CN217035727U - Self-supporting solid electrolyte membrane and lithium ion battery - Google Patents

Abstract

The utility model relates to a self-supporting solid electrolyte membrane and a lithium ion battery, wherein the self-supporting solid electrolyte membrane comprises a polymer microporous filter membrane, and ionic liquid and sulfide solid electrolyte which are arranged in holes of the polymer microporous filter membrane; the surface of the sulfide solid electrolyte is coated with an ionic liquid. The self-supporting solid electrolyte membrane can realize self-supporting and has excellent electrical property.

Description

Self-supporting solid electrolyte membrane and lithium ion battery

Technical Field

The utility model relates to the technical field of batteries, in particular to a self-supporting solid electrolyte membrane and a lithium ion battery.

Background

Solid electrolysisAs an important component of solid-state batteries, substances have been receiving attention from many researchers. The ceramic electrolyte generally has high ionic conductivity and good compatibility with the positive electrode. However, the hardness of the ceramic electrolyte is high, and the contact between the electrode and the electrolyte is poor, resulting in high interface resistance. The sulfide electrolyte has the advantages of low synthesis temperature and high ionic conductivity, but the application of the sulfide electrolyte is limited by the defects of sensitivity to air, incompatibility with oxide cathode materials and the like. Solid polymer electrolytes are considered to be one of the most promising candidates because of their good flexibility and ease of large-scale processing, however, the conductivity of polymer electrolytes is generally low. Therefore, it has been a focus of much research to improve the performance of polymer electrolytes by compounding a small amount of inorganic fillers with the polymer electrolytes. The composite electrolyte has the advantages of both inorganic solid electrolyte and polymer solid electrolyte, and has good mechanical property and processability. However, during repetition of lithium intercalation/deintercalation, the interface between the solid electrolyte and the electrode is unstable, and Li⁺The problems of uneven deposition, easy induction of lithium dendrite growth and the like often result in low coulombic efficiency and serious potential safety hazard.

CN113948766A discloses a multilayer composite solid electrolyte membrane and a method for manufacturing the same, the disclosed preparation method comprises a first layer of composite solid electrolyte membrane and a second layer of composite solid electrolyte membrane, the first layer of composite solid electrolyte membrane comprises polymer 1, inorganic material, ionic liquid and lithium salt, and the second layer of composite solid electrolyte membrane comprises polymer 2, inorganic material, fire retardant and lithium salt. The method disclosed by the method adopts the ionic liquid, so that more channels can be provided for the migration of lithium ions. The inorganic material is compounded with the polymer, so that the crystallinity of the polymer can be effectively reduced, and the ionic conductivity is improved.

CN111816910A discloses a composite solid electrolyte membrane, a preparation method thereof and a lithium ion battery, wherein the composite solid electrolyte membrane comprises the following components in percentage by mass: 0.1-80% of inorganic electrolyte porous fiber, 20-99.8% of polymer electrolyte and 0.1-20% of plasticizer. The composite solid electrolyte membrane disclosed by the utility model is characterized in that an inorganic electrolyte and a polymer electrolyte are compounded, the structure and the composition of materials are reasonably designed, the inorganic electrolyte is designed into a porous fiber structure, and small molecular substances such as a plasticizer, an inorganic powder filler and the like are enriched in pores by utilizing the physical adsorption and the chemical adsorption of the pores, so that the interface contact between the polymer electrolyte and the inorganic electrolyte is improved, the ionic conductivity of the composite solid electrolyte membrane is improved, and the mechanical strength of the composite solid electrolyte membrane is improved.

However, none of the above solid electrolyte membranes relate to how to design self-supporting properties, and although sulfide solid electrolytes have high electrical conductivity and good mechanical ductility, the current use of sulfides and polymers for preparing composite electrolyte membranes is limited due to incompatibility of sulfides with many solvents; in addition, the conductivity and the gel content of the composite electrolyte membrane need to be balanced, generally, the lower the gel content is, the higher the conductivity is, but the lower the gel content is, the film forming state of the composite membrane is affected, and the composite membrane cannot be self-supported and even can be cracked in the using process.

In view of the foregoing, it is important to develop a solid electrolyte membrane that is self-supporting and has excellent electrical properties.

SUMMERY OF THE UTILITY MODEL

In view of the shortcomings of the prior art, it is an object of the present invention to provide a self-supporting solid electrolyte membrane that is capable of being self-supporting and has excellent electrical properties, and a lithium ion battery.

