. For example, method M comprises steps (a) and (b), meaning that the method may comprise steps (a) and (b) performed sequentially, or may comprise steps (b) and (a) performed sequentially. For example, method M may further include step (c), meaning that step (c) may be added to method M in any order, e.g., method M may include steps (a), (b), and (c), may include steps (a), (c), and (b), may include steps (c), (a), and (b), and so on.

In the present application, the open technical features or technical solutions described by words such as "contain", "include" and the like are considered to provide both closed features or solutions composed of the listed members and open features or solutions including additional members in addition to the listed members unless otherwise stated. For example, a includes a1, a2, and a3, and may include other members or no additional members unless otherwise specified, and may be considered as providing both the feature or scheme of "a consists of a1, a2, and a3" or "a is selected from a1, a2, and a3" and the feature or scheme of "a includes not only a1, a2, and a3 but also other members".

In the present application, a (e.g., B), where B is one non-limiting example of a, is understood not to be limited to B, unless otherwise stated.

In the present application, "optional" refers to the presence or absence of the possibility, i.e., to any one of the two parallel schemes selected from "with" or "without". If multiple "alternatives" occur in a technical solution, if no particular description exists and there is no contradiction or mutual constraint, then each "alternative" is independent. The description of the application, such as "optionally including," "optionally containing," and the like, is intended to cover "optionally including" as an example, meaning "may or may not include," unless otherwise specified.

In the present application, unless otherwise indicated, the term "and/or" corresponding feature or aspect includes any one of two or more of the listed items in relation to each other, as well as any and all combinations of the listed items in relation to each other, where any and all combinations include any two of the listed items in relation to each other, any more of the listed items in relation to each other, or all combinations of the listed items in relation to each other. For example, "a and/or B" means A, B and "a and B in combination". Wherein "comprising A and/or B" may mean "comprising A, comprising B, and comprising A and B", and "comprising A, comprising B, or comprising A and B", as appropriate, may be understood according to the statement in which they are located.

As used herein, "a combination thereof," "any combination thereof," and the like include all suitable combinations of any two or more of the listed items.

As used herein, "suitable" means "in" suitable combination "," suitable means "," any suitable means ", and the like, is based on the technical scheme capable of implementing the present application.

Herein, "preferred," "better," "preferred," are merely to describe embodiments or examples that are better suited, and it should be understood that they are not to limit the scope of the application. If there are multiple "preferences" in a solution, if there is no particular description and there is no conflict or constraint, then each "preference" is independent of the others.

In the present application, "further," "still further," "special," "for example," "such as," "example," "illustrated," etc. are for descriptive purposes and are not to be construed as limiting the scope of the application.

In the present application, the terms "first", "second", "third", "fourth", "fifth", "sixth", etc. are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or quantity or as implying an importance or quantity of a technical feature indicated. Also, "first," "second," "third," "fourth," "fifth," "sixth," etc. are for non-exhaustive list description purposes only, and should not be construed as limiting the number of closed forms.

In the present application, unless expressly stated or limited otherwise, a first feature "up" or "down" a second feature may be the first and second features in direct contact, or the first and second features in indirect contact via an intervening medium. In the present application, unless explicitly specified and defined otherwise, the first feature "up" or "down" on the second feature may indicate the mutual positional relationship of the level, or may indicate only the existence of the adhering relationship without limiting the mutual positional relationship of the level.

In the present application, the term "room temperature" generally refers to 4 ℃ to 35 ℃ and may refer to 20±5 ℃. In some embodiments or examples of the present application, room temperature refers to 20 ℃ to 30 ℃.

In the present application, referring to a unit of a data range, if a unit is only carried behind a right end point, the units indicating the left and right end points are the same. For example, 3 to 5 hours or 3 to 5 hours each represent the unit of the left end point "3" and the right end point "5" as h (hours), and have the same meaning as 3 to 5 hours. Moreover, similar descriptions of other parameters such as temperature, dimensions, etc. are to be understood in the same manner.

The weight or mass of the relevant components mentioned in the embodiments or examples of the present application may refer not only to the content of each component but also to the proportional relationship of the weight or mass of each component, and thus, it is within the scope of the present application as long as the content of the relevant components is scaled up or down according to the embodiments or examples of the present application. Further, the mass involved in the embodiments or examples of the present application may be in the form of micrograms (μg), milligrams (mg), grams (g), kilograms (kg) and other mass units known in the chemical industry. Unless otherwise stated, the mass ratio is equal to the corresponding weight ratio, such as mass of substance A is m1, weight is W1, mass of substance B is m2, and weight is W2, then the mass ratio of the two is m1/m2 numerically equal to the corresponding weight ratio W1/W2.

In the present application, wt% means weight percent by weight, which is numerically equal to the corresponding mass percent by mass, unless otherwise stated. In the present application, the term "0" and "0wt%" are used interchangeably with the same meaning for weight percent.

The parameter units referred to in this application, unless otherwise stated, are nm for nanometer, μm for micrometer, S/cm for Siemens per centimeter, V for volt, kV for kilovolt, mA for milliamp, hz for Hertz, mPa.S for milliPa.s, mg/cm ² for milligrams per square centimeter, g/cm ² for grams per square centimeter, g/cm ³ for grams per cubic centimeter, and C for degrees Celsius.

In the present application, "greater than or equal to" and ". Gtoreq" have the same meaning and are used interchangeably, and "less than or equal to", "less than or equal to" and ". Ltoreq.have the same meaning and are used interchangeably, and" greater than "may be equivalently represented as" >, "less than" may be equivalently represented as "<". In the present application, unless otherwise stated, "greater than or equal to" and "greater than or equal to" may be regarded as providing both schemes of "greater than" and "equal to" as well. In the present application, unless otherwise stated, "less than or equal to" and "less than or equal to" may be regarded as also providing both "less than" and "equal to" schemes.

In the present application, the exemplary descriptions related to "in some embodiments (or examples)", "in one embodiment (or example)", etc. may cover, but are not limited to, the meaning that these schemes may be combined with other schemes to form new technical schemes in a suitable manner.

In the present application, unless otherwise specified, the "solid-state battery" provided in the present application refers to a battery in which an electrolyte in the battery includes a solid electrolyte, and in general, the solid-state battery includes a positive electrode layer, a solid electrolyte layer, and a negative electrode layer. During the charge and discharge of the battery, active ions are inserted and extracted back and forth between the positive electrode layer and the negative electrode layer. The solid electrolyte layer plays a role in conducting ions between the positive electrode layer and the negative electrode layer, and can also isolate the positive electrode layer from the negative electrode layer so as to play a role in preventing the positive electrode from being shorted, so that an isolating film in a conventional lithium ion battery can be omitted from being arranged in the solid battery. The solid-state battery introduces nonflammable solid electrolyte to replace organic electrolyte in the traditional liquid lithium ion battery, so that the safety of the battery is greatly improved. Besides improving safety, the solid-state battery can be better adapted to anode and cathode materials with high energy density, reduces the weight of the system, and is beneficial to improving the energy density.

In the present application, unless otherwise specified, "solid electrolyte" refers to an electrolyte material or electrolyte substance that exists in a solid state during storage and preparation of a solid state battery and components constituting the solid state battery, and during operation of the solid state battery. It is understood that solid electrolytes exist in solid form, including but not limited to at room temperature.

In the present application, the electrode layer may be a positive electrode layer or a negative electrode layer, and the electrode layer includes an electrode active material, unless otherwise specified. The electrode active material may be a positive electrode active material or a negative electrode active material. The electrode active material may be contained in the electrode active material particles as particles. The electrode active particles may be positive electrode active particles or negative electrode active particles. "electrode active material" in an electrode layer refers to a material capable of reversibly intercalating and deintercalating active ions. Unless otherwise specified, "negative electrode active material" refers to a material for a negative electrode layer that is capable of reversibly intercalating and deintercalating active ions, and "positive electrode active material" refers to a material for a positive electrode layer that is capable of reversibly deintercalating and intercalating active ions. When the solid-state battery is charged, active ions are extracted from the positive electrode and are embedded into the negative electrode through the solid electrolyte layer, and when the solid-state battery is discharged, active ions are extracted from the negative electrode and are embedded into the positive electrode. The active ion is not particularly limited, and may be lithium ion, in which case it corresponds to a lithium ion solid-state battery.

In the present application, "electrode active particles" refer to particles containing an electrode active material.

In the present application, "electrode active material", "active material" and "active material" have the same meaning and are used interchangeably, and "positive electrode active material" have the same meaning and are used interchangeably, and "negative electrode active material" have the same meaning and are used interchangeably. The "positive electrode active material" and the "positive electrode active material" have the same meaning and are used interchangeably, and the "negative electrode active material" have the same meaning and are used interchangeably.

In the present application, unless otherwise specified, the "electrode active material layer" includes at least one of a positive electrode active material layer in a positive electrode layer and a negative electrode active material layer in a negative electrode layer, and the electrode active material layer may refer to either the positive electrode active material layer or the negative electrode active material layer, depending on the detailed case. It is understood that the positive electrode active material layer contains a positive electrode active material, and the negative electrode active material layer contains a negative electrode active material. In the present application, the "electrode active material layer" may also be simply referred to as "active material layer".

In the present application, the positive electrode layer includes at least a positive electrode active material layer unless otherwise stated.

In the present application, the positive electrode active material layer includes at least positive electrode active particles, and usually also positive electrode electrolyte particles, unless otherwise specified.

In the present application, unless otherwise specified, "positive electrode active particles" refer to particles containing a positive electrode active material, which have the ability to reversibly release and intercalate active ions.

In the present application, unless otherwise specified, "positive electrode electrolyte particles" and "positive electrode solid electrolyte" have the same meaning, and are used interchangeably to refer to solid electrolytes that can be used in a positive electrode film or a positive electrode layer. The positive electrode electrolyte particles can play roles in enhancing the ion conduction capability of a positive electrode film or a positive electrode layer and reducing interface impedance, and can promote the charge transfer efficiency of a positive electrode active substance and the outside and the sufficient release of the capacity of the positive electrode active substance.

In the present application, the anode layer includes at least an anode active material layer unless otherwise stated.

In the present application, the anode active material layer includes at least anode active particles, and may or may not include anode electrolyte particles, unless otherwise stated.

In the present application, unless otherwise specified, "anode active particles" refer to particles containing an anode active material, which have the ability to reversibly intercalate and deintercalate active ions.

In the present application, unless otherwise specified, "anode electrolyte particles" and "anode solid electrolyte" have the same meaning, and are used interchangeably to refer to solid electrolytes that can be used in an anode film or an anode layer. The negative electrode electrolyte particles can play roles in enhancing the ion conduction capability of a negative electrode film or a negative electrode layer and reducing interface impedance, and can promote the charge transfer efficiency of a negative electrode active substance and the outside and the sufficient release of the capacity of the negative electrode active substance.

In solid-state batteries, interface contact and interface stability problems are one of the pain points that limit the performance of the battery, and poor interface contact can affect the cycling performance of the battery. Due to the "solid-solid contact" characteristics present in solid-state batteries, the contact between the particulate matter inside the electrode layers includes a large number of point contacts, and does not completely wet the electrode active material as the electrolyte in liquid batteries, thereby causing insufficient interfacial ion transport within the electrode layers, and thus resulting in non-optimal performance of the solid-state battery. By doping the solid electrolyte material into the electrode layer, the ion conducting capacity of the electrode layer can be theoretically enhanced, the charge transfer efficiency of the electrode active material and the outside and the sufficient release of the capacity thereof are promoted, and the impedance is reduced. Among the numerous solid electrolyte materials, sulfide solid electrolyte is one of the most promising solid electrolyte materials for practical and industrial purposes due to its extremely high ionic conductivity (about 10 ^-3～10^-2 S/cm) and excellent mechanical properties, such as good flexibility, so that it has excellent ion conductivity and good deformability.

