CN105811002A - Organic and inorganic composite all-solid-state electrolyte and all-solid-state battery formed from same - Google Patents

Abstract

The invention relates to an organic and inorganic composite all-solid-state electrolyte, in particular to an organic polycarbonate macromolecule and inorganic fast-ion conductor composite all-solid-state electrode and preparation and application of an all-solid-state battery formed from the same. The organic and inorganic composite all-solid-state electrolyte comprises polycarbonate macromolecule, an inorganic fast-ion conductor, a lithium salt and a porous rigid support material, the thickness of the organic and inorganic composite all-solid-state electrolyte is 5-2,000 micrometers, the mechanical strength is 2-150MPa, the room-temperature ionic conductivity is 1*10<-4>-6*10<-3> S/cm, and an electrochemical window is greater than 4V. The organic and inorganic composite all-solid-state electrolyte provided by the invention is easy to prepare and simple to form, has favorable mechanical property, and is relatively high in room-temperature ionic conductivity and relatively wide in electrochemical window; and meanwhile, by the organic and inorganic composite all-solid-state electrolyte, the growth of lithium dendrites of a negative electrode can be effectively prevented, the interface stability is improved, and the long-circulation and safe application performance of the battery are further improved.

Description

An organic-inorganic composite all-solid-state electrolyte and an all-solid-state lithium battery composed of the same

technical field

The invention relates to a solid electrolyte, in particular to the preparation and application of an organic-inorganic composite all-solid electrolyte and an all-solid secondary lithium battery composed of the same.

Background technique

In recent years, with the development of electric vehicles and grid energy storage, people's demand for high-safety, high-energy-density power batteries and energy storage systems has become more and more urgent. Among commercial electrochemical energy storage devices, lithium-ion batteries are undoubtedly the best choice. At present, there are two main types of electrolytes used in commercial lithium-ion batteries: one is a liquid electrolyte, and the other is a gel electrolyte. The liquid electrolyte is composed of lithium salts (such as LiPF ₆ , LiTFSI and LiBF ₄ , etc.), organic solvents (such as cyclic carbonates, chain carbonates, carboxylates, etc.) and various functional additives. Gel electrolyte is a gel formed by absorbing electrolyte solution in a porous polymer matrix. Like the liquid electrolyte, the electrolyte in the gel electrolyte plays the role of ion conduction and the formation of a stable solid electrolyte membrane (SEI) on the surface of the negative electrode. The above two electrolytes have high ionic conductivity, can effectively infiltrate the electrodes, and can form a stable solid electrolyte film on the electrode surface, so the existing commercial lithium-ion batteries have low battery internal resistance and good cycle stability sex. However, both liquid electrolytes and gel electrolytes contain a large amount of flammable and volatile organic solvents. When the internal temperature of the battery rises due to high current charging and discharging or short circuit, the chemical reaction between the electrolyte and the electrodes will accelerate rapidly, causing thermal runaway. This process is accompanied by the generation of a large amount of gas, which eventually leads to the failure of the battery seal and a fire, combustion and explosion. In recent years, safety accidents of large-capacity lithium-ion batteries have occurred frequently. Although measures such as adding flame retardants, using high-temperature-resistant ceramic diaphragms, surface modification of positive and negative materials, optimizing battery structure design, optimizing BMS, coating phase-change flame-retardant materials on the outer surface of batteries, and improving cooling systems can achieve considerable To a certain extent, the safety of existing lithium-ion batteries can be improved, but these measures cannot fundamentally eliminate the safety hazards of large-capacity battery systems, especially when batteries are used under extreme conditions and safety problems occur in local battery cells.

In order to solve the problems faced by existing commercial liquid lithium-ion batteries, researchers are vigorously developing lithium-ion batteries using solid electrolytes, which have the following advantages:

1) The solid electrolyte is non-volatile and generally non-flammable, so it is solid and has excellent safety;

2) The solid electrolyte can maintain stability in a wide temperature range, and is suitable for a wide range of temperatures, especially at high temperatures;

3) Some solid electrolytes are not sensitive to moisture, can maintain good chemical stability in the air for a long time, and are easy to prepare;

4) Solid electrolyte materials have a wide electrochemical window, which makes high-voltage electrode materials expected to be applied, thereby improving battery energy density;

5) The solid electrolyte is dense and has high strength and hardness, which can effectively prevent the penetration of lithium dendrites, which makes it possible for metallic lithium to be used as a negative electrode.

