All-solid-state battery cell having three-dimensional interpenetrating lithium-ion conduction network, preparation method therefor and use thereof

Abstract

The present invention relates to an all-solid-state battery cell having a three-dimensional interpenetrating lithium-ion conduction network, a preparation method therefor and a use thereof. In the present invention, positive electrode powders A, B and C having different particle sizes and compositions are sequentially, uniformly and electrostatically sprayed onto a mold; then a sulfide electrolyte layer is formed on a composite positive electrode layer by means of spraying; composite negative electrode powders D and E that are uniformly mixed and have different particle sizes and compositions are sequentially, uniformly and electrostatically sprayed onto the surface of the electrolyte layer; finally, the powders are integrally compacted by means of warm isostatic pressing so as to obtain an all-solid-state battery cell, and the all-solid-state battery cell is assembled into a solid-state battery. The present invention provides a new battery structure design, and by introducing a low-viscosity thermoplasticizer and an electrostatic dry spraying technique to construct the three-dimensional interpenetrating lithium-ion conduction network, significantly enhances lithium ion migration efficiency, and also enhances the stability of an interface between an electrode and a solid-state electrolyte, so as to reduce the interface impedance of a sulfide solid-state battery, thereby achieving better capacity retention, longer cycle life, and better safety performance.

Description

A solid-state battery cell with a three-dimensional interlaced lithium-ion conduction network, its preparation method, and its applications. Technical Field

[0001] This invention belongs to the field of solid-state batteries, specifically relating to an all-solid-state battery cell with a three-dimensional interlaced lithium-ion conduction network, its preparation method, and its application. Background Technology

[0002] All-solid-state sulfide batteries offer significant safety advantages over traditional liquid-electrolyte lithium-ion batteries due to their non-flammability and stable operation over a wider temperature range. Furthermore, the use of highly ionicly conductive sulfide electrolytes promises higher energy density, longer cycle life, and the ability to utilize metallic lithium as the anode material, thereby significantly improving overall battery performance. Current main challenges facing all-solid-state battery technology include low lithium-ion conductivity, poor interfacial contact, and interfacial impedance issues caused by cracking during charge-discharge cycles.

[0003] Despite the significant safety improvements offered by solid-state electrolytes, they still face a major technical bottleneck in practical applications – interfacial impedance. This problem manifests itself in several ways: 1. High initial interfacial impedance: Because the positive electrode, solid electrolyte, and negative electrode are all solid materials, direct contact between them is not as easy as in liquid electrolytes to form a good conductive path, resulting in a high initial interfacial impedance. 2. Poor interfacial bonding performance: The contact surfaces between solid materials are often not as smooth as those in liquid electrolytes, making it difficult to ensure an ideal bonding state between the layers during battery manufacturing. 3. Interfacial changes during charge and discharge: During battery charge and discharge, the positive and negative electrode materials undergo volume changes (expansion or contraction), which further deteriorates the already less-than-ideal interfacial bonding, thus increasing the interfacial impedance.

[0004] This invention proposes a novel battery structure design that constructs a three-dimensional interlaced lithium-ion conduction network by introducing a low-viscosity thermoplasticizer and electrostatic dry spraying technology. This significantly improves lithium-ion migration efficiency and enhances the interfacial stability between the electrode and the solid electrolyte, thereby reducing the interfacial impedance of the sulfide solid battery to achieve better capacity retention, longer cycle life, and better safety performance. Summary of the Invention

[0005] The purpose of this invention is to address the problems existing in the prior art by providing an all-solid-state battery cell with a three-dimensional interlaced lithium-ion conduction network, its preparation method, and its applications. This invention constructs a three-dimensional interlaced lithium-ion conduction network by introducing a low-viscosity thermoplasticizer (TPA, etc.) and electrostatic dry spraying technology. Specifically, positive electrode, sulfide electrolyte, and negative electrode powders are mixed according to different particle sizes and ratios, and then electrostatically sprayed and integrally pressed to obtain an all-solid-state sulfide battery cell with a three-dimensional interlaced lithium-ion conduction network. Further assembly yields an all-solid-state sulfide battery.