For sulfur silver germanium ore type sulfide solid electrolytes containing Li element, P element, S element and Cl element, sintering is generally performed by using precursor raw materials including Li ₂S、P₂S₅ and LiCl, sulfur (S) loss is generally generated during sintering, and impurity phases such as LiCl are easily included in the sintered product. The existence of the impurity phase can prevent the ion transmission of the sulfur silver germanium ore type sulfide solid electrolyte, so that the ion conductivity of the solid electrolyte material is not ideal.

When the excessive Cl element exists in the sulfur silver germanium ore type sulfide solid electrolyte, the S content is obviously reduced along with S loss during sintering, the impurity phase content such as LiCl and the like is higher, ion transmission is seriously hindered, and the ion conductivity of the solid electrolyte material is obviously reduced.

The application provides a sulfide solid electrolyte, a preparation method thereof, a solid electrolyte membrane, an electrode plate, a solid battery and an electric device, and can also provide a positive electrode membrane, a negative electrode membrane and a secondary battery. The sulfide solid electrolyte has higher ionic conductivity and can effectively improve the rate performance of a secondary battery or a solid battery.

In a first aspect of the application, a sulfide solid electrolyte is provided that includes a sulfur silver germanium ore-type crystalline phase.

In some embodiments, the sulfur silver germanium ore type crystal phase comprises Li element, P element, S element, M element and T element, wherein the M element is selected from one or two of Se element and Te element, and the T element is selected from one or two of Cl element and Br element.

In some embodiments, in the sulfur silver germanium ore type crystal phase, the atomic number ratio of the T element to the P element is written as 1+x, and x >0.

In some embodiments, in the sulfur silver germanium ore type crystal phase, the atomic number ratio of the M element to the P element is denoted as y, and y >0.

In some embodiments, a sulfide solid electrolyte is provided that includes a sulfur silver germanium ore-type crystalline phase;

In the sulfur silver germanium ore type crystal phase, the atomic number ratio of the M element to the P element is denoted as y, and y >0.

In the present application, unless otherwise specified, "sulfide electrolyte" and "sulfide solid electrolyte" have the same meaning and are used interchangeably, and refer to a sulfide-form solid electrolyte in which sulfur (S) element is included in the sulfide form. The "sulfide electrolyte" according to the embodiment or example of the present application may be contained in any one of the solid electrolyte layer, the positive electrode layer, and the negative electrode layer, in the electrolyte substance of the solid electrolyte layer, in the positive electrode electrolyte particles, or in the negative electrode electrolyte particles.

In the present application, unless otherwise specified, "sulfur silver germanium ore-type crystal phase" means a sulfide solid electrolyte having the same or similar crystal structure as sulfide solid electrolyte Li ₆PS₅ Cl, belonging to a cubic crystal system, sulfur silver germanium ore-type crystal phase corresponds to sulfur silver germanium ore-type sulfide solid electrolyte, and "sulfur silver germanium ore-type sulfide solid electrolyte" means a sulfide solid electrolyte having the same or similar crystal structure as sulfide solid electrolyte Li ₆PS₅ Cl.

In the sulfide solid electrolyte provided by the application, in the crystal structure of the sulfur silver germanium ore type crystal phase, the T element is excessive ((1+x) >1, namely x > 0), and meanwhile, M element capable of compensating S loss is introduced.

In the present application, unless otherwise specified, "atomic number ratio" means the number ratio of a specified element or atom, and may be measured in units of moles, in which case "atomic mole ratio" corresponds.

In the present application, it is possible to determine whether the sulfide solid electrolyte includes a sulfur silver germanium ore type crystal phase according to an X-ray diffraction (XRD) pattern, unless otherwise specified. In the present application, unless otherwise specified, an X-ray diffraction pattern of a sulfide solid electrolyte is obtained by using Cu kα rays using a powder sample. Typically, the 2-theta (°) scan range includes at least 10 ° -50 ° (the scan range may include 10 ° -80 °), and the 2-theta (°) scan speed may be 0.02 °/second. In some embodiments, XRD test instruments and parameters are Bruker-D8 advance, cu target K alpha 1 rays are adopted, the wavelength lambda is 0.15406nm, the X-ray tube is controlled at 40kV and 40mA, the scanning range of 2 theta (DEG) is 10 DEG-80 DEG, and the scanning speed of 2 theta (DEG) is 0.02 DEG/second. The skilled person can determine whether the sulfide solid electrolyte to be measured includes a sulfur silver germanium ore type crystal phase according to the comparison with the XRD standard spectrum of Li ₆PS₅ Cl. In some embodiments, the X-ray diffraction pattern of the sulfide solid electrolyte has peaks at about 14.6 °, 17.4 °, 20.2 °,20.5 °, 24.0 °, 26.9 °, 29.5 °, 32.6 °, 36.5 °, 41.5 °, and 47.3 ° of the 2θ (°) diffraction angles of the following group. The actual X-ray diffraction pattern may have a slight shift (for example, ±δ°) in position depending on the measurement factors such as the measurement instrument and the measurement condition, but it is understood that it is possible for those skilled in the art to identify "whether or not the X-ray diffraction pattern including slightly different characteristic peaks substantially constitutes a sulfur silver germanium ore type crystal phase" as a whole. Unless otherwise stated, "±δ°" merely indicates an error in the diffraction angle position of the peak, irrespective of the peak shape and peak width of the peak. Numerically, regarding the foregoing peak position shift ±δ°, δ may be a value of 0.4, 0.3, 0.2, 0.1, etc., depending on the measurement, for example, δ=0.2 in some embodiments.

In the present application, unless otherwise specified, the chemical formula can be determined by determining the kind of elements and the atomic number ratio of each element in the sulfide solid electrolyte according to an element analysis method such as an inductively coupled plasma spectrometer (ICP method).

When the sulfide solid electrolyte is used as a solid electrolyte material in a secondary battery or a solid-state battery, the sulfide solid electrolyte can be used as the solid electrolyte material in one or more structural layers of the solid electrolyte layer, the positive electrode layer and the negative electrode layer, so that the resistance of the solid-state battery can be effectively reduced, the rate performance of the secondary battery or the solid-state battery can be improved, and the secondary battery or the solid-state battery can have better electrochemical performance under high rate.

In some embodiments, 0< x≤0.8 in the sulfur silver germanium ore type crystalline phase. X may also be any one of the following values, greater than 0 and less than or equal to any one of the following values, or a range selected from any two of the following values, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, etc., without limitation.

In some embodiments, 0< y≤0.1 in the sulfur silver germanium ore type crystalline phase. Y may be any one of the following values, greater than 0 and less than or equal to any one of the following values, or a range selected from any two of the following values, such as 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, etc., without limitation.

In some embodiments, in the sulfur silver germanium ore type crystal phase, the atomic number ratio of Li element, P element, S element, M element and T element is (6-x): 1 (5-x-y): y (1+x), wherein 0< x≤0.8, 0< y≤0.1. Where x and y may be combined in any suitable manner. x and y may also refer to any suitable value or range, respectively, in the context.

In some embodiments, the silver germanium sulfide ore type crystalline phase satisfies one or more of the following characteristics (any numerical parameter of the following characteristics may also be selected from any suitable value or range in context):

In the sulfur silver germanium ore type crystal phase, x is more than or equal to 0 and less than or equal to 0.8, alternatively, x is more than or equal to 0.05 and less than or equal to 0.8, further alternatively, x is more than or equal to 0.1 and less than or equal to 0.8, and further alternatively, x is more than or equal to 0.3 and less than or equal to 0.8;

In the sulfur silver germanium ore type crystal phase, y is more than or equal to 0 and less than or equal to 0.1, alternatively, y is more than or equal to 0.02 and less than or equal to 0.1, and further alternatively, y is more than or equal to 0.02 and less than or equal to 0.09.

In the present application, the atomic number ratio of the S element to the P element in the sulfur silver germanium ore type crystal phase can be described as 5-x-y.

In some embodiments, 4.1≤5-x-y <5.0. Without limitation, 5-x-y may also be any one of the following values, greater than or equal to any one of the following values and less than 5.0, greater than or equal to any one of the following values and less than 4.7, or a range selected from any two of the following values 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 4.95, etc.

In some of these embodiments, 4.1< (5-x-y) <4.7.

In some embodiments, the T element comprises Cl element in the sulfur silver germanium ore type crystal phase.

In some embodiments, in the sulfur silver germanium ore type crystal phase, the M element includes a Se element.

In some embodiments, in the sulfur silver germanium ore type crystal phase, the T element includes Cl element and the M element includes Se element.

In the present application, the atomic number ratio of Cl element and Br element in the sulfur silver germanium ore type crystal phase can be described as R _Cl/Br.

R _Cl/Br may be, without limitation, (0-1): (0-1), alternatively (1) (0-1), alternatively (0-1): 1

In the present application, in the sulfur silver germanium ore type crystal phase, the atomic number ratio of Se element and Te element can be described as R _Se/Te.

R _Se/Te may be, without limitation, (0-1): (0-1), alternatively (0-1): 1.

The value of R _Cl/Br or R _Se/Te in any of the above ratios may be any one of the values from 0 to1 or a range selected from any two of the values from 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.55, 0.6, 0.625, 0.64, 0.65, 0.7, 0.75, 0.8, 0.825, 0.9, 0.95, 1, etc.

In some embodiments, the silver germanium sulfide ore type crystalline phase satisfies one or both of the following characteristics (any numerical parameter of the following characteristics may also be selected from any suitable value or range in context):

in the sulfur silver germanium ore type crystal phase, the atomic number ratio of Se element and Te element is 1 or more.

In some embodiments, the 2 θ (°) diffraction angle in the X-ray diffraction pattern of the sulfide solid electrolyte has a characteristic peak that conforms to the sulfur silver germanium ore type crystalline phase. The definition and identification method of the 'sulfur silver germanium ore type crystal phase' can be referred to as the foregoing.

In some embodiments, the diffraction angles of 2θ (°) in the X-ray diffraction pattern of the sulfide solid electrolyte have peaks at 15.5±δ°, 18.1±δ°, 25.6±δ°, 30.1±δ°, 31.4±δ°, 39.8±δ°, 45.1±δ°, 47.9±δ° and 52.5±δ°, wherein δ may be referred to above, and alternatively δ is 0.2 or 0.1.

In some embodiments, the diffraction angles of 2θ (°) in the X-ray diffraction pattern of the sulfide solid electrolyte have peaks at 15.5±0.2°, 18.1±0.2°, 25.6±0.2°, 30.1±0.2°, 31.4±0.2°, 39.8±0.2°, 45.1±0.2°, 47.9±0.2° and 52.5±0.2°.

The relative content of the impurity phases can be judged according to the comparison of the intensity of the main diffraction peak (the strongest diffraction peak) and the intensity of the impurity phase diffraction peak of the sulfur-silver-germanium ore type crystal phase in the XRD pattern.

In some embodiments, the sulfide solid electrolyte has an X-ray diffraction pattern with diffraction angles of 2θ (°) having no diffraction peaks at 34.9±0.2°, 29.2±0.2° and 33.9±0.2°, at which the impurity content is very small. Wherein, the 2 theta diffraction peak of LiCl is corresponding to the vicinity of 34.9 degrees.

