Solid-state electrolyte membrane and method for producing the same

Abstract

The application discloses a kind of solid electrolyte membrane and preparation method thereof, specifically, polymer matrix material, lithium salt, fast ion conductor particles are added to specific solvent to obtain sol-like mixed solution, then solid electrolyte slurry is titrated on fiber non-woven fabric according to preset amount, ensure that it is fully infiltrated solid electrolyte slurry, then dry treatment is carried out to remove residual organic solvent, finally, rolling treatment is carried out to obtain the solid electrolyte membrane with fiber non-woven fabric as base. Compared with the solid electrolyte membrane independently formed on polytetrafluoroethylene mold or glass plate, the process is simpler and has excellent mechanical properties and thermal stability. On the other hand, while effectively inhibiting lithium dendrite growth, it ensures high lithium ion mobility and gives the solid lithium ion battery excellent cycle performance and higher retention capacity, with excellent application prospects.

Description

Technical Field

[0001] This invention belongs to the field of lithium-ion battery technology, specifically relating to a solid electrolyte membrane and its preparation method. Background Technology

[0002] With the development of new energy technologies, lithium-ion batteries have stood out among many rechargeable batteries due to their advantages such as low self-discharge rate, long lifespan, and no memory effect. However, currently commercialized lithium-ion batteries face many problems due to the use of highly chemically active, flammable, and volatile non-aqueous electrolyte solutions. For example, in cases of overcharging, over-discharging, or internal short circuits, the electrolyte may overheat and spontaneously combust, leading to explosions and other safety hazards. Solid-state lithium-ion batteries, on the other hand, use an electrolyte membrane to replace the separator and electrolyte, effectively avoiding many safety issues associated with liquid electrolytes and significantly improving energy density and electrochemical performance.

[0003] Most solid electrolyte membranes prepared in current research are directly formed on polytetrafluoroethylene (PTFE) molds or glass plates to obtain independently formed electrolyte membranes. However, this method has significant drawbacks. The preparation process is lengthy and requires strict control over drying time and temperature. The resulting electrolyte membranes often adhere to the PTFE template, leading to membrane damage and severe powdering. This can then cause lithium dendrites to penetrate the electrolyte membrane during subsequent battery assembly, resulting in short circuits between the positive and negative electrodes or collapse of the positive electrode structure. In contrast, while some electrode / electrolyte membranes prepared using slurry coating technology have a slightly shorter preparation cycle, they are prone to separation from the current collector substrate under improper process conditions, affecting electrochemical performance. Therefore, the preparation of a solid electrolyte membrane that is quick to form, simple to process, and possesses high mechanical and electrochemical properties is of paramount importance. Summary of the Invention

[0004] In view of the shortcomings and difficulties in the prior art, the present invention aims to provide a solid electrolyte membrane and its preparation method, the solid electrolyte membrane prepared by the invention having excellent mechanical properties and high ionic conductivity.

[0005] This invention is achieved through the following technical solution:

[0006] A solid electrolyte membrane is provided, wherein the solid electrolyte membrane is obtained by cross-linking a solid electrolyte slurry with a fiber nonwoven fabric. The polymer in the solid electrolyte slurry is divided into rigid segment polymers and flexible segment polymers. The cross-linking of the rigid segment polymers with the fibers forms the main part of the three-dimensional conduction network. The flexible segment polymers fill the excessive pores in the fiber nonwoven fabric and serve as an auxiliary part of the conduction network. Finally, fast ion conductor particles and lithium salts are uniformly dispersed on the conduction network and cross-linked with the fibers to form new lithium ion transport channels.