[0006] The objective of this invention can be achieved through the following methods:

[0007] This invention provides an all-solid-state battery cell with a three-dimensional interlaced lithium-ion conduction network. The all-solid-state battery cell is a pressed layered powder cell. The layered powder cell includes an electrolyte powder layer and a positive electrode powder layer and a negative electrode powder layer respectively disposed on both sides of the electrolyte powder layer.

[0008] The positive electrode powder layer includes a composite positive electrode powder C layer, a composite positive electrode powder B layer, and a composite positive electrode powder A layer, which are arranged sequentially from the inside to the outside on one side of the electrolyte powder layer; wherein, the particle size of each component in the composite positive electrode powder A is 10μm≤D≤15μm, the particle size of each component in the composite positive electrode powder B is 5μm≤D≤10μm, and the particle size of each component in the composite positive electrode powder C is Dmax≤5μm;

[0009] The negative electrode powder layer includes a composite negative electrode powder layer D and a composite negative electrode powder layer E, which are arranged sequentially from the inside to the outside on the other side of the electrolyte powder layer; wherein, the particle size of each component in the composite negative electrode powder D is 5μm≤Dmax, and the particle size of each component in the composite negative electrode powder E is 5μm≤D≤10μm.

[0010] The particle size Dmax of the electrolyte powder is ≤5μm.

[0011] The structural composition and particle size range of the battery cell in this invention are shown in the table below:

[0012] This invention utilizes gradient changes in particle size and electrolyte content within the positive and negative electrode powder layers to form a three-dimensional interlaced lithium-ion conduction network. Through electrostatic spraying and integrated pressing, an all-solid-state battery cell is obtained. The positive electrode powder consists of three different particle sizes (A, B, and C) in corresponding proportions. The negative electrode powder consists of two different particle sizes (D and E) in corresponding proportions. During the spraying preparation of the layered powder cell, electrostatic spraying is performed sequentially in the following order: composite positive electrode powder A, composite positive electrode powder B, composite positive electrode powder C, electrolyte powder, composite negative electrode powder D, and composite negative electrode powder E, or vice versa. The spraying method is electrostatic spraying. Preferably, the positive electrode powder layer is sprayed first, followed by the electrolyte powder layer, and finally the negative electrode powder layer. The layered powder cell is pressed using a warm isostatic pressing method; the temperature during warm isostatic pressing is 120-180℃, and the pressure is 100-300 MPa.

[0013] In one embodiment of the present invention, the particle size of the composite positive electrode powder C is preferably 2μm≤D≤5μm, the particle size of the composite negative electrode powder D layer is preferably 2μm≤D≤5μm, and the particle size of the electrolyte powder is preferably 3μm≤D≤5μm.

[0014] As one embodiment of the present invention, the particle size difference between composite positive electrode powder A and composite positive electrode powder B, composite positive electrode powder B and composite positive electrode powder C, and composite negative electrode powder D and composite negative electrode powder E is 2-5 μm.

[0015] In one embodiment of the present invention, the particle size difference between the electrolyte powder and the composite positive electrode powder C, and between the electrolyte powder and the composite negative electrode powder D, is 0-2 μm.

[0016] As one embodiment of the present invention, the positive electrode powder includes a positive electrode material, a sulfide electrolyte, a conductive agent, a thermoplastic material, and a binder.

[0017] As one embodiment of the present invention, the proportions of each component in the positive electrode powder by mass are as follows:

[0018] Composite cathode powder A comprises: 75-85 parts cathode material, 10-20 parts sulfide electrolyte, 1-3 parts conductive agent, 0.8-1.2 parts binder, and 2-4 parts thermoplastic material;

[0019] Composite cathode powder B comprises: 45-55 parts cathode material, 40-50 parts sulfide electrolyte, 1-3 parts conductive agent, 0.8-1.2 parts binder, and 2-4 parts thermoplastic material;

[0020] The composite cathode powder C comprises: 15-25 parts cathode material, 70-80 parts sulfide electrolyte, 1-3 parts conductive agent, 0.8-1.2 parts binder, and 2-4 parts thermoplastic material.

[0021] As one embodiment of the present invention, the composite negative electrode includes a negative electrode material, silicon oxide, sulfide electrolyte, conductive agent, binder and thermoplastic material.

