Dry-method negative plate, solid-state battery and preparation method
By using a double-layer dry anode design and combining fibrous and non-fibrous binders, the particle size and morphology of silicon materials were adjusted, solving the problem of poor interfacial contact caused by volume expansion in solid electrolytes for silicon-based anodes, and achieving battery performance with high energy density and long cycle life.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-17
- Publication Date
- 2026-04-07
AI Technical Summary
In existing technologies, silicon-based anodes suffer from high mechanical stress and poor interfacial contact due to volume expansion in solid electrolytes, which affects lithium-ion transport and battery safety. Furthermore, existing dry processes are unable to effectively solve this problem.
A double-layer dry anode design is adopted, using a composite of fibrous and non-fibrous binders to adjust the distribution of anode materials. Combined with silicon materials of different particle sizes and morphologies, a stable interface contact is formed, enhancing the contact effect of internal battery components.
A high-energy-density battery with long cycle life and high-rate performance has been achieved. By optimizing interface contact and material distribution, the stability and capacity of the battery have been improved.
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Figure CN121812464A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of battery technology, and in particular to a dry-process negative electrode, a solid-state battery, and a method for its preparation. Background Technology
[0002] Applying dry electrode technology is a synergistic solution for building next-generation high-energy-density, high-capacity, and high-safety batteries. Its core value lies in its solvent-free dry powder mixing and compaction technology, which creates ideal conditions for the large-scale application of electrodes, especially high-capacity active materials such as silicon-based materials. This process significantly improves the compaction density and active material loading of the electrode, directly enabling a leap in battery energy density. Simultaneously, it is perfectly compatible with new material systems such as silicon anodes and can seamlessly integrate pre-lithiation technology, effectively compensating for lithium consumption and thus fully releasing the ultra-high capacity potential of the material. In terms of safety, the dry process completely eliminates the risk of side reactions caused by solvent residues, fundamentally enhancing the chemical stability of the battery; the resulting stable electrode structure effectively suppresses the breakage and shedding of active materials during cycling, maintaining interface stability and significantly improving the long-term reliability of the battery. In summary, dry electrodes, with their three-in-one advantages of "higher (energy density), more (capacity), and greater safety," combined with the potential for green manufacturing and cost reduction, are becoming a key innovation driving the advancement of battery technology.
[0003] Silicon expands by 280%-300% in volume when fully lithiated. This massive, repeated expansion and contraction generates enormous mechanical stress between the rigid solid-state electrolyte (SSE) and silicon particles. This can cause the silicon particles to separate from the SSE particles, losing physical contact and disrupting ion transport pathways. Stress can also cause cracks or even breakage in the brittle SSE layer, leading to internal short circuits in the battery and potentially pulverizing the silicon particles themselves. Unlike liquid electrolytes, which can form "surface contact" or be completely wetted, the contact between solid-state electrolytes and silicon particles is typically limited to "point contact," resulting in a high initial interfacial impedance. Volume changes continuously disrupt and rebuild the interface, but the newly formed interface is often not an optimal ion transport channel. Electrochemical instability may exist between silicon and certain types of SSEs, forming a high-resistivity interfacial layer that further hinders lithium-ion transport. Summary of the Invention
[0004] The purpose of this invention is to overcome the shortcomings and defects of the prior art and to provide a solid-state battery.
[0005] To achieve the above objectives, this application adopts the following solution:
[0006] A dry-process negative electrode sheet includes a negative electrode current collector and an electrode film disposed on the surface of the negative electrode current collector; the electrode film includes a second active material layer close to the negative electrode current collector and a first active material layer away from the negative electrode current collector.
[0007] The first active material layer includes a first negative electrode material, a first electrolyte material, a first additive material, and a fibrous binder;
[0008] The second active material layer includes a second negative electrode material, a second electrolyte material, a second additive material, and a non-fibrous binder.
[0009] The non-fibrous adhesives include one or more of sodium carboxymethyl cellulose, water-based electrode adhesives, styrene-butadiene rubber, sodium alginate, polyacrylonitrile, polyurethane, polyacrylic acid, polyvinylidene fluoride, polyisobutylene, and polymethacrylate.
