Buffer material for solid-state battery or battery module as well as preparation method and application of buffer material

Abstract

The invention provides a buffer material for a solid-state battery or a battery module as well as a preparation method and application of the buffer material. The buffer material comprises the following raw materials: silicone rubber, a reinforcing material, aramid fibers and a vulcanizing agent. According to the invention, through the synergistic effect of the silicone rubber, the reinforcing material and the aramid fiber in the raw materials, the compression stress of the buffer material is greatly improved, so that the problem of volume expansion of a battery cell of a solid-state battery or a solid-state battery module can be effectively solved, and the safety and the electrochemical performance of the battery are improved.

Description

Technical Field

[0001] This invention belongs to the field of solid-state battery technology, and relates to a buffer material for solid-state batteries or battery modules, its preparation method and application. Background Technology

[0002] Currently, with the widespread use of new energy electric vehicles, the safety and reliability of automotive batteries are receiving increasing attention. As the core component of the entire new energy vehicle, the environmental sealing and shock absorption components of the battery are particularly important. The power battery pack of an electric vehicle typically consists of multiple cells. When a cell is overcharged or overheats, its volume expands. To avoid hard contact between cells, buffer materials need to be added between them to absorb this volume expansion. Furthermore, elastic buffer materials are also required for shock absorption and drop protection of the cells.

[0003] Currently, elastic cushioning materials include foam, polymer layers, or silicone. For example, CN116826324A discloses a cushioning pad that is directly adhered to a bare battery cell. This pad replenishes the battery with electrolyte through compressible foam and provides space for cell expansion, improving the battery's cycle performance. Another example is CN116826324A, which discloses a cushioning pad, battery cell, battery, and electrical device for mounting on a bare battery cell. It includes an adhesive layer and a slow-release layer disposed on one side of the adhesive layer. The slow-release layer is made of porous compressible foam and a slow-release agent filled within the porous compressible foam. The adhesive layer is made of at least one of colloidal silicone, sodium silicate, and aluminum phosphate. Yet another example is CN212161908U, which discloses a safety protection foam structure for use between battery cells. This structure includes a foam layer for cushioning, heat-insulating silicone layers disposed on both outer surfaces of the foam layer, and a glass fiber layer disposed on the outer surface of the heat-insulating silicone layer.

[0004] The buffer materials in the aforementioned existing technologies can only solve the cell expansion problem of liquid lithium-ion batteries; they cannot solve the problem of solid-state lithium-ion batteries, where cell volume expansion is more pronounced. Because solid-state batteries use solid electrolytes, the cell volume expansion is more severe during charging and discharging, requiring buffer materials with higher compressibility to solve this problem.

[0005] Therefore, how to effectively solve the problem of cell volume expansion in solid-state batteries is an urgent technical issue that needs to be addressed. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a buffer material for solid-state batteries or battery modules, its preparation method, and its applications. In this invention, the synergistic effect of silicone rubber, reinforcing materials, and aramid fibers in the raw materials significantly enhances the compressive stress of the buffer material, thereby effectively solving the volume expansion problem of solid-state battery cells or solid-state battery modules, and improving battery safety and electrochemical performance.

[0007] To achieve this objective, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides a buffer material for solid-state batteries or battery modules, wherein the raw materials of the buffer material include: silicone rubber, reinforcing material, aramid fiber and vulcanizing agent.

[0009] It should be noted that the silicone rubber in this invention is a raw rubber material that has not undergone any cross-linking.

[0010] The buffer material provided by this invention combines silicone rubber, reinforcing materials, and aramid fibers in a synergistic manner. Under the cross-linking effect of a vulcanizing agent, a buffer material with excellent compressive stress and hardness is obtained. When used in solid-state batteries or solid-state battery modules, it can effectively solve the problem of cell volume expansion and improve battery safety and electrochemical performance.

[0011] In this invention, silicone rubber, reinforcing materials, aramid fibers, and vulcanizing agents are all indispensable. Without any one of these conditions, the compressive stress of the buffer material cannot be significantly increased, thus preventing it from playing a role in solid-state batteries or solid-state battery modules.

[0012] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. The technical objectives and beneficial effects of the present invention can be better achieved and realized through the following preferred technical solutions.

