CN117624810A - Super-ion conductor material, preparation method and application thereof, ultrathin solid electrolyte membrane and lithium battery - Google Patents

Abstract

The invention relates to the technical field of batteries, and discloses a super-ion conductor material, a preparation method and application thereof, an ultrathin solid electrolyte membrane and a lithium battery. The super ion conductor material comprises a polymer substrate and a modifier doped in the polymer substrate; wherein the modifier is a small molecule additive or an inorganic filler modified by the small molecule additive; the small molecule additive has a strong electron donating group. The preparation method is selected from one of a solution blending method, a thermally induced phase separation method and a 3D printing method. The super-ion conductor material can be used for preparing metal batteries, secondary ion batteries, flexible batteries, capacitors or hybrid power energy storage devices as a diaphragm, solid electrolyte or binder. The solid electrolyte membrane prepared by the invention has the advantages of ultra-thin, high ionic conductivity and high mechanical strength, and the assembled battery has lower overpotential, higher energy density and excellent cycle performance.

Description

Superionic conductor materials and their preparation methods and applications, ultrathin solid electrolyte membranes and lithium battery

Technical field

The invention relates to the field of battery technology, and specifically relates to a superionic conductor material and its preparation method and application, ultra-thin solid electrolyte membrane and lithium battery.

Background technique

After experiencing rapid development, lithium-ion batteries have been widely used in portable devices, electric vehicles and large-scale energy storage. However, commercial intercalated lithium-ion batteries are approaching their energy density limit and cannot meet the growing demand for higher energy density in large-scale storage devices. At the same time, in the pursuit of higher energy density, safety issues such as leakage, fire and explosion originating from organic liquid electrolytes have become particularly important. Lithium metal has ultra-high theoretical capacity (3860mAh g ^-1 ), the lowest redox potential (-3.04V vs. standard hydrogen electrode) and low weight (0.534g cm ^-3 ), and is considered the best choice for anode materials . However, during the lithium deposition or stripping process of metallic lithium batteries, the growth of lithium dendrites in the liquid electrolyte further aggravates safety issues. The dendrites may penetrate the porous separator, causing internal circuit short circuits and even fire hazards.

In order to fundamentally solve the above problems, using solid electrolytes instead of flammable liquid electrolytes is an effective method. The inherent low permeability of redox byproducts in solid electrolytes enables the utilization of high-capacity cathodes, and the broad electrochemical stability window makes solid electrolytes suitable for high-voltage cathodes. Additionally, solid-state electrolytes allow the implementation of bipolar designs in which multiple solid-state cells are alternately stacked in a single package, allowing for higher output voltages, fewer packages, higher energy density, and lower cost. The possibility of integrating solid-state electrolytes into flexible batteries also enables applications in wearable devices.

Solid electrolytes can be divided into inorganic solid electrolytes, polymer solid electrolytes and composite solid electrolytes according to their different components. The inorganic filler in the inorganic solid electrolyte can provide the solid electrolyte with high mechanical strength and ionic conductivity, but its compatibility with the electrode interface is poor; the polymer solid electrolyte has good flexibility and can maintain good interface contact with the electrode, but Its ionic conductivity is low; the composite solid electrolyte introduces inorganic fillers on the basis of the polymer solid electrolyte, which improves the mechanical properties and ionic conductivity of the solid electrolyte while ensuring the electrode interface contact. It is an effective way to improve the comprehensive performance of the solid electrolyte. Strategy.

Currently, there is an urgent need in this field to develop an ultra-thin material with high ionic conductivity and high mechanical strength.

Contents of the invention

The purpose of the present invention is to overcome the problems existing in the prior art and provide a superionic conductor material and its preparation method and application, an ultrathin solid electrolyte membrane and a lithium battery.

In particular, the present invention utilizes the strong electronegativity of small molecule groups to prepare ultra-thin solid electrolytes with small molecule additives through solution blending methods and thermally induced phase separation methods to increase the number of dissociated ions in the electrolyte and construct High-speed ion transmission path, resulting in a solid electrolyte with ultra-thin, high mechanical strength and high ion conductivity. The electrolyte can be used in the construction of high-energy-density metal anode batteries, and can also be used as a separator or electrolyte component of fuel cells, flexible batteries, etc.

In order to achieve the above object, a first aspect of the present invention provides a superionic conductor material, wherein the superionic conductor material includes a polymer substrate and a modifier doped in the polymer substrate, and the modifier It is a small molecule additive or an inorganic filler modified by a small molecule additive; the small molecule additive has a strong electron donating group.

A second aspect of the present invention provides a method for preparing the superionic conductor material described in the first aspect, wherein the method is selected from one of a solution blending method, a thermally induced phase separation method and a 3D printing method.

A third aspect of the present invention provides a superion conductor material prepared by the preparation method described in the second aspect.

A fourth aspect of the present invention provides that the superionic conductor material described in the first or third aspect can be used as a separator, solid electrolyte or binder in the preparation of metal batteries, secondary ion batteries, flexible batteries, capacitors or hybrid energy storage devices. Applications.

A fifth aspect of the present invention provides a solid electrolyte membrane made of the superion conductor material described in the first or third aspect.

A sixth aspect of the present invention provides a lithium battery including the solid electrolyte membrane of the fifth aspect.

Through the above technical solutions, the beneficial technical effects achieved by the present invention are as follows:

(1) The superionic conductor material provided by the present invention uses small molecule additives with strong electron donating groups to induce changes in the polymer base chain segment configuration, thereby obtaining superionic conductor materials with high ionic conductivity and high mechanical strength. When formed into a film, it can be made to have an ultra-thin thickness.

(2) The present invention uses small molecule additives or inorganic fillers modified with small molecule additives as modifiers, which have good compatibility with the polymer base and can be directly blended to obtain a uniform solution, and the preparation is relatively simple.