In some embodiments, there are no lin hetero-phase peaks in the X-ray diffraction pattern of the sulfide solid electrolyte.

In some embodiments, no distinct heterogeneous diffraction peaks such as lits are observed in the X-ray diffraction pattern of the sulfide solid electrolyte.

In some embodiments, the mass ratio of the sulfur silver germanium ore type crystal phase in the sulfide solid electrolyte may be greater than 85wt%, or may be greater than any one of the following percentages, or greater than or equal to any one of the following percentages, or may be selected from a range consisting of any one of the following percentages and 100wt%, or may be selected from a range consisting of any two of the following percentages, 90wt%, 92wt%, 94wt%, 95wt%, 96wt%, 97wt%, 98wt%, etc.

In some embodiments, the X-ray diffraction pattern of the sulfide solid electrolyte is obtained by using Cu ka radiation, and in some embodiments, the X-ray diffraction pattern of the sulfide solid electrolyte is obtained by using Cu ka 1 radiation.

In some embodiments, the X-ray diffraction pattern of the sulfide solid electrolyte is obtained by powder X-ray diffraction testing.

the sulfide solid electrolyte has no LiT hetero-phase peak in the X-ray diffraction diagram;

Diffraction angles of 2 theta (°) of an X-ray diffraction pattern of the sulfide solid electrolyte were free of diffraction peaks at 34.9±0.2°, 29.2±0.2° and 33.9±0.2°;

In a second aspect of the present application, there is provided a method for producing a sulfide solid electrolyte which can be used for producing the sulfide solid electrolyte described in the first aspect of the present application.

In some embodiments, the method of preparing a sulfide solid electrolyte includes the steps of:

S100, providing a precursor mixture comprising Li ₂S、P₂S₅, an optional elemental sulfur, an elemental M and LiT according to the required stoichiometric ratio of raw materials, wherein the elemental M is selected from one or two of an elemental Se and an elemental Te, T is halogen, and LiT is selected from one or two of an elemental LiCl and an elemental LiBr;

S200, sintering the precursor mixture in an inert atmosphere to prepare sulfide solid electrolyte comprising a sulfur silver germanium ore type crystal phase;

In the silver germanium sulfide ore type crystal phase, the atomic number ratio of the T element to the P element is denoted as 1+x, and the atomic number ratio of the m element to the P element is denoted as y, and in some embodiments, the silver germanium sulfide ore type crystal phase satisfies x >0 and y >0.

In the present application, the reference to "providing according to the desired raw material stoichiometric ratio" in step S100 means providing at the raw material stoichiometric ratio required to obtain the target chemical formula, unless otherwise specified. In the case of target chemical formula determination, one skilled in the art can select the appropriate precursor starting materials and the appropriate starting material stoichiometry.

In the application, unless otherwise stated, the "M simple substance" is a Se simple substance, a Te simple substance or a combination of a Se simple substance and a Te simple substance.

In some embodiments, the elemental M includes elemental Se, which may further be elemental Se.

In some embodiments, the elemental M includes elemental Te, which may further be elemental Te.

In some embodiments, the sintering temperature may be 450 ℃ to 530 ℃ in the step of sintering the precursor mixture in an inert atmosphere.

In step S200, the sintering temperature may be, without limitation, 450 to 530 ℃, or may be any two temperatures or a range selected from any two temperatures including 450, 460, 470, 480, 490, 500, 510, 520, 530, etc.

Without limitation, in step S200, the inert atmosphere may be an argon atmosphere.

In some embodiments, the sulfide solid electrolyte produced by the production method of the second aspect is the sulfide solid electrolyte described in the first aspect of the present application.

In a third aspect of the present application, there is provided a solid electrolyte membrane comprising at least one of the sulfide solid electrolyte described in the first aspect of the present application and the sulfide solid electrolyte produced by the production method described in the second aspect of the present application.

The solid electrolyte membrane may be, without limitation, a separate solid electrolyte membrane sheet for assembling a solid state battery, or a solid electrolyte membrane layer present in a composite structure.

The solid electrolyte membrane may be prepared by a method conventional in the solid state battery art, such as pressing a solid electrolyte material into a film.

In some embodiments, the solid electrolyte membrane is an all-solid electrolyte membrane.

In the present application, unless otherwise specified, "all-solid electrolyte membrane" refers to a solid electrolyte membrane in which constituent materials are all solid.

In still another aspect of the present application, there is provided a solid electrolyte membrane comprising at least one of the sulfide solid electrolyte described in the first aspect of the present application and the sulfide solid electrolyte produced by the production method described in the second aspect of the present application.

In still another aspect of the present application, there is provided a positive electrode film comprising a positive electrode active material layer comprising at least one of the sulfide solid electrolyte described in the first aspect of the present application and the sulfide solid electrolyte produced by the production method described in the second aspect of the present application.

The positive electrode film may be, without limitation, a separate positive electrode film sheet or a positive electrode sheet for use in assembling a solid-state battery, or a positive electrode film layer existing in a multilayer composite structure, for example, constituent materials of the positive electrode film layer may be pressed into a film on the surface of the solid electrolyte layer. As a non-limiting example, the positive electrode film may be a positive electrode layer or a portion of a positive electrode layer of a solid state battery.

In some embodiments, the negative electrode film is an all-solid-state positive electrode film.

In the present application, unless otherwise specified, "all-solid-state positive electrode film" refers to a positive electrode film in which constituent materials are all solid.

In still another aspect of the present application, there is provided a positive electrode sheet comprising a positive electrode current collector and a positive electrode active material layer located on at least one side of the positive electrode current collector, the positive electrode active material layer comprising at least one of the sulfide solid electrolyte described in the first aspect of the present application and the sulfide solid electrolyte prepared by the preparation method described in the second aspect of the present application.

In still another aspect of the present application, there is provided a negative electrode film comprising a negative electrode active material layer comprising at least one of the sulfide solid electrolyte described in the first aspect of the present application and the sulfide solid electrolyte produced by the production method described in the second aspect of the present application.

The anode film may be, without limitation, a separate anode film or an anode tab for use in assembling a solid-state battery, or an anode film layer present in a multilayer composite structure, for example, constituent materials of the anode film layer may be pressed into a film on the surface of a solid electrolyte layer. As a non-limiting example, the anode film may be an anode layer or a portion of an anode layer of a solid-state battery.

In some embodiments, the anode film is an all-solid anode film.

In the present application, unless otherwise specified, "all-solid-state anode film" refers to an anode film in which constituent materials are all solid.

In still another aspect of the present application, there is provided a negative electrode sheet comprising a negative electrode current collector and a negative electrode active material layer on at least one side of the negative electrode current collector, the negative electrode active material layer comprising at least one of the sulfide solid electrolyte described in the first aspect of the present application and the sulfide solid electrolyte prepared by the preparation method described in the second aspect of the present application.

The solid electrolyte membrane, the positive electrode membrane or the negative electrode membrane provided with the sulfide solid electrolyte can effectively reduce the resistance, can endow the corresponding secondary battery or solid battery with better multiplying power performance, and can enable the secondary battery or solid battery to have better electrochemical performance under high multiplying power.

In a fourth aspect of the present application, there is provided an electrode sheet comprising an electrode active material layer, the electrode active material layer comprising an electrode active material, the electrode active material layer further comprising at least one of a sulfide solid electrolyte described in the first aspect of the present application and a sulfide solid electrolyte prepared by a preparation method described in the second aspect of the present application.

In the present application, the electrode tab includes an electrode active material layer unless otherwise stated. As described above, the electrode active material layer includes an electrode active material. In the electrode sheet, the electrode active material may itself constitute particulate matter, or may be contained in the electrode active particles. The electrode active material layer in the electrode sheet provided in this aspect further includes a sulfide solid electrolyte, and further, the electrode active material layer includes at least one of the sulfide solid electrolyte described in the first aspect of the present application and the sulfide solid electrolyte prepared by the preparation method described in the second aspect of the present application, unless otherwise specified.

In some embodiments, the electrode active material layer comprises electrode active particles, and the electrode active material layer further comprises at least one of the sulfide solid electrolyte described in the first aspect of the present application and the sulfide solid electrolyte prepared by the preparation method described in the second aspect of the present application. The electrode plate can be a positive electrode plate, and the electrode active particles are positive electrode active particles, at this time, a positive electrode plate is provided, which comprises a positive electrode active material layer, wherein the positive electrode active material layer comprises positive electrode active particles and the sulfide solid electrolyte. The electrode plate can also be a negative electrode plate, and the electrode active particles are negative electrode active particles, at this time, a negative electrode plate is provided, which comprises a negative electrode active material layer, wherein the negative electrode active material layer comprises the negative electrode active particles and the sulfide solid electrolyte.

The electrode pole piece provided with the sulfide solid electrolyte can reduce the internal resistance of the pole piece, promote the capacity exertion of active substances in the pole piece, and endow the corresponding secondary battery or solid battery with better multiplying power performance.

In still another aspect of the present application, there is provided a secondary battery comprising at least one of the sulfide solid electrolyte described in the first aspect of the present application, the sulfide solid electrolyte prepared by the preparation method described in the second aspect of the present application, the solid electrolyte membrane described in the third aspect of the present application, the aforementioned positive electrode film, the aforementioned negative electrode film, and the electrode tab described in the fourth aspect of the present application.

In the present application, the "secondary battery" provided in the foregoing of the present application includes a positive electrode tab, a negative electrode tab, and a solid electrolyte layer between the positive electrode tab and the negative electrode tab, unless otherwise specified.

In the present application, the "positive electrode sheet" includes a positive electrode active material layer unless otherwise stated. In some embodiments, the positive electrode sheet in the secondary battery is the aforementioned positive electrode film.

In the present application, the "anode tab" includes an anode active material layer unless otherwise stated. In some embodiments, the negative electrode tab in the secondary battery is the aforementioned negative electrode film.

In the present application, unless otherwise specified, the "solid electrolyte layer" includes a solid electrolyte. In some embodiments, the solid electrolyte layer is a solid electrolyte membrane layer formed from the solid electrolyte membrane described in the third aspect of the application.

When the secondary battery is charged, active ions are extracted from the positive electrode and are inserted into the negative electrode through the solid electrolyte layer, and when the secondary battery is discharged, active ions are extracted from the negative electrode and are inserted into the positive electrode. The active ion is not particularly limited, and may be lithium ion, in which case it corresponds to a lithium ion secondary battery.

In a fifth aspect of the present application, there is provided a solid-state battery comprising at least one of the sulfide solid electrolyte described in the first aspect of the present application, the sulfide solid electrolyte prepared by the preparation method described in the second aspect of the present application, the solid electrolyte membrane described in the third aspect of the present application, the aforementioned positive electrode film, the aforementioned negative electrode film, and the electrode sheet described in the fourth aspect of the present application.

In some embodiments, the solid-state battery includes at least one of the sulfide solid electrolyte described in the first aspect of the present application, the sulfide solid electrolyte prepared by the preparation method described in the second aspect of the present application, the solid electrolyte membrane described in the third aspect of the present application, and the electrode sheet described in the fourth aspect of the present application.

In some embodiments, the positive electrode layer in the solid-state battery includes the positive electrode film described above, and further may be the positive electrode film described above.

In some embodiments, the negative electrode layer in the solid-state battery includes the aforementioned negative electrode film, and further may be the aforementioned negative electrode film.