In summary, from the analysis of basic characteristics, if a suitable material system is found, an all-solid-state lithium battery using a solid electrolyte can have excellent safety characteristics, cycle characteristics, high energy density and low cost.

Solid electrolytes can be broadly classified into polymer solid electrolytes and inorganic solid electrolytes. Polymer solid electrolyte is an electrolyte material composed of lithium salt and polymer. It has high electrical conductivity above the glass transition temperature, and has good flexibility and tensile shear properties, and is easy to prepare into flexible and bendable batteries. In the polymer solid electrolyte, through the interaction with the polymer, the lithium salt can dissociate positive and negative ions to a certain extent, and complex with the polar group of the polymer to form a complex. During the peristaltic process of polymer chain segments, positive and negative ions are continuously dissociated from the original groups and complexed with adjacent groups. Under the action of an external electric field, the directional movement of ions can be realized, thereby realizing the conduction of positive and negative ions. Patent CN101440177A discloses a method for preparing a polymer solid electrolyte. In this method, epoxy resin and nitrile rubber are blended as the matrix of the solid electrolyte, and the matrix is dissolved in tetrahydrofuran together with lithium perchlorate, and then prepared by solution casting Composite polymer solid electrolyte, the maximum ionic conductivity of the prepared polymer solid electrolyte is 9×10 ^-5 S cm ^-1 at 20 ^o C. CN201410683144.1 discloses a polyethylene oxide-based all-solid-state polymer electrolyte, whose room temperature conductivity is 10 ^-5 S cm ^-1 . Polymer electrolytes have low room temperature ionic conductivity, which is difficult to meet the application of room temperature lithium-ion batteries. Compared with polymer solid electrolytes, inorganic solid electrolytes can maintain chemical stability in a wide temperature range, have a wide electrochemical window, and have higher mechanical strength, so batteries based on inorganic solid electrolytes have higher safety characteristics. CN103594726A discloses a garnet-structured lanthanum lithium tantalate-based solid electrolyte material and a preparation method thereof. The conductivity of the electrolyte material at room temperature is at most 6×10 ^-4 S cm ^-1 . Invention patent application specification CN201410710254.2 discloses an inverse perovskite sulfide solid electrolyte with an ionic conductivity of 10 ^-3 S cm ^-1 at 20 ^o C. Although the ionic conductivity at room temperature is high, the inorganic solid electrolyte is brittle, poor in flexibility, complex in preparation process, and high in cost. Organic-inorganic composite all-solid electrolyte, by combining solid polymer electrolyte and inorganic solid electrolyte, can take into account the advantages of both, easy processing and molding, high ionic conductivity, high electrochemical stability and many other advantages, to maximize the realization of solid electrolyte Comprehensive performance improvement.

Contents of the invention

The technical scheme that the present invention adopts for realizing the above object is:

An organic-inorganic composite all-solid electrolyte, which is composed of polycarbonate polymers, lithium salts, porous rigid support materials, and inorganic fast ion conductors; its thickness is 5 μm-2000 μm; its mechanical strength is 2 MPa-150 MPa , the ionic conductivity at room temperature is 1×10 ^-4 S/cm-6×10 ^-3 S/cm, and the electrochemical window is greater than 4 V.

The polycarbonate macromolecule has a structure as shown in general formula 1:

Formula 1

Wherein, the value of a is 1-50000, and the value of b is 1-50000.

R1 is _:

, or

R2 is _:

, or

In the above substituents, X is fluorine, phenyl, hydroxyl or lithium sulfonate; wherein the value of m1 is 0-2, the value of n1 is 0-2, and m1 and n1 are different from 0; the value of m2 is 0-2, the value of n2 is 0-2, and m2 and n2 are different from 0; the value of m3 is 0-2, the value of n3 is 0-2, and m3 and n3 are different from 0; The mass fraction of carbonate polymers in the organic-inorganic composite all-solid electrolyte is 3%-85%;