(3) Different small molecule additives can be added according to different functional groups of the polymer. Groups such as amino, hydroxyl and ester groups connected to nitro, carboxyl or carbonyl groups can be used as strong electron donating groups through electron repulsion or attraction. The corresponding polymer group configuration changes to achieve the formation of high-speed ion transmission channels and improve ion transmission efficiency.

(4) The groups in small molecule additives can also induce the dissociation of metal ion salts into metal ions, increasing the proportion of carriers in the system and facilitating ion transport; different small molecule additives can also be grafted onto polymer chains Or block to change the polymer morphology, bring enhanced and toughening effect to the polymer substrate, improve the self-supporting property of the substrate, and also provide conditions for the preparation of ultra-thin and high-tough superionic conductors.

(5) The prepared solid electrolyte membrane has the advantages of ultra-thinness, high ionic conductivity, and high mechanical strength. The assembled battery has lower overpotential, higher energy density, and excellent cycle performance. The ultra-thin solid electrolyte prepared by the invention can be applied to metal batteries, secondary ion batteries, flexible batteries, capacitors or hybrid energy storage devices, etc.

Description of drawings

Figure 1 is a scanning electron microscope image of a cross-section of the superionic conductor material prepared in Example 1 of the present invention;

Figure 2 is a scanning electron microscope image of the surface of the superionic conductor material prepared in Example 1 of the present invention;

Figure 3 is an Arrhenius curve diagram of the superionic conductor material prepared in Example 1 of the present invention;

Figure 4 is a stress-strain curve of the superionic conductor material prepared in Example 1 of the present invention;

Figure 5 is a linear scanning voltammogram of the superionic conductor material prepared in Example 1 of the present invention;

Figure 6 is a cycle performance diagram of a symmetrical battery assembled with superionic conductor materials prepared in Example 1 of the present invention;

Figure 7 is a cycle performance diagram of a full battery assembled with superionic conductor materials prepared in Example 1 of the present invention at a current density of 0.2C.

Detailed ways

The endpoints of ranges and any values disclosed herein are not limited to the precise range or value, but these ranges or values are to be understood to include values approaching such ranges or values. For numerical ranges, the endpoint values of each range, the endpoint values of each range and individual point values, and the individual point values can be combined with each other to obtain one or more new numerical ranges. These values The scope shall be deemed to be specifically disclosed herein.

A first aspect of the present invention provides a superionic conductor material, which includes a polymer substrate and a modifier doped in the polymer substrate;

Wherein, the modifier is a small molecule additive or an inorganic filler modified by a small molecule additive; the small molecule additive carries a strong electron donating group.

In the present invention, small molecule additives with strong electron-donating groups or inorganic fillers modified by small molecule additives are doped into the polymer base, and can be combined with the polymer through blocking, grafting and other methods to modify it. properties, which promotes the reduction of the particle size of the polymer units and the formation of a tighter cross-linked structure, which greatly improves the mechanical properties of the superionic conductor material, thus bringing about better self-supporting ability and providing information for the preparation of superionic conductors. prerequisites. In addition, the strong electronegativity of small molecular groups can effectively improve the arrangement of charged groups within the polymer chain. Higher electronegativity can improve the dissociation of metal ion salts and increase the proportion of amorphous forms of the polymer. Preparation conditions for chain segment movement; at the same time, it can also provide a reliable path for the transmission of ions, build a high-speed channel for ion transmission, thereby improving the ionic conductivity of the material.

When the modifier is an inorganic filler modified with a small molecule additive, the inorganic filler can bring a new ion transmission path to the superionic conductor, provide its own mechanical strength, and further enhance the comprehensive performance of the superionic conductor.

When the superionic conductor material in the present invention is prepared into a film, an ultra-thin effect can also be obtained.

In the present invention, "small molecule additive" refers to an organic substance or polymer with a strong electron donating group that can produce electronic effects with the polymer substrate. When it is a polymer, its weight average molecular weight is much lower than that of the polymer substrate. Inorganic fillers can be MOF, MXene or vermiculite. Organic substances or polymers used as small molecule additives have good interfacial compatibility with polymers in superionic conductors.

In some embodiments of the invention, the polymer substrate is selected from the group consisting of polyethylene oxide, polyacrylonitrile, polyethylene carbonate, polymethylmethacrylate, polyvinylidene fluoride, and poly(vinylidene fluoride- At least one of hexafluoropropylene), preferably poly(vinylidene fluoride-hexafluoropropylene).

Poly(vinylidene fluoride-hexafluoropropylene) is a commonly used solid electrolyte polymer matrix. Its excellent mechanical properties, good thermal stability and chemical properties ensure the safety performance of solid electrolytes. Compared with polyethylene oxide Although this type of polymer has low ionic conductivity, its good compatibility and mechanical properties provide more possibilities for its modification.

For polyvinylidene fluoride polymers, small molecules with strong electronegative groups can effectively improve the arrangement of fluorine atoms within the chain segments. Higher electronegativity improves the dissociation of metal ion salts and improves polymerization. The irregular proportions of matter prepare conditions for chain segment movement; at the same time, it can also provide a reliable path for ion transmission and build a high-speed channel for ion transmission. The good self-supporting and mechanical properties of this type of polymer also provide conditions for the preparation of new solid electrolytes.

In some embodiments of the present invention, the strong electron donating group is selected from at least one of amino, hydroxyl and ester groups connected to nitro, carboxyl or carbonyl groups.

In some embodiments of the invention, the small molecule additive is selected from polyvinylpyrrolidone, aspartic acid, hydroxybenzotriazole, 2,4,6-triaminopyrimidine, 4-aminobenzoic acid and ethylenediamine At least one kind of tetraacetic acid is preferably ethylenediaminetetraacetic acid.