[0013] Preferably, the raw materials of the cushioning material, by weight, include:

[0014] 100 parts of silicone rubber

[0015] 20 to 70 parts of reinforcing material

[0016] 0.1 to 10 parts of aramid fiber

[0017] Vulcanizing agent: 0.1 to 6 parts.

[0018] For example, the weight percentage of the reinforcing material can be 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, or 70 parts, etc.; the weight percentage of the aramid fiber can be 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 parts, etc.; the weight percentage of the sulfide can be 0.1, 0.5, 1, 2, 3, 4, 5, or 6 parts, etc., but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0019] In this invention, by adjusting the weight range of silicone rubber, reinforcing material, aramid fiber and vulcanizing agent, it is more beneficial to improve the compressive stress of the buffer material.

[0020] Preferably, the silicone rubber comprises vinyl silicone rubber.

[0021] It should be noted that the types of silicone rubber that can be used to prepare cushioning materials in this invention are all applicable to this invention; therefore, no special limitations are made on the specific model and type of vinyl silicone rubber selected, and those skilled in the art can make adaptive selections and adjustments according to actual needs.

[0022] For example, the vinyl silicone rubber includes, but is not limited to, methyl vinyl silicone rubber and / or methyl phenyl vinyl silicone rubber.

[0023] Preferably, the average molecular weight of the vinyl silicone rubber is 300,000 to 600,000, such as 300,000, 330,000, 350,000, 380,000, 400,000, 430,000, 450,000, 480,000, 500,000, 530,000, 550,000, 580,000 or 600,000, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0024] Preferably, in the vinyl silicone rubber, the mass percentage of vinyl groups is 0.02% to 5%, such as 0.02%, 0.05%, 0.1%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, or 5%, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0025] In this invention, the vinyl silicone rubber is selected from materials with an average molecular weight of 300,000 to 600,000 and / or a mass percentage of vinyl groups of 0.02% to 5%, which can yield a cushioning material with superior performance.

[0026] Preferably, the reinforcing material comprises fumed silica.

[0027] In this invention, fumed silica is used as a reinforcing material, which works synergistically with silicone rubber and aramid fiber. This is more conducive to generating greater compressive stress under 25% compression conditions, resulting in tighter contact between solid-state battery cells and more stable internal contact within the solid-state battery.

[0028] Preferably, the specific surface area of ​​the fumed silica is 150 m². 2 / g~400m 2 / g, for example, 150m 2 / g、175m 2 / g、200m 2 / g、225m 2 / g、250m 2 / g、275m 2 / g、300m 2 / g、320m 2 / g, 350m 2 / g、375m 2 / g or 400m 2 / g, etc., but not limited to the listed values; other unlisted values ​​within this range also apply.

[0029] In this invention, a specific surface area of ​​150 m² is selected. 2 / g~400m 2 Using fumed silica at a concentration of / g as a reinforcing material can better exert its reinforcing effect and improve the performance of silicone rubber. If the specific surface area of ​​the fumed silica is too small, that is, the particle size of the silica is too large, it is not conducive to the uniform mixing of silicone rubber and silica, and the performance of silicone rubber will deteriorate. If the specific surface area of ​​the silica is too large, that is, the particle size of the silica is too small, the silica is prone to agglomeration, and the performance of silicone rubber will also deteriorate.

[0030] Preferably, the length of the aramid fiber is 1mm to 10mm, such as 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm or 10mm, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0031] Preferably, the diameter of the aramid fiber monofilament is 1μm to 20μm, such as 1μm, 2μm, 3μm, 4μm, 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, 11μm, 12μm, 13μm, 14μm, 15μm, 16μm, 17μm, 18μm, 19μm or 20μm, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0032] Preferably, the vulcanizing agent comprises a bis(2,4)-tetrachlorovulcanizing agent.

[0033] In this invention, the vulcanizing agent plays a role in vulcanization and crosslinking. In addition to the aforementioned bis(2,4)-2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane (bis(2,5-dimethyl- ...

[0034] Preferably, the raw materials of the cushioning material further include structure control agents and / or auxiliary materials.

