All-solid-state battery and preparation method and application thereof

Abstract

The embodiment of the invention provides an all-solid-state battery and a preparation method and application thereof, and relates to the technical field of batteries. The all-solid-state battery comprises at least two stacked all-solid-state battery units, each all-solid-state battery unit comprises a positive plate, a negative plate and an electrolyte plate, the root of a positive tab of the positive plate is coated with an elastic insulating material, and the surfaces of the positive tab and the negative tab are coated with a soft conductive material. According to the all-solid-state battery, the thickness difference between the all-solid-state battery units and the tabs is effectively reduced in the stacking process of the at least two all-solid-state battery units, shear stress can be absorbed through plastic deformation in the isostatic pressing treatment, the tabs are prevented from being broken, and the performance of the all-solid-state battery is optimized.

Description

Technical Field

[0001] The present application relates to the technical field of batteries, and in particular, to a all-solid-state battery, a preparation method thereof, and an application thereof. Background Art

[0002] With the continuous growth of the demand for renewable energy and high-efficiency energy storage systems, all-solid-state batteries are crucial in fields such as electric vehicles, portable electronic devices, and large-scale energy storage systems due to their superior performance and safety.

[0003] In the process of using all-solid-state batteries to replace the electrolytes of traditional liquid lithium-ion batteries, their industrialization faces the problem of low ion transport efficiency at the solid-solid interface. The current main method is to improve the compaction density of the battery core through an isostatic pressing process to optimize the ion transport path, that is, placing the battery core in a flexible mold and then applying uniform high pressure in all directions to increase the contact area between the solid electrolyte and the electrode material, optimizing the ion transport path, and thus improving the overall performance of the battery.

[0004] However, in the isostatic pressing process, the thickness difference between the battery core body including multiple layers of coatings and current collectors and the tab forms a rigid contact interface during the pressing process, generating shear stress, which easily leads to tab fracture or damage and causes battery open-circuit failure. Summary of the Invention

[0005] The embodiments of the present application provide an all-solid-state battery, a preparation method thereof, and an application thereof, which are used to solve the problem of battery open-circuit failure caused by tab fracture or damage due to stress concentration at the tab root during the densification process of all-solid-state batteries.

[0006] In a first aspect, the embodiments of the present application provide an all-solid-state battery, including at least two stacked all-solid-state battery units, and each all-solid-state battery unit includes a positive electrode sheet, a negative electrode sheet, and an electrolyte sheet;

[0007] Wherein, an elastic insulating material is coated on the root of the positive tab in the positive electrode sheet, and a soft conductive material is coated on the surface of the positive tab;

[0008] A soft conductive material is coated on the surface of the negative tab in the negative electrode sheet.

[0009] In a possible implementation manner, the soft conductive materials coated on the surfaces of the positive tabs in each all-solid-state battery unit are adhered to each other;

[0010] The soft conductive materials coated on the surfaces of the negative tabs in each all-solid-state battery unit are adhered to each other.

[0011] In a possible implementation manner, the surface area of the soft conductive material coated on the tab in each all-solid-state battery unit is less than or equal to the surface area of the tab.

[0012] In a possible implementation, in each all-solid-state battery cell, the thickness of the positive electrode active material coating is less than or equal to the thickness of the elastic insulating material coated on the root of the positive electrode tab, and the thickness of the positive electrode active material coating is less than or equal to the thickness of the soft conductive material coated on the surface of the positive electrode tab.

[0013] In a possible implementation, the root of the negative electrode tab in the negative electrode sheet is coated with an elastic insulating material.

[0014] In a possible implementation, in each all-solid-state battery cell, the thickness of the negative electrode active material coating is less than or equal to the thickness of the elastic insulating material coated on the root of the negative electrode tab, and the thickness of the negative electrode active material coating is less than or equal to the thickness of the soft conductive material coated on the surface of the negative electrode tab.

[0015] In a possible implementation, in each all-solid-state battery cell, the elastic insulating material coated on the root of the positive electrode tab is connected to the positive electrode edge buffer zone, and the soft conductive material coated on the surface of the positive electrode tab is connected to the elastic insulating material coated on the root of the positive electrode tab.