In some embodiments, the solid electrolyte layer in the solid-state battery includes the solid electrolyte membrane described in the third aspect of the present application, and further may be the solid electrolyte membrane described in the third aspect of the present application.

The "solid-state battery" provided in the fifth aspect of the present application includes at least one of the sulfide solid electrolyte described in the first aspect of the present application and the sulfide solid electrolyte produced by the production method described in the second aspect of the present application, and thus is a sulfide solid-state battery.

In the present application, unless otherwise specified, "sulfide solid state battery" refers to a solid state battery in which the electrolyte referred to in the battery includes sulfide solid electrolyte. The sulfide solid electrolyte may be located at least one position among the positive electrode layer, the negative electrode layer, and the solid electrolyte layer of the sulfide solid state battery. The sulfide solid state battery may further be an all solid state battery.

In the present application, unless otherwise specified, the "all-solid-state battery" refers to a solid-state battery in which the electrolyte in the battery is a solid electrolyte, and in this case, the positive electrode layer, the negative electrode layer, and the electrolyte portion are all solid materials, and the battery is not provided with a liquid electrolyte, and thus may be referred to as an "all-solid-state battery".

In the present application, the "solid-state battery" in any of the embodiments or examples may be, but is not limited to, a sulfide all-solid-state battery, unless otherwise specified. Unless otherwise indicated, a "sulfide all-solid state battery" refers to an all-solid state battery in which the electrolyte involved in the battery includes a sulfide solid electrolyte. Wherein the sulfide solid electrolyte may be located at least one position among the positive electrode layer, the negative electrode layer, and the solid electrolyte layer of the sulfide all-solid state battery.

The kinds of solid electrolytes present in different film layers of the secondary battery or the solid-state battery may be the same or different. For example, the solid electrolyte in the positive electrode electrolyte particles, the negative electrode electrolyte particles, and the solid electrolyte layer may be the same or different.

In the secondary battery or the solid-state battery provided by the present application, at least one of the positive electrode electrolyte particles, the negative electrode electrolyte particles, and the solid electrolyte in the solid electrolyte layer contains the sulfide solid electrolyte described in the first aspect of the present application.

For the secondary battery or the solid-state battery provided with the aforementioned sulfide solid electrolyte, the sulfide solid electrolyte may be provided at one or more of the positive electrode layer, the negative electrode layer, and the solid electrolyte layer.

As non-limiting examples, the solid electrolyte in the positive electrode electrolyte particles, the negative electrode electrolyte particles, and the solid electrolyte layer may each independently include solid electrolyte materials known in the art to be useful for solid state batteries, for example, may each independently include one or more of sulfide-based solid electrolytes, halide-based solid electrolytes, oxide-based solid electrolytes, polymer-based solid electrolytes, and the like.

In a sixth aspect of the present application, there is provided an electric device comprising at least one of the sulfide solid electrolyte according to the first aspect of the present application, the sulfide solid electrolyte prepared by the preparation method according to the second aspect of the present application, the solid electrolyte membrane according to the third aspect of the present application, the aforementioned positive electrode membrane, the aforementioned negative electrode membrane, the electrode tab according to the fourth aspect of the present application, the aforementioned secondary battery, and the solid state battery according to the fifth aspect of the present application.

In some embodiments, the electrical device comprises at least one of the sulfide solid electrolyte described in the first aspect of the present application, the sulfide solid electrolyte prepared by the preparation method described in the second aspect of the present application, the solid electrolyte membrane described in the third aspect of the present application, the electrode sheet described in the fourth aspect of the present application, and the solid battery described in the fifth aspect of the present application.

The following are some descriptions about the solid electrolyte layer.

The solid electrolyte layer plays a role in conducting ions between the positive electrode layer and the negative electrode layer, and can isolate the positive electrode layer from the negative electrode layer so as to play a role in preventing positive and negative electrodes from being shorted.

It is understood that the solid electrolyte layer includes a solid electrolyte. The solid electrolyte in the solid electrolyte layer may be a solid electrolyte material known in the art as useful for solid state batteries.

In some embodiments, the solid electrolyte layer comprises the sulfide solid electrolyte described in the first aspect of the application.

In some embodiments, the solid electrolyte layer may be pressed from a solid electrolyte material into a solid electrolyte membrane, which may be a solid electrolyte membrane sheet or a solid electrolyte membrane layer.

In some embodiments, the thickness of the solid electrolyte layer may be 0.1 μm to 1000 μm, alternatively 10 μm to 100 μm, 100 μm to 800 μm, 500 μm to 800 μm, etc.

The following are some descriptions regarding the positive electrode film and positive electrode layer.

In the present application, unless otherwise specified, "positive electrode film" means a film capable of functioning as a positive electrode of a solid-state battery, including at least a positive electrode active material layer, and generally including a positive electrode current collector.

The positive electrode layer may be provided by a positive electrode sheet or a positive electrode membrane usable in the art for a solid-state battery, or constituent materials of the positive electrode layer may be directly pressed into a positive electrode membrane layer on one side surface of the solid electrolyte layer. The positive electrode membrane can be combined with other membranes suitable for positive electrodes to form a positive electrode sheet or a positive electrode layer.

The positive electrode layer may be prepared by a dry method or a wet method. For example, the positive electrode film may be formed by dry pressing, and may be a positive electrode film sheet or a positive electrode film layer. For another example, the positive electrode film may be wet-coated, and the positive electrode film may be a positive electrode film layer.

In some embodiments, the positive electrode film includes a positive electrode current collector and a positive electrode active material layer disposed on at least one surface of the positive electrode current collector, and the definition of the positive electrode active material layer may be referred to above.

In some embodiments, the positive current collector may employ a metal foil or a composite current collector. For example, as the metal foil, aluminum foil may be used. In the positive electrode current collector, the composite current collector may include a polymer material base layer and a metal layer formed on at least one surface of the polymer material base layer. In the positive electrode current collector, the composite current collector may be obtained by forming a metal material on a polymer material substrate. In the positive electrode current collector, non-limiting examples of the metal material may include one or more of aluminum, aluminum alloy, nickel alloy, titanium alloy, silver alloy, and the like. In the positive electrode current collector, non-limiting examples of the polymer material substrate may include one or more of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), and the like.

In the positive electrode film or positive electrode layer, the thickness of the positive electrode active material layer is 30 μm to 400 μm, alternatively 60 μm to 130 μm, and may be any one thickness or a range selected from any two thicknesses of 30 μm, 40 μm, 50 μm, 60 μm, 80 μm, 100 μm, 120 μm, 130 μm, 140 μm, 150 μm, 160 μm, 180 μm, 200 μm, and the like.

In the present application, the "thickness of the positive electrode active material layer" refers to the total thickness in the positive electrode film or positive electrode layer unless otherwise specified. When the positive electrode active material layer is provided on both sides of the positive electrode current collector, the thickness of the positive electrode active material layer means the sum of the thicknesses of both sides.

As a non-limiting example, the positive electrode current collector has two surfaces facing away in its own thickness direction, and the positive electrode active material layer is provided on either or both of the two surfaces facing away from the positive electrode current collector.

The positive electrode film and the positive electrode layer each include a positive electrode active material layer including positive electrode active particles containing a positive electrode active material.

The weight percentage of the positive electrode active particles or positive electrode active material in the positive electrode active material layer may be 70wt% or more, 80wt% or more, 90wt% or more, or any one of 70wt%, 75wt%, 80wt%, 82wt%, 84wt%, 85wt%, 86wt%, 88wt%, 90wt%, 92wt%, 94wt%, 95wt%, 96wt%, 97wt%, 98wt%, 99wt% or the like, or an interval selected from any two of the following.

In some embodiments, the positive electrode active material layer includes positive electrode electrolyte particles. The weight ratio of the positive electrode electrolyte particles in the positive electrode active material layer may be, without limitation, 0.1wt% to 30wt%, alternatively 5wt% to 20wt%, and the weight ratio of the positive electrode electrolyte particles in the positive electrode active material layer may be any one of the following weight percentages or a range ：0.1wt％、0.2wt％、0.4wt％、0.5wt％、0.6wt％、0.8wt％、1wt％、1.2wt％、1.5wt％、1.6wt％、1.8wt％、2wt％、2.5wt％、3wt％、3.5wt％、4wt％、5wt％、6wt％、7wt％、8wt％、9wt％、10wt％、12wt％、14wt％、15wt％、16wt％、18wt％、20wt％、22wt％、24wt％、25wt％、26wt％、28wt％、30wt％ selected from any two of the following weight percentages, or the like.

In some embodiments, the positive electrode active material layer includes positive electrode active particles and positive electrode electrolyte particles.

In some embodiments, the positive electrode active material in the positive electrode active particles may employ a positive electrode active material for a battery, which is well known in the art. As a non-limiting example, the positive electrode active material may include one or more of olivine structured lithium-containing phosphates, lithium transition metal oxides, and their respective modified compounds. However, the present application is not limited to these materials, and other conventional materials that can be used as a battery positive electrode active material may be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of the lithium transition metal oxide may include, but are not limited to, one or more of lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt aluminum oxide, modified compounds thereof, and the like. non-limiting examples of olivine structured lithium-containing phosphates may include, but are not limited to, one or more of lithium iron phosphate, a composite of lithium iron phosphate and carbon, lithium manganese phosphate, a composite of lithium manganese phosphate and carbon. Non-limiting examples of lithium cobalt oxide may include LiCoO ₂, non-limiting examples of lithium nickel oxide may include LiNiO ₂, non-limiting examples of lithium manganese oxide may include LiMnO ₂、LiMn₂O₄, etc., non-limiting examples of lithium nickel cobalt manganese oxide may include LiNi _1/3Co_1/3Mn_1/3O₂ (may also be abbreviated as NCM ₃₃₃)、LiNi_0.5Co_0.2Mn_0.3O₂ (may also be abbreviated as NCM ₅₂₃)、LiNi_0.5Co_0.25Mn_0.25O₂ (may also be abbreviated as NCM ₂₁₁)、LiNi_0.6Co_0.2Mn_0.2O₂ (may also be abbreviated as NCM ₆₂₂)、LiNi_0.8Co_0.1Mn_0.1O₂ (may also be abbreviated as NCM ₈₁₁)) etc. Non-limiting examples of lithium nickel cobalt aluminum oxide may include LiNi _0.80Co_0.15Al_0.05O₂. Examples of lithium iron phosphate are LiFePO ₄ (which may also be referred to simply as LFP). Examples of lithium manganese phosphate are LiMnPO ₄.

Taking a solid-state battery in which active ions include lithium ions as an example, it is understood that the solid-state battery is accompanied by deintercalation and consumption of lithium (Li) during charge and discharge, and the content of Li in the positive electrode layer varies when the battery is discharged to different states. In the exemplary description of the positive electrode active material in the present application, the Li content may be in an initial state of the material or may be in a non-initial state after charge-discharge cycles unless otherwise specified. When the positive electrode active material is applied to a positive electrode layer in a solid-state battery system, the content of Li in the positive electrode active material contained in the positive electrode layer generally changes through charge and discharge cycles. The content of Li may be measured by atomic molar content, but is not limited thereto. With regard to "the content of Li is the material initial state", the material initial state refers to a state placed before the positive electrode layer. It is understood that new materials or new materials obtained by appropriate modification based on the listed positive electrode active materials are also within the scope of positive electrode active materials, the foregoing appropriate modification indicating acceptable modification modes for the positive electrode active materials, such as coating modification, for example. In the exemplary description of the positive electrode active material in the present application, the content of oxygen (O) is generally a theoretical state value, the atomic molar content of oxygen is changed due to lattice oxygen release, and the actual O content is floated. The content of O may be measured by atomic molar content, but is not limited thereto.