[0010] Preferably, the fibrous binder includes one or more of polytetrafluoroethylene, ethylene-tetrafluoroethylene copolymer, polypropylene, polyethylene, ethylene-octene copolymer, and polyimide.
[0011] The mass ratio of the first negative electrode material, the first electrolyte material, the second additive material, and the fibrous binder is (40-70):(20-50):(1-5):(1-2): preferably (50-55):(40-45):(3-4):(1-2); more preferably 55:40:3:2.
[0012] Preferably, the mass ratio of the second negative electrode material, the second electrolyte material, the second additive material, and the non-fibrous binder is (60-80):(1-10):(1-10):(1-5); more preferably (55-60):30:(5-7):(5-8); and even more preferably 60:30:5:5.
[0013] The particle size of the first solid electrolyte is 3-10 μm, preferably 3 μm, and the particle size of the second solid electrolyte is 0.5-5 μm, preferably 0.5 μm;
[0014] Preferably, the thickness of the first active material layer is 2-20 μm; more preferably, it is 10 μm.
[0015] Preferably, the thickness of the second active material layer is 30-60 μm; more preferably, it is 40 μm.
[0016] The first negative electrode material in the first active material layer comprises a negative electrode active material with a particle size D50 of 1um-3um and a negative electrode active material with a particle size D50 of 5um-10um, with a material mass content M1, and the ratio of M1 to S1 is 1:1.5-2.5; preferably 1:2.
[0017] Preferably, the second negative electrode active material in the second active material layer comprises a negative electrode active material with a particle size D50 of 0.1um-0.5um and a negative electrode active material with a particle size D50 of 0.5um-1um and a material content S2, wherein M2:S2 is 1:1.2-1.5; preferably 1:1.5.
[0018] The first negative electrode material and the second negative electrode material are independently at least one of graphite-based materials, silicon materials, or graphite / silicon composite materials;
[0019] Preferably, the first electrolyte material and the second electrolyte material are independently at least one of oxide electrolyte, polymer electrolyte, sulfide electrolyte and halide electrolyte;
[0020] Preferably, the first additive material and the second additive material include at least one of a conductive agent material, a mixed ion-conducting material, and a three-dimensional framework material; preferably, the conductive agent material includes at least one of conductive carbon black, carbon nanofibers, vapor-grown carbon fibers, and vapor-grown carbon nanofibers; preferably, the mixed ion-conducting material includes at least one of polystyrene sulfonate, polyethylene dioxythiophene, polymethoxyethoxyethoxythiophene, and polytetramethylzidinoxy-vinyl methacrylate; preferably, the three-dimensional framework material includes at least one of copper-hexahydroxytriphenylene and hexahydroxytriphenylene.
[0021] The negative electrode current collector is a carbon-coated copper foil with a thickness of 4-10 μm.
[0022] This invention also includes a method for preparing the dry-process negative electrode, comprising the following steps:
[0023] S1: The first negative electrode active material, the first electrolyte material, the first additive and the fiberizing binder are mixed and fiberized in a mixer, a twin-screw extruder and a kneading machine to obtain the fiberized dry first active material layer material; the first active material layer material is formed into a film at high temperature using a film forming machine and then sheared to obtain the first active material layer.
[0024] S2: The second negative electrode active material, the second electrolyte material, the second additive, and the non-fibrous binder are mixed in a mixer and dispersed non-fibrously to obtain a dry second active material layer material; the second active material layer material is formed into a film at high temperature using a film forming machine and then sheared to obtain the second active material layer; steps S1 and S2 are not in any particular order; steps S1 and S2 are not in any particular order.
[0025] S3: The first active material layer and the second active material layer are rolled and compounded to a certain thickness at high temperature, and the two compounded negative electrode layer films are compounded with the negative electrode current collector and cut thin as a whole. Then, the dry negative electrode sheet can be obtained by isostatic pressing at high temperature for a period of time.
[0026] 8. The preparation method according to claim 7, characterized in that, in S1, the fiberization process is as follows: initial fiberization speed, 500-1000 rpm, time, 10-30 min, temperature controlled at 0-10℃; increase the rotation speed to 8000-15000 rpm, increase the temperature to 80-100℃; high-speed stirring for 3-10 min;
[0027] In step S2, the non-fibrous mixing speed is 3000-5000 rpm, the time is 30-90 min, and the temperature is controlled at 25℃-60℃.