In the present invention, "polyvinylpyrrolidone" refers to an oligomer product with a weight average molecular weight Mw ~ 10,000.

In some embodiments of the present invention, the inorganic filler modified by the small molecule additive is selected from at least one of ethylenediaminetetraacetic acid-titanium carbon interlayer compound and 4-aminobenzoic acid-molybdenum selenide.

In some embodiments of the present invention, the mass ratio of the modifier and the polymer base is 1:10-100, preferably 1:50-100. In the present invention, if the amount of modifier is too much, agglomeration may occur and the polymer cannot interact; if the amount of modifier is too little, the best effect cannot be achieved.

A second aspect of the present invention provides a method for preparing the superionic conductor material described in the first aspect, wherein the method is selected from one of a solution blending method, a thermally induced phase separation method and a 3D printing method.

In the present invention, the preparation method is preferably a solution blending method, which has the advantages of simple steps, high repeatability, and the ability to prepare stable samples.

In some embodiments of the invention, the solution blending method includes the following steps:

(1) First mix the polymer solution and the modifier solution to obtain a mixed solution;

(2) Add a metal ion salt to the mixed solution obtained in step (1) for a second mixing to obtain a superion conductor solution;

(3) Use the superion conductor solution obtained in step (2) directly as a superion conductor material, or apply it to a flat plate and then perform first drying to obtain a superion conductor material.

In some embodiments of the invention, the thermally induced phase separation method includes the following steps:

(1’) Perform a third mixing of the modifier, polymer and metal ion salt with the solvent to obtain a mixed solution;

(2') Wash the mixed solution obtained in step (1') with an extractant and then centrifuge, remove the lower suspension to obtain a superionic conductor material; or, apply the mixed solution obtained in step (1') to a flat plate and then perform the third step. After the second drying, it is washed with an extractant, and after the third drying, a superion conductor material is obtained.

In the present invention, "coating on a flat plate" refers to scraping or drop coating. The scraping flat plate is glass, polytetrafluoroethylene plate, ceramic plate, silicon wafer, etc.; the drip coating flat plate is polytetrafluoroethylene with a diameter of 2-20 mm. Vinyl or silicon wafers, etc.

By adjusting the addition ratio of small molecule additives and changing the synthesis time or temperature for preparing superionic conductors, the thickness of the conductor can be subjectively controlled. It also has high mechanical properties and ionic conductivity, effectively improving the energy density of the full battery.

In some embodiments of the present invention, the mass ratio of the modifier and polymer is 1:1-100, preferably 1:10-50.

In some embodiments of the present invention, the mass ratio of the metal ion salt and the polymer is 1:1-20, preferably 1:1-5.

In some embodiments of the present invention, the solvent used in steps (1) and (1') is selected from the group consisting of N-methylpyrrolidone, N,N-dimethylformamide, anhydrous acetonitrile, dibromomethane, acetone and At least one of methanol.

In some embodiments of the present invention, the extraction agent described in step (2') is selected from the group consisting of acetyl tributyl citrate, toluene, dichloromethane, chloroform, gasoline, diethyl ether, straight-run gasoline, n-butanol and At least one type of carbon tetrachloride.

In some embodiments of the invention, the metal ion salt is selected from the group consisting of lithium sulfate, lithium nitrate, lithium chloride, lithium hexafluorophosphate, lithium bisfluorosulfonimide, lithium bistrifluoromethanesulfonimide, zinc sulfate, nitric acid In zinc, zinc chloride, zinc bisfluoromethanesulfonimide, sodium sulfate, sodium nitrate, sodium chloride, sodium hexafluorophosphate, potassium sulfate, potassium nitrate, potassium chloride and potassium bisfluoromethanesulfonimide At least one.

In some embodiments of the present invention, the first drying method is selected from one of normal temperature drying, vacuum drying, heating drying or freeze drying.

In some embodiments of the present invention, the first drying conditions include: temperature is 30-120°C; time is 1-12 hours.

In some embodiments of the present invention, the third mixing conditions include: stirring; temperature of 30-200°C, and time of 1-24 hours.

In some embodiments of the present invention, the second drying conditions include: vacuum drying; a temperature of 60-120°C and a time of 3-12 hours.

In some embodiments of the present invention, the third drying conditions include: a temperature of 25-60°C and a time of 6-12 hours.

A third aspect of the present invention provides a superion conductor material prepared by the preparation method described in the second aspect.

The electron donating effect of the small and medium molecule additives in the present invention helps the positive and negative ions in the electrolyte to effectively dissociate, increasing the carrier ratio in the conductor. At the same time, the attraction and repulsion of the strong electronegative groups to the polymer structure can effectively transform the polymer substrate. The structure forms a high-speed ion transmission path to ensure the rapid transmission of metal ions.

A fourth aspect of the present invention provides that the superionic conductor material described in the first or third aspect can be used as a separator, solid electrolyte or binder in the preparation of metal batteries, secondary ion batteries, flexible batteries, capacitors or hybrid energy storage devices. Applications.

A fifth aspect of the present invention provides a solid electrolyte membrane made of the superion conductor material described in the first or third aspect.

In some embodiments of the present invention, the solid electrolyte membrane has a thickness of 1-10 μm, a room temperature ionic conductivity of 5×10 ^-5 -5×10 ^-2 S cm ^-1 , and a Young's modulus of 1-10 GPa .

A sixth aspect of the present invention provides a lithium battery including the solid electrolyte membrane of the fifth aspect.

Batteries assembled through solid electrolyte membranes have lower overpotential and higher energy density as well as excellent cycle performance.

The present invention will be described in detail below through examples.