The inorganic fast ion conductors are Li ₇ La ₃ Zr ₂ O ₁₂ , Li ₁₀ GeP ₂ S ₁₂ , Li ₃ OCl _0.5 Br _0.5 , Li _3x La _(2/3)-x TiO ₃ (0.04<x<0.14) , Li ₅ La ₃ M ₂ O ₁₂ (M=Ta, Nb), Li _5.5 La ₃ Nb _1.75 In _0.25 O ₁₂ , Li ₃ N-LiX (X=Cl, Br, I), Li ₁₄ Zn(GeO ₄ ) _4. One or more of LiZr ₂ (PO4) ₃ , Li ₃ OCl, LiPON, Li ₂ SM _a S _b (M=Al, Si, P; where the values of a and b are 1-3), inorganic The mass fraction of the fast ion conductor in the organic-inorganic composite all-solid electrolyte is 1%-50%;

The lithium salt is one or more of lithium perchlorate, lithium hexafluorophosphate, lithium dioxalate borate, lithium hexafluoroarsenate, lithium tetrafluoroborate, lithium trifluoromethanesulfonate, and lithium difluoromethanesulfonylimide ; The mass fraction of lithium salt in the organic-inorganic composite all-solid electrolyte is 3%-42%;

The porous rigid support material is cellulose non-woven film, seaweed fiber non-woven film; aramid non-woven film; polyaryl sulfone amide non-woven film; polypropylene non-woven film; glass fiber, polyethylene terephthalate One of ester film and polyimide non-woven film, the mass fraction of porous rigid support material in organic-inorganic composite all-solid-state electrolyte is 5%-30%.

The preferred technical solution is:

The polycarbonate polymer is polypropylene carbonate or polyethylene carbonate; the amount of polycarbonate polymer added to the organic-inorganic composite all-solid electrolyte is 30%-75%;

The inorganic fast ion conductors are Li ₇ La ₃ Zr ₂ O ₁₂ , Li ₁₀ GeP ₂ S ₁₂ ; the addition amount of the inorganic fast ion conductors in the organic-inorganic composite all-solid electrolyte is 5%-30%;

The lithium salt is lithium perchlorate or lithium bisfluoromethanesulfonylimide; the amount of lithium salt added to the organic-inorganic composite all-solid electrolyte is 5%-20%;

The porous rigid support material is a cellulose nonwoven membrane or a polyimide nonwoven membrane, and the mass fraction of the porous rigid support material in the organic-inorganic composite all-solid-state electrolyte is 10%-25%.

A more preferred technical solution is:

The polycarbonate polymer is polypropylene carbonate; the addition amount of polycarbonate polymer in the organic-inorganic composite all-solid electrolyte is 40%-65%;

The inorganic fast ion conductor is Li ₇ La ₃ Zr ₂ O _12; the addition amount of the inorganic fast ion conductor in the organic-inorganic composite all-solid electrolyte is 8%-20%;

The lithium salt is lithium bisfluoromethanesulfonylimide; the amount of lithium salt added to the organic-inorganic composite all-solid electrolyte is 10%-15%;

The solvent is N,N-dimethylformamide;

The porous rigid support material is a cellulose non-woven membrane, and the mass fraction of the porous rigid support material in the organic-inorganic composite all-solid-state electrolyte is 15%-25%.

A preparation method of an organic-inorganic composite all-solid-state electrolyte:

1) Dissolve the polycarbonate polymer and lithium salt in the solvent, stir until completely dissolved, and obtain a uniform polycarbonate polymer/lithium salt solution;

2) Add the inorganic fast ion conductor to the above homogeneous solution, and continue to stir until the mixture is even;

3) Form the above-mentioned uniformly mixed solution on a porous rigid support material to form a membrane, and dry it in vacuum to obtain an organic-inorganic composite all-solid-state electrolyte.

The polycarbonate macromolecule has a structure as shown in general formula 1:

Formula 1

Wherein, the value of a is 1-50000, and the value of b is 1-50000.

R1 is _:

, or

R2 is _:

, or

X in the above substituents is fluorine, phenyl, hydroxyl or lithium sulfonate. The value of m1 is 0-2, the value of n1 is 0-2; the value of m2 is 0-2, the value of n2 is 0-2; the value of m3 is 0-2, the value of n3 is 0-2; the mass fraction of polycarbonate polymers in the organic-inorganic composite all-solid electrolyte is 3%-85%;