In order to achieve the purpose, the utility model adopts the following technical scheme:

in a first aspect, the present invention provides a self-supporting solid state electrolyte membrane comprising a polymeric microporous filtration membrane and ionic liquid and sulfide solid state electrolyte disposed within pores of the polymeric microporous filtration membrane;

the surface of the sulfide solid electrolyte is coated with an ionic liquid.

In the utility model, the polymer microporous filter membrane is used as a mechanical carrier, provides certain strength and has uniform poresHole energy induced Li⁺The growth of dendrites is inhibited; in addition, by adding the ionic liquid to coat the surfaces of the sulfide particles, the sulfide particles of the continuous phase provide ion transmission channels, and Li can be regulated and controlled⁺The interface between the electrolyte and the metal negative electrode is stabilized, so that the problem of short circuit caused by the growth of lithium dendrite in the circulation process of the battery assembled by using the electrolyte membrane is avoided, the self-supporting solid electrolyte membrane shows excellent room-temperature ionic conductivity, and the battery assembled by using the self-supporting solid electrolyte membrane has good circulation performance.

Preferably, the surface of the polymer microporous filter membrane is provided with a coating layer;

the coating layer includes an ionic liquid and a sulfide solid electrolyte.

In the present invention, the reason why the surface of the polymer microporous filtration membrane is provided with the coating layer is that: because the mixed solution exists on the upper surface and the lower surface of the microporous filter membrane, sulfide particles coated with the ionic liquid can be separated out on the surface of the filter membrane after the solution is volatilized, and a layer of sulfide particles on the surface can well cover holes of the microporous filter membrane, so that the surface of the obtained electrolyte membrane is smoother.

Preferably, the thickness of the self-supporting solid electrolyte membrane is 100-.

In the utility model, the conductivity of the self-supporting solid electrolyte membrane is further improved by controlling the thickness of the self-supporting solid electrolyte membrane, the reason for controlling the thickness in the range is to balance the relationship between the self-supporting strength of the electrolyte membrane and the performance of the cell, and the excessively high thickness can cause overlong ion transmission path and increased polarization of the cell; the thickness is too thin, which causes problems such as low mechanical strength of the electrolyte membrane, and rupture due to pressure applied during the assembly of the battery.

Preferably, the thickness of the polymeric microporous filtration membrane is 80-100 μm, such as 82 μm, 84 μm, 86 μm, 88 μm, 90 μm, 92 μm, 94 μm, 96 μm, 98 μm, and the like.

Preferably, the pore size of the polymeric microfiltration membrane is 0.45 to 3 μm, e.g. 0.5 μm, 1 μm, 1.5 μm, 2 μm, 2.5 μm, etc.

Preferably, the porosity of the polymeric microporous filtration membrane is 50% to 80%, such as 55%, 60%, 65%, 70%, 75%, etc.

Preferably, the particle size of the sulfide solid electrolyte is 1 to 3 μm, such as 1.5 μm, 2 μm, 2.5 μm, and the like.

In the present invention, the particle diameter of the sulfide solid electrolyte needs to be controlled within a small range because the relationship between the processability and the electrical conductivity of the sulfide electrolyte is balanced; the particle size is too large, so that the dissolution in the solution is poor; if the particle size is too small, the conductivity is low.

Preferably, the pores of the polymeric microporous filtration membrane comprise Y-shaped through-holes and/or column-shaped through-holes.

In the utility model, the holes are respectively and independently present, or are partially communicated, or are completely communicated, and the column-shaped through holes can comprise regular column-shaped through holes, such as a square column shape, a rectangular column shape and the like; irregular cylindrical through holes, such as trapezoidal cross section cylindrical through holes, irregular quadrilateral cross section cylindrical through holes, and the like, can also be included.

Preferably, the polymer microporous filter membrane comprises any one of a polyvinylidene fluoride layer, a polytetrafluoroethylene layer, a nylon layer, a polysulfone layer, a polyether sulfone layer, a polypropylene layer, a cellulose diacetate layer, a cellulose triacetate layer or an ethyl cellulose layer.