[0028] The present invention also includes a solid-state battery, comprising the aforementioned dry-process negative electrode, counter electrode, and solid electrolyte membrane; the solid electrolyte membrane comprises a third solid electrolyte; preferably, the particle size of the third solid electrolyte is 1-10 μm, more preferably 1 μm.
[0029] The present invention also includes a method for preparing the solid-state battery, comprising the following steps: pressing a third solid electrolyte powder into a sheet to obtain a solid electrolyte membrane, and assembling the counter electrode and the dry negative electrode sheet into a mold; after assembly, applying pressure and tightening the nut at the top of the mold to obtain the solid-state battery; preferably, the battery assembly environment is in a glove box with an argon atmosphere or a dry room with a dew point requirement of ≤-60℃.
[0030] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0031] This invention designs a double-layer dry anode sheet, introduces fibrous binders and non-fibrous binders for composite, and adjusts the distribution of anode material types to maintain good interfacial contact between the components inside the solid dry anode sheet during battery cycling, thereby obtaining a high-energy-density battery with long cycle life and high rate performance. Attached Figure Description
[0032] Figure 1 This is a schematic diagram of the dry-process negative electrode sheet of the present invention. Detailed Implementation
[0033] The present invention will be further described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
[0034] Example 1:
[0035] The dry-process negative electrode sheet includes a carbon-coated copper foil negative electrode current collector 1 and an electrode film disposed on the surface of the negative electrode current collector; the electrode film includes a second active material layer 2 close to the negative electrode current collector and a first active material layer 3 away from the negative electrode current collector;
[0036] The first active material layer comprises a first negative electrode material, a first electrolyte material, an additive material, and a non-fibrous binder material in a mass ratio of 55:40:3:2. The first negative electrode active material in the first active material layer is a silicon material with a mixed particle size distribution, containing 55% silicon, with a large particle size D50 of 8 μm and a small particle size D50 of 3 μm; the mass ratio of small to large particle sizes is 1:2. The first electrolyte material is a sulfide solid electrolyte, specifically Li6PS5Cl, with a particle size D50 of 3 μm. The first layer additive is polyethylene dioxythiophene; the fibrous binder is polytetrafluoroethylene.
[0037] The second active material layer comprises a second negative electrode material, an electrolyte material, an additive material, and a non-fibrous binder material in a mass ratio of 60:30:5:5. In the second dry-process negative electrode layer, the second negative electrode active material is a silicon material with a mixed particle size distribution, containing 60% silicon. The large particle size (D50) is 0.6 μm, and the small particle size (D50) is 0.2 μm, with a small particle size to large particle size mass ratio of 1:1.5. The second electrolyte material is a polymer solid electrolyte (PVBL) with a particle size (D50) of 0.5 μm; the second layer additive is VGCF. The non-fibrous binder is polyvinylidene fluoride (PVDF).
[0038] The preparation steps for dry-process negative electrode sheets are as follows:
[0039] S1: Silicon material, Li6PS5Cl, PEDOT, and PTFE in corresponding proportions are mixed and fiberized in a mixer, twin-screw extruder, and kneader. The initial fiberization speed is 600 rpm for 20 minutes, and the temperature is controlled at 0-10℃. The speed is then increased to 10000 rpm, and the temperature is increased to 80-100℃. High-speed stirring is carried out for 5 minutes to obtain the first active material layer after fiberization. The first dry anode layer material is then formed into a film at 100℃ using a film forming machine and thinned to 10 μm to obtain the first active material layer.
[0040] S2: Silicon material, PVBL, VGCF, and PVDF in corresponding proportions are mixed in a mixer, and then the mixture is ball-milled to disperse the non-fibrous binder. The non-fibrous mixing speed is 4000 rpm for 60 minutes, and the temperature is controlled at 40℃-50℃; the dispersed second active material layer is obtained. The second dry anode layer material is formed into a film at 100℃ using a film forming machine and then cut to a thickness of 40µm to obtain the second active material layer.