In some embodiments, the positive electrode active material layer includes a conductive agent (may be referred to as a positive electrode conductive agent). As a non-limiting example, the positive electrode conductive agent may be a carbon conductive agent. The carbon conductive agent may include, without limitation, one or more of superconducting carbon, acetylene black, carbon black, ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers. In some embodiments, the positive electrode conductive agent may include, but is not limited to, one or more of SP, KS-6, acetylene black, ketjen black ECP with branched structure, SFG-6, vapor grown carbon fiber VGCF, carbon Nanotubes (CNTs), graphene, and the like. The weight percentage of the positive electrode conductive agent in the positive electrode active material layer may be, without limitation, 0 to 10wt%, further may be 0 to 8wt%, further may be 0 to 5wt%, further may be 0.1wt% to 3wt%, based on the total weight of the positive electrode active material layer. The weight percentage of the positive electrode conductive agent in the positive electrode active material layer may also be 0.1wt% to 5wt%, 0.2wt% to 5wt%, 0.5wt% to 5wt%, 0.1wt% to 3wt%, and the like.

In some embodiments, the positive electrode active material layer optionally includes a binder (may be referred to as a positive electrode binder). As non-limiting examples, the positive electrode binder may include one or more of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene-propylene terpolymers, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymers, tetrafluoroethylene-hexafluoropropylene copolymers, and fluoroacrylate resins. Typically, the weight percentage of the positive electrode binder in the positive electrode active material layer may be 0 to 10wt%, further may be 0 to 8wt%, further may be 0.1wt% to 5wt%, and further may be 1wt% to 5wt%, based on the total weight of the positive electrode active material layer.

The positive electrode active material layer may include, without limitation, positive electrode active particles, positive electrode electrolyte particles, a positive electrode conductive agent, and a positive electrode binder. The types and amounts of the components may be referred to in the context of the present application.

In some embodiments, the positive electrode electrolyte particles comprise the sulfide solid electrolyte described in the first aspect of the application.

In some embodiments, the positive electrode sheet may be prepared by dry mixing the above components used to prepare the positive electrode sheet, such as positive electrode active particles, positive electrode electrolyte particles, positive electrode conductive agent, optional positive electrode binder, and any other components, then heating and pressurizing the mixed materials to form a dough-like material, hot rolling the dough-like material to form a self-supporting positive electrode sheet, hot rolling the self-supporting positive electrode sheet with a positive electrode current collector to form a self-supporting positive electrode sheet, and compositing the self-supporting positive electrode sheet with at least one side (single side or double sides) of the positive electrode current collector to obtain the positive electrode sheet. Without limitation, a double planetary mixer may be used for dry mixing. The kneading may be carried out, without limitation, by heating and pressurizing with an internal mixer. The temperature at which the hot rolling is performed may be, without limitation, 75 ℃ to 85 ℃, further such as 78 ℃, 80 ℃, 82 ℃, etc. The method for assembling the solid-state battery by using the positive electrode membrane can be suitable for industrial mass production. The negative electrode film or sheet can be prepared by a similar method.

In some embodiments, the positive electrode sheet may be prepared by dispersing the above-described components for preparing the positive electrode sheet, such as positive electrode active particles, positive electrode electrolyte particles, positive electrode conductive agent, positive electrode binder, and any other components, in an organic solvent to form a positive electrode slurry. Further, the positive electrode slurry is coated on at least one side surface of the positive electrode current collector, and the positive electrode membrane is obtained after the procedures of drying, pressing and the like. The organic solvent in the positive electrode slurry may include one or more of paraxylene, trimethylbenzene, butyl butyrate, heptane, etc., and may further be paraxylene. The surface of the positive electrode current collector coated with the positive electrode slurry can be a single surface of the positive electrode current collector or two surfaces of the positive electrode current collector. The solid content of the positive electrode slurry may be 40wt% to 80wt%. The viscosity of the positive electrode slurry at room temperature can be adjusted to 5000 mPas to 25000 mPas. When the positive electrode slurry is coated, the coating unit area density (one side) on a dry weight basis (minus solvent) may be 15mg/cm ²～35mg/cm². The positive electrode membrane may have a compacted density of 3.0g/cm ³～3.6g/cm³, optionally 3.3g/cm ³～3.5g/cm³.

The term "compacted density" as used herein has a meaning well known in the art and is one of the reference indicators of the energy density of a material. In the present application, unless otherwise specified, the compacted density of an electrode layer refers to the ratio of the mass of an electrode active material layer to its volume. The compacted density of the positive electrode layer, positive electrode sheet, positive electrode film or positive electrode film refers to the ratio of the mass of the positive electrode active material layer to its volume, and the compacted density of the negative electrode layer, negative electrode sheet, negative electrode film or negative electrode film refers to the ratio of the mass of the negative electrode active material layer to its volume.

Compacted density = coated areal density/electrode active material layer thickness.

Coating area density = slurry dry weight/electrode active material layer area.

The thickness of both sides of the electrode active material layer corresponds to the sum of the densities of the coated surfaces of both sides, and the thickness of one side corresponds to the density of the coated surface of one side, and when the electrode active material layers on both sides of the current collector are substantially uniform, it can be calculated as compact density=one-side coated surface density/one-side thickness of the electrode active material layer.

The "single side" and "double side" of the electrode active material layer are with respect to the positional distribution pattern of the current collector.

The following are some descriptions about the anode film and the anode layer.

In the present application, unless otherwise specified, "anode film" means a film capable of functioning as an anode of a solid-state battery, including at least an anode active material layer, and may further include an anode current collector.

The negative electrode layer may be provided by a negative electrode tab or a negative electrode film usable in the art for a solid-state battery, or constituent materials of the negative electrode layer may be directly pressed into a negative electrode film layer on one side surface of the solid electrolyte layer. The negative electrode membrane can be combined with other membranes suitable for negative electrodes to form a negative electrode sheet or a negative electrode layer.

The negative electrode layer may be prepared by a dry method or a wet method. For example, the negative electrode film may be formed by dry pressing, and may be a negative electrode film sheet or a negative electrode film layer. For another example, the negative electrode film may be wet-coated, and the negative electrode film may be a negative electrode film layer.

The anode film and the anode layer each include an anode active material layer including anode active particles containing an anode active material. The negative electrode active material layer may or may not include, without limitation, negative electrode electrolyte particles.

In some embodiments, the negative electrode active material layer includes negative electrode electrolyte particles, further, the negative electrode electrolyte particles may include the sulfide solid electrolyte described in the first aspect of the present application.

Without limitation, the weight percentage of the anode active particles or the anode active material in the anode active material layer may be 80wt% or more, and further 90wt% or more.

In some embodiments, the anode active particles or anode active material is a lithium indium alloy (InLi alloy).

In some embodiments, the negative electrode layer is InLi alloy film.

In some embodiments, the negative electrode active material may also employ a negative electrode active material that is well known in the art as useful for solid state batteries. As non-limiting examples, the negative electrode active material may include one or more of elemental silicon, elemental tin, silicon carbon negative electrode, silicon oxide, graphite, and metallic lithium. However, the present application is not limited to these materials or substances, and other conventional materials that can be used as a negative electrode active material of a battery may be used. These negative electrode active materials may be used alone or in combination of two or more.

In some embodiments, the negative electrode tab or the negative electrode membrane may include a negative electrode current collector and a negative electrode active material layer disposed on at least one surface of the negative electrode current collector, the negative electrode active material layer including a negative electrode active material. As a non-limiting example, the anode current collector has two surfaces facing away in its own thickness direction, and the anode active material layer is provided on either or both of the two surfaces facing away from the anode current collector. In some embodiments, the negative electrode current collector may employ a metal foil or a composite current collector. For example, as the metal foil, copper foil may be used. In the negative electrode current collector, the composite current collector may include a polymer material base layer and a metal layer formed on at least one surface of the polymer material base material. In the negative electrode current collector, the composite current collector may be formed by forming a metal material on a polymer material substrate. In the negative electrode current collector, non-limiting examples of the metal material may include one or more of copper, copper alloy, nickel alloy, titanium alloy, silver alloy, and the like. In the negative electrode current collector, non-limiting examples of the polymer material substrate may include one or more of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), and the like.

In some embodiments, the anode active material layer optionally includes a conductive agent, denoted anode conductive agent. The negative electrode conductive agent may include, without limitation, one or more of superconducting carbon, acetylene black, carbon black, ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers. In the anode active material layer, the weight percentage of the anode conductive agent may be 0 to 10wt%, further alternatively 0 to 5wt%, further alternatively 0.1wt% to 3wt%.

In some embodiments, the anode active material layer optionally includes a binder (denoted anode binder). As non-limiting examples, the anode binder may include one or more of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene-propylene terpolymers, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymers, tetrafluoroethylene-hexafluoropropylene copolymers, and fluoroacrylate resins. Without limitation, the weight ratio of the negative electrode binder in the negative electrode active material layer may be 0 to 10wt%, further may be 0 to 5wt%, further may be 1wt% to 5wt%, and further may be 1wt% to 3wt%.

In some embodiments, the anode active material layer optionally includes other adjuvants, such as a thickener (e.g., sodium carboxymethyl cellulose (CMC-Na)), and the like. The weight percentage of other auxiliary agents in the anode active material layer can be 0-15 wt%, further optionally 0-10 wt%, further optionally 0-5 wt%, further optionally 0-3 wt%, and further optionally 0-2 wt%.

In some embodiments, the negative electrode sheet may be prepared by dry mixing the above components used to prepare the negative electrode sheet, such as the negative electrode active particles, optional negative electrode electrolyte particles, negative electrode conductive agent, optional negative electrode binder, and any other components, then heating and pressurizing the mixed material to form a dough-like material, hot rolling the dough-like material to form a self-supporting negative electrode sheet, hot rolling the self-supporting negative electrode sheet with a negative electrode current collector to form a self-supporting negative electrode sheet, and the self-supporting negative electrode sheet may be compounded on at least one side (single side or double sides) of the negative electrode current collector to obtain the negative electrode sheet. Without limitation, a double planetary mixer may be used for dry mixing. The kneading may be carried out, without limitation, by heating and pressurizing with an internal mixer. The method for assembling the solid-state battery by using the negative electrode film can be suitable for industrial mass production. When the anode material is prepared into the anode active material layer by a dry method, an anode conductive agent may be provided in the anode material, and the conductivity of the anode active material layer may be improved.

In some embodiments, the negative electrode sheet or sheet may be prepared by dispersing the components described above for preparing the negative electrode sheet or sheet, such as the negative electrode active particles, optional negative electrode electrolyte particles, negative electrode conductive agent, negative electrode binder, and any other components, in a solvent (non-limiting examples of solvents are paraxylene) to form a negative electrode slurry. Further, the negative electrode slurry is coated on at least one side surface of the negative electrode current collector, and the negative electrode plate or the negative electrode membrane can be obtained after the procedures of drying, pressing and the like. The surface of the negative electrode current collector coated with the negative electrode slurry may be a single surface of the negative electrode current collector or may be two surfaces of the negative electrode current collector. The solid content of the negative electrode slurry may be 30wt% to 70wt%, and may be selected to be 40wt% to 60wt%. The viscosity of the negative electrode slurry at room temperature may be adjusted to 2000 mPas to 10000 mPas, and optionally 3000 mPas to 10000 mPas. When the negative electrode slurry is coated, the coating unit area density (one side) in dry weight (minus solvent) may be 1.5mg/cm ²～18mg/cm², but is not limited thereto. The compacted density of the negative electrode sheet or negative electrode film may be 1.0g/cm ³～2.0g/cm³, optionally 1.0g/cm ³～1.8g/cm³.