Preferably, the sulfide solid state electrolyte comprises Li₂S-P₂P₅、Li_3.4Si_0.4P_0.6S₄、Li₁₀SiP₂S₁₂、Li_0.35Si_1.35P_1.65S₁₂、Li_9.54Si_1.74P_1.44S_11.7Cl_0.3、Li₁₀GeP₂S₁₂、Li_10.35Ge_1.35P_0.75S₄、Li_3.25Ge_0.25P_0.75S₄、Li₁₀GeP₂S_11.7O_0.3、Li_9.6P₃S₁₂、Li₇P₃S₁₁、Li₉P₃S₉O₃、Li_9.81Sn_0.81P_2.19S₁₂、Li₁₀(Si_0.5Ge_0.5)P₂S₁₂、Li(Ge_0.5Sn_0.5)P₂S₁₂、Li(Si_0.5Sn_0.5)P₂S₁₂、Li₆PS₅X、Li₇P₂S₈X or Li₁₀SnP₂S₁₂Any one of the above;

wherein, X is selected from any one of Cl, Br or I.

Illustratively, the ionic liquid includes any one of pyrrole ionic liquid, quaternary ammonium salt ionic liquid, imidazole ionic liquid or piperidine ionic liquid.

Preferably, the ionic liquid comprises 1-butyl-1-methylpyrrolidine bistrifluoromethanesulfonimide.

Illustratively, the method for producing a self-supporting solid electrolyte membrane according to the present invention comprises the steps of:

and mixing the sulfide solid electrolyte, the ionic liquid and the solvent to form a mixed solution, dropwise coating the mixed solution on the polymer microporous filter membrane, allowing the ionic liquid coated with the sulfide solid electrolyte to enter holes of the polymer microporous filter membrane, and drying to obtain the self-supporting solid electrolyte membrane.

Illustratively, the mass percentage of the ionic liquid is 1% to 10%, such as 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, etc., based on 100% of the total mass of the mixed solution.

Preferably, the solvent in the mixed solution includes any one of methanol, ethanol, isopropanol, benzene, toluene, xylene, cyclohexane or diethyl ether.

Illustratively, the drying manner includes natural volatilization of the solvent and drying.

Illustratively, the time for the solvent to evaporate naturally is 5-15h, such as 6h, 8h, 10h, 12h, 14h, and the like.

Illustratively, the temperature of the drying is 50-100 ℃, such as 55 ℃, 60 ℃, 65 ℃, 70 ℃, 75 ℃, 80 ℃, 85 ℃, 90 ℃, 95 ℃ and the like.

Illustratively, the drying time is more than or equal to 10h, such as 10h, 12h, 14h, 20h and the like.

In a second aspect, the present invention provides a lithium ion battery comprising a positive electrode sheet, the self-supporting solid electrolyte membrane of the first aspect, and a negative electrode sheet, which are stacked.

Compared with the prior art, the utility model has the following beneficial effects:

(1) the solid electrolyte membrane has self-supporting property and electrical property, a small amount of ionic liquid is added to coat the surfaces of the sulfide particles, and the sulfide particles in the continuous phase provide ion transmission channels, so that the composite electrolyte membrane shows excellent room-temperature ionic conductivity; a cell assembled by using the electrolyte membrane has good cycle performance.

(2) The tensile strength of the self-supporting solid electrolyte membrane is more than 100.2MPa, and the self-supporting solid electrolyte membrane has smaller descending amplitude relative to the tensile strength of a PVDF micro-filtration membrane and can meet the self-supporting requirement; the solid electrolyte membrane has excellent electrical property, the ionic conductivity is more than 0.82mS/cm, the first-circle discharge specific capacity is more than 220.3mAh/g, the coulombic efficiency is more than 99.5%, and the capacity retention rate after 10 cycles is more than 97.2%.

Drawings

FIG. 1 is a schematic view of the structure of a supporting solid electrolyte membrane described in example 1;

FIG. 2a is a schematic representation of the structure of a polymeric microporous filter membrane in a self-supporting solid electrolyte membrane as described in example 1;

FIG. 2b is a longitudinal cross-sectional view of FIG. 2 a;

FIG. 3 is a graph showing the results of an ion conductivity test of a self-supporting solid electrolyte membrane according to example 1;

FIG. 4 is a graph showing the results of an ion conductivity test of the self-supporting solid electrolyte membrane described in comparative example 1;

wherein, 1-polymer microporous filter membrane; 2-a coating layer; 3-sulfide solid electrolyte coated with ionic liquid.