[0022] The composite negative electrode powder D comprises the following components in parts by weight: 25-35 parts of negative electrode material, 55-65 parts of sulfide electrolyte, 5-10 parts of silicon oxide, 1-3 parts of conductive agent, 0.8-1.2 parts of binder, and 1-3 parts of thermoplastic material.

[0023] The composite negative electrode powder E comprises the following components in parts by weight: 55-65% negative electrode material, 10-20 parts sulfide electrolyte, 15-25 parts silicon oxide, 1-3 parts conductive agent, 0.8-1.2 parts binder, and 1-3 parts thermoplastic material.

[0024] Preferably, the cathode material in the cathode powder includes one or more of the following: nickel-cobalt-manganese ternary cathode material, lithium-rich manganese-based cathode material, and lithium iron phosphate cathode material.

[0025] Preferably, the negative electrode material in the negative electrode powder is graphite.

[0026] Preferably, the sulfide electrolyte in the electrolyte powder, positive electrode powder, and negative electrode powder includes one of LPSCl (silver-germanium sulfide electrolyte) and LGPS (lithium-germanium-phosphorus-sulfur electrolyte). Preferably, they are the same electrolyte.

[0027] Preferably, the conductive agent in the positive electrode powder and the negative electrode powder is VGCF (carbon nanofiber).

[0028] Preferably, the binder in the positive electrode powder and negative electrode powder is one or more of PTFE (polytetrafluoroethylene) and PVDF (polyvinylidene fluoride). The binder is preferably 0.4-0.6 parts of PTFE and 0.4-0.6 parts of PVDF.

[0029] Preferably, the thermoplastic material in the positive electrode powder and negative electrode powder includes one of polyamide, polyethylene, polypropylene, polyvinyl chloride, polystyrene, and polyoxymethylene. The thermoplastic material is a low-viscosity thermoplasticizer, preferably polyamide (TPA), whose molecular structure is as follows:

[0030] Thermoplastic materials can enhance the mechanical properties of solid electrolytes. Solid electrolytes are relatively brittle, while thermoplastic materials can serve as a flexible matrix, improving the electrolyte's flexibility and impact resistance, preventing breakage during battery assembly or use. Secondly, they help improve the interfacial compatibility between the electrolyte and electrodes. This allows for better contact between the solid electrolyte and electrode materials, reducing interfacial resistance and improving the battery's electrochemical performance, such as ionic conductivity.

[0031] In one embodiment of the present invention, the thickness of the positive electrode powder layer is 75-90 μm, the thickness of the electrolyte powder layer is 45-60 μm, and the thickness of the negative electrode powder layer is 75-90 μm. Specifically, the thickness of the composite positive electrode powder layer A is 25-30 μm, the thickness of the composite positive electrode powder layer B is 25-30 μm, and the thickness of the composite positive electrode powder layer C is 25-30 μm. The thickness of the composite negative electrode powder layer D is 37.5-45 μm, and the thickness of the composite negative electrode powder layer E is 37.5-45 μm.

[0032] The present invention also provides a method for preparing the all-solid-state battery cell, comprising the following steps:

[0033] S1. According to the structure of the layered powder cell, the interlayer powder layer is sprayed sequentially to obtain the layered powder cell.

[0034] S2. Press the obtained layered powder cell to obtain the all-solid-state battery cell.

[0035] In one embodiment of the present invention, in step S1, the spraying method is electrostatic spraying. Preferably, the positive electrode powder layer is sprayed first, followed by the electrolyte powder layer, and finally the negative electrode powder layer.

[0036] In one embodiment of the present invention, in step S2, the pressing method is warm isostatic pressing. The temperature of warm isostatic pressing is 120-180℃, and the pressure is 100-300MPa, preferably 130-200MPa. The pressing direction is perpendicular to the direction of the powder layer.

[0037] The resulting all-solid-state battery cell comprises, in sequence, a composite positive electrode layer, an electrolyte layer, and a composite negative electrode layer. There are no obvious interface boundaries between the composite positive electrode and the electrolyte, or between the electrolyte and the composite negative electrode, which reduces the impact of interface resistance on the cell.