[0007] The above-mentioned method for preparing solid electrolyte membranes includes the following steps:

[0008] (1) Preparation of solid electrolyte slurry: The selected polymer, lithium salt, and fast ion conductor particles are dried in a vacuum drying oven for more than 24 hours. One or more rigid segment polymers are weighed according to a preset ratio and dissolved in a preset amount of solvent by physical blending. After stirring in a constant temperature water bath for a first predetermined time, a first type of sol-gel mixture is obtained. Subsequently, one or more flexible segment polymers are weighed according to a preset ratio and directly added to the first type of sol-gel mixture for constant temperature stirring. After stirring for a second predetermined time, a second type of sol-gel mixture is obtained. One or more lithium salts are weighed according to a preset ratio and directly added to the second type of sol-gel mixture for constant temperature stirring. After stirring for a third predetermined time, a third type of sol-gel mixture is obtained. Finally, one or more fast ion conductor particles are weighed according to a preset ratio and directly added to the third type of sol-gel mixture for constant temperature stirring. After stirring for a fourth predetermined time, a fourth type of sol-gel mixture is obtained. This is the solid electrolyte slurry.

[0009] (2) Impregnation treatment: The nonwoven fabric is impregnated in the solid electrolyte slurry obtained in step (1), with a preset drip rate of 10 μL / cm. 2 -200μL / cm 2 After the electrolyte slurry is fully impregnated for 15-30 minutes, it is placed in a forced-air drying oven to remove residual organic solvents and then transferred to a vacuum drying oven. After drying at 60℃-150℃ for 1-2 hours, a composite solid electrolyte membrane with fiber nonwoven fabric as the substrate is obtained.

[0010] (3) Compaction treatment: The solid electrolyte membrane with fiber nonwoven fabric as the substrate is compacted in a press at a pressure range of 6MPa-45MPa to obtain a thickness range of 10μm-70μm and a compaction density of 5g / cm³. 3 -30g / cm 3 Furthermore, the tensile strength of the solid electrolyte membrane is greater than 10 MPa. After the above-mentioned compaction treatment, the high compaction density can significantly make the pore size and pore distribution of the composite solid electrolyte membrane more uniform, the polymer, lithium salt, and fast ion conductor particles more uniformly distributed on the fiber, reduce the contact resistance and charge exchange impedance between the electrolyte membrane and the electrode, increase the area that can participate in lithium ion transport, and thus significantly improve the electrochemical performance of the material.

[0011] Further, the solvent in step (1) is one or more of acetone, N,N-dimethylformamide (DMF), acetonitrile, N-methylpyrrolidone (NMP), tetrahydrofuran (THF), dimethylacetamide (DMAC), tetramethylurea (TMU), and dimethyl sulfoxide (DMSO).

[0012] Further, in step (1), according to mass percentage (wt.%), the mass proportion of the rigid segment polymer ranges from 50 wt.% to 65 wt.%, and the mass proportion of the flexible segment polymer ranges from 10 wt.% to 30 wt.%. The rigid segment polymer is one or more of succinic anionyl nitrile (SN), polyethylene oxide (PEO), polyvinylidene fluoride (PVDF), polyacrylonitrile (PAN), polymethyl methacrylate (PMMA), polymethyl ethylene carbonate (PPC), and hexamethylene diisocyanate (HDI). The flexible segment polymer is one or more of polyvinyl acetate (PVAC), polyethylene glycol (PEG), tetraethylene glycol dimethyl ether (TEGDME), ethylene ethylene carbonate (VEC), and trimethoxymethylsilane (MTM).

[0013] Further, in step (1), the mass percentage of fast ion conductor particles ranges from 2 wt.% to 30 wt.%. Specifically, fast ion conductor particles such as Perovskit-type Li 1 / 2 La 1 / 2 TiO3 or NASICON type AM2(PO4)3, where A = Li, Na, M = Ge, Ti, Zr or Garnet type A3B2(XO4)3, where A = Ca, Mg, Y, La, B = Al, Fe, Ga, Ge, Mn, Ni, V, X = Si, Ge, Al or LISICON type Li 14 ZnGe4O 16 Or Li of type LISICON 4-x Ge 1-x P x One or more of S4. According to the aforementioned preset ratio, on the one hand, the crystallinity of the polymer is reduced, and on the other hand, its glass transition temperature T is lowered. g This provides more amorphous regions that can quickly conduct lithium ions. On the other hand, the addition of a small number of fast ion conductor particles does not cause large-area agglomeration.