If no specific conditions are specified in the following Examples and Comparative Examples, the conditions should be carried out in accordance with conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not indicated, they are all conventional products that can be purchased commercially.

Test Methods:

Thickness test: Add the superionic conductor material between two weighing papers and use a thickness gauge to measure the thickness.

Room temperature ion conductivity test: Sandwich the superionic conductor material between two stainless steel gaskets and connect it to the electrochemical workstation for AC impedance testing at a frequency of 1MHz-0.1Hz.

Young's modulus test: The tensile speed is 5mm min ^-1 , cut the sample into a dumbbell-shaped spline, and enter the thickness, width and length of the spline working area.

Electrochemical performance testing: Assemble symmetrical cells and full cells for testing and analysis. The entire process of assembling the battery needs to be in a glove box filled with argon. The symmetrical battery assembly process is as follows: place the negative electrode case, lithium sheet, superion conductor material, lithium sheet, and positive electrode case in order, put them into the packaging machine and pressurize to 50MPa; The full battery assembly process is as follows: place the negative electrode shell, lithium sheet, superion conductor material, positive electrode sheet, and positive electrode shell in order, put them into the packaging machine and pressurize them to 50MPa.

Cycle performance: Conduct constant current charge and discharge test and analysis on symmetrical batteries under stepped current density. The test conditions are: voltage range 2.5-4.2V, current density 0.1mA cm ^-2 .

Reversible specific capacity: Constant current charge and discharge test and analysis of the full battery. The test conditions are: voltage range 2.5-4.2V, current density 0.2C.

Source of materials:

Poly(vinylidene fluoride-hexafluoropropylene): purchased from GISMA-ALDRICH Company, analytically pure AR, weight average molecular weight Mw ~ 455000;

Polyvinylpyrrolidone: purchased from Sinopharm Chemical Reagent Co., Ltd., analytical grade AR, weight average molecular weight Mw ~ 10000;

Ethylenediaminetetraacetic acid: purchased from Sinopharm Chemical Reagent Co., Ltd., analytical grade AR, molecular weight 292.24;

Polyvinylidene fluoride: purchased from Aladdin Company, analytically pure AR, weight average molecular weight Mw ~ 400000;

Polyethylene oxide: purchased from Aladdin Company, analytically pure AR, weight average molecular weight Mw ~ 600000.

The ethylenediaminetetraacetic acid-titanium carbon interlayer compound is prepared by the following method: add ethylenediaminetetraacetic acid and titanium carbon interlayer compound (also known as MXene or Ti ₂ C ₃ ) into ethanol at a mass ratio of 1:10, at room temperature After ultrasonic stirring for 12 hours, centrifuge at 8000 rpm in a centrifuge, collect the precipitate, and dry at room temperature for 12 hours to obtain the ethylenediaminetetraacetic acid-titanium carbon interlayer compound.

Example 1

This example is used to illustrate the preparation of superionic conductor materials by solution blending method.

Weigh 0.04g of ethylenediaminetetraacetic acid and dissolve it in 20mL of N,N-dimethylformamide. Dissolve 2g of poly(vinylidene fluoride-hexafluoropropylene) in 30mL of N,N-dimethylformamide. After stirring for 12 hours, mix and stir for 12 hours, and then add 1.3g of lithium bistrifluoromethanesulfonyl imide. After stirring for 4 hours, cast a 100 μm thick solution on the glass plate, and then dry it at 120°C for 12 hours in a vacuum environment to obtain the superion conductor material. .

The superionic conductor material has a thickness of only 5 μm, a room temperature ionic conductivity of 3.48×10 ^-4 S cm ^-1 and a Young's modulus of 10 GPa.

Scanning electron microscopy testing was performed on the cross-section of the superionic conductor material, and its thickness was only 5.1 μm, as shown in Figure 1.

Scanning electron microscopy tests were conducted on the surface of the superionic conductor material, and the spherical structures on the surface were closely connected, as shown in Figure 2.

Testing the AC impedance of the superionic conductor material at different temperatures, the calculated ionic conductivity at room temperature is 3.48×10 ^-4 S cm ^-1 , and the conductor complies with Arrhenius’ law. The higher the temperature, the higher the ionic conductivity. high, as shown in Figure 3.

A tensile test was performed on the material, and its Young's modulus was found to be 10GPa, as shown in Figure 4.

Assemble the symmetrical battery and conduct a linear sweep voltammetry test, and the electrochemical window can be found to be approximately 4.8V, as shown in Figure 5.

The symmetrical battery was assembled for testing, and it can cycle stably for 2000h, with an overpotential of only 10mV, as shown in Figure 6.

The full battery was assembled and tested. It can cycle stably for 400 cycles, has a high specific capacity of 162.4mAh g ^-1 , and an energy density of 516Wh kg ^-1 , as shown in Figure 7.

Example 2

The operating conditions are the same as in Example 1, except that the thickness of the solution poured on the glass plate is 150 μm, the thickness of the obtained superionic conductor material can reach 10 μm, and the ionic conductivity at room temperature is 3.41×10 ^-4 S cm ^-1 , Young's The modulus is 10GPa.

The symmetrical battery was assembled for testing, and it can cycle stably for 1300 hours with an overpotential of only 30mV.

The full battery was assembled for testing and found to be able to cycle stably for 500 cycles with an energy density of 498.3Wh kg ^-1 .

Example 3

The operating conditions are the same as in Example 1, except that the thickness of the solution poured on the glass plate is 200 μm, the thickness of the obtained superion conductor material can reach 20 μm, the ionic conductivity at room temperature is 3.43×10 ^-4 S cm ^-1 , and the Young's mold The amount is 10GPa.

The symmetrical battery was assembled for testing and it can cycle stably for 1500 hours with an overpotential of only 50mV.