[0035] The raw materials of the buffer material provided by the present invention may also include additional structure control agents to prevent the rubber from hardening, viscosity increase and mechanical property decrease due to the interaction of hydroxyl groups on the surface of the reinforcing material. By passivating the active hydroxyl groups on the filler surface, the formation of a three-dimensional network structure is prevented, thereby maintaining the processing performance of silicone rubber. Other auxiliary materials with other functions may also be added. Those skilled in the art can make adaptive selections and adjustments according to actual needs.

[0036] Preferably, the raw materials of the cushioning material, by weight, include:

[0037] 100 parts of silicone rubber

[0038] 20 to 70 parts of reinforcing material

[0039] 0.1 to 10 parts of aramid fiber

[0040] Vulcanizing agent: 0.1 to 6 parts;

[0041] 1 to 2 parts of structure control agent

[0042] 5 to 30 servings of supplementary materials.

[0043] For example, the weight percentage of the reinforcing material can be 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, or 70 parts, etc.; the weight percentage of the aramid fiber can be 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 parts, etc.; the weight percentage of the sulfide can be 0.1, 0.5, 1, 2, 3, 4, 5, or 6 parts, etc.; the weight percentage of the structure control agent can be 1, 1.3, 1.5, 1.8, or 2 parts, etc.; and the weight percentage of the auxiliary material can be 5, 8, 10, 13, 15, 18, 20, 23, 25, 28, or 30 parts, etc.; however, it is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0044] Preferably, the viscosity of the structure control agent is 38 mm.2 / s~45mm 2 / s, for example, 38mm 2 / s, 39mm 2 / s, 40mm 2 / s, 41mm 2 / s, 42mm 2 / s, 43mm 2 / s, 44mm 2 / s or 45mm 2 / s, etc., but not limited to the listed values; other unlisted values ​​within this range also apply.

[0045] Preferably, the structure control agent comprises hydroxyl silicone oil.

[0046] More preferably, the mass percentage of hydroxyl groups in the hydroxyl silicone oil is 8% to 10%, such as 8%, 8.5%, 9%, 9.5%, or 10%, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0047] In this invention, a viscosity of 38 mm is selected. 2 / s~45mm 2 Hydroxyl silicone oil of / s acts as a structure control agent, better ensuring the processing performance of silicone rubber.

[0048] Preferably, the particle size of the auxiliary material is greater than 2000 mesh.

[0049] Preferably, the auxiliary material includes a flame retardant material, which includes any one or a combination of at least two of the following: silica powder, zinc borate, aluminum hydroxide, or magnesium hydroxide.

[0050] In a second aspect, the present invention provides a method for preparing a buffer material for a solid-state battery or battery module as described in the first aspect, the method comprising the following steps:

[0051] The buffer material for solid-state batteries is obtained by mixing silicone rubber, reinforcing materials, aramid fibers and vulcanizing agents, and then vulcanizing.

[0052] The preparation method provided by this invention is simple to operate, requires no additional complex processing, and is suitable for large-scale production and daily life.

[0053] Preferably, the mixed raw materials further include crosslinking agents and / or auxiliary materials.

[0054] Preferably, the vulcanization temperature is 100℃~200℃, such as 100℃, 110℃, 120℃, 130℃, 140℃, 150℃, 160℃, 170℃, 180℃, 190℃ or 200℃, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0055] Preferably, the vulcanization time is 10 to 60 minutes, such as 10 minutes, 15 minutes, 20 minutes, 25 minutes, 30 minutes, 35 minutes, 40 minutes, 45 minutes, 50 minutes, 55 minutes, or 60 minutes, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0056] In this invention, no special restrictions are placed on the preparation order of the raw materials; those skilled in the art can make adaptive selections and adjustments according to actual needs.

[0057] For example, to achieve a more uniform mixing, silicone rubber, fumed silica, and structure control agents (optionally added) can be mixed first and kneaded to obtain compound base rubber A; then aramid fibers and auxiliary materials (optionally added) can be added and kneaded again to obtain compound base rubber B; finally, a vulcanizing agent can be added and vulcanized to obtain the desired cushioning material.

[0058] Thirdly, the present invention provides a solid-state battery, the solid-state battery comprising a buffer material as described in the first aspect or a buffer material prepared by the preparation method described in the second aspect;

[0059] The buffer material is located on the surface of the solid-state battery cell.