The positive electrode sheet, the solid electrolyte membrane and the negative electrode sheet can be stacked in sequence, the solid electrolyte is placed between the positive electrode membrane and the negative electrode membrane, and the solid battery cell is prepared by hot rolling.

The positive electrode membrane, the solid electrolyte membrane and the negative electrode membrane can be stacked in sequence, and the solid electrolyte is placed between the positive electrode membrane and the negative electrode membrane, and the solid battery core is prepared by hot rolling.

In some embodiments, the solid-state battery cell 5 includes a solid-state cell 52.

In some embodiments, the solid state cell is an all solid state cell.

In some embodiments, solid state cell 52 (which may be an all-solid state cell) includes a positive electrode layer 200, a solid electrolyte layer 100, and a negative electrode layer 300, which are stacked in sequence, an example of which may be seen in fig. 1.

In some embodiments, the solid state battery may include an outer package. The outer package can be used to encapsulate the solid state battery cells described above.

In some embodiments, the outer package of the solid-state battery may be a hard shell, such as a hard plastic shell, an aluminum shell, a steel shell, or the like. The outer package of the solid-state battery may also be a pouch, such as a pouch-type pouch. The material of the soft bag can be plastic, and further, non-limiting examples of the plastic can comprise one or more of polypropylene, polybutylene terephthalate, polybutylene succinate and the like.

The shape of the solid-state battery cell is not particularly limited in the present application, and may be cylindrical, square, or any other shape. For example, fig. 2 is a solid-state battery cell 5 of a square structure as one example.

In some of these embodiments, referring to fig. 3, the overpack may include a housing 51 and a cover 53. The housing 51 may include a bottom plate and a side plate connected to the bottom plate, where the bottom plate and the side plate enclose a receiving chamber. The housing 51 has an opening communicating with the accommodation chamber, and the cover plate 53 can be provided to cover the opening to close the accommodation chamber. The solid state battery 52 is enclosed in the receiving cavity. The number of the solid-state battery cells 52 included in the solid-state battery cell 5 may be one or more, and those skilled in the art may select the solid-state battery cell according to actual requirements.

The solid-state battery may be the battery module 4 or the battery pack 1.

The battery module includes at least one solid-state battery cell. The number of solid-state battery cells included in the battery module may be one or more, and one skilled in the art may select an appropriate number according to the application and capacity of the battery module.

Fig. 4 is a battery module 4 as an example. Referring to fig. 4, in the battery module 4, a plurality of solid-state battery cells 5 may be sequentially arranged in the longitudinal direction of the battery module 4. Of course, the arrangement may be performed in any other way. The plurality of solid-state battery cells 5 may be further fixed by fasteners.

Alternatively, the battery module 4 may further include a case having an accommodating space in which the plurality of solid-state battery cells 5 are accommodated.

In some embodiments, the above battery modules may be further assembled into a battery pack, and the number of battery modules included in the battery pack may be one or more, and one skilled in the art may select an appropriate number according to the application and capacity of the battery pack.

Fig. 5 and 6 are battery packs 1 as an example. Referring to fig. 5 and 6, a battery case and a plurality of battery modules 4 disposed in the battery case may be included in the battery pack 1. The battery box includes an upper box body 2 and a lower box body 3, and the upper box body 2 can be covered on the lower box body 3 and forms a closed space for accommodating the battery module 4. The plurality of battery modules 4 may be arranged in the battery box in any manner.

In some of these embodiments, the power device comprises a solid state battery of any of the embodiments provided herein.

Without limitation, solid-state batteries may be used as a power source for electrical devices, as well as an energy storage unit for electrical devices. The powered devices may include, but are not limited to, mobile devices, electric vehicles, electric trains, boats and ships, and satellites, energy storage systems, and the like. The mobile device may be, for example, a cellular phone, a notebook computer, etc., and the electric vehicle may be, for example, a pure electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, an electric bicycle, an electric scooter, an electric golf cart, an electric truck, an electric motorcycle, an electric tool, etc., but is not limited thereto. The power utilization device can be applied to the fields of military equipment, aerospace and the like, and can also be applied to energy storage power supply systems of hydraulic power, firepower, wind power, solar power stations and the like.

As the electric device, a solid-state battery may be selected according to its use requirement.

Fig. 7 shows an example of the power utilization device 6. The electric device is a pure electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle or the like. To meet the high power and high energy density requirements of the power device for solid state batteries, a battery pack or battery module may be employed.

As another example, the device may be a cell phone, tablet computer, notebook computer, or the like. The device is generally required to be light and thin, and a solid-state battery can be used as a power source.

Some embodiments of the application are described below. The following examples are illustrative only and are not to be construed as limiting the application. The examples are not to be construed as limiting the scope of the application in any way, as defined by the description hereinabove, or as limiting the scope of the application in any way, as defined by the literature in the field. The reagents or apparatus used are not manufacturer specific, are conventional products commercially available or can be synthesized in a conventional manner from commercially available products.

In the following examples, room temperature is 20 ℃ to 30 ℃.

In the following examples, unless otherwise indicated, the amount of "M element (e.g., se element, te element, or a combination thereof)" expressed in wt% refers to the weight percentage of the mixture to be sintered, and in the following examples, the mixture to be sintered is the precursor mixture unless otherwise indicated.

Note that, in the following embodiments and examples, sulfide all-solid-state batteries are used as non-limiting examples of solid-state batteries.

In the following examples, unless otherwise specified, the positive electrode active particle NCM ₈₁₁ powder had a D _v of 4 μm (the positive electrode active material was NCM ₈₁₁),Li₆PS₅ Cl sulfide electrolyte D _v of 1 μm).

In the present application, D _v, unless otherwise indicated, represents the particle size corresponding to a cumulative volume distribution percentage of the multiparticulate mixture of 50%.

D _v test:

in the following examples and comparative examples, the D _v of the positive electrode active material and the sulfide solid electrolyte was tested and confirmed by using a method of using a Markov 2000 (MasterSizer 2000) laser particle sizer, referring to a standard procedure of GB/T19077-2016/ISO 13320:2009, specifically, a test procedure of taking a proper amount of a sample to be tested (the sample concentration ensures 8% -12% (W/v) of light shielding degree), adding 20mL of paraxylene (the dispersing agent ammonium polycarboxylic acid is also added when the sulfide solid electrolyte is tested), and simultaneously, exceeding 5min (53 KHz/120W) to ensure that the sample is completely dispersed, and then measuring the sample according to the GB/T19077-2016/ISO 13320:2009 standard.

1. Sulfide solid electrolyte, solid electrolyte membrane, and preparation of all-solid-state battery

Preparation of sulfide solid electrolyte

The target chemical formula is Li _6-xPS_5-x-yM_yT_1+x. Referring to table 1, the m element is one or both of Se element and Te element, and the T element is one or both of Cl element and Br element.

Example 1.M element is Se element, T element is Cl element, and target chemical formula is Li _5.7PS_4.68Se_0.02T_1.3.

2.2Mol of Li ₂S、0.5mol P₂S₅ and 1.3mol of LiCl raw material powder are respectively weighed according to the stoichiometric ratio of the raw materials Li _5.7PS_4.7Cl_1.3, 3wt% of selenium simple substance is additionally weighed and uniformly mixed to obtain a precursor mixture, the precursor mixture is placed in an atmosphere (argon) furnace for sintering for 8 hours at the temperature of 530 ℃, and then the sintered body is crushed to obtain the sulfur silver germanium ore type sulfide solid electrolyte powder.

Examples 2-3 target chemical formulas were Li _5.7PS_4.65Se_0.05T_1.3 (example 2), li _5.7PS_4.61Se_0.09T_1.3 (example 3).

A sulfide solid electrolyte was prepared in substantially the same manner as in example 1 except that the addition amount of elemental selenium was varied. The procedure was the same as in example 1 except that the addition amount of elemental selenium was changed to 6wt% (example 2) and 10wt% (example 3), respectively.

Example 4. Target chemical formula is Li _5.95PS_4.9Se_0.05Cl_1.05.

A sulfide solid electrolyte was produced in substantially the same manner as in example 1 except that the stoichiometric ratio of the raw materials of Li, P, S and Cl was changed to 6% by weight based on the amount of Li _5.95PS_4.95Cl_1.05 and Se added.

Example 5 the target chemical formula is Li _5.9PS_4.85Te_0.05Br_1.1.

A sulfide solid electrolyte was produced in substantially the same manner as in example 1 except that the stoichiometric ratios of the raw materials of Li, P, S and Br were such that Li _5.9PS_4.9Br_1.1, the simple substance Se was replaced with the simple substance Te, and the addition amount of the simple substance Te was 6% by weight.

Example 6 the target chemical formula is Li _5.9PS_4.87Se_0.02Te_0.01Cl_0.6Br_0.5.

A sulfide solid electrolyte was produced in substantially the same manner as in example 1 except that the stoichiometric ratio of the raw materials of Li, P, S, cl and Br was 3% by weight based on the amount of Li _5.9PS_4.9Cl_0.6Br_0.5, and the amount of Se elemental added was 2% by weight.

Example 7. Target chemical formula is Li _5.95PS_4.85Se_0.1Cl_1.05.

A sulfide solid electrolyte was produced in substantially the same manner as in example 1 except that the stoichiometric ratio of the raw materials of Li, P, S and Cl was 12% by weight based on the amount of Li _5.95PS_4.95Cl_1.05 and Se added.

Example 8 the target chemical formula is Li _5.5PS_4.47Se_0.03Cl_1.5.

2.0Mol of Li ₂S、0.5mol P₂S₅ and 1.5mol of LiCl raw material powder are respectively weighed according to the stoichiometric ratio of the raw materials Li _5.5PS_4.5Cl_1.5, and in addition, 4wt% of selenium simple substance is weighed and uniformly mixed to obtain a precursor mixture, the precursor mixture is placed in an atmosphere (argon) furnace for sintering at 500 ℃ for 8 hours, and then the sintered body is crushed to obtain the sulfur silver germanium ore type sulfide solid electrolyte powder.

Examples 9-10 target chemical formulas were Li _5.5PS_4.44Se_0.06Cl_1.5 (example 9), li _5.5PS_4.41Se_0.09Cl_1.5 (example 10).

The procedure of examples 9 to 10 was the same as that of example 8, except that the addition amounts of the elemental selenium were changed to 7wt% and 10wt%, respectively.

Example 11 the target chemical formula is Li _5.2PS_4.17Se_0.03Cl_1.8.

1.7Mol of Li ₂S、0.5mol P₂S₅ and 1.8mol of LiCl raw material powder are respectively weighed according to the stoichiometric ratio of the raw materials Li _5.2PS_4.2Cl_1.8, and in addition, 4wt% of selenium simple substance is weighed and uniformly mixed to obtain a precursor mixture, the precursor mixture is placed in an atmosphere (argon) furnace for sintering at 480 ℃ for 8 hours, and then the sintered body is crushed to obtain the sulfur silver germanium ore type sulfide solid electrolyte powder.

Examples 12-13 target chemical formulas were Li _5.2PS_4.14Se_0.06Cl_1.8 (example 12), li _5.2PS_4.11Se_0.09Cl_1.8 (example 13).