[0014] Further, in step (1), the lithium salt mass percentage ranges from 2 wt.% to 38 wt.%, according to mass percentage (wt.%). Specifically, the lithium salt is one or more of lithium perchlorate (LiClO4), lithium hexafluoroarsenate (LiAsF6), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium trifluoromethanesulfonate (LiTF), lithium bis(fluorosulfonyl)imide (LiFSI), lithium di(oxalateborate)borate (LiBOB), and lithium di(fluorooxalateborate)borate (LiDFOB).

[0015] Furthermore, the first predetermined time in step (1) is 1-2 hours. Specifically, the heating temperature for stirring in the constant temperature water bath is 40℃-60℃, and the stirring rotor speed range is 2000r / min-2500r / min. Using the above-mentioned speed can make the first type of sol-gel mixture more uniform and reduce the generation of bubbles.

[0016] Furthermore, the second predetermined time in step (1) is 1-2 hours. Specifically, the heating temperature for stirring in the constant temperature water bath is 40℃-60℃, and the stirring rotor speed range is 2000r / min-2500r / min. Using the above-mentioned speed can make the second type of sol-gel mixture more uniform and reduce the generation of bubbles.

[0017] Furthermore, the third predetermined time in step (1) is 2-3 hours. Specifically, the heating temperature for stirring in the constant temperature water bath is 40℃-60℃, and the stirring rotor speed range is 2000r / min-2500r / min. Using the above-mentioned speed can make the third type of sol-gel mixture more uniform and reduce the generation of bubbles.

[0018] Furthermore, after adding the fast ion conductor particles in step (1), the fourth predetermined time is set to 2-3 hours. Specifically, the heating temperature for stirring in the constant temperature water bath is 40℃-60℃, and the stirring rotor speed range is 2000r / min-2500r / min. Depending on the selected polymer material, the pH value inside the fourth type of sol-gel mixture will change, and the external appearance will show a significant color change.

[0019] All the steps described above can be completed in an inert atmosphere or at room temperature.

[0020] The solid electrolyte membrane of this invention is prepared by directly impregnating a fiber nonwoven fabric in a solid electrolyte slurry. This method utilizes the advantages of nonwoven fabric, such as high liquid absorption and low susceptibility to chemical reactions. With flexible segments in the polymer filling the excessively large pores in the nonwoven fabric, new rapid lithium-ion migration channels are constructed through cross-linking of rigid segments, fast-ion conductor particles, lithium salt, and fibers in the nonwoven fabric. The process is simple and has a short cycle time, yielding a solid electrolyte membrane with high Young's modulus and flexural strength, adaptable to various battery assembly forms such as pouch, button, cylindrical, and blade batteries. Furthermore, this method is low-cost and has low environmental requirements, making it more suitable for large-scale continuous production of solid electrolyte membranes in industry.

[0021] Compared with existing inventions, the beneficial effects of the present invention are:

[0022] First, the preparation method has a short process cycle and a simple preparation process, making it easy to carry out large-scale continuous production.

[0023] Secondly, the solid electrolyte membrane is cross-linked and formed on a fiber nonwoven fabric. The polymer, fast ion conductor particles, and lithium salt are uniformly dispersed on the three-dimensional conductive network. This not only does not hinder the conduction of lithium ions in the electrolyte, but also the ionic conductivity of the prepared solid electrolyte membrane is even slightly higher than that of the pure solid electrolyte film. This preparation method significantly enhances the mechanical properties, thermal stability, and electrochemical performance of the solid electrolyte membrane.