Detailed Description

For the purpose of facilitating an understanding of the present invention, the present invention will now be described by way of examples. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitation of the present invention.

Example 1

The present embodiment provides a self-supporting solid state electrolyte membrane, a schematic structural diagram of which is shown in fig. 1, where the self-supporting solid state electrolyte membrane includes a polymer microporous filter membrane 1, an ionic liquid and a sulfide solid state electrolyte disposed in pores of the polymer microporous filter membrane, and a coating layer 2 disposed on a surface of the polymer microporous filter membrane.

The schematic structure diagram of the polymer microporous filter membrane in the self-supporting solid electrolyte membrane is shown in fig. 2a, and the cross-sectional view thereof is shown in fig. 2b, which schematically shows that the structure of the holes comprises a Y-shaped through hole and a rectangular parallelepiped column-shaped through hole, each hole independently exists, and the schematic structure of the sulfide solid electrolyte 3 coated with the ionic liquid.

The thickness of the self-supporting solid electrolyte membrane is 100 μm;

the material of the polymer microporous filter membrane is polyvinylidene fluoride (PVDF), which is purchased from Tianjin Jinteng experiment equipment Co., Ltd, and the model is as follows: TJMF50, 100 μm thick, 1.5 μm pore size on average, 70% porosity on average, and 105.3MPa tensile strength.

The preparation method of the self-supporting solid electrolyte membrane comprises the following steps:

(1)Li₆PS₅preparation of Cl electrolyte: according to the following steps: 1: 2 weight ratio of Li in an appropriate amount₂S (purity 99.9%), P₂S₅Mixing (purity 99.9%) and LiCl (purity 99.9%) powder in a ball mill at a mixing speed of 200rpm for 2h, and then increasing the ball milling speed to 500rpm for ball milling for 10 h; subsequently, the mixture was sintered in a crucible at 550 ℃ for 5h, slowly cooled to room temperature. Sintering the Li₆PS₅Screening Cl powder to obtain electrolyte particles with uniform particles, wherein the average particle size is 2 mu m;

(2)IL-Li₆PS₅preparing a Cl-PVDF composite electrolyte membrane: 5.6g of Li were weighed₆PS₅Dissolving Cl electrolyte in a certain amount of ethanol, respectively adding 1 wt% of 1-butyl-1-methylpyrrolidine bistrifluoromethanesulfonylimide ionic liquid, and performing magnetic stirring and ultrasonic dispersion for 2 hours to obtain Li₆PS₅A solution of Cl-ethanol; then dripping the prepared solution on the surface of a PVDF (polyvinylidene fluoride) microporous filter membrane, obtaining the PVDF microporous filter membrane completely soaked in the solution by means of solution diffusion and permeation, transferring the PVDF microporous filter membrane into a vacuum oven for drying at 80 ℃ for 12 hours after the solvent naturally volatilizes for 12 hours at room temperature in a glove box, and preparing the self-supporting ionic liquid coated Li₆PS₅A Cl-PVDF composite electrolyte membrane.

Example 2

The embodiment provides a self-supporting solid electrolyte membrane, which comprises a polymer microporous filter membrane, ionic liquid and sulfide solid electrolyte arranged in the pores of the polymer microporous filter membrane, and a coating layer arranged on the surface of the polymer microporous filter membrane.

The structure of the pores of the polymer microporous filter membrane in the self-supporting solid electrolyte membrane comprises a Y-shaped through hole and a column-shaped through hole, and all the pores are communicated.

The thickness of the self-supporting solid electrolyte membrane is 130 μm;

the material of the polymer microporous filter membrane is polyvinylidene fluoride (PVDF), which is purchased from Tianjin Jinteng experiment equipment Co., Ltd, and the model is as follows: TJMF50, 100 μm thick, 1.5 μm pore size on average, 70% porosity on average, and 105.3MPa tensile strength.