The inorganic fast ion conductors are Li ₇ La ₃ Zr ₂ O ₁₂ , Li ₁₀ GeP ₂ S ₁₂ , Li ₃ OCl _0.5 Br _0.5 , Li _3x La _(2/3)-x TiO ₃ (0.04<x<0.14) , Li ₅ La ₃ M ₂ O ₁₂ (M=Ta, Nb), Li _5.5 La ₃ Nb _1.75 In _0.25 O ₁₂ , Li ₃ N-LiX (X=Cl, Br, I), Li ₁₄ Zn(GeO ₄ ) _4. One or more of LiZr ₂ (PO4) ₃ , Li ₃ OCl, LiPON, Li ₂ SM _a S _b (M=Al, Si, P; where the values of a and b are 1-3), inorganic The mass fraction of the fast ion conductor in the organic-inorganic composite all-solid electrolyte is 1%-50%;

The lithium salt is one or more of lithium perchlorate, lithium hexafluorophosphate, lithium dioxalate borate, lithium hexafluoroarsenate, lithium tetrafluoroborate, lithium trifluoromethanesulfonate, and lithium difluoromethanesulfonylimide ; The mass fraction of lithium salt in the organic-inorganic composite all-solid electrolyte is 3%-42%;

The porous rigid support material is cellulose non-woven film, seaweed fiber non-woven film; aramid non-woven film; polyaryl sulfone amide non-woven film; polypropylene non-woven film; glass fiber, polyethylene terephthalate One of ester film and polyimide non-woven film, the mass fraction of porous rigid support material in organic-inorganic composite all-solid-state electrolyte is 5%-30%;

The solvent is acetonitrile, dimethyl sulfoxide, sulfolane, dimethyl sulfite, diethyl sulfite, acetone, tetrahydrofuran, chloroform, ethyl acetate, N-methylpyrrolidone, N,N-dimethyl One or more of methyl formamide and N,N-dimethylacetamide.

The preferred technical solution is:

The polycarbonate polymer is polypropylene carbonate or polyethylene carbonate; the amount of polycarbonate polymer added to the organic-inorganic composite all-solid electrolyte is 30%-75%;

The inorganic fast ion conductors are Li ₇ La ₃ Zr ₂ O ₁₂ , Li ₁₀ GeP ₂ S ₁₂ ; the addition amount of the inorganic fast ion conductors in the organic-inorganic composite all-solid electrolyte is 5%-30%;

The lithium salt is lithium perchlorate or lithium bisfluoromethanesulfonylimide; the amount of lithium salt added to the organic-inorganic composite all-solid electrolyte is 5%-20%;

The porous rigid support material is a cellulose nonwoven membrane or a polyimide nonwoven membrane, and the mass fraction of the porous rigid support material in the organic-inorganic composite all-solid-state electrolyte is 10%-25%.

A more preferred technical solution is:

The polycarbonate polymer is polypropylene carbonate; the addition amount of polycarbonate polymer in the organic-inorganic composite all-solid electrolyte is 40%-65%;

The inorganic fast ion conductor is Li ₇ La ₃ Zr ₂ O _12; the addition amount of the inorganic fast ion conductor in the organic-inorganic composite all-solid electrolyte is 8%-20%;

The lithium salt is lithium bisfluoromethanesulfonylimide; the amount of lithium salt added to the organic-inorganic composite all-solid electrolyte is 10%-15%;

The solvent is N,N-dimethylformamide;

The porous rigid support material is a cellulose non-woven membrane, and the mass fraction of the porous rigid support material in the organic-inorganic composite all-solid-state electrolyte is 15%-25%.

An application of an organic-inorganic composite all-solid electrolyte, which is used to prepare an all-solid lithium battery.

Furthermore, the application of the organic-inorganic composite all-solid electrolyte in the preparation of an all-solid lithium metal battery, an all-solid lithium ion battery or an all-solid lithium-sulfur battery.

An all-solid secondary lithium battery, comprising a positive electrode, a negative electrode, and an electrolyte between the positive and negative electrodes, the electrolyte being an organic-inorganic composite all-solid electrolyte;

The active material of the positive electrode is lithium cobalt oxide, lithium iron phosphate, lithium manganese iron phosphate, lithium manganate, lithium nickel manganese oxide, lithium-rich manganese base, ternary material, sulfur, sulfur compound, lithium iron sulfate, lithium ion One or more of fluorophosphate, lithium vanadium fluorophosphate, lithium iron fluorophosphate, lithium manganese oxide, conductive polymer;

The active material of negative electrode is lithium metal, lithium metal alloy, graphite, hard carbon, molybdenum disulfide, lithium titanate, carbon silicon composite material, carbon germanium composite material, carbon tin composite material, antimony oxide, antimony carbon composite material, tin antimony One or more of composite materials, lithium titanium oxide, and lithium metal nitride.