[0024] Third, the preparation method of this solid electrolyte membrane is applicable to all solid electrolyte systems, including polymer electrolyte systems, inorganic electrolyte systems, and organic-inorganic composite electrolyte systems. Detailed Implementation

[0025] This invention provides a solid electrolyte membrane and its preparation method. Specific embodiments are provided to describe the process route and core technical concept of this invention in detail and clearly. However, these embodiments are only a part of the complete system and should not be construed as limiting the invention. Based on the described embodiments, any specific embodiments obtained by those skilled in the art without creative breakthroughs in the technical route and solution of this invention are within the protection scope of this invention.

[0026] Unless otherwise specified, all experimental materials selected were commercially available.

[0027] Example 1

[0028] (1) Preparation of solid electrolyte slurry: The raw materials were weighed according to the following mass percentage (wt.%) ratio: PVDF: 50%, PVAC: 20%, LiTF: 20%, LLZTO: 10%. The rigid segment polymer of PVDF was dissolved in 9 mL of DMF solvent by physical blending. After stirring at 2500 r / min for 1 h in a 60℃ constant temperature water bath, a first type of sol-gel mixture was obtained. The flexible segment polymer of PVAC was then directly added to the first type of sol-gel mixture. After stirring at 2500 r / min for 1 h in a 60℃ constant temperature water bath, a second type of sol-gel mixture was obtained. Then, LiTF particles were directly added to the second type of sol-gel mixture, and stirred at 2000 r / min for 3 h in a 50℃ constant temperature water bath to obtain the third type of sol-gel mixture. Finally, LLZTO fast ion conductor particles were directly added to the third type of sol-gel mixture, and stirred at 2000 r / min for 3 h in a 50℃ constant temperature water bath to obtain the fourth type of sol-gel mixture, i.e., solid electrolyte slurry.

[0029] (2) Wetting: Cut laboratory cleanroom paper into 19mm round slices using a microtome. Use a pipette to drop the solid electrolyte slurry obtained in step (1) onto the cleanroom paper. The preset wetting volume is 150μL / cm. 2 After being fully soaked for 25 minutes, it was placed in an 80°C forced-air drying oven and dried for 1 hour to remove residual organic solvents. Then it was transferred to a vacuum drying oven and dried at 60°C for 1 hour to prepare a composite solid electrolyte membrane with fiber nonwoven fabric as the substrate.

[0030] (3) Compaction treatment: The prepared solid electrolyte membrane was compacted on a press at a pressure of 45 MPa to obtain a thickness of 26 μm and a compaction density of 13.8 g / cm³. 3 Electrolyte membrane.

[0031] Example 2

[0032] (1) Preparation of solid electrolyte slurry: The raw materials were weighed according to the following mass percentage (wt.%) ratio: PVDF: 50%, PVAC: 20%, LiTF: 20%, LLZTO: 10%. The solid electrolyte slurry was prepared according to step (1) in Example 1.

[0033] (2) Infiltration: Cut laboratory cleanroom paper into 19mm round slices using a microtome. Use a pipette to titrate the solid electrolyte slurry obtained in step (1) onto the cleanroom paper. The preset titration amount is 100μL / cm. 2After being fully soaked for 20 minutes, it was placed in an 80℃ forced-air drying oven and dried for 1 hour to remove residual organic solvents. Then it was transferred to a vacuum drying oven and dried at 60℃ for 1 hour to prepare a composite solid electrolyte membrane with fiber nonwoven fabric as the substrate.

[0034] (3) Compaction treatment: The prepared solid electrolyte membrane was compacted on a press with a preset pressure of 34 MPa to obtain a thickness of 43 μm and a compaction density of 11.9 g / cm³. 3 Electrolyte membrane.

[0035] Example 3

[0036] (1) Preparation of solid electrolyte slurry: The raw materials were weighed according to the following mass percentage (wt.%) ratio: PVDF: 50%, PVAC: 20%, LiTF: 20%, LLZTO: 10%. The solid electrolyte slurry was prepared according to step (1) in Example 1.