The full battery was assembled for testing and found to cycle stably for 800 cycles with an energy density of 463.2Wh kg ^-1 .

Example 4

The operating conditions were the same as in Example 1, except that the drying temperature was 80°C, the thickness of the obtained superionic conductor material was 10 μm, the room temperature ionic conductivity was 4.2×10 ^-4 S cm ^-1 , and the Young's modulus was 3.2GPa.

Assemble the symmetrical battery for testing. It can cycle stably for 1000h and the overpotential is 30mV.

The full battery was assembled for testing and found to be stable for 300 cycles with an energy density of 486.6Wh kg ^-1 .

Example 5

The operating conditions were the same as in Example 1, except that the drying time was 1 hour, the thickness of the obtained superionic conductor material was 10 μm, the room temperature ionic conductivity was 4.8×10 ^-4 S cm ^-1 , and the Young's modulus was 1.2 GPa.

The symmetrical battery was assembled for testing, and it can cycle stably for 1200 hours with an overpotential of 35mV.

The full battery was assembled for testing and found to be able to cycle stably for 350 cycles with an energy density of 496.6Wh kg ^-1 .

Example 6

The operating conditions were the same as in Example 1, except that polyvinylpyrrolidone was used instead of ethylenediaminetetraacetic acid. The thickness of the superionic conductor material obtained was 10 μm, the ionic conductivity at room temperature was 0.9×10 ^-4 S cm ^-1 , and the Young's mode The amount is 0.3GPa.

Assemble the symmetrical battery for testing. It can cycle stably for 800h and the overpotential is 50mV.

The full battery was assembled for testing and found to be able to cycle stably for 500 cycles with an energy density of 483.0Wh kg ^-1 .

Example 7

The operating conditions are the same as in Example 1, except that an ethylenediaminetetraacetic acid-titanium carbon interlayer compound is used instead of ethylenediaminetetraacetic acid. The thickness of the obtained superionic conductor material is 20 μm, and the room temperature ionic conductivity is 3.21×10 ^-4 S cm ^-1 , Young's modulus is 9.6GPa.

Assemble the symmetrical battery for testing. It can cycle stably for 1000h and the overpotential is 30mV.

The full battery was assembled for testing and found to cycle stably for 300 cycles with an energy density of 501.2Wh kg ^-1 .

Example 8

The operating conditions are the same as in Example 1, except that polyethylene oxide is used instead of poly(vinylidene fluoride-hexafluoropropylene). The thickness of the superionic conductor material obtained is 50 μm, and the room temperature ionic conductivity is 7.12×10 ^-4 S cm ^-1 , Young's modulus is 0.2GPa.

Assemble the symmetrical battery for testing. It can cycle stably for 1000 hours and the overpotential is 45mV.

The full battery was assembled for testing and found to be stable for 500 cycles with an energy density of 364.3Wh kg ^-1 .

Example 9

The operating conditions are the same as in Example 1, except that polyvinylidene fluoride is used instead of poly(vinylidene fluoride-hexafluoropropylene). The thickness of the superionic conductor material obtained is 35 μm, and the room temperature ion conductivity is 3.42×10 ^-4 S cm ^-1 , Young's modulus is 7.31GPa.

Assemble the symmetrical battery for testing, and it can cycle stably for 1200 hours with an overpotential of 30mV.

The full battery was assembled for testing and found to be stable for 500 cycles with an energy density of 433.7Wh kg ^-1 .

Example 10

The operating conditions were the same as in Example 1, except that the amount of ethylenediaminetetraacetic acid was 0.02g, the thickness of the superionic conductor material obtained was 10 μm, the room temperature ionic conductivity was 2.31×10 ^-4 S cm ^-1 , and the Young's model The amount is 8.32GPa.

Assemble the symmetrical battery for testing. It can cycle stably for 1500h and the overpotential is 20mV.

The full battery was assembled for testing and found to be stable for 500 cycles with an energy density of 493.3Wh kg ^-1 .

Example 11

The operating conditions were the same as in Example 1, except that the amount of ethylenediaminetetraacetic acid was 0.06g, the thickness of the obtained superionic conductor material was 25 μm, the room temperature ionic conductivity was 1.88×10 ^-4 S cm ^-1 , and the Young's model The amount is 6.61GPa.

Assemble the symmetrical battery for testing. It can cycle stably for 1000 hours and the overpotential is 35mV.

The full battery was assembled for testing and found to be able to cycle stably for 400 cycles with an energy density of 477.7Wh kg ^-1 .

Example 12

The operating conditions are the same as in Example 1, except that the amount of ethylenediaminetetraacetic acid is 0.1g, the thickness of the superionic conductor material obtained is 30 μm, the room temperature ionic conductivity is 1.56×10 ^-4 S cm ^-1 , and the Young's model The amount is 6.00GPa.

Assemble the symmetrical battery for testing. It can cycle stably for 1000h and the overpotential is 40mV.

The full battery was assembled for testing and found to be able to cycle stably for 400 cycles with an energy density of 463.2Wh kg ^-1 .

Example 13

The operating conditions are the same as in Example 1, except that the amount of ethylenediaminetetraacetic acid is 0.2g, the thickness of the obtained superionic conductor material is 30 μm, the room temperature ionic conductivity is 1.06×10 ^-4 S cm ^-1 , and the Young's model The amount is 5.11GPa.

Assemble the symmetrical battery for testing. It can cycle stably for 1000h and the overpotential is 50mV.

The full battery was assembled for testing and found to cycle stably for 400 cycles with an energy density of 455.9Wh kg ^-1 .