[0060] Fourthly, the present invention also provides a solid-state battery module, the solid-state battery module comprising the buffer material as described in the first aspect or the buffer material prepared by the preparation method described in the second aspect;

[0061] The buffer material is located between the cells of the solid-state battery module in the form of a buffer layer.

[0062] The buffer material in this invention can be used in the cells of solid-state batteries or solid-state battery modules, and the specific application method of the buffer material is not limited. Any method of using the buffer material in solid-state batteries or solid-state battery modules that can be reasonably known by those skilled in the art is applicable to this invention.

[0063] Compared with the prior art, the present invention has the following beneficial effects:

[0064] The buffer material provided by this invention combines silicone rubber, reinforcing materials, and aramid fibers in a synergistic manner. Under the cross-linking effect of a vulcanizing agent, a buffer material with excellent compressive stress and hardness is obtained. When used in solid-state batteries or solid-state battery modules, it can effectively solve the problem of cell volume expansion and improve battery safety and electrochemical performance. Detailed Implementation

[0065] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0066] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this application; the terms “comprising” and “having” and any variations thereof in this application are intended to cover non-exclusive inclusion.

[0067] The sources of the raw materials used in the embodiments and comparative examples of this invention are as follows:

[0068] Methyl vinyl silicone rubber: raw rubber, Shandong Dayi Chemical Co., Ltd., DY-V110;

[0069] Bis(2,4)24 vulcanizing agent: CAS number 14643-87-9;

[0070] 2,4-Dichlorobenzoyl peroxide vulcanizing agent: CAS number 133-14-2;

[0071] Hydroxy silicone oil: Product brand: Dow Corning PMX-0930.

[0072] Example 1

[0073] This embodiment provides a buffer material for solid-state batteries or battery modules. The raw materials of the buffer material, by weight, are as follows:

[0074] 100 parts of methyl vinyl silicone rubber raw material

[0075] 70 parts of fumed silica

[0076] 5 parts aramid fiber

[0077] 3 parts of bis(2,4)-dichlorosulfurizing agent;

[0078] 1 part hydroxy silicone oil

[0079] 30 sets of auxiliary materials;

[0080] Among them, the specific surface area of ​​fumed silica is 300 m².2 / g; the length range of aramid fibers is 5~6mm, and the diameter of a single filament is 8~12μm; the auxiliary materials include zinc borate and aluminum hydroxide, and the mass ratio of zinc borate to aluminum hydroxide is 1:3.

[0081] The preparation method of the buffer material is as follows:

[0082] (1) Weigh the raw rubber and fumed silica according to the above formula, and add the raw rubber, fumed silica and hydroxyl silicone oil to the kneader and knead for 1 hour at room temperature of 25°C. During the kneading process, control the temperature to be less than 80°C to obtain the compound base rubber A.

[0083] (2) Weigh out appropriate amounts of aluminum hydroxide, zinc borate, aramid fiber and compound base rubber A according to the above formula and add them to the kneader at room temperature until all components are mixed evenly. Vacuum is applied and kept for 1 hour. Vacuum is then stopped to obtain compound rubber B.

[0084] (3) Mix the compound B with the 24-dichlorocuring agent on a two-roll mill and vulcanize it at 150°C for 40 minutes to obtain the buffer material.

[0085] Example 2

[0086] This embodiment provides a buffer material for solid-state batteries or battery modules. The raw materials of the buffer material, by weight, are as follows:

[0087] 100 parts of methyl vinyl silicone rubber raw material

[0088] 20 parts of fumed silica

[0089] 0.1 parts aramid fiber

[0090] 0.1 parts of bis(2,4)24 vulcanizing agent;

[0091] 1.5 parts hydroxy silicone oil

[0092] 5 sets of auxiliary materials;

[0093] Among them, the specific surface area of ​​fumed silica is 150 m². 2 / g; the length range of aramid fibers is 1~2mm, and the diameter of a single filament is 1~3μm; the auxiliary materials include zinc borate and aluminum hydroxide, and the mass ratio of zinc borate to aluminum hydroxide is 1:3.