[0037] (2) Infiltration: Cut laboratory cleanroom paper into 19mm round slices using a microtome. Use a pipette to titrate the solid electrolyte slurry obtained in step (1) onto the cleanroom paper. The preset titration amount is 70μL / cm. 2 After being fully soaked for 15 minutes, it was placed in an 80°C forced-air drying oven and dried for 1 hour to remove residual organic solvents. Then it was transferred to a vacuum drying oven and dried at 60°C for 1 hour to prepare a composite solid electrolyte membrane with fiber nonwoven fabric as the substrate.

[0038] (3) Compaction treatment: The prepared solid electrolyte membrane was compacted on a press with a preset pressure of 23 MPa to obtain a thickness of 57 μm and a compaction density of 8.8 g / cm³. 3 Electrolyte membrane.

[0039] Example 4

[0040] (1) Preparation of solid electrolyte slurry: The raw materials were weighed according to the following mass percentage (wt.%): PEO: 56%, PEG: 14%, LiClO4: 15%, LLZTO: 15%. A physical blending method was used. PEO rigid segment polymer was dissolved in 10 mL of THF solvent and stirred at 2500 rpm for 1 hour in a 60°C water bath to obtain a first type of sol-gel mixture. Then, PEG flexible segment polymer was added to the first type of sol-gel mixture, and stirred at 2500 rpm for 1 hour in a 60°C water bath to obtain a second type of sol-gel mixture. Next, LiClO4 particles were directly added to the second type of sol-gel mixture, and stirred at 2000 rpm for 3 hours in a 50°C water bath to obtain a third type of sol-gel mixture. Finally, LLZTO fast ion conductor particles were directly added to the third type of sol-gel mixture, and stirred at 2000 rpm for 3 hours in a 50°C water bath to obtain a fourth type of sol-gel mixture, i.e., a solid electrolyte slurry.

[0041] (2) Infiltration: Cut laboratory cleanroom paper into 19mm round slices using a microtome. Use a pipette to titrate the third type of gel-like mixed solution obtained in step (1) onto the cleanroom paper. The preset titration amount is 150μL / cm. 2 After being fully soaked for 25 minutes, it was placed in an 80℃ forced-air drying oven for 3 hours to remove residual organic solvents. Then it was transferred to a vacuum drying oven and dried at 60℃ for 1 hour to prepare a composite solid electrolyte membrane with fiber nonwoven fabric as the substrate.

[0042] (3) Compaction treatment: The prepared solid electrolyte membrane was compacted on a press with a preset pressure of 45 MPa to obtain a thickness of 31 μm and a compaction density of 14.4 g / cm³. 3 Electrolyte membrane.

[0043] Example 5

[0044] (1) Preparation of solid electrolyte slurry: The raw materials were weighed according to the following mass percentage (wt.%) ratio: PEO: 56%, PEG: 14%, LiClO4: 15%, LLZTO: 15%. The solid electrolyte slurry was prepared according to the method in step (1) of Example 4.

[0045] (2) Impregnation: The laboratory clean paper was cut into 19 mm round slices on a microtome. The third type of gel-like mixed solution obtained in step (1) was titrated onto the clean paper using a pipette. The preset titration amount was 100 μL. After waiting for 20 min to fully impregnate, it was placed in an 80℃ forced-air drying oven to dry for 1 h. After removing the residual organic solvent, it was transferred to a vacuum drying oven and dried at 60℃ for 1 h to prepare a composite solid electrolyte membrane with fiber nonwoven fabric as the substrate.

[0046] (3) Compaction treatment: The prepared solid electrolyte membrane was compacted on a press with a preset pressure of 34 MPa to obtain a thickness of 44 μm and a compaction density of 11.6 g / cm³. 3 Electrolyte membrane.

[0047] Example 6

[0048] (1) Preparation of solid electrolyte slurry: The raw materials were weighed according to the following mass percentage (wt.%) ratio: PEO: 56%, PEG: 14%, LiClO4: 15%, LLZTO: 15%. The solid electrolyte slurry was prepared according to the method in step (1) of Example 4.