The preparation method of the self-supporting solid electrolyte membrane comprises the following steps:

(1)Li₆PS₅preparation of Cl electrolyte: according to the following steps: 1: 2 weight ratio of Li in an appropriate amount₂S (purity 99.9%), P₂S₅Mixing (purity 99.9%) and LiCl (purity 99.9%) powder in a ball mill, and mixingThe speed is 200rpm, the mixing time is 2 hours, and then the ball milling speed is increased to 500rpm for ball milling for 10 hours; subsequently, the mixture was sintered in a crucible at 550 ℃ for 5h, slowly cooled to room temperature. Sintering the Li₆PS₅Screening Cl powder to obtain electrolyte particles with uniform particles, wherein the average particle size is 2 mu m;

(2)IL-Li₆PS₅preparing a Cl-PVDF composite electrolyte membrane: 5.6g of Li were weighed₆PS₅Dissolving Cl electrolyte in a certain amount of ethanol, adding 2 wt% of 1-butyl-1-methylpyrrolidine bistrifluoromethanesulfonylimide ionic liquid, and performing magnetic stirring and ultrasonic dispersion for 2 hours to obtain Li₆PS₅A solution of Cl-ethanol; then dripping the prepared solution on the surface of a PVDF (polyvinylidene fluoride) microporous filter membrane, obtaining the PVDF microporous filter membrane completely soaked in the solution by means of solution diffusion and permeation, transferring the PVDF microporous filter membrane into a vacuum oven for drying at 80 ℃ for 12 hours after the solvent naturally volatilizes for 12 hours at room temperature in a glove box, and preparing the self-supporting ionic liquid coated Li₆PS₅A Cl-PVDF composite electrolyte membrane.

Example 3

The embodiment provides a self-supporting solid electrolyte membrane, which comprises a polymer microporous filter membrane, ionic liquid and sulfide solid electrolyte arranged in the pores of the polymer microporous filter membrane, and a coating layer arranged on the surface of the polymer microporous filter membrane.

The structure of the polymer microporous filter membrane hole in the self-supporting solid electrolyte membrane comprises a Y-shaped through hole, a cuboid column-shaped through hole and a trapezoidal column-shaped through hole, wherein the cuboid column-shaped through hole is communicated with the trapezoidal column-shaped through hole.

The thickness of the self-supporting solid electrolyte membrane is 170 μm;

the material of the polymer microporous filter membrane is polyvinylidene fluoride (PVDF) which is purchased from Tianjin Jinteng experimental equipment Limited company and has the model number: TJMF50, 100 μm thick, 1.5 μm pore size on average, 70% porosity on average, and 105.3MPa tensile strength.

The preparation method of the self-supporting solid electrolyte membrane comprises the following steps:

(1)Li₆PS₅preparation of Cl electrolyte: according to the following steps: 1: 2 weight ratio of Li in an appropriate amount₂S (purity 99.9%), P₂S₅Mixing (purity 99.9%) and LiCl (purity 99.9%) powder in a ball mill at a mixing speed of 200rpm for 2h, and then increasing the ball milling speed to 500rpm for ball milling for 10 h; subsequently, the mixture was sintered in a crucible at 550 ℃ for 5h, slowly cooled to room temperature. Sintering the Li₆PS₅Screening Cl powder to obtain electrolyte particles with uniform particles, wherein the average particle size is 1 mu m;

(2)IL-Li₆PS₅preparing a Cl-PVDF composite electrolyte membrane: 5.6g of Li were weighed₆PS₅Dissolving Cl electrolyte in a certain amount of ethanol, adding 5 wt% of 1-butyl-1-methylpyrrolidine bistrifluoromethanesulfonylimide ionic liquid, and performing magnetic stirring and ultrasonic dispersion for 2 hours to obtain Li₆PS₅A solution of Cl-ethanol; then dripping the prepared solution on the surface of a PVDF (polyvinylidene fluoride) microporous filter membrane, obtaining the PVDF microporous filter membrane completely soaked in the solution by means of solution diffusion and permeation, transferring the PVDF microporous filter membrane into a vacuum oven for drying at 80 ℃ for 12 hours after the solvent naturally volatilizes for 12 hours at room temperature in a glove box, and preparing the self-supporting ionic liquid coated Li₆PS₅A Cl-PVDF composite electrolyte membrane.

Example 4

The embodiment provides a self-supporting solid electrolyte membrane, which comprises a polymer microporous filter membrane, ionic liquid and sulfide solid electrolyte arranged in the pores of the polymer microporous filter membrane, and a coating layer arranged on the surface of the polymer microporous filter membrane.

The structure of the pores of the microporous polymer filter membrane in the self-supporting solid electrolyte membrane comprises Y-shaped through holes, and each pore exists independently.