The procedure of examples 12 to 13 was the same as in example 11, except that the addition amounts of elemental selenium were changed to 7wt% and 10wt%, respectively.

Example 14 the target chemical formula is Li _5.2PS_4.1Se_0.1Cl_1.8.

The procedure of example 14 was followed except that the addition amount of the elemental selenium was changed to 12wt%, respectively, to the same procedure as in example 11.

Example 15 the target chemical formula is Li _5.2PS_4.1Se_0.08Te_0.02Cl_1.5Br_0.3.

A sulfide solid electrolyte was produced in substantially the same manner as in example 11 except that the stoichiometric ratio of the raw materials of Li, P, S and Cl was changed to 3% by weight in accordance with the addition amount of Li _5.2PS_4.2Cl_1.5Br_0.3 and the simple substance of Se, respectively, and the remaining steps of example 15 were the same as in example 11.

Comparative example 1. Target chemical formula is Li ₆PS₅Cl_1.3.

2.5Mol of Li ₂S、0.5mol P₂S₅ and 1mol of LiCl raw material powder are respectively weighed according to the stoichiometric ratio of the raw materials, the raw material powder is uniformly mixed to obtain a raw material mixture, the raw material mixture is placed in an atmosphere (argon) furnace for sintering at 550 ℃ for 8 hours, and then the sintered body is crushed to obtain the sulfur silver germanium ore type sulfide solid electrolyte powder.

Comparative example 2 the target chemical formula is Li _5.7PS_4.7Cl_1.3.

2.2Mol of Li ₂S、0.5mol P₂S₅ and 1.3mol of LiCl raw material powder are respectively weighed according to the stoichiometric ratio of the raw materials Li _5.7PS_4.7Cl_1.3, the raw materials are uniformly mixed to obtain a raw material mixture, the raw material mixture is placed in an atmosphere (argon) furnace for sintering at 530 ℃ for 8 hours, and then the sintered body is crushed to obtain the sulfur silver germanium ore type sulfide solid electrolyte powder.

Comparative example 3 the target chemical formula is Li _5.5PS_4.5Cl_1.5.

2.0Mol of Li ₂S、0.5mol P₂S₅ and 1.5mol of LiCl raw material powder are respectively weighed according to the stoichiometric ratio of the raw materials Li _5.5PS_4.5Cl_1.5, the raw materials are uniformly mixed to obtain a raw material mixture, the raw material mixture is placed in an atmosphere (argon) furnace for sintering at 500 ℃ for 8 hours, and then the sintered body is crushed to obtain the sulfur silver germanium ore type sulfide solid electrolyte powder.

Comparative example 4. Target chemical formula is Li _5.2PS_4.2Cl_1.8.

1.7Mol of Li ₂S、0.5mol P₂S₅ and 1.8mol of LiCl raw material powder are respectively weighed according to the stoichiometric ratio of the raw materials Li _5.2PS_4.2Cl_1.8, the raw materials are uniformly mixed to obtain a raw material mixture, the raw material mixture is placed in an atmosphere (argon) furnace for sintering at 480 ℃ for 8 hours, and then the sintered body is crushed to obtain the sulfur silver germanium ore type sulfide solid electrolyte powder.

(II) preparation of solid electrolyte film (solid electrolyte film sheet form) and all-solid Battery

Examples 1 to 15 correspond to the sulfide solid electrolyte powders prepared in the first (first) step of examples 1 to 15, respectively:

Sulfide solid electrolyte powder (prepared in examples 1-15) was pressed under 360MPa to a dense solid electrolyte membrane under an argon atmosphere.

In an argon atmosphere, weighing NCM ₈₁₁ powder, sulfide solid electrolyte Li ₆PS₅ Cl, conductive carbon fiber (VGCF) and a binder PTFE according to a weight ratio of 85:13:1:1, uniformly mixing in a double-planetary mixer, heating and pressurizing the uniformly mixed powder in an internal mixer to be kneaded into a bulk material, carrying out hot rolling at 80 ℃ to form a self-supporting positive plate, and then compounding with a current collector Al foil hot roll to obtain the positive plate (positive plate film).

And placing the positive electrode plate on one side of the solid electrolyte membrane, and stacking InLi alloy on the other side of the solid electrolyte membrane to serve as a negative electrode layer to assemble the all-solid battery, wherein the solid electrolyte membrane is used as a solid electrolyte layer, and the positive electrode plate is used as a positive electrode layer. The battery test window is 2.6-4.3V vs Li.

Comparative examples 1 to 4:

The substantially same method as in example 1 was employed, except that the sulfide solid electrolyte powder used for producing the solid electrolyte membrane was replaced with the sulfide solid electrolyte powder produced in comparative examples 1 to 4.

Table 1. The parameters (M element type and content, T element type and content, x, y) related to the target chemical formula Li _6-xPS_5-x- _yM_yT_1+x of the sulfide solid electrolytes prepared in examples 1 to 15 and comparative examples 1 to 4 can be referred to in Table 1.

Table 1. Chemical formula-related information and M elemental addition amount information of sulfide solid electrolytes prepared in examples 1 to 15 and comparative examples 1 to 4.

In table 1, "Se simple substance addition amount" and "Te simple substance addition amount" are the mass ratio of Se simple substance and Te simple substance to the sintered mixture, respectively, and the percentage units are wt%. In various embodiments, the sintered mixture is a precursor mixture unless otherwise indicated.

2. The positive electrode layer is provided with the sulfide solid electrolyte provided by the application and the preparation of a solid-state battery (all-solid-state secondary battery, sulfide all-solid-state battery).

Examples P1 to P15 correspond to the sulfide solid electrolyte powders prepared in the first (first) step of examples 1 to 15, respectively:

In an argon atmosphere, anode active particles NCM ₈₁₁ powder, sulfide solid electrolyte powder (prepared in examples 1-15 and used as anode electrolyte particles), conductive carbon fiber (VGCF and used as anode conductive agent) and a binder PTFE are weighed according to the weight ratio of 85:13:1:1, the raw materials are uniformly mixed in a double planetary mixer, the uniformly mixed powder is heated and pressurized in an internal mixer and kneaded into a bulk material, then the bulk material is heated and pressed into a self-supporting anode sheet at 80 ℃, and then the self-supporting anode sheet is compounded with a current collector Al foil hot roll to obtain the anode sheet (anode sheet).

In argon atmosphere, the sulfide solid electrolyte powder Li ₆PS₅ Cl is pressed into a compact solid electrolyte membrane under the action of 360 MPa.

Comparative example P1.

An all-solid battery was produced by substantially the same method as in example P8, except that the positive electrode electrolyte particles in the composite positive electrode powder were replaced with Li ₆PS₅ Cl in comparative example 1.

3. The negative electrode layer is provided with the sulfide solid electrolyte provided by the application and the preparation of a solid-state battery (all-solid-state secondary battery, sulfide all-solid-state battery).

Examples N1 to N15 correspond to the sulfide solid electrolyte powders prepared in the first (first) step of examples 1 to 15, respectively:

In an argon atmosphere, weighing raw materials of NCM ₈₁₁ powder, sulfide solid electrolyte Li ₆PS₅ Cl, conductive carbon fiber (VGCF) and a binder PTFE according to a weight ratio of 85:13:1:1, and manually grinding in a mortar until the raw materials are uniformly mixed to obtain composite anode powder. And (3) uniformly spreading the composite anode powder on one side surface of the solid electrolyte membrane, cold pressing the composite anode powder into a sheet, maintaining the pressure at 420MPa for 5min, and forming the composite membrane formed by the anode layer and the solid electrolyte layer.

In an argon atmosphere, negative electrode active particle Si powder, sulfide solid electrolyte powder (prepared as negative electrode electrolyte particles in examples 1 to 15) and a negative electrode binder PVDF were dispersed in a solvent paraxylene (solid content 60 wt%) in a weight ratio of 80:17:3, and coated on the other side of the solid electrolyte layer in a composite membrane sheet in accordance with a coating surface density of 2.5mg/cm ² on a dry weight basis (excluding the solvent), and dried to form a negative electrode layer, to obtain a sulfide all-solid battery comprising a positive electrode layer (corresponding to a positive electrode film), a solid electrolyte layer (corresponding to a solid electrolyte film), and a negative electrode layer (corresponding to a negative electrode film) laminated in this order.

Comparative example N1.

An all-solid battery was produced by substantially the same method as in example N8, except that the negative-positive electrolyte particles in the negative electrode layer were replaced with Li ₆PS₅ Cl in comparative example 1.

4. Testing and analysis of materials

Testing and analyzing method

1. Elemental analysis

And analyzing the element types and the proportions of the sulfide solid electrolyte by adopting an inductively coupled plasma spectrometer (ICP meter) to determine the chemical formula of the sulfide solid electrolyte.

And ThermoFisher ICAP Pro, a testing instrument.

2. Analysis of crystalline phases

An X-ray diffraction (XRD) pattern was used to determine whether the sulfide solid electrolyte included a sulfur silver germanium ore type crystalline phase and how much of the impurity phase.

And the sample to be tested is sulfide solid electrolyte powder.

Bruker-D8 advanced. The Cu target K alpha 1 rays are adopted, the wavelength lambda is 0.15406nm, the X-ray tube is controlled at 40kV and 40mA, the scanning range of 2 theta (°) is 10-80 degrees, and the scanning speed of 2 theta (°) is 0.02 degrees/second.

Analytical method according to the comparison with XRD standard spectrum of Li ₆PS₅ Cl, it is determined whether the sulfide solid electrolyte to be tested includes sulfur silver germanium ore type crystal phase.

3. Ion conductivity test

Ion conductivity was determined by alternating current impedance spectroscopy (EIS).

And the sample to be tested is sulfide solid electrolyte powder.

Test sample preparation, namely pouring 120mg of solid electrolyte powder to be tested into a tabletting mold with the diameter of 10mm, and pressing the electrolyte powder into a compact disc under 360MPa to obtain the solid electrolyte membrane serving as the test sample.

Test method the solid electrolyte membrane was clamped in a mold with a 10mm diameter cylindrical stainless steel current collector at 120MPa, after which the current collector was connected to an electrochemical workstation and the electrolyte sheet was subjected to electrochemical impedance testing (EIS) at a bias voltage of 10mV and a frequency in the range of 10 ⁶ Hz to 10 Hz. The ion conductivity (sigma) can be calculated by using the curve from the high frequency band to the low frequency band in the electrochemical impedance spectrum, and marking the intersection point of the curve and the Z' axis as a resistance value R through a formula (1):

where d is the thickness of the solid electrolyte membrane, and A is the contact area of the electrolyte membrane and the current collector.

The sulfide solid electrolyte powders prepared in examples 1 to 15 correspond to test examples 1 to 15, respectively, the sulfide solid electrolyte powders prepared in comparative examples 1 to 4 correspond to test comparative examples 1 to 4, respectively, and the test results can be referred to as "ionic conductivity" in Table 2.

4. First discharge capacity

The assembled all-solid-state battery is charged to 3.68V (4.3V for lithium potential) at the current density of 0.1C, kept stand for 10min, and then discharged to 2.18V (2.8V for lithium potential) at the current density of 0.1C, so that the first discharge capacity of the battery is obtained. The cells were tested at 25±3 ℃, where 1 c=200 mA/g. The test results can be seen in table 3.

5. Rate capability

The testing method comprises the steps of fixing the charging multiplying power of an all-solid-state battery to be 0.1C, discharging the battery at multiplying powers of 0.1C,0.33C,1C,2C and 3C respectively, wherein each multiplying power circulates for 3 circles, the voltage testing window of the battery is 2.8-4.3V vs. Li+/Li, and the battery is tested at 25+/-3 ℃, wherein 1 C=200 mA/g. The test results can be seen in table 3.