[0049] (2) Infiltration: Cut laboratory cleanroom paper into 19mm round slices using a microtome. Use a pipette to titrate the third type of gel-like mixed solution obtained in step (1) onto the cleanroom paper. The preset titration amount is 70μL / cm. 2 After being fully soaked for 15 minutes, it was placed in an 80°C forced-air drying oven and dried for 1 hour to remove residual organic solvents. Then it was transferred to a vacuum drying oven and dried at 60°C for 1 hour to prepare a composite solid electrolyte membrane with fiber nonwoven fabric as the substrate.

[0050] (3) Compaction treatment: The prepared solid electrolyte membrane was compacted on a press with a preset pressure of 23 MPa to obtain a thickness of 60 μm and a compaction density of 8.7 g / cm³. 3 Electrolyte membrane.

[0051] Examples 1-6 also provide a solid-state lithium-ion battery. This solid-state lithium-ion battery is assembled using the solid electrolyte membrane with a fiber nonwoven fabric substrate as the electrolyte layer, lithium iron phosphate as the positive electrode, and lithium metal as the negative electrode, as prepared above. During battery assembly, a small amount of wetting agent is selectively added to the surface of the solid electrolyte membrane according to the characteristics of the selected polymer material. The electrochemical performance of the solid-state lithium battery prepared in this example was tested at room temperature / 0.2C. A comparative example was set up, in which a corresponding lithium iron phosphate positive electrode sheet was added, and a liquid electrolyte and separator were assembled to form a liquid lithium-ion battery with a lithium metal negative electrode structure. Charge and discharge tests were performed, and the charge and discharge voltage was set to 2.5V-4.1V. The electrochemical performance results are shown in Table 1.

[0052] Table 1. Test results of charge-discharge performance of solid-state lithium-ion batteries in each embodiment and comparative sample.

[0053]

[0054]

[0055] The embodiments and comparative examples described above are only illustrative and do not limit the scope of the invention. Furthermore, the technical features described in the claims are similar to the examples and can be combined to construct new systems. To ensure clarity, not all combinations are described in detail. However, as long as there is no contradiction in the combination of these technical systems, they should be considered to be within the scope of this specification.

[0056] Specifically, any changes or adjustments made by those skilled in the art without departing from the core technical approach of this specification are within the scope of protection of this invention.

Claims

1. A solid state electrolyte membrane, characterized by: The solid-state electrolyte membrane is obtained by cross-linking a solid-state electrolyte slurry and a fiber non-woven fabric, wherein the polymer in the solid-state electrolyte slurry is divided into rigid chain segment polymers and flexible chain segment polymers, the rigid chain segment polymers and the fibers are cross-linked to build a main part of a three-dimensional conductive network, the flexible chain segment polymers fill large pores in the fiber non-woven fabric and serve as an auxiliary part of the conductive network, finally, fast ionic conductor particles and lithium salt are uniformly dispersed on the conductive network to build new lithium ion transmission channels after being mixed and cross-linked with the fibers; The preparation method of the solid-state electrolyte membrane comprises the following steps: S1, preparation of a solid-state electrolyte slurry (1-1) One or more rigid chain segment polymers are weighed according to a preset proportion, the rigid chain segment polymers are dissolved in a preset amount of solvent by physical blending, and a first sol-like mixed solution is obtained after stirring in a constant-temperature water bath for a first predetermined time; (1-2) One or more flexible chain segment polymers are weighed according to a preset proportion, and then the flexible chain segment polymers are added to the first sol-like mixed solution, and a second sol-like mixed solution is obtained after constant-temperature stirring for a second predetermined time; (1-3) One or more lithium salts are weighed according to a preset proportion and directly added to the second sol-like mixed solution for constant-temperature stirring, and a third sol-like mixed solution is obtained after stirring for a third predetermined time; (1-4) One or more fast ionic conductor particles are weighed according to a preset proportion and directly added to the third sol-like mixed solution for constant-temperature stirring, and a fourth sol-like mixed solution, i.e., a solid-state electrolyte slurry, is obtained after stirring for a fourth predetermined time; S2, infiltration treatment The solid-state electrolyte slurry prepared in step S1 is infiltrated into a fiber non-woven fabric according to a preset amount, the fiber non-woven fabric is fully infiltrated, then drying treatment is performed to remove residual solvent, and finally a solid-state electrolyte composite membrane with the fiber non-woven fabric as a substrate is prepared; S3, rolling treatment The solid-state electrolyte membrane prepared in step S2 is subjected to a calendering treatment in a press machine, and the thickness of the solid-state electrolyte membrane obtained by the calendering treatment is 10 µm-70 µm, the compacted density is 5 g / cm 3 -30 g / cm 3 , and the tensile strength is greater than 10 MPa.