Among them, the positive electrode suitable for all-solid-state secondary lithium-sulfur batteries is sulfur and sulfur compounds, and the negative electrode is metal lithium and metal lithium alloys.

The invention relates to the preparation of an all-solid secondary lithium battery. The above-mentioned electrolyte is used to separate the positive and negative pole pieces, and the all-solid secondary lithium battery is sealed.

The advantages that the present invention has:

The organic-inorganic composite all-solid electrolyte in the present invention is composed of a polycarbonate solid polymer electrolyte and an inorganic fast ion conductor. It not only has good flexibility and tensile shear performance of polycarbonate solid polymer electrolyte, but also inherits many advantages of inorganic fast ion conductors such as good chemical stability, wide electrochemical window, high mechanical strength, etc., and has excellent comprehensive performance.

The organic-inorganic composite all-solid electrolyte obtained in the present invention is easy to prepare, simple to shape, has a mechanical strength of 2 MPa-150 MPa, and an ion conductivity of 1× ^10-4 S/cm-6× ^10-3 S/cm at room temperature. The window is greater than 4 V. At the same time, the solid electrolyte effectively inhibits the growth of lithium dendrites in the negative electrode, and improves the interface stability and long-term cycle performance. Moreover, no flammable and explosive organic solvents are used in the electrolyte of the present invention, which eliminates the potential safety hazard and greatly improves the safe use performance of the lithium battery. It can be applied to all-solid-state lithium batteries (including lithium-sulfur batteries), all-solid-state lithium-ion batteries and other secondary high-energy lithium batteries.

Description of drawings

Figure 1 is a scanning electron microscope picture of the organic-inorganic composite all-solid polyelectrolyte provided in Example 1 of the present invention.

Figure 2 is the 1 C charge-discharge curve of the lithium iron phosphate/lithium battery assembled with the organic-inorganic composite all-solid electrolyte of Example 1 at room temperature.

Fig. 3 is a long-term cycle curve after the lithium-sulfur battery is assembled using the organic-inorganic composite all-solid-state electrolyte prepared in Example 2.

detailed description

The invention aims to solve the problem that the existing electrochemical energy storage lithium-ion battery system adopts liquid electrolyte, which is easy to leak, corrode, and has potential safety hazards, or the problem that the gel electrolyte itself has poor mechanical properties and is difficult to form. The invention provides an organic-inorganic composite all-solid electrolyte to improve the safe performance of the existing battery.

Example 1

Add 2 g of polypropylene carbonate and 18 g of N,N-dimethylacetamide into a 100 ml reagent bottle, then stir at room temperature for 6 h to obtain a homogeneous polypropylene carbonate solution. Then, 0.2 g of lithium dioxalate borate and 0.25 g of Li ₇ La ₃ Zr ₂ O ₁₂ were added into the above uniform solution, and stirred at room temperature for 1 day to obtain a uniform mixed solution. The solution was evenly poured onto the cellulose non-woven fabric, dried in a vacuum oven at 60 °C for 1 day, and dried to obtain a polypropylene carbonate-Li ₇ La ₃ Zr ₂ O ₁₂ organic-inorganic composite all-solid electrolyte.

Example 2

Add 2 g of polypropylene carbonate and 16 g of tetrahydrofuran into a 100 ml reagent bottle, then stir at room temperature for 6 h to obtain a homogeneous polypropylene carbonate solution. Then 0.2 g lithium bisfluoromethanesulfonimide and 0.2 g Li ₁₀ GeP ₂ S ₁₂ were added to the above homogeneous solution, and stirred at room temperature for 12 h to obtain a uniform mixed solution. The solution was uniformly poured onto the glass fiber, dried in a vacuum oven at 100 °C for 1 day, and dried to obtain a polypropylene carbonate-Li ₁₀ GeP ₂ S ₁₂ organic-inorganic composite all-solid electrolyte.

Example 3

Add 4 g polyethylene carbonate and 36 g N,N-dimethylformamide into a 250 ml reagent bottle, then stir at room temperature for 8 h to obtain a homogeneous polyethylene carbonate solution. Then 0.4 g of lithium perchlorate and 0.5 g of Li ₁₀ GeP ₂ S ₁₂ were added into the above homogeneous solution, and stirred at room temperature for 15 h to obtain a uniform mixed solution. The solution was uniformly poured on the polyimide non-woven film, dried in a vacuum oven at 60 °C for 1 day, and dried to obtain a polyethylene carbonate-Li ₁₀ GeP ₂ S ₁₂ organic-inorganic composite all-solid electrolyte.