Example 14

The operating conditions were the same as in Example 1, except that the amount of ethylenediaminetetraacetic acid was 0.4g, the thickness of the obtained superionic conductor material was 50 μm, the room temperature ionic conductivity was 8.31×10 ^-5 S cm ^-1 , and the Young's model The amount is 1.32GPa.

Assemble the symmetrical battery for testing. It can cycle for 400 hours and the overpotential is 105mV.

The full battery was assembled for testing. After 100 cycles, the battery was short-circuited and the energy density was 325.8Wh kg ^-1 .

Example 15

The operating conditions were the same as in Example 1, except that the amount of ethylenediaminetetraacetic acid was 0.6g, the thickness of the obtained superionic conductor material was 73 μm, the room temperature ionic conductivity was 6.60×10 ^-5 S cm ^-1 , and the Young's model The amount is 852MPa.

Assemble the symmetrical battery for testing. It can cycle for 300 hours and the overpotential is 150mV.

The full battery was assembled for testing. After 100 cycles, the battery was short-circuited and the energy density was 280.7Wh kg ^-1 .

Comparative example 1

The operating conditions are the same as Example 1, except that the N,N-dimethylformamide solution of ethylenediaminetetraacetic acid is not prepared. The thickness of the obtained superionic conductor material reaches 50 μm, and the room temperature ionic conductivity is only 5.4×10 ^{- 5} S cm ^-1 , Young's modulus is 132MPa.

Assemble the symmetrical battery for testing. It can only cycle for 100h and the overpotential is 325mV.

The full battery was assembled and tested. It can cycle 100 times and has an energy density of 368.3Wh kg ^-1 .

Comparative example 2

The operating conditions are the same as in Example 1, except that alumina powder is used instead of ethylenediaminetetraacetic acid. The thickness of the superionic conductor material obtained exceeds 100 μm, and the ionic conductivity at room temperature is only 3.2×10 ^-5 Scm ^-1 . The Young's model The amount is 311MPa.

Assemble the symmetrical battery for testing. After 50 hours of cycling, it is short-circuited and the overpotential is 1.2V.

After assembling the full battery for testing, it can cycle for 50 cycles before short-circuiting, and the energy density is only 231.6Wh kg ^-1 .

Comparative example 3

The operating conditions are the same as in Example 1, except that MXene powder is used instead of ethylenediaminetetraacetic acid. The thickness of the superionic conductor material obtained can reach 50 μm, and the ionic conductivity at room temperature is only 6.21×10 ^-5 Scm ^-1 . The amount is 301MPa.

Assemble the symmetrical battery for testing. After 100 hours of cycling, the battery becomes short-circuited and the overpotential is 520mV.

After assembling the full battery for testing, the battery was short-circuited after 100 cycles and the energy density was only 210.3Wh kg ^-1 .

Example 16

This example is used to illustrate the preparation of superionic conductor materials through thermally induced phase separation.

Weigh 0.04g of ethylenediaminetetraacetic acid, 2g of poly(vinylidene fluoride-hexafluoropropylene), and 1.3g of lithium bistrifluoromethanesulfonimide and dissolve them in 50 mL of methanol. After stirring at 60°C for 12 hours, place on a glass plate. Pour a solution with a thickness of 100 μm, and then dry it at 120°C for 12 hours in a vacuum environment to separate the solid phase of the solution. After forming a solid structure, use acetyl tributyl citrate to wash and extract excess solvent, and dry in air to obtain a superion conductor material.

The thickness of this superionic conductor material can reach 20 μm, the room temperature ionic conductivity is 1.1×10 ^-4 S cm ^-1 , and the Young's modulus is 328.8MPa.

Assemble the symmetrical battery for testing, and it can cycle stably for 1500 hours, and the overpotential is about 50mV.

The full battery was assembled and tested, and it can cycle stably for 500 cycles with an energy density of 453.2Wh kg ^-1 .

Example 17

The operating conditions are the same as in Example 16, except that the thickness of the solution poured on the glass plate is 150 μm, the thickness of the obtained superionic conductor material can reach 10 μm, the ionic conductivity at room temperature is 1.29×10 ^-4 S cm ^-1 , and the Young's mold The amount is 682.3MPa.

A symmetrical battery was assembled for testing, and it can cycle stably for 1100 hours with an overpotential of 20mV.

The full battery was assembled and tested, and it can cycle stably for 650 cycles with an energy density of 446.8Wh kg ^-1 .

Example 18

The operating conditions are the same as in Example 16, except that the thickness of the solution poured on the glass plate is 200 μm, the thickness of the obtained superionic conductor material can reach 20 μm, the room temperature ionic conductivity is 1.33×10 ^-4 S cm ^-1 , and the Young's mold The amount is 702.1MPa.

Assemble the symmetrical battery for testing. It can cycle stably for 1000 hours and the overpotential is 45mV.

The full battery was assembled for testing and found to be able to cycle stably for 500 cycles with an energy density of 428.2Wh kg ^-1 .

Example 19

The operating conditions were the same as in Example 16, except that the stirring temperature was 80°C, the thickness of the superionic conductor material was 10 μm, the room temperature ionic conductivity was 2.3×10 ^-4 S cm ^-1 , and the Young's modulus was 584.5MPa.

Assemble the symmetrical battery for testing. It can cycle stably for 1500h and the overpotential is 30mV.

The full battery was assembled for testing and found to be able to cycle stably for 500 cycles with an energy density of 451.6Wh kg ^-1 .

Example 20

The operating conditions are the same as in Example 16, except that the drying time is 1 hour, the thickness of the superionic conductor material is 10 μm, the room temperature ionic conductivity is 2.6×10 ^-4 S cm ^-1 , and the Young's modulus is 523.8 MPa.

A symmetrical battery was assembled for testing, and it can cycle stably for 600 hours with an overpotential of 35mV.