2. The method of claim 1, wherein: In step S1, the mass percentage (wt. %) is that the mass of the rigid chain segment polymer, the flexible chain segment polymer, the lithium salt and the fast ionic conductor particle accounts for 50%-65%, 10%-30%, 2%-38% and 2%-30% of the total mass of the raw materials, respectively.

3. The method of claim 1, wherein: In step (1-1), the rigid chain segment polymer is one or more of polyethylene oxide (PEO), polyvinylidene fluoride (PVDF), polyacrylonitrile (PAN), polymethyl acrylate (PMMA) and polymethyl ethylene carbonate (PPC).

4. The method of claim 1, wherein: In step (1-2), the flexible chain segment polymer is polyvinyl acetate (PVAC) and / or polyethylene glycol (PEG).

5. The method of claim 1, wherein: In step (1-3), the lithium salt is one or more of lithium perchlorate (LiClO4), lithium hexafluoroarsenate (LiAsF6), lithium bis-trifluoromethanesulfonimide (LiTFSI), lithium triflate (LiTF), lithium bisfluorosulfonylimide (LiFSI), lithium bis(oxalato)borate (LiBOB) and lithium difluoro(oxalato)borate (LiDFOB).

6. The method of claim 1, wherein: The fast ion conductor particles mentioned in the steps (1-4) are one or more of the Perovskit type Li 1 / 2 La 1 / 2 TiO3or NASICON type AM2(PO4)3, wherein A = Li, Na, M = Ge, Ti, Zr or Garnet type A3B2(XO4)3, wherein A = Ca, Mg, Y, La, B = Al, Fe, Ga, Ge, Mn, Ni, V, X = Si, Ge, Al or LISICON type Li 14 ZnGe4O 16 .

7. The method of claim 1, wherein: The solvent in the step (1-1) is one or more of acetone, N, N-dimethylformamide (DMF), acetonitrile, N-methyl pyrrolidone (NMP), tetrahydrofuran (THF), dimethylacetamide (DMAC), tetramethylurea (TMU), dimethyl sulfoxide (DMSO).

8. The method of claim 1, wherein: The first predetermined time in the step (1-1) is 1 h-2 h, the second predetermined time in the step (1-2) is 1 h-2 h, the third predetermined time in the step (1-3) is 2 h-3 h, and the fourth predetermined time in the step (1-4) is 2 h-3 h; the constant temperature stirring in the steps (1-1), (1-2), (1-3), (1-4) is that the heating temperature of stirring in the constant temperature water bath is 40 ℃-60 ℃, and the stirring rotor speed range is 2000 r / min-2500 r / min.

9. The method of claim 1, wherein: The preset amount of infiltration in the step S2 is 10 µL / cm 2 - 200 µL / cm 2 The infiltration time is 15 min-30 min; the fiber non-woven fabric in the step S2 is at least one of laboratory dust-free paper, aramid fiber non-woven fabric, polypropylene fiber non-woven fabric, polyester fiber non-woven fabric, nylon fiber non-woven fabric, acrylic fiber non-woven fabric, and ethylene fiber non-woven fabric; the pressure range of the rolling treatment in the step S3 is 6 MPa-45 MPa, and the pressure stability is ≤1 MPa / 10 min.

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