(II) analysis of test results

1. Elemental analysis

The chemical formulas of the sulfide solid electrolytes prepared in examples 1 to 15 and comparative examples 1 to 4 were confirmed to be substantially identical to the target chemical formulas by ICP test. Taking example 8 as an example, the actual test result of the elemental composition of the objective sulfide solid electrolyte Li _5.5PS_4.47Se_0.03Cl_1.5 is that the atomic number ratio of Li: P: S: se: cl is=5.51:1.02:4.40:0.03:1.49.

2. According to the XRD analysis results, the sulfide solid electrolytes prepared in examples 1 to 15 and comparative examples 1 to 4 each formed a sulfur silver germanium ore type crystal phase. In addition, the impurity phase content in the sulfur silver germanium ore type sulfide solid electrolyte of each example was relatively low. See table 2. As an example, X-ray diffraction (XRD) patterns of sulfide solid electrolytes prepared in example 8 and comparative example 3 can be referred to fig. 8.

3. Ion conductivity

The hydrogen sulfide release amounts and the ionic conductivity test results of the sulfide solid electrolytes prepared in examples 1 to 15 and comparative examples 1 to 4 can be referred to in Table 2.

The sulfide solid electrolytes Li _6-xPS_5-x-yM_yT_1+x of examples 1 to 15 each satisfied x >0 and y >0 compared to comparative example 1, and the sulfide solid electrolytes prepared in examples 1 to 15 each had a higher ion conductivity compared to comparative example 1. Examples 1-2 compared to comparative example 2, examples 8-10 compared to comparative example 3, and examples 11-14 compared to comparative example 4, all produced sulfide solid electrolytes also had significantly reduced hydrogen sulfide release, while also having better ionic conductivity. See table 2.

4. Cell performance

The solid-state batteries of examples 1 to 15 each had better initial discharge capacity and rate performance than comparative example 1. In addition, examples 1-2 compared to comparative example 2, examples 8-10 compared to comparative example 3, and examples 11-14 compared to comparative example 4, all produced solid-state batteries having lower impurity content and higher ion conductivity. See table 3.

As an example, the sulfide solid electrolyte provided in the first aspect of the present application was not provided in the positive electrode layer of comparative example P1, and both the first discharge capacity and the rate performance were significantly deteriorated, as compared to example P8. See table 3.

As an example, the sulfide solid electrolyte provided in the first aspect of the present application was not provided in the negative electrode layer of comparative example N1, with respect to example N2, and both the first discharge capacity and the rate performance were significantly deteriorated. See table 3.

The solid-state batteries of examples 1 to 15 each use the sulfide solid electrolyte described in the first aspect of the present application in a solid electrolyte layer, effectively reducing the resistance of the solid-state battery, and the solid-state battery has excellent rate performance, enabling better electrochemical performance at high rates.

Examples P1 to P15 the sulfide solid electrolyte described in the first aspect of the present application was used as positive electrode electrolyte particles in the positive electrode layer, not only reducing the internal resistance of the electrode sheet, but also promoting the capacity exertion of the positive electrode active material in the positive electrode layer.

Examples N1 to N15 the sulfide solid electrolyte described in the first aspect of the present application was used as negative electrode electrolyte particles in the negative electrode layer, not only reducing the internal resistance of the electrode sheet, but also promoting the capacity exertion of the positive electrode active material in the negative electrode layer.

Table 2.

Table 3.

The foregoing description of various embodiments is intended to highlight differences between the various embodiments, which may be the same or similar to each other by reference, and is not repeated herein for the sake of brevity. The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be regarded as the scope of the description.

The present application is not limited to the above embodiment. The above embodiments are merely examples, and embodiments having substantially the same configuration and the same effects as those of the technical idea within the scope of the present application are included in the technical scope of the present application. The examples described above represent only a few embodiments of the application, which are described in more detail, but are not to be construed as limiting the scope of the patent. Further, various modifications that can be made to the embodiments and other modes of combining some of the constituent elements in the embodiments, which are conceivable to those skilled in the art, are also included in the scope of the present application within the scope not departing from the gist of the present application.

Claims

1. A sulfide solid electrolyte, characterized by comprising an argyrodite-type crystal phase;

The argyrodite-type crystal phase includes Li, P, S, M and T elements; wherein the M element is selected from one or both of Se and Te, and the T element is selected from one or both of Cl and Br;

In the argyrodite-type crystal phase, the atomic number ratio of the T element to the P element is 1+x, and x>0;

In the argyrodite-type crystal phase, the atomic number ratio of the M element to the P element is denoted as y, and y>0.

2 . The sulfide solid electrolyte according to claim 1 , wherein in the argyrodite-type crystal phase, 0<x≤0.8.

3 . The sulfide solid electrolyte according to claim 1 , wherein in the argyrodite-type crystal phase, 0<y≤0.1.

4. The sulfide solid electrolyte according to any one of claims 1 to 3, characterized in that in the argyrodite-type crystal phase, the atomic number ratio of Li element, P element, S element, M element and T element is (6-x):1:(5-x-y):y:(1+x), wherein 0<x≤0.8, 0<y≤0.1.

5 . The sulfide solid electrolyte according to claim 1 , wherein the chemical formula of the argyrodite-type crystal phase is Li _6-x PS _5-xy _My T _1+x .

6 . The sulfide solid electrolyte according to claim 1 , wherein the chemical formula of the argyrodite-type crystal phase is Li _6-x PS _5-xy Se _y Cl _1+x .

7. The sulfide solid electrolyte according to any one of claims 1 to 5, wherein the argyrodite-type crystal phase satisfies one or more of the following characteristics:

In the argyrodite-type crystal phase, 0.05≤x≤0.8; optionally, 0.1≤x≤0.8; further optionally, 0.3≤x≤0.8;

In the argyrodite-type crystal phase, 0.02≤y≤0.1; optionally, 0.02≤y≤0.09.

8 . The sulfide solid electrolyte according to claim 1 , wherein 0.3≤x≤0.8, and 0.02≤y≤0.09.

9. The sulfide solid electrolyte according to any one of claims 1 to 5, characterized in that, in the argyrodite-type crystal phase, the atomic number ratio of the S element to the P element is expressed as 5-x-y, and 4.1≤(5-x-y)<5.0.

10. The sulfide solid electrolyte according to claim 9, wherein 4.1<(5-x-y)<4.7.

11. The sulfide solid electrolyte according to any one of claims 1 to 10, wherein the argyrodite-type crystal phase satisfies one or both of the following characteristics:

In the argyrodite-type crystal phase, the T element includes Cl element;

In the argyrodite-type crystal phase, the M element includes Se.

12. The sulfide solid electrolyte according to any one of claims 1 to 11, wherein the argyrodite-type crystal phase satisfies one or both of the following characteristics:

In the argyrodite-type crystal phase, the atomic number ratio of the Cl element to the Br element is greater than or equal to 1;

In the argyrodite-type crystal phase, the atomic number ratio of the Se element to the Te element is greater than or equal to 1.

13. The sulfide solid electrolyte according to any one of claims 1 to 12, characterized in that the argyrodite-type crystal phase has any one of the following chemical formulas: Li _5.7 PS _4.65 Se _0.05 Cl _1.3 , Li _5.5 PS _4.44 Se _0.06 Cl ₁ Br _0.5 , Li _5.5 PS _4.44 Se _0.05 Te _0.01 Cl ₁ Br _0.5 , and Li _5.5 PS _4.44 Se _0.06 Cl _1.5 .

14 . The sulfide solid electrolyte according to claim 1 , wherein a 2θ (°) diffraction angle in an X-ray diffraction pattern of the sulfide solid electrolyte has a characteristic peak consistent with the argyrodite-type crystal phase.

15. The sulfide solid electrolyte according to claim 14, characterized in that it satisfies at least one of the following characteristics:

The 2θ (°) diffraction angle in the X-ray diffraction pattern of the sulfide solid electrolyte has peaks at 15.5±δ°, 18.1±δ°, 25.6±δ°, 30.1±δ°, 31.4±δ°, 39.8±δ°, 45.1±δ°, 47.9±δ° and 52.5±δ°, wherein δ is 0.2 or 0.1;

There is no LiT impurity phase peak in the X-ray diffraction pattern of the sulfide solid electrolyte;

The X-ray diffraction pattern of the sulfide solid electrolyte has no diffraction peaks at 2θ (°) diffraction angles of 34.9±0.2°, 29.2±0.2°, and 33.9±0.2°;

The X-ray diffraction pattern of the sulfide solid electrolyte is obtained by using Cu Kα radiation;

The X-ray diffraction pattern of the sulfide solid electrolyte is obtained by powder X-ray diffraction testing.

16. A method for preparing a sulfide solid electrolyte, characterized in that it comprises the following steps:

Providing a precursor mixture comprising Li ₂ S, P ₂ S ₅ , an optional sulfur element, M element, and LiT according to a desired raw material stoichiometric ratio; wherein the M element is selected from one or both of Se and Te, T is a halogen, and LiT is selected from one or both of LiCl and LiBr;

The precursor mixture is sintered in an inert atmosphere to prepare a sulfide solid electrolyte including an argyrodite-type crystal phase; in the argyrodite-type crystal phase, the atomic number ratio of the T element to the P element is recorded as 1+x, and the atomic number ratio of the M element to the P element is recorded as y, and the argyrodite-type crystal phase satisfies x>0 and y>0.

17. The method for preparing a sulfide solid electrolyte according to claim 16, wherein one or more of the following characteristics are met:

In the step of sintering the precursor mixture in an inert atmosphere, the sintering temperature is 450° C. to 530° C.;

The prepared sulfide solid electrolyte is the sulfide solid electrolyte described in any one of claims 1 to 15.

18. A solid electrolyte membrane, characterized in that it comprises at least one of the sulfide solid electrolyte according to any one of claims 1 to 15 and the sulfide solid electrolyte prepared by the preparation method according to claim 16 or 17.

19. An electrode plate, characterized in that it comprises an electrode active material layer, wherein the electrode active material layer comprises an electrode active substance, and further comprises at least one of the sulfide solid electrolyte according to any one of claims 1 to 15 and the sulfide solid electrolyte prepared by the preparation method according to claim 16 or 17.

20. The electrode plate according to claim 19, wherein the electrode plate is a positive electrode plate, the electrode active material layer is referred to as a positive electrode active material layer, and the electrode active substance is referred to as a positive electrode active substance;

Alternatively, the electrode plate is a negative electrode plate, the electrode active material layer is recorded as a negative electrode active material layer, and the electrode active substance is recorded as a negative electrode active substance.

21. A solid-state battery, characterized in that it comprises at least one of the sulfide solid electrolyte according to any one of claims 1 to 15, the sulfide solid electrolyte prepared by the preparation method according to claim 16 or 17, the solid electrolyte membrane according to claim 18, and the electrode plate according to claim 19 or 20.

22. The solid-state battery according to claim 21, characterized in that the solid-state battery is a sulfide all-solid-state battery.

23. An electrical device, characterized in that it comprises at least one of the sulfide solid electrolyte according to any one of claims 1 to 15, the sulfide solid electrolyte prepared by the preparation method according to claim 16 or 17, the solid electrolyte membrane according to claim 18, the electrode plate according to claim 19 or 20, and the solid-state battery according to claim 21 or 22.