[0038] This invention also provides an application of an all-solid-state battery cell in the fabrication of all-solid-state batteries. Specifically, the all-solid-state battery cell is subjected to tab welding and encapsulation to obtain a finished all-solid-state battery with a three-dimensional interlaced lithium-ion conduction network.

[0039] The positive electrode powder of the present invention is uniformly electrostatically sprayed into a mold in sequence A, B, and C; then a layer of sulfide electrolyte is sprayed onto the composite positive electrode layer; subsequently, the uniformly mixed composite negative electrode powder is uniformly electrostatically sprayed onto the surface of the electrolyte layer in sequence D and E; the powder is integrally pressed by warm isostatic pressing to obtain a three-dimensional interlaced lithium-ion conduction network all-solid-state cell, which can be further used in all-solid-state batteries.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] (1) The proportion of sulfide electrolyte in the composite positive electrode layers A, B, and C gradually increases, and the proportion of sulfide electrolyte in the composite negative electrode layers D and E gradually increases, so that lithium ions are interleaved in the composite positive and negative electrode layers, forming a three-dimensional interleaved lithium ion conduction network, which makes lithium ion insertion / extraction more convenient and faster, thereby reducing the resistance of the battery.

[0042] (2) By adopting the above technical solution, the composite positive electrode electrostatic powder spraying, electrolyte powder spraying and composite negative electrode powder spraying are configured step by step according to the above particle size and composition ratio. When the composite positive electrode layer, electrolyte layer and composite negative electrode layer are sprayed step by step, the electrolyte powder is better integrated with the composite negative electrode layer and composite positive electrode layer to form a three-dimensional interlaced lithium ion conduction network, thereby strengthening the bonding between the two sides of the electrolyte layer and the composite positive electrode layer and the composite negative electrode layer respectively, while weakening the interface effect to reduce the interface impedance. Detailed Implementation

[0043] The present invention will now be described in detail with reference to specific embodiments. The following examples are implemented under the premise of the technical solution of the present invention, providing detailed implementation methods and specific operating procedures, which will help those skilled in the art to further understand the present invention. It should be noted that the scope of protection of the present invention is not limited to the following embodiments; any adjustments and improvements made under the concept of the present invention are all within the scope of protection of the present invention.

[0044] Examples 1-3

[0045] Fabrication of an all-solid-state battery with a three-dimensional interlaced lithium-ion conduction network, comprising an integrated spray-coated composite positive electrode layer, an electrolyte layer, and a composite negative electrode layer.

[0046] (1) The composite positive electrode layer is composed of positive electrode powder and LPSCl, VGCF, TPA, PTFE and PVDF.

[0047] The composite cathode is composed of three different particle sizes, A, B, and C, in corresponding proportions. The particle size of composite cathode A is Dmax≤15μm, the particle size of composite cathode B is Dmax≤10μm, and the particle size of composite cathode C is Dmax≤5μm.

[0048] The composite cathode A consists of 80% cathode material, 14% LPSCl, 2% VGCF, 0.5% PTFE, 0.5% PVDF, and 3% TPA.

[0049] The composite cathode B is composed of 50% cathode material, 44% LPSCl, 2% VGCF, 0.5% PTFE, 0.5% PVDF, and 3% TPA.

[0050] The composite cathode C consists of 20% cathode material, 74% LPSCl, 2% VGCF, 0.5% PTFE, 0.5% PVDF, and 3% TPA.

[0051] (2) The electrolyte layer is composed of LPSCl with a particle size Dmax≤5μm.

[0052] (3) The composite negative electrode layer is composed of graphite, silicon oxide, LPSCl, VGCF, PTFE, PVDF and TPA;

[0053] The composite negative electrode is composed of two different particle sizes, D and E, and their corresponding ratios. The particle size of composite negative electrode D is Dmax≤10μm, and the particle size of composite negative electrode E is Dmax≤5μm.

[0054] The composite negative electrode D is composed of 30% graphite, 60% LPSCl, 7% silicon oxide, 0.5% PTFE, 0.5% PVDF, and 2% TPA.

[0055] The composite negative electrode E is composed of 62% graphite, 15% LPSCl, 20% silicon oxide, 0.5% PTFE, 0.5% PVDF, and 2% TPA.