[0094] The preparation method of the buffer material is as follows:

[0095] (1) Weigh the raw rubber and fumed silica according to the above formula, and add the raw rubber, fumed silica and hydroxyl silicone oil to the kneader and knead for 1 hour at room temperature of 25°C. During the kneading process, control the temperature to be less than 80°C to obtain the compound base rubber A.

[0096] (2) Weigh out appropriate amounts of aluminum hydroxide, zinc borate, aramid fiber and compound base rubber A according to the above formula and add them to the kneader at room temperature until all components are mixed evenly. Vacuum is applied and kept for 1 hour. Vacuum is then stopped to obtain compound rubber B.

[0097] (3) Mix the compound B with a 24-dichlorocuring agent on a two-roll mill and vulcanize it at 100°C for 40 minutes to obtain the buffer material.

[0098] Example 3

[0099] This embodiment provides a buffer material for solid-state batteries or battery modules. The raw materials of the buffer material, by weight, are as follows:

[0100] 100 parts of methyl vinyl silicone rubber raw material

[0101] 45 parts of fumed silica

[0102] 10 parts of aramid fiber

[0103] 6 parts of bis(2,4)-dichlorosulfurizing agent;

[0104] 2 parts hydroxy silicone oil

[0105] 20 sets of auxiliary materials;

[0106] Among them, the specific surface area of ​​fumed silica is 400 m². 2 / g; the length range of aramid fibers is 9~10mm, and the diameter of a single filament is 18~20μm; the auxiliary materials include zinc borate and aluminum hydroxide, and the mass ratio of zinc borate to aluminum hydroxide is 1:3.

[0107] The preparation method of the buffer material is as follows:

[0108] (1) Weigh the raw rubber and fumed silica according to the above formula, and add the raw rubber, fumed silica and hydroxyl silicone oil to the kneader and knead for 1 hour at room temperature of 25°C. During the kneading process, control the temperature to be less than 80°C to obtain the compound base rubber A.

[0109] (2) Weigh out appropriate amounts of aluminum hydroxide, zinc borate, aramid fiber and compound base rubber A according to the above formula and add them to the kneader at room temperature until all components are mixed evenly. Vacuum is applied and kept for 1 hour. Vacuum is then stopped to obtain compound rubber B.

[0110] (3) Mix the compound B with a 24-dichlorocuring agent on a two-roll mill and vulcanize it at 200°C for 40 minutes to obtain the buffer material.

[0111] Example 4

[0112] This embodiment provides a buffer material for solid-state batteries or battery modules. The raw materials of the buffer material, by weight, are as follows:

[0113] 100 parts of methyl vinyl silicone rubber raw material

[0114] 70 parts of fumed silica

[0115] 5 parts aramid fiber

[0116] 3 parts of 2,4-dichlorobenzoyl peroxide;

[0117] 1 part hydroxy silicone oil

[0118] 30 sets of auxiliary materials;

[0119] Among them, the specific surface area of ​​fumed silica is 300 m². 2 / g; the length range of aramid fibers is 5~6mm, and the diameter of a single filament is 8~12μm; the auxiliary materials include zinc borate, aluminum hydroxide and silica powder, and the mass ratio of zinc borate, aluminum hydroxide and silica powder is 1:3:1.

[0120] The preparation method of the buffer material is as follows:

[0121] (1) Weigh the raw rubber and fumed silica according to the above formula, and add the raw rubber, fumed silica and hydroxyl silicone oil to the kneader and knead for 1 hour at room temperature of 25°C. During the kneading process, control the temperature to be less than 80°C to obtain the compound base rubber A.

[0122] (2) Weigh out appropriate amounts of aluminum hydroxide, zinc borate, silica powder, aramid fiber and compound base rubber A according to the above formula and add them to the kneader at room temperature until all components are mixed evenly. Vacuum is drawn and kept for 1 hour. Vacuum is then stopped to obtain compound rubber B.

[0123] (3) Mix the compound B with the 24-dichlorocuring agent on a two-roll mill and vulcanize it at 150°C for 40 minutes to obtain the buffer material.

[0124] Example 5

[0125] The difference between this embodiment and Embodiment 1 is that this embodiment does not contain the crosslinking agent hydroxyl silicone oil and auxiliary materials.

[0126] The proportions of other raw materials, preparation methods and parameters are the same as in Example 1.