[0041] S3: The first and second active material layer films are laminated by multi-roll continuous rolling at 100°C. The laminated films are then combined with a carbon-coated copper foil current collector. Subsequently, the film is subjected to isobaric treatment at 200 MPa and 80°C for 15 min to obtain an areal capacity of 6 mAh / cm³. 2 Dry-process negative electrode sheet.
[0042] The counter electrode of the solid-state battery is a lithium-indium alloy sheet (the mass ratio of lithium to indium in the lithium-indium alloy sheet is 1:5). The electrolyte layer is made by pressing a third solid electrolyte, a sulfide electrolyte powder with a D50 of 1 μm, into a sheet.
[0043] The preparation steps of a solid-state lithium-ion battery are as follows: The third solid electrolyte powder is loaded into a mold and pressed into a sheet, which is then placed into the mold along with a lithium-indium alloy sheet for assembly. After assembly, the pressure is increased to 1.5t, and the nut at the top of the mold is tightened to obtain a dry-process negative electrode lithium-ion battery. The battery assembly environment is a glove box or dry room with an argon atmosphere and a dew point requirement of ≤-60℃.
[0044] Example 2
[0045] The preparation method is the same as that in Example 1, except that the particle size D50 of the first electrolyte material in Example 2 is 10 μm and the particle size D50 of the second electrolyte material is 5 μm.
[0046] Example 3
[0047] The preparation method is the same as that in Example 1, except that the material used in Example 3 is a pure small particle negative electrode active material, that is, the particle size D50 of the first negative electrode material in the first dry negative electrode layer is 0.6 μm, and the particle size D50 of the second negative electrode active material in the second active material layer is 0.1 μm.
[0048] Example 4
[0049] The preparation method is the same as in Example 1, except that in Example 4, the large particle size D50 of the silicon material mixed with the first dry anode material in the first dry anode layer is 10 μm and the small particle size D50 is 5 μm; and the large particle size D50 of the silicon material mixed with the second dry anode material in the second dry anode layer is 3 μm and the small particle size D50 is 1 μm.
[0050] Example 5
[0051] The preparation method is the same as in Example 1, except that the mass ratio of the first negative electrode active material, the first electrolyte material, the additive material and the fibrous binder in Example 5 is 50:45:4:1, and the mass ratio of the second negative electrode active material, the second electrolyte material, the additive material and the non-fibrous binder is 55:30:7:8.
[0052] Comparative Example 1
[0053] The preparation method is the same as in Example 1, except that the non-fibrous binder in the second dry negative electrode layer in Comparative Example 1 is replaced with the same mass of fibrous binder.
[0054] Comparative Example 2
[0055] The preparation method is the same as that in Example 1, except that the double-layer dry anode layer in Comparative Example 2 does not contain any additives.
[0056] Comparative Example 3
[0057] The preparation method is the same as in Example 1, except that the particle size ratio of the first electrolyte material of the negative electrode, the second electrolyte material of the negative electrode, and the third electrolyte material of the electrolyte layer in Comparative Example 3 is 1:1:1, and all of them are 1 μm.
[0058] Comparative Example 4
[0059] The preparation method is the same as in Example 1, except that the particle size D50 of the third electrolyte material in the electrolyte layer in Example 4 is 10 μm.
[0060] Comparative Example 5
[0061] The preparation method is the same as in Example 1, except that the negative electrode active materials of the first dry negative electrode layer and the second dry negative electrode layer in Comparative Example 5 are both pure large-particle negative electrode active materials. The particle size D50 of the first negative electrode active material in the first dry negative electrode layer is 15 μm, and the particle size D50 of the second negative electrode active material in the second dry negative electrode layer is 8 μm.
[0062] Performance testing: The dry-process negative electrode batteries prepared in Examples 1-5 and Comparative Examples 1-5 were subjected to charge-discharge cycle tests at an environment of 25℃~35℃ to measure their cycle performance. The specific capacity of the first constant-capacity discharge was observed and compared, the number of cycles with a capacity retention rate ≥80%, the operating voltage range of -0.4~1.5V, and the cycle rate of 0.05C.