Example 4

Add 3 g of polybutylene carbonate and 20 g of acetone into a 100 ml reagent bottle, and then stir at room temperature for 6 h to obtain a homogeneous polybutylene carbonate solution. Then, 0.6 g of lithium hexafluorophosphate and 0.4 g of Li ₇ La ₃ Zr ₂ O ₁₂ were added into the above uniform solution, and stirred at room temperature for 15 h to obtain a uniform mixed solution. The solution was uniformly poured onto the polyarylsulfone amide nonwoven membrane, dried in a vacuum oven at 80°C for 1 day, and dried to obtain polybutylene carbonate-Li ₇ La ₃ Zr ₂ O ₁₂ organic-inorganic composite all-solid electrolyte.

Example 5

Add 4 g of polyethylene carbonate and 36 g of acetonitrile into a 250 ml reagent bottle, then stir at room temperature for 8 h to obtain a homogeneous polyethylene carbonate solution. Then, 0.8 g lithium tetrafluoroborate and 0.6 g LiPON were added into the above homogeneous solution, and stirred at room temperature for 5 h to obtain a uniform mixed solution. The solution was uniformly poured onto the aramid nonwoven membrane, dried in a vacuum oven at 80 °C for 1 day, and dried to obtain a polyethylene carbonate-LiPON organic-inorganic composite all-solid-state electrolyte.

Example 6

Add 3 g of polybutylene carbonate and 24 g of acetone into a 100 ml reagent bottle, and then stir at room temperature for 7 h to obtain a homogeneous polybutylene carbonate solution. Then 0.5 g lithium dioxalate borate and 0.7 g LiZr ₂ (PO4) were added into the above homogeneous solution, and stirred at room temperature for 1 day to obtain a uniform mixed solution. The solution was poured evenly on the seaweed fiber non-woven membrane, dried in a vacuum oven at 40 °C for 1 day, and dried to obtain polyethylene carbonate-LiZr ₂ (PO4) organic-inorganic composite all-solid-state electrolyte.

Characterization of electrolyte properties:

Film thickness: Use a micrometer (accuracy: 0.01 mm) to test the thickness of the organic-inorganic composite all-solid electrolyte, randomly take 5 points on the sample, and take the average value.

Ionic conductivity: The electrolyte is sandwiched between two pieces of stainless steel and placed in a 2032 battery case. The sodium ion conductivity is measured by electrochemical impedance spectroscopy, using the formula: σ = L/AR _b , where L is the thickness of the electrolyte, A is the room temperature area of the stainless steel sheet, and R _b is the measured impedance.

Electrochemical window: The electrolyte is sandwiched by stainless steel sheets and sodium sheets, and placed in a 2032 battery case. The electrochemical window was measured by linear voltammetry scanning with an electrochemical workstation, the initial potential was 2.5 V, the highest potential was 5.5 V, and the scanning speed was 1 mV/s. (See Table 1).

The obtained results are listed in Table 1. It can be seen from the results in Table 1 that the mechanical strength of the organic-inorganic composite all-solid electrolyte provided by the present invention is higher than 2 Mpa; the ion conductivity range at room temperature is 1×10 ^-5 S/cm-6×10 ^-3 S/cm, it can be charged and discharged at a large rate; the electrochemical window is greater than 4 V, and it can be charged and discharged at a higher voltage, thereby increasing the energy density.

Testing battery performance involves the following steps:

(1) Preparation of positive electrode sheet

A Dissolve polyvinylidene fluoride (PVdF) in N,N-2-methylpyrrolidone at a concentration of 0.1 mol/L.

B After mixing PVdF, positive electrode active material, and conductive carbon black at a mass ratio of 10:80:10, grind for at least 1 hour.

C Apply the slurry obtained in the previous step evenly on the aluminum foil with a thickness of 100-120 μm, first dry it at 60 ℃, then dry it in a vacuum oven at 120 ℃, roll it, punch it, weigh it and continue Dry in a vacuum oven at 120°C and store in a glove box for later use.

D Crop to size.

(2) Preparation of negative electrode sheet

A Dissolve PVdF in N,N-2-methylpyrrolidone at a concentration of 0.1 mol/L.