The thickness of the self-supporting solid electrolyte membrane is 200 μm;

the material of the polymer microporous filter membrane is polyvinylidene fluoride (PVDF), which is purchased from Tianjin Jinteng experiment equipment Co., Ltd, and the model is as follows: TJMF50, a thickness of 100 μm, an average pore diameter of 1.5 μm, an average porosity of 70%, and a tensile strength of 105.3 MPa.

The preparation method of the self-supporting solid electrolyte membrane comprises the following steps:

(1)Li₆PS₅preparation of Cl electrolyte: according to the following steps: 1: 2 weight ratio of Li in an appropriate amount₂S (purity 99.9%), P₂S₅Mixing (purity 99.9%) and LiCl (purity 99.9%) powder in a ball mill at a mixing speed of 200rpm for 2h, and then increasing the ball milling speed to 500rpm for ball milling for 10 h; subsequently, the mixture was sintered in a crucible at 550 ℃ for 5h, slowly cooled to room temperature. Sintering the Li₆PS₅Screening Cl powder to obtain electrolyte particles with uniform particles, wherein the average particle size is 3 mu m;

(2)IL-Li₆PS₅preparing a Cl-PVDF composite electrolyte membrane: 5.6g of Li were weighed₆PS₅Dissolving Cl electrolyte in a certain amount of ethanol, adding 10 wt% of 1-butyl-1-methylpyrrolidine bistrifluoromethanesulfonimide ionic liquid, and performing magnetic stirring and ultrasonic dispersion for 2 hours to obtain Li₆PS₅A solution of Cl-ethanol; then dripping the prepared solution on the surface of a PVDF (polyvinylidene fluoride) microporous filter membrane, obtaining the PVDF microporous filter membrane completely soaked in the solution by means of solution diffusion and permeation, transferring the PVDF microporous filter membrane into a vacuum oven for drying at 80 ℃ for 12 hours after the solvent naturally volatilizes for 12 hours at room temperature in a glove box, and preparing the self-supporting ionic liquid coated Li₆PS₅A Cl-PVDF composite electrolyte membrane.

Comparative example 1

This comparative example provides a solid electrolyte membrane whose starting materials include thermoplastic polyurethane rubber (TPU) and Li as described in example 1₆PS₅Cl。

The preparation method of the solid electrolyte membrane comprises the following steps:

weighing TPU and LiTFSI according to a proportion, dissolving the TPU and the LiTFSI in a proper amount of Tetrahydrofuran (THF) solution, and magnetically stirring the mixture for 2 hours at 50 ℃; and simultaneously, dispersing a certain amount of Li6PS5Cl in a THF solution, mixing the two solutions after the two solutions form a uniform dispersion liquid, continuously stirring for 2 hours after mixing, coating the mixture on the surface of centrifugal paper, wherein the coating thickness is 60 mu m, and drying in vacuum for 24 hours to obtain the solid electrolyte membrane.

Performance test

The solid electrolyte membranes described in examples 1 to 4 and comparative example 1 were subjected to the following tests:

(1) ionic conductivity: cutting the solid electrolyte membrane into a wafer with the diameter of 10mm, putting the cut wafer into a die sleeve with the diameter of 10mm, applying pressure of 300Mpa to further compact the obtained electrolyte membrane, carrying out alternating current impedance test, and calculating the ionic conductivity according to an impedance value and an Arrhenius formula;

(2) and (3) testing mechanical properties: the Tensile strength of the electrolyte membrane is tested with reference to GB/T1040.3-2006 Test for Tensile Properties of plastics and ASTM D882-10 Standard Test Method for Tensile Properties of Plastic Sheeting.

(3) And (3) testing the battery: compounding the purchased indium sheet and lithium sheet in an argon glove box, and cutting the compounded indium sheet and lithium sheet into a wafer with the diameter of 16mm as a negative electrode; and blanking the sulfide electrolyte membrane into wafers with the diameter of 16mm for later use, placing the anode wafers with the diameter of 16mm punched In advance on an anode shell of the button cell, sequentially placing the composite electrolyte membrane and the Li-In cathode, respectively adding a gasket, an elastic sheet and a cathode shell, and applying pressure of 50Mpa to seal the button cell. And (3) carrying out cycle performance test on the assembled solid-state battery under the following test conditions: at 30 ℃, the charge-discharge multiplying power is 0.1C, and the voltage range is 2.5-4.25V (Li)⁺/Li)。

The test results are summarized in table 1 and fig. 3-4.