[0016] In a possible implementation, in each all-solid-state battery cell, the elastic insulating material coated on the root of the negative electrode tab is connected to the negative electrode active material coating, and the soft conductive material coated on the surface of the negative electrode tab is connected to the elastic insulating material coated on the root of the negative electrode tab.

[0017] In a possible implementation, in each all-solid-state battery cell, the length of the positive electrode tab is greater than or equal to the sum of the length of the soft conductive material coated on the surface of the positive electrode tab and the length of the elastic insulating material coated on the root of the positive electrode tab;

[0018] and / or,

[0019] In each all-solid-state battery cell, the width of the positive electrode tab is less than or equal to the width of the elastic insulating material coated on the root of the positive electrode tab, and the width of the positive electrode tab is equal to the width of the soft conductive material coated on the surface of the positive electrode tab.

[0020] In a possible implementation, in each all-solid-state battery cell, the length of the negative electrode tab is greater than or equal to the sum of the length of the soft conductive material coated on the surface of the negative electrode tab and the length of the elastic insulating material coated on the root of the negative electrode tab;

[0021] and / or,

[0022] In each all-solid-state battery cell, the width of the negative electrode tab is less than or equal to the width of the elastic insulating material coated on the root of the negative electrode tab, and the width of the negative electrode tab is equal to the width of the soft conductive material coated on the surface of the negative electrode tab.

[0023] In a possible implementation, the elastic insulating material is at least one of silicone, polyurethane, fluororubber, acrylic foam, modified rubber, thermoplastic elastomer, and polyimide;

[0024] And / or, the soft conductive material is at least one of silver-based conductive adhesive, carbon nanotube conductive adhesive, and graphene conductive adhesive.

[0025] In a second aspect, an embodiment of the present application provides a method for manufacturing an all-solid-state battery, the method comprising:

[0026] Preparing a positive electrode sheet, a negative electrode sheet, and an electrolyte sheet;

[0027] Stacking the positive electrode sheet, the electrolyte sheet, and the negative electrode sheet in sequence, coating an elastic insulating material at the root of the positive electrode tab of the positive electrode sheet, and coating a soft conductive material on the surface of the positive electrode tab; coating a soft conductive material on the surface of the negative electrode tab of the negative electrode sheet to obtain an all-solid-state battery unit;

[0028] Stacking at least two all-solid-state battery units, encapsulating them, and performing isostatic pressing densification treatment to obtain the all-solid-state battery according to any possible one of the first aspect.

[0029] In a possible implementation, the coating of the soft conductive material on the surface of the negative electrode tab of the negative electrode sheet includes:

[0030] Coating a soft conductive material on the surface of the negative electrode tab of the negative electrode sheet, and coating an elastic insulating material at the root of the negative electrode tab.

[0031] In a possible implementation, the elastic insulating material is at least one of silicone, polyurethane, fluororubber, acrylic foam, modified rubber, thermoplastic elastomer, and polyimide;

[0032] And / or, the soft conductive material is at least one of silver-based conductive adhesive, carbon nanotube conductive adhesive, and graphene conductive adhesive.

[0033] In a third aspect, an embodiment of the present application provides an electrical device, including a device main body and the all-solid-state battery according to any possible one of the first aspect.

[0034] An all-solid-state battery provided by an embodiment of the present application, a preparation method and an application thereof. The all-solid-state battery includes at least two stacked all-solid-state battery units. Each all-solid-state battery unit includes a positive electrode sheet, a negative electrode sheet and an electrolyte sheet. An elastic insulating material is coated on the root of the positive electrode tab of the positive electrode sheet, and a soft conductive material is coated on the surfaces of the positive electrode tab of the positive electrode sheet and the negative electrode tab of the negative electrode sheet. During the stacking process of at least two all-solid-state battery units, the thickness difference between the all-solid-state battery unit and the electrode tab is reduced. Shear stress can be absorbed through plastic deformation during isostatic pressing treatment, avoiding the fracture of the electrode tab and optimizing the performance of the all-solid-state battery. Description of the Drawings

[0035] The drawings herein are incorporated into the specification and constitute a part of this specification, showing embodiments consistent with the present application, and are used together with the specification to explain the principles of the present application.