[0063] The test results are as follows. The table shows the performance test results of the dry-process negative electrode lithium-ion batteries of Examples 1-5 and Comparative Examples 1-5:
[0064] Table 1
[0065]
[0066]
[0067] As can be seen from Examples 1-5 and Comparative Examples 1-5, in the double-layer dry negative electrode layer design, the mass content of fibrous binder in the first dry negative electrode layer is 2%, the mass content of non-fibrous binder in the second dry negative electrode layer is 5%, and the particle size ratio of the first negative electrode electrolyte material, the second negative electrode electrolyte material, and the electrolyte layer is 3:0.5:1, which is the optimal embodiment and can effectively improve the battery cycle performance.
[0068] Comparative Example 1 shows that using only fibrous binder in the second dry-process negative electrode layer reduces cycle performance because PTFE has weak adhesion to small-particle-size negative electrode materials. Using only fibrous binder in the double-layer electrode leads to a decrease in electrode cohesion and poor bonding with the current collector, affecting the normal performance of the battery. Comparative Example 2 shows that the absence of additives in the dry-process negative electrode reduces the electron and ion transport pathways within the electrode, resulting in lower battery capacity and a decrease in cycle count. Comparative Example 3 shows that the first electrolyte material and the second electrolyte material of the negative electrode... When the particle size ratio of the feedstock and electrolyte layer is the same, the performance of the electrolyte material is limited, leading to a decrease in battery capacity and cycle performance. Comparative Example 4 shows that the third solid electrolyte material in the electrolyte layer has a particle size D50 of 10 μm. Large-particle-size electrolytes help maximize the capacity of the negative electrode material, but large-particle-size materials have low compaction density, high porosity, and poor interparticle adhesion, resulting in reduced battery cycle performance. Comparative Example 5 shows that both double-layer negative electrode layers use pure large-particle-size silicon negative electrode material for dry film formation, resulting in low electrode compaction density, poor interfacial stability between components, and poor capacity and cycle performance. Examples 1-5 show that the double-layer dry negative electrode structure design mainly focuses on matching the particle size and morphology of the material as the second dry negative electrode layer. Adjusting the matching of negative electrode materials with different morphologies and particle sizes with the binder, and controlling the thickness of the first dry negative electrode layer to ≤20 μm, reduces electrolyte material side reactions, which helps improve the cycle performance and stability of the dry negative electrode battery. Furthermore, as can be seen from Examples 1-5, when the D50 of the third solid electrolyte is 1µm, the performance and cycle stability of the solid-state battery can be effectively improved.
[0069] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention.
[0070] Therefore, the embodiments should be regarded as exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of the equivalents of the claims be included within the invention.
[0071] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.
Claims
1. A dry-process negative electrode, characterized in that, It includes a negative electrode current collector and an electrode film disposed on the surface of the negative electrode current collector; the electrode film includes a second active material layer close to the negative electrode current collector and a first active material layer away from the negative electrode current collector; The first active material layer includes a first negative electrode material, a first electrolyte material, a first additive material, and a fibrous binder; The second active material layer includes a second negative electrode material, a second electrolyte material, a second additive material, and a non-fibrous binder.
2. The dry-process negative electrode sheet according to claim 1, characterized in that, The non-fibrous adhesives include one or more of sodium carboxymethyl cellulose, water-based electrode adhesives, styrene-butadiene rubber, sodium alginate, polyacrylonitrile, polyurethane, polyacrylic acid, polyvinylidene fluoride, polyisobutylene, and polymethacrylate. Preferably, the fibrous binder includes one or more of polytetrafluoroethylene, ethylene-tetrafluoroethylene copolymer, polypropylene, polyethylene, ethylene-octene copolymer, and polyimide.
3. The dry-process negative electrode sheet according to claim 1, characterized in that, The mass ratio of the first negative electrode material, the first electrolyte material, the second additive material, and the fibrous binder is (40-70):(20-50):(1-5):(1-2); preferably (50-55):(40-45):(3-4):(1-2); more preferably... Preferably, the mass ratio of the second negative electrode material, the second electrolyte material, the second additive material, and the non-fibrous binder is (60-80):(1-10):(1-10):(1-5); more preferably (55-60):30:(5-7):(5-8); and even more preferably 60:30:5:
5.