TABLE 1

The data in the table 1 are analyzed, so that the solid electrolyte membrane has self-supporting property and electrical property, the tensile strength is more than 100.2MPa, the reduction range is smaller compared with the tensile strength of a PVDF micro-filtration membrane, and the self-supporting requirement can be met; the solid electrolyte membrane has excellent electrical property, the ionic conductivity is more than 0.82mS/cm, the first-loop discharge specific capacity is more than 220.3mAh/g, the coulombic efficiency is more than 99.5%, and the capacity retention rate is more than 97.2% after 10 cycles.

As a result of analyzing comparative example 1 and example 1, it was found that comparative example 1 was inferior in performance to example 1, the results of the cell test of the solid electrolyte membrane assembly described in examples 1 to 4 are shown in fig. 3, and the results of the cell test of the solid electrolyte membrane assembly described in comparative example 1 are shown in fig. 4, demonstrating that the solid electrolyte membrane according to the present invention was superior in performance.

The applicant states that the present invention is illustrated by the above examples to show the detailed method of the present invention, but the present invention is not limited to the above detailed method, that is, it does not mean that the present invention must rely on the above detailed method to be carried out. It should be understood by those skilled in the art that any modifications of the present invention, equivalent substitutions of the raw materials of the product of the present invention, and the addition of auxiliary components, selection of specific modes, etc., are within the scope and disclosure of the present invention.

Claims (10)

1. A self-supporting solid electrolyte membrane is characterized by comprising a polymer microporous filter membrane, and ionic liquid and sulfide solid electrolyte which are arranged in holes of the polymer microporous filter membrane;

the sulfide solid electrolyte surface is coated with an ionic liquid.

2. The self-supporting solid electrolyte membrane according to claim 1, wherein a surface of the polymer microporous filtration membrane is provided with a coating layer;

the coating comprises an ionic liquid and a sulfide solid electrolyte.

3. The self-supporting solid electrolyte membrane according to claim 1 or 2, characterized in that the thickness of the self-supporting solid electrolyte membrane is 100-200 μm.

4. A self-supporting solid state electrolyte membrane according to claim 1 or 2, wherein the thickness of the polymeric microporous filter membrane is 80-100 μm.

5. A self-supporting solid state electrolyte membrane according to claim 1 or 2, wherein the pore size of the polymeric microporous filter membrane is 0.45-3 μm.

6. The self-supporting solid electrolyte membrane according to claim 1 or 2, characterized in that the particle size of the sulfide solid electrolyte is 1-3 μm.

7. The self-supporting solid electrolyte membrane according to claim 1 or 2, wherein the pores of the polymeric microporous filtration membrane comprise Y-shaped and/or column-shaped through-holes.

8. The self-supporting solid electrolyte membrane according to claim 1, wherein the polymeric microporous filtration membrane comprises any one of a polyvinylidene fluoride layer, a polytetrafluoroethylene layer, a nylon layer, a polysulfone layer, a polyethersulfone layer, a polypropylene layer, a cellulose diacetate layer, a cellulose triacetate layer, or an ethyl cellulose layer.

9. The self-supporting solid state electrolyte membrane according to claim 1, wherein the sulfide solid state electrolyte comprises Li₂S-P₂P₅、Li_3.4Si_0.4P_0.6S₄、Li₁₀SiP₂S₁₂、Li_0.35Si_1.35P_1.65S₁₂、Li_9.54Si_1.74P_1.44S_11.7Cl_0.3、Li₁₀GeP₂S₁₂、Li_10.35Ge_1.35P_0.75S₄、Li_3.25Ge_0.25P_0.75S₄、Li₁₀GeP₂S_11.7O_0.3、Li_9.6P₃S₁₂、Li₇P₃S₁₁、Li₉P₃S₉O₃、Li_9.81Sn_0.81P_2.19S₁₂、Li₁₀(Si_0.5Ge_0.5)P₂S₁₂、Li(Ge_0.5Sn_0.5)P₂S₁₂、Li(Si_0.5Sn_0.5)P₂S₁₂、Li₆PS₅X、Li₇P₂S₈X or Li₁₀SnP₂S₁₂Any one of the above;

wherein, X is selected from any one of Cl, Br or I.

10. A lithium ion battery comprising a positive electrode sheet, the self-supporting solid state electrolyte membrane of any one of claims 1 to 9, and a negative electrode sheet arranged in a stack.

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