[0127] Example 6

[0128] The difference between this embodiment and Embodiment 1 is that the weight of fumed silica in this embodiment is 80 parts.

[0129] The proportions of other raw materials, preparation methods and parameters are the same as in Example 1.

[0130] Example 7

[0131] The difference between this embodiment and Embodiment 1 is that the weight of fumed silica in this embodiment is 10 parts.

[0132] The proportions of other raw materials, preparation methods and parameters are the same as in Example 1.

[0133] Example 8

[0134] The difference between this embodiment and Embodiment 1 is that the specific surface area of ​​the fumed silica in this embodiment is 100 m². 2 / g.

[0135] The proportions of other raw materials, preparation methods and parameters are the same as in Example 1.

[0136] Example 9

[0137] The difference between this embodiment and Embodiment 1 is that the specific surface area of ​​the fumed silica in this embodiment is 400 m². 2 / g.

[0138] The proportions of other raw materials, preparation methods and parameters are the same as in Example 1.

[0139] Example 10

[0140] The difference between this embodiment and Embodiment 1 is that the weight fraction of aramid fiber in this embodiment is 15 parts.

[0141] The proportions of other raw materials, preparation methods and parameters are the same as in Example 1.

[0142] Example 11

[0143] The difference between this embodiment and Embodiment 1 is that the length of the aramid fiber in this embodiment is 13~15mm.

[0144] The proportions of other raw materials, preparation methods and parameters are the same as in Example 1.

[0145] Example 12

[0146] The difference between this embodiment and Embodiment 1 is that the length range of the aramid fiber in this embodiment is <1mm.

[0147] The proportions of other raw materials, preparation methods and parameters are the same as in Example 1.

[0148] Example 13

[0149] The difference between this embodiment and Embodiment 1 is that the diameter of the aramid fiber monofilament in this embodiment is 23~25μm.

[0150] The proportions of other raw materials, preparation methods and parameters are the same as in Example 1.

[0151] Example 14

[0152] The difference between this embodiment and Embodiment 1 is that the diameter of the aramid fiber monofilament in this embodiment is 500nm~800nm.

[0153] The proportions of other raw materials, preparation methods and parameters are the same as in Example 1.

[0154] Comparative Example 1

[0155] The difference between this comparative example and Example 1 is that aramid fibers are replaced with carbon fibers in this comparative example.

[0156] The proportions of other raw materials, preparation methods and parameters are the same as in Example 1.

[0157] Comparative Example 2

[0158] The difference between this comparative example and Example 1 is that aramid fibers are replaced with glass fibers in this comparative example.

[0159] The proportions of other raw materials, preparation methods and parameters are the same as in Example 1.

[0160] Comparative Example 3

[0161] The difference between this comparative example and Example 1 is that this comparative example does not contain aramid fibers.

[0162] The proportions of other raw materials, preparation methods and parameters are the same as in Example 1.

[0163] Comparative Example 4

[0164] The difference between this comparative example and Example 1 is that this comparative example does not contain fumed silica.

[0165] The proportions of other raw materials, preparation methods and parameters are the same as in Example 1.

[0166] Comparative Example 5

[0167] The difference between this comparative example and Example 5 is that this comparative example does not contain aramid fibers.

[0168] The proportions of other raw materials, preparation methods and parameters are the same as in Example 5.

[0169] The buffer materials prepared in Examples 1-14 and Comparative Examples 1-5 were tested for hardness and compressive stress.

[0170] Hardness test (Shore hardness): Tested according to GB / T 531.1-2018 standard.

[0171] Compressive stress test: Tested according to GB / T 18242.2 standard.