[0056] (4) The preparation method of the above-mentioned three-dimensional interlaced lithium-ion conduction network all-solid-state battery cell includes the following steps:

[0057] The uniformly mixed composite positive electrode powder was electrostatically sprayed onto the mold in sequence A, B, and C (total thickness of the positive electrode powder layer is 80 μm, and the thickness of each layer is the same); then a layer of sulfide electrolyte (thickness 50 μm) was sprayed onto the composite positive electrode layer; subsequently, the uniformly mixed composite negative electrode powder was electrostatically sprayed onto the surface of the electrolyte layer in sequence D and E (total thickness of the negative electrode powder layer is 80 μm, and the thickness of each layer is the same); the powder was integrally pressed using warm isostatic pressing (temperature is 150℃, pressure is 150 MPa) to obtain a three-dimensional interlaced lithium-ion conduction network all-solid-state battery cell;

[0058] (5) The above-mentioned cells are welded with tabs and packaged with aluminum-plastic film to obtain a finished three-dimensional interlaced lithium-ion conduction network all-solid-state battery.

[0059] The specific implementation methods are shown in the table below:

[0060] Table 1 Specific parameters of Examples 1-3

[0061] Examples 4-6

[0062] The difference between Examples 4-6 and Examples 1-3 is that their sulfide electrolyte is LGPS, and the isostatic pressure treatment temperature is 150℃ and the pressure is 150MPa.

[0063] The performance tests of the all-solid-state batteries with a three-dimensional interlaced lithium-ion conduction network obtained in Examples 1-6 are shown in Table 2 below.

[0064] The tests for all-solid-state lithium batteries are as follows:

[0065] The all-solid-state lithium battery was placed under a constant temperature condition of 25°C and charged at a constant current value of 0.1C (10h, calculated based on the mass of the positive electrode active material) relative to the theoretical capacity of the all-solid-state lithium battery, ending the charging process at a voltage of 4.3V. Then, it was discharged at the same 0.1C rate, ending the discharge at a voltage of 2.5V. The coulombic efficiency and discharge capacity of the battery were obtained in this way. Starting from the second cycle, 100 charge-discharge cycles were performed at 0.2C. The greater the discharge capacity retention after 300 cycles, the better the cycle performance. Table 2 shows the cycle performance test results of the three-dimensional interlaced lithium-ion conduction network all-solid-state batteries obtained in Examples 1-6.

[0066] Table 2 Performance of Examples 1-6

[0067] Comparative Examples 1-6

[0068] The difference between Comparative Examples 1-6 and Examples 1-6 is that only an equal amount of composite positive electrode A and an equal amount of composite negative electrode E are selected for the composite positive electrode. The test results are shown in Table 3.

[0069] Table 3 Performance of Comparative Examples 1-6

[0070] Comparing the test results of Examples 1-6 and the comparative examples, it can be seen that the all-solid-state battery with the three-dimensional interlaced lithium-ion conduction network formed by the technical solution of the present invention has superior performance compared with the battery formed by pressing a single-layer composite positive electrode A and a composite negative electrode E. This is beneficial to the internal lithium-ion transport and internal resistance reduction of the all-solid-state battery with the three-dimensional interlaced lithium-ion conduction network of the present application.

[0071] Comparative Example 7

[0072] The difference between Comparative Example 7 and Example 1 is that the pressure of the isostatic pressure is 150 MPa and the temperature is 25°C.

[0073] Comparative Example 8

[0074] The difference between Comparative Example 8 and Example 1 is that the pressure of the isostatic pressure is 100 MPa and the temperature is 150 °C.

[0075] The results for Comparative Examples 7-8 are shown in Table 4:

[0076] Table 4. Test results for comparative examples 7-8

[0077] The results of Comparative Example 7 and Example 1 show that isostatic temperature has a significant impact on battery performance; the performance of the cell without temperature treatment is worse than that with temperature treatment. This is because applying temperature helps the TPA solidify the cell structure, preventing the positive and negative electrodes from expanding and rebounding during charging and discharging.

[0078] The results of Comparative Example 8 and Example 1 show that the performance of the battery cell is worse when a small pressure is applied than when a large pressure is applied. This is because applying a large pressure helps to compact the battery cell structure, preventing structural collapse during charging and discharging.