B After mixing PVdF, negative electrode active material, and conductive carbon black at a mass ratio of 10:80:10, grind for at least 1 hour.

C Apply the slurry obtained in the previous step evenly on the copper foil with a thickness of 100-120μm, first dry it at 60°C, then dry it in a vacuum oven at 120°C, roll it, punch it, and weigh it Continue to dry in a vacuum oven at 120°C and store in a glove box for later use.

D Crop to size.

(3) Battery assembly

(4) Battery charge and discharge performance test

The test method is as follows: use the LAND battery charge and discharge instrument to test the charge and discharge curve and long-term cycle performance of the all-solid-state secondary lithium battery. (See Figures 2 and 3).

It can be seen from Figure 2 that the lithium iron phosphate/lithium metal battery assembled with organic-inorganic composite all-solid electrolyte has a specific discharge capacity of 120 mAh g ^-1 and a relatively stable charge-discharge curve.

It can be seen from Figure 3 that the long-term cycle performance of the lithium iron phosphate/lithium metal battery assembled with the organic-inorganic composite all-solid electrolyte is relatively stable.

Table 1

Claims (8)

1. an organo-mineral complexing all solid state electrolyte, it is characterised in that: this organo-mineral complexing all solid state electrolyte is by gathering Carbonates macromolecule, inorganic fast ionic conductor, lithium salts and porous rigid backing material are constituted；Its thickness be 5 μm- 2000 μm；Mechanical strength is 2 MPa-150 MPa, and conductivity at room temperature is 1 × 10^-4 S/cm - 6×10^-3 S/cm, electricity Chemistry window is more than 4 V.

2. the organo-mineral complexing all solid state electrolyte as described in claim 1, it is characterised in that:

Described Merlon family macromolecule has a structure as shown in formula 1:

Formula 1

Wherein, the value of a is 1-50000, and the value of b is 1-50000；

R₁For:

,Or,

R₂For:

,Or,

In above-mentioned substituent group, X is fluorine, phenyl, hydroxyl or Sulfonic Lithium；Wherein the value of m1 is 0-2, and the value of n1 is 0-2, and m1 It is 0 time different from n1；The value of m2 is 0-2, and the value of n2 is 0-2, and is 0 when m2 from n2 is different；The value of m3 is 0-2, n3 Value be 0-2, and be 0 when m3 from n3 is different；Merlon family macromolecule is in organo-mineral complexing all solid state electrolyte Mass fraction is 3 %-85 %；

Described inorganic fast ionic conductor is Li₇La₃Zr₂O₁₂、Li₁₀GeP₂S₁₂、Li₃OCl_0.5Br_0.5、Li_3xLa_(2/3)-xTiO₃ (0.04 < x < 0.14), Li₅La₃M₂O₁₂(M=Ta, Nb), Li_5.5La₃Nb_1.75In_0.25O₁₂、Li₃N-LiX(X=Cl, Br, I), Li₁₄Zn(GeO₄)₄、LiZr₂(PO4)₃、Li₃OCl、LiPON、Li₂S-M_aS_b(M=Al, Si, P；Wherein the value of a and b is 1-3) One or several, inorganic fast ionic conductor mass fraction in organo-mineral complexing all solid state electrolyte is 1 %-50 %；

Described lithium salts is lithium perchlorate, lithium hexafluoro phosphate, dioxalic acid Lithium biborate, hexafluoroarsenate lithium, LiBF4, trifluoromethyl Sulfonic Lithium, double fluoromethane sulfimide lithium one or several；Lithium salts matter in organo-mineral complexing all solid state electrolyte Amount mark is 3 %-42 %；

Described porous rigid backing material is cellulose non-woven film, alginate fibre nonwoven film；Aramid fiber nonwoven film；Aromatic polysulfonamide without Spin film；Polypropylene non-woven film；One in glass fibre, pet film, polyimides nonwoven film is many Rigid backing material mass fraction in organo-mineral complexing all solid state electrolyte in hole is 5 %-30 %.

3. the preparation method of the organo-mineral complexing all solid state electrolyte described in a claim 1, it is characterised in that:

1) Merlon family macromolecule and lithium salts being dissolved in solvent, stirring, to being completely dissolved, obtains homogeneous polycarbonate-based Macromolecule/lithium salt solution；

2) in above-mentioned homogeneous solution, add inorganic fast ionic conductor, continue stirring after addition to mix homogeneously；

3) by the solution of above-mentioned mix homogeneously masking on porous rigid backing material, vacuum drying, obtain organo-mineral complexing All solid state electrolyte.