[0172] The test results for the above tests are shown in Table 1:

[0173] Table 1

[0174] Hardness (°) 25% compressive stress (MPa) Example 1 85 15 Example 2 82 12 Example 3 85 13 Example 4 80 11 Example 5 Processing is difficult, and samples cannot be prepared. Processing is difficult, and samples cannot be prepared. Example 6 Processing is difficult, and samples cannot be prepared. Processing is difficult, and samples cannot be prepared. Example 7 75 9 Example 8 70 8 Example 9 The rubber compound is difficult to process, making it impossible to prepare samples. The rubber compound is difficult to process, making it impossible to prepare samples. Example 10 The rubber compound is difficult to process, making it impossible to prepare samples. The rubber compound is difficult to process, making it impossible to prepare samples. Example 11 The rubber compound is difficult to process, making it impossible to prepare samples. The rubber compound is difficult to process, making it impossible to prepare samples. Example 12 70 9 Example 13 75 9 Example 14 Agglomeration makes the rubber compound difficult to process and prevents sample preparation. Agglomeration makes the rubber compound difficult to process and prevents sample preparation. Comparative Example 1 75 7 Comparative Example 2 75 7 Comparative Example 3 70 6 Comparative Example 4 60 5 Comparative Example 5 75 10

[0175] In summary, the buffer material provided by this invention, in which silicone rubber, reinforcing materials and aramid fibers work synergistically, and under the cross-linking effect of a vulcanizing agent, a buffer material with excellent compressive stress and hardness is obtained; when used in solid-state batteries or solid-state battery modules, it can effectively solve the problem of cell volume expansion and improve battery safety and electrochemical performance.

[0176] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A buffer material for a solid-state battery or battery module, characterized by, The raw materials of the buffer material include: silicone rubber, reinforcing material, aramid fiber and vulcanizing agent.

2. The buffer material for a solid-state battery or a battery module according to claim 1, characterized by, The raw materials of the buffer material include, in parts by weight: Silicone rubber 100 parts Reinforcing material 20 parts to 70 parts Aramid fiber 0.1 part to 10 parts Vulcanizing agent 0.1 part to 6 parts.

3. The buffer material for a solid-state battery or a battery module according to claim 1, characterized by, The silicone rubber includes vinyl silicone rubber; The average molecular weight of the vinyl silicone rubber is 300,000 to 600,000; The mass fraction of vinyl groups in the vinyl silicone rubber is 0.02% to 5%.

4. The buffer material for a solid-state battery or a battery module according to claim 1, characterized by, The reinforcing material includes fumed silica; the fumed silica has a specific surface area of 150 m 2 / g~400 m 2 / g; And / or, the length of the aramid fiber is 1mm to 10mm; the diameter of the aramid fiber is 1μm to 20μm; And / or, the vulcanizing agent includes bis-ditetravulcanizing agent.

5. The buffer material for a solid-state battery or a battery module according to claim 1, characterized by, The raw materials of the buffer material further include structure control agent and / or auxiliary material.

6. The buffer material for a solid-state battery or a battery module according to claim 5, characterized by, The raw materials of the buffer material include, in parts by weight: Silicone rubber 100 parts Reinforcing material 20 parts to 70 parts Aramid fiber 0.1 part to 10 parts Vulcanizing agent 0.1 part to 6 parts Structure control agent 1 part to 2 parts Auxiliary material 5 parts to 30 parts and / or the viscosity of the structure control agent is 38 mm 2 / s~45mm 2 / s; And / or, the structure control agent includes hydroxyl silicone oil; And / or, the particle size of the auxiliary material is greater than 2000 mesh; And / or, the auxiliary material includes flame retardant material, and the flame retardant material includes any one or a combination of at least two of silicone powder, zinc borate, aluminum hydroxide or magnesium hydroxide.

7. A method of producing a buffer material for a solid-state battery or a battery module according to any one of claims 1 to 6, characterized in that, The preparation method includes the following steps: Mixing silicone rubber, reinforcing material, aramid fiber and vulcanizing agent, vulcanization treatment, to obtain the buffer material for solid-state battery.

8. The preparation method according to claim 7, characterized in that, The mixed raw materials further include crosslinking agent and / or auxiliary material; And / or, the temperature of the vulcanization treatment is 100℃ to 200℃, and the time of the vulcanization is 10min to 60min.

9. A solid state battery, characterized by The solid-state battery includes the buffer material according to any one of claims 1-6 or the buffer material prepared by the preparation method according to claim 7 or 8; The buffer material is located on the surface of the battery cell of the solid-state battery.

10. A solid state battery module, characterized by The solid-state battery module includes the buffer material according to any one of claims 1-6 or the buffer material prepared by the preparation method according to claim 7 or 8; The buffer material is in the form of a buffer layer between the battery cells of the solid-state battery module.