[0079] Comparative Example 9 (Comparison with constant particle size)

[0080] The difference between Comparative Example 9 and Example 1 is that the compositions of A, B, and C remain unchanged, and the particle size is 5 μm.

[0081] Comparative Example 9 used less cathode material and achieved a similar effect to Comparative Example 1 by setting a gradient in composition. Example 1, which further sets a particle size gradient, achieved even better results.

[0082] Comparative Example 10 (Comparison with constant particle size)

[0083] The difference between Comparative Example 10 and Example 1 is that the compositions of D and E remain unchanged, and the particle size of D and E is 5 μm.

[0084] Comparative Example 11 (Comparison with unchanged composition)

[0085] The difference between Comparative Example 11 and Example 1 is that the composite positive electrodes A, B, and C each contain the following composition: 50% positive electrode material, 44% LPSCl, 2% VGCF, 0.5% PTFE, 0.5% PVDF, and 3% TPA; and the composite negative electrodes D and E each contain the following composition: 30% graphite, 60% LPSCl, 7% silicon oxide, 0.5% PTFE, 0.5% PVDF, and 2% TPA.

[0086] Comparative Example 12 (Comparison of Preparation Methods)

[0087] The difference between Comparative Example 12 and Example 1 is that the positive electrode powder, electrolyte powder, and negative electrode powder are sprayed and pressed respectively to obtain a composite positive electrode layer, an electrolyte layer, and a composite negative electrode layer, which are then assembled to obtain a battery cell.

[0088] Table 5. Test results for comparative examples 9-12

[0089] Comparing the results of Examples 9 and 10 with Example 1, it can be seen that the particle sizes of A, B, and C are all Dmax≤5μm, lacking a particle size distribution gradient, and their performance is poor. Therefore, the present invention's scheme constructs a three-dimensional staggered lithium-ion conduction network with a particle size distribution gradient, which improves battery performance.

[0090] Comparative results from Example 11 and Example 1 show that the particle sizes of D and E are both Dmax≤5μm, exhibiting no particle size distribution gradient, resulting in poor performance. Therefore, the present invention's scheme, which constructs a three-dimensional staggered lithium-ion conduction network with a particle size distribution gradient, improves battery performance.

[0091] Comparative Example 12 and Example 1 show that the finished battery cell produced by pressing only positive electrode, electrolyte, and negative electrode powder has poor performance. This is because the absence of electrolyte, thermoplasticizer, and conductive agent in the positive and negative electrode materials leads to poor ion and electron conduction in the battery cell. The absence of thermoplasticizer causes powder to fall off and the structure to collapse during the pressing process, resulting in poor performance.

[0092] The above specific embodiments are merely explanations of the present invention and are not intended to limit the present invention. After reading this specification, those skilled in the art can make modifications to these embodiments without contributing any inventive step, but as long as they are within the scope of the claims of the present invention, they are protected by patent law.

Claims

1. A solid-state battery cell with a three-dimensional interlaced lithium-ion conduction network, characterized in that, The all-solid-state battery cell is a pressed layered powder cell; the layered powder cell includes an electrolyte powder layer, and a positive electrode powder layer and a negative electrode powder layer respectively disposed on both sides of the electrolyte powder layer; The positive electrode powder layer includes a composite positive electrode powder C layer, a composite positive electrode powder B layer, and a composite positive electrode powder A layer, which are arranged sequentially from the inside to the outside on one side of the electrolyte powder layer; wherein, the particle size of each component in the composite positive electrode powder A is 10μm≤D≤15μm, the particle size of each component in the composite positive electrode powder B is 5μm≤D≤10μm, and the particle size of each component in the composite positive electrode powder C is Dmax≤5μm; The negative electrode powder layer includes a composite negative electrode powder layer D and a composite negative electrode powder layer E, which are arranged sequentially from the inside to the outside on the other side of the electrolyte powder layer; wherein, the particle size of each component in the composite negative electrode powder D is Dmax≤5μm, and the particle size of each component in the composite negative electrode powder E is 5μm≤D≤10μm. The particle size Dmax of the electrolyte powder is ≤5μm.