The full battery was assembled for testing and found to be stable for 300 cycles with an energy density of 466.1Wh kg ^-1 .

Example 21

The operating conditions are the same as in Example 16, except that the drying temperature is 100°C, the thickness of the obtained ion conductor material can reach 30 μm, the room temperature ion conductivity is 3.1×10 ^-4 S cm ^-1 , and the Young's modulus is 498.2MPa.

The symmetrical battery was assembled for testing, and it can cycle stably for 1300 hours with an overpotential of 40mV.

The full battery was assembled for testing and found to be able to cycle stably for 350 cycles with an energy density of 436.1Wh kg ^-1 .

Example 22

The operating conditions are the same as in Example 16, except that polyvinylpyrrolidone is used instead of ethylenediaminetetraacetic acid. The thickness of the solid electrolyte membrane obtained can reach 10 μm, the ionic conductivity at room temperature is 1.1×10 ^-4 S cm ^-1 , and the Young's model The amount is 0.72GPa.

The symmetrical battery was assembled for testing, and it can cycle stably for 500 hours, with an overpotential of 32mV.

The full battery was assembled and tested, and it can cycle stably for 500 cycles with an energy density of 453.2Wh kg ^-1 .

Example 23

The operating conditions are the same as in Example 16, except that an ethylenediaminetetraacetic acid-titanium carbon interlayer compound is used instead of ethylenediaminetetraacetic acid. The thickness of the superionic conductor material is 30 μm, and the room temperature ion conductivity is 2.71×10 ^-4 S cm ^-1 , Young's modulus is 6.4GPa.

Assemble the symmetrical battery for testing. It can cycle stably for 800h and the overpotential is 20mV.

The full battery was assembled for testing and found to be able to cycle stably for 400 cycles with an energy density of 478.5Wh kg ^-1 .

Example 24

The operating conditions are the same as in Example 16, except that the amount of ethylenediaminetetraacetic acid is 0.02g, the thickness of the superionic conductor material obtained can reach 10 μm, and the ionic conductivity at room temperature is 1.07×10 ^-4 S cm ^-1 , Young's The modulus is 532.3MPa.

Assemble the symmetrical battery for testing. It can cycle stably for 1500h and the overpotential is 20mV.

The full battery was assembled for testing and found to be stable for 500 cycles with an energy density of 484.2Wh kg ^-1 .

Example 25

The operating conditions are the same as in Example 16, except that the amount of ethylenediaminetetraacetic acid is 0.06g, the thickness of the superionic conductor material obtained can reach 10 μm, the room temperature ionic conductivity is 1.0×10 ^-4 S cm ^-1 , Young's The modulus is 670.3MPa.

Assemble the symmetrical battery for testing. It can cycle stably for 1000 hours and the overpotential is 35mV.

The full battery was assembled for testing and found to be stable for 500 cycles with an energy density of 455.2Wh kg ^-1 .

Example 26

The operating conditions are the same as in Example 16, except that the amount of ethylenediaminetetraacetic acid is 0.1g, the thickness of the superionic conductor material obtained can reach 50 μm, and the room temperature ionic conductivity is only 8.31×10 ^-5 Scm ^-1 , Young's The modulus is 481.9MPa.

Assemble the symmetrical battery for testing. After 500 hours of cycling, the battery becomes short-circuited and the overpotential is 100mV.

The full battery was assembled for testing. After 100 cycles, the battery was short-circuited and the energy density was 311.6Wh kg ^-1 .

Example 27

The operating conditions are the same as in Example 16, except that the amount of ethylenediaminetetraacetic acid is 0.2g, the thickness of the superionic conductor material obtained can reach 80 μm, and the ionic conductivity at room temperature is only 6.81×10 ^-5 Scm ^-1 , Young's The modulus is 261.0MPa.

Assemble the symmetrical battery for testing. After 300 hours of cycling, the battery becomes short-circuited and the overpotential is 250mV.

The full battery was assembled for testing. After 100 cycles, the battery was short-circuited and the energy density was 292.6Wh kg ^-1 .

Comparative example 4

The operating conditions are the same as in Example 10, except that no ethylenediaminetetraacetic acid is added to methanol. The thickness of the solid electrolyte membrane obtained exceeds 150 μm, the ionic conductivity at room temperature is 1.51×10 ^-5 S cm ^-1 , and the Young's modulus is 62MPa.

Assemble the symmetrical battery for testing. After 100 hours of cycling, the battery is short-circuited and the overpotential is 423mV.

The full battery was assembled for testing. After 45 cycles, the battery was short-circuited and the energy density was 254.1Wh kg ^-1 .

Comparative example 5

The operating conditions are the same as in Example 10, except that alumina powder is used instead of ethylenediaminetetraacetic acid. The thickness of the superionic conductor material obtained exceeds 300 μm, and the ionic conductivity at room temperature is only 1.1×10 ^-5 Scm ^-1 . The Young's model The amount is 131MPa.

Assemble the symmetrical battery for testing. After 100 hours of cycling, it is short-circuited and the overpotential is 0.6V.

After assembling the full battery for testing, it can cycle for 50 cycles before short-circuiting, and the energy density is only 278.0Wh kg ^-1 .

Comparative example 6

The operating conditions are the same as in Example 10, except that MXene powder is used instead of ethylenediaminetetraacetic acid. The thickness of the superionic conductor material obtained can reach 100 μm, and the ionic conductivity at room temperature is only 3.21×10 ^-5 S cm ^-1 , Young's The modulus is 632MPa.

Assemble the symmetrical battery for testing. After 150 hours of cycling, the battery is short-circuited and the overpotential is 470mV.

The full battery was assembled for testing. After 50 cycles, the battery was short-circuited and the energy density was 278.1Wh kg ^-1 .