4. The dry-process negative electrode sheet according to claim 1, characterized in that, The particle size of the first solid electrolyte is 3-10 μm, preferably 3 μm, and the particle size of the second solid electrolyte is 0.5-5 μm, preferably 0.5 μm; Preferably, the thickness of the first active material layer is 2-20 μm; more preferably, it is 10 μm. Preferably, the thickness of the second active material layer is 30-60 μm; more preferably, it is 40 μm.
5. The dry-process negative electrode sheet according to claim 1, characterized in that, The first negative electrode material in the first active material layer comprises a negative electrode active material with a particle size D50 of 1um-3um and a negative electrode active material with a particle size D50 of 5um-10um, with a material mass content M1 and a material mass content S1, and the ratio of M1 to S1 is 1:1.5-2.
5. Preferably, the second negative electrode active material in the second active material layer comprises a negative electrode active material with a particle size D50 of 0.1um-0.5um and a negative electrode active material with a particle size D50 of 0.5um-1um and a particle size S2, wherein the ratio of M2 to S2 is 1:1.2-1.
5.
6. The dry-process negative electrode sheet according to claim 1, characterized in that, The first negative electrode material and the second negative electrode material are independently at least one of graphite-based materials, silicon materials, or graphite / silicon composite materials; Preferably, the first electrolyte material and the second electrolyte material are independently at least one of oxide electrolyte, polymer electrolyte, sulfide electrolyte and halide electrolyte; Preferably, the first additive material and the second additive material include at least one of a conductive agent material, a mixed ion-conducting material, and a three-dimensional framework material; preferably, the conductive agent material includes at least one of conductive carbon black, carbon nanofibers, vapor-grown carbon fibers, and vapor-grown carbon nanofibers; preferably, the mixed ion-conducting material includes at least one of polystyrene sulfonate, polyethylene dioxythiophene, polymethoxyethoxyethoxythiophene, and polytetramethylzidinoxy-vinyl methacrylate; preferably, the three-dimensional framework material includes at least one of copper-hexahydroxytriphenylene and hexahydroxytriphenylene. The negative electrode current collector is a carbon-coated copper foil with a thickness of 4-10 μm.
7. A method for preparing a dry-process negative electrode sheet according to any one of claims 1-6, characterized in that, Includes the following steps: S1: The first negative electrode active material, the first electrolyte material, the first additive and the fiberizing binder are mixed and fiberized in a mixer, a twin-screw extruder and a kneading machine to obtain the fiberized dry first active material layer material; the first active material layer material is formed into a film at high temperature using a film forming machine and then sheared to obtain the first active material layer. S2: The second negative electrode active material, the second electrolyte material, the second additive, and the non-fibrous binder are mixed in a mixer and dispersed non-fibrously to obtain a dry second active material layer material; the second active material layer material is formed into a film at high temperature using a film forming machine and then sheared to obtain the second active material layer; steps S1 and S2 are not in any particular order. S3: The first active material layer and the second active material layer are rolled and compounded to a certain thickness at high temperature, and the two compounded negative electrode layer films are compounded with the negative electrode current collector and cut thin as a whole. Then, the dry negative electrode sheet can be obtained by isostatic pressing at high temperature for a period of time.
8. The preparation method according to claim 7, characterized in that, The fiberization process in S1 is as follows: initial fiberization speed, 500-1000 rpm, time, 10-30 min, temperature controlled at 0-10℃; increase the speed to 8000-15000 rpm, increase the temperature to 80-100℃; high-speed stirring for 3-10 min. In step S2, the non-fibrous mixing speed is 3000-5000 rpm, the time is 30-90 min, and the temperature is controlled at 25℃-60℃.
9. A solid-state battery, characterized in that, It includes the dry negative electrode, counter electrode, and solid electrolyte membrane as described in any one of claims 1-6; the solid electrolyte membrane includes a third solid electrolyte; preferably, the particle size of the third solid electrolyte is 1-10 μm, more preferably 1 μm.
10. A method for preparing a solid-state battery according to claim 9, characterized in that, The process includes the following steps: pressing the third solid electrolyte powder into a sheet to obtain a solid electrolyte membrane, and assembling the counter electrode and the dry negative electrode sheet into a mold; after assembly, applying pressure and tightening the nut at the top of the mold to obtain a solid battery; preferably, the battery assembly environment is in a glove box with an argon atmosphere or a dry room with a dew point requirement of ≤-60℃.