2. The all-solid-state battery cell according to claim 1, characterized in that, The particle size difference between composite positive electrode powder A and composite positive electrode powder B, composite positive electrode powder B and composite positive electrode powder C, and composite negative electrode powder D and composite negative electrode powder E is 2-5 μm. And / or, the particle size difference between the electrolyte powder and the composite positive electrode powder C, and between the electrolyte powder and the composite negative electrode powder D, is 0-2 μm.

3. The all-solid-state battery cell according to claim 1, characterized in that, Positive electrode powder includes positive electrode material, sulfide electrolyte, conductive agent, thermoplastic material, and binder.

4. The all-solid-state battery cell according to claim 3, characterized in that, The components in the positive electrode powder, by mass, are as follows: Composite cathode powder A comprises: 75-85 parts cathode material, 10-20 parts sulfide electrolyte, 1-3 parts conductive agent, 0.8-1.2 parts binder, and 2-4 parts thermoplastic material; Composite cathode powder B comprises: 45-55 parts cathode material, 40-50 parts sulfide electrolyte, 1-3 parts conductive agent, 0.8-1.2 parts binder, and 2-4 parts thermoplastic material; The composite cathode powder C comprises: 15-25 parts cathode material, 70-80 parts sulfide electrolyte, 1-3 parts conductive agent, 0.8-1.2 parts binder, and 2-4 parts thermoplastic material.

5. The all-solid-state battery cell according to claim 1, characterized in that, The negative electrode powder includes negative electrode material, silicon dioxide, sulfide electrolyte, conductive agent, thermoplastic material, and binder.

6. The all-solid-state battery cell according to claim 5, characterized in that, The proportions of each component in the negative electrode powder by mass are as follows: The composite negative electrode powder D comprises the following components in parts by weight: 25-35 parts of negative electrode material, 55-65 parts of sulfide electrolyte, 5-10 parts of silicon oxide, 1-3 parts of conductive agent, 0.8-1.2 parts of binder, and 1-3 parts of thermoplastic material. The composite negative electrode powder E comprises the following components in parts by weight: 55-65 parts of negative electrode material, 10-20 parts of sulfide electrolyte, 15-25 parts of silicon oxide, 1-3 parts of conductive agent, 0.8-1.2 parts of binder, and 1-3 parts of thermoplastic material.

7. The all-solid-state battery cell according to claim 1, characterized in that, The cathode material in the cathode powder includes one or more of the following: nickel-cobalt-manganese ternary cathode material, lithium-rich manganese-based cathode material, and lithium iron phosphate cathode material; And / or, the negative electrode material in the negative electrode powder is graphite; And / or, the sulfide electrolytes in the electrolyte powder, positive electrode powder, and negative electrode powder include one of LPSCl and LGPS; And / or, the conductive agent in the positive electrode powder and negative electrode powder is VGCF; And / or, the binder in the positive electrode powder and negative electrode powder is one or more of PTFE and PVDF; And / or, the thermoplastic material in the positive electrode powder and negative electrode powder includes one of polyamide, polyethylene, polypropylene, polyvinyl chloride, polystyrene, and polyoxymethylene.

8. The all-solid-state battery cell according to claim 1, characterized in that, The thickness of the positive electrode powder layer is 75-90 μm, the thickness of the electrolyte powder layer is 45-60 μm, and the thickness of the negative electrode powder layer is 75-90 μm. And / or, the thickness of the composite cathode powder A layer is 25-30 μm, the thickness of the composite cathode powder B layer is 25-30 μm, and the thickness of the composite cathode powder C layer is 25-30 μm; And / or, the thickness of the composite negative electrode powder D layer is 37.5-45 μm, and the thickness of the composite negative electrode powder E layer is 37.5-45 μm.

9. A method for preparing an all-solid-state battery cell as described in claim 1, characterized in that, Includes the following steps: S1. According to the structure of the layered powder cell, the interlayer powder layer is sprayed sequentially to obtain the layered powder cell. S2. Press the obtained layered powder cell to obtain the all-solid-state battery cell.

10. The application of the all-solid-state battery cell as described in claim 1 in the preparation of all-solid-state batteries.

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