According to the results of the examples and comparative examples, it can be seen that adding small molecule additives (such as ethylenediaminetetraacetic acid, polyvinylpyrrolidone) or small molecule additive-modified inorganic fillers (such as ethylenediaminetetraacetic acid- Titanium-carbon interlayer compound), super-ion conductor materials with ultra-thin, high ionic conductivity and high mechanical strength can be obtained. Batteries assembled as solid electrolyte membranes have low overpotential, high energy density and excellent cycle performance. Depending on the doping amount of small molecule additives, the performance improvements in various aspects are also different.

The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, including the combination of various technical features in any other suitable manner. These simple modifications and combinations should also be regarded as the disclosed content of the present invention. All belong to the protection scope of the present invention.

Claims (10)

1. A super-ionic conductor material, characterized in that the super-ionic conductor material comprises a polymer substrate and a modifier doped in the polymer substrate;

wherein the modifier is a small molecule additive or an inorganic filler modified by the small molecule additive; the small molecule additive has a strong electron donating group.

2. The material of claim 1, wherein the polymeric substrate is selected from at least one of polyethylene oxide, polyacrylonitrile, polyvinyl carbonate, polymethyl methacrylate, polyvinylidene fluoride, and poly (vinylidene fluoride-hexafluoropropylene), preferably poly (vinylidene fluoride-hexafluoropropylene);

preferably, the strong electron donating group is selected from at least one of amino, hydroxyl, and ester groups to which nitro, carboxyl, or carbonyl groups are attached;

preferably, the small molecule additive is selected from at least one of polyvinylpyrrolidone, aspartic acid, hydroxybenzotriazole, 2,4, 6-triaminopyrimidine, 4-aminobenzoic acid and ethylenediamine tetraacetic acid, preferably ethylenediamine tetraacetic acid;

preferably, the small molecule additive modified inorganic filler is selected from at least one of ethylenediamine tetraacetic acid-titanium carbon interlayer compound and 4-aminobenzoic acid-molybdenum selenide;

preferably, the mass ratio of the modifier to the polymer substrate is 1:10-100, preferably 1:50-100.

3. A method of preparing a super-ionic conductor material according to claim 1 or 2, wherein the method is selected from one of a solution blending method, a thermally induced phase separation method and a 3D printing method, preferably a solution blending method.

4. A method of preparation according to claim 3, wherein the solution blending method comprises the steps of:

(1) First mixing a polymer solution and a modifier solution to obtain a mixed solution;

(2) Adding metal ion salt into the mixed solution obtained in the step (1) for secondary mixing to obtain a super-ion conductor solution;

(3) And (3) directly taking the super-ionic conductor solution obtained in the step (2) as a super-ionic conductor material, or coating the super-ionic conductor material on a flat plate and then performing first drying to obtain the super-ionic conductor material.

5. A method of preparation according to claim 3, wherein the thermally induced phase separation method comprises the steps of:

(1') carrying out third mixing on a modifier, a polymer and a metal ion salt with a solvent to obtain a mixed solution;

(2 ') washing the mixed solution obtained in the step (1') with an extractant, centrifuging, and taking out the lower suspension to obtain the super-ion conductor material; or, coating the mixed solution obtained in the step (1') on a flat plate, performing second drying, then washing with an extractant, and performing third drying to obtain the super-ionic conductor material.

6. The preparation method according to claim 4 or 5, wherein the mass ratio of the modifier to the polymer is 1:1-100, preferably 1:10-50;

preferably, the mass ratio of the metal ion salt to the polymer is 1:1-20, preferably 1:1-5;

preferably, the solvent used in steps (1) and (1') is selected from at least one of N-methylpyrrolidone, N-dimethylformamide, anhydrous acetonitrile, dibromomethane, acetone and methanol;

preferably, the extractant in the step (2') is at least one selected from acetyl tributyl citrate, toluene, methylene dichloride, chloroform, gasoline, diethyl ether, straight-run gasoline, n-butanol and carbon tetrachloride;

preferably, the metal ion salt is selected from at least one of lithium sulfate, lithium nitrate, lithium chloride, lithium hexafluorophosphate, lithium bis-fluorosulfonyl imide, lithium bis-trifluoromethanesulfonyl imide, zinc sulfate, zinc nitrate, zinc chloride, zinc bis-fluoromethanesulfonyl imide, sodium sulfate, sodium nitrate, sodium chloride, sodium hexafluorophosphate, potassium sulfate, potassium nitrate, potassium chloride, and potassium bis-fluoromethanesulfonyl imide;

preferably, the first drying mode is selected from one of normal temperature drying, vacuum drying, heating drying or freeze drying;

preferably, the first drying conditions include: the temperature is 30-120 ℃; the time is 1-12h;

preferably, the conditions of the third mixing include: stirring; the temperature is 30-200 ℃ and the time is 1-24h;

preferably, the second drying conditions include: vacuum drying; the temperature is 60-120 ℃ and the time is 3-12h;

preferably, the third drying conditions include: the temperature is 25-60 ℃ and the time is 6-12h.

7. A super ion conductor material produced according to the production method of any one of claims 3 to 6.

8. Use of the super-ionic conductor material according to any one of claims 1-2 and 7 as a separator, solid-state electrolyte or binder in the preparation of a metal battery, a secondary ion battery, a flexible battery, a capacitor or a hybrid energy storage device.

9. A solid electrolyte membrane made from the super ionic conductor material of any one of claims 1-2 and 7;

preferably, the solid electrolyte membrane has a thickness of 1-10 μm and an ion conductivity at room temperature of 5X 10 ^-5 -5×10 ^-2 S cm ^-1 Young's modulus of 1-10GPa.

10. A lithium battery comprising the solid electrolyte membrane of claim 9.