4. the preparation method of a kind of organo-mineral complexing all solid state electrolyte as described in claim 3, it is characterised in that:

Described Merlon family macromolecule has a structure as shown in formula 1:

Formula 1

Wherein, the value of a is 1-50000, and the value of b is 1-50000；

R₁For:

,Or

R₂For:

,Or

In above-mentioned substituent group, X is fluorine, phenyl, hydroxyl or Sulfonic Lithium；Wherein the value of m1 is 0-2, and the value of n1 is 0-2, and m1 It is 0 time different from n1；The value of m2 is 0-2, and the value of n2 is 0-2, and is 0 when m2 from n2 is different；The value of m3 is 0-2, n3 Value be 0-2, and be 0 when m3 from n3 is different；Merlon family macromolecule is in organo-mineral complexing all solid state electrolyte Mass fraction is 3 %-85%；

Described inorganic fast ionic conductor is Li₇La₃Zr₂O₁₂、Li₁₀GeP₂S₁₂、Li₃OCl_0.5Br_0.5、Li_3xLa_(2/3)-xTiO₃ (0.04 < x < 0.14), Li₅La₃M₂O₁₂(M=Ta, Nb), Li_5.5La₃Nb_1.75In_0.25O₁₂、Li₃N-LiX(X=Cl, Br, I), Li₁₄Zn(GeO₄)₄、LiZr₂(PO4)₃、Li₃OCl、LiPON、Li₂S-M_aS_b(M=Al, Si, P；Wherein the value of a and b is 1-3) One or several, inorganic fast ionic conductor mass fraction in organo-mineral complexing all solid state electrolyte is 1 %-50 %；

Described lithium salts is lithium perchlorate, lithium hexafluoro phosphate, dioxalic acid Lithium biborate, hexafluoroarsenate lithium, LiBF4, trifluoromethyl Sulfonic Lithium, double fluoromethane sulfimide lithium one or several；Lithium salts matter in organo-mineral complexing all solid state electrolyte Amount mark is 3 %-42 %；

Described porous rigid backing material is cellulose non-woven film, alginate fibre nonwoven film；Aramid fiber nonwoven film；Aromatic polysulfonamide without Spin film；Polypropylene non-woven film；One in glass fibre, pet film, polyimides nonwoven film is many Rigid backing material mass fraction in organo-mineral complexing all solid state electrolyte in hole is 5 %-30 %.

5. the preparation method of the organo-mineral complexing all solid state electrolyte as described in claim 3, it is characterised in that: described solvent For acetonitrile, dimethyl sulfoxide, sulfolane, dimethyl sulfite, sulfurous acid diethyl ester, acetone, oxolane, chloroform, second One or more in acetoacetic ester, N-Methyl pyrrolidone, N,N-dimethylformamide and DMAC N,N' dimethyl acetamide.

6. the application in all solid state serondary lithium battery of the organo-mineral complexing all solid state electrolyte described in a claim 1.

7. an all solid state serondary lithium battery, including positive pole, negative pole, the electrolyte between both positive and negative polarity, it is characterised in that: institute Stating electrolyte is the organo-mineral complexing full solid state polymer electrolyte described in claim 1；The active material of described positive pole is Cobalt acid lithium, LiFePO4, iron manganese phosphate for lithium, LiMn2O4, nickel ion doped, lithium-rich manganese-based, ternary material, sulfur, sulfur compound, sulphuric acid One in ferrum lithium, lithium ion fluorophosphate, lithium vanadium fluorophosphate, lithium ferrum fluorophosphate, lithium manganese oxide, conducting polymer or Several；

The active material of negative pole be lithium metal, lithium metal alloy, graphite, hard carbon, molybdenum bisuphide, lithium titanate, carbon-silicon composite material, Carbon germanium composite, carbon tin composite material, stibium oxide, antimony carbon composite, stannum antimony composite, Li-Ti oxide, lithium metal One or more in nitride.

8. the preparation of an all solid state serondary lithium battery, it is characterised in that: entirely solid with the organo-mineral complexing described in claim 1 Both positive and negative polarity pole piece is separated by state electrolyte, seals to obtain all solid state serondary lithium battery.