[0036] Figure 1 It is a schematic structural diagram of an all-solid-state battery provided by the present application;

[0037] Figure 2(a) is a schematic surface diagram of a positive electrode sheet of an all-solid-state battery provided by the present application;

[0038] Figure 2(b) is a schematic cross-sectional diagram of a positive electrode sheet of an all-solid-state battery provided by the present application;

[0039] Figure 3(a) is a schematic surface diagram of a negative electrode sheet of an all-solid-state battery provided by the present application;

[0040] Figure 3(b) is a schematic cross-sectional diagram of a negative electrode sheet of an all-solid-state battery provided by the present application;

[0041] Figure 4 It is a schematic flow diagram of a preparation method of a solid-state battery provided by the present application.

[0042] Through the above-mentioned drawings, specific embodiments of the present application have been shown, and there will be more detailed descriptions hereinafter. These drawings and textual descriptions are not intended to limit the scope of the concept of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments.

[0043] Description of the Reference Numerals:

[0044] 101: Soft conductive material; 102: Elastic insulating material; 103: Positive electrode sheet; 104: Positive electrode tab; 105: Negative electrode sheet; 106: Negative electrode tab; 107: Electrolyte sheet; 201: Positive electrode current collector; 202: Positive electrode active material; 203: Positive electrode edge buffer zone; 301: Negative electrode current collector; 302: Negative electrode active material. Detailed Embodiments

[0045] Exemplary embodiments will be described in detail herein, and examples thereof are shown in the accompanying drawings. When the following description refers to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0046] First, the application background of the present application is explained as follows:

[0047] As a new type of high-energy density energy storage battery, the solid-state battery uses a solid electrolyte to replace the electrolyte of a traditional liquid lithium-ion battery, and has advantages such as high safety, large energy density, and wide applicable temperature range. It is of great significance for promoting the innovation of energy technology and providing a safer, more efficient, and more environmentally friendly energy storage solution.

[0048] The all-solid-state battery technology achieves higher safety by abandoning the electrolyte, but its industrialization is limited by the inefficient ion transport at the solid-solid interface between the solid electrolyte and the electrode. The current mainstream solution is to apply isotropic high pressure to the battery cell through an isostatic pressing process, and use a flexible mold to uniformly compress the battery cell structure to enhance the physical contact between the solid electrolyte and the electrode particles, shorten the ion migration path, and thereby improve the overall performance of the battery.

[0049] However, due to the poor deformation ability of the positive / negative electrode sheets, electrolyte sheets, and current collectors of the all-solid-state battery under high pressure, the stress in the thickness difference region cannot be released through plastic deformation. During the isostatic pressing process, due to the thickness difference between the battery cell body containing multiple layers of coatings and the tab, a rigid contact boundary is formed due to the incoordination of compression deformation under high pressure, and shear stress accumulates at the root of the tab, which is likely to cause mechanical fracture or microscopic damage to the tab material, ultimately resulting in battery open circuit failure, becoming the core technical problem to be solved urgently in the large-scale manufacturing of all-solid-state batteries.

[0050] Based on the above technical problems, when the inventor was researching how to solve the problem that the ear tab is prone to break due to the cumulative shear stress at the root of the ear tab, it was found that by coating an elastic insulating material on the root of the positive ear tab of multiple stacked all-solid-state battery cells, and coating a soft conductive material on the surfaces of the positive ear tab and the negative ear tab, the elastic modulus of the elastic insulating material and the soft conductive material is lower than that of the solid electrolyte, so as to effectively reduce the thickness difference between the all-solid-state battery cell and the ear tab during the stacking process of at least two all-solid-state battery cells, and then absorb the shear stress through plastic deformation during the isostatic pressing process, avoid the breakage of the ear tab, and optimize the performance of the all-solid-state battery. At the same time, coating an elastic insulating material on the root of the positive ear tab of multiple stacked all-solid-state battery cells, and coating a soft conductive material on the surfaces of the positive ear tab and the negative ear tab does not require modification of the existing lamination equipment, and the preparation cost is relatively low. Based on this, the present application provides an all-solid-state battery and its preparation method and application.

[0051] The technical solution of the present application and how the technical solution of the present application solves the above technical problems will be described in detail below with specific embodiments. These specific embodiments below can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below with reference to the accompanying drawings.

[0052] Figure 1 The structural schematic diagram of an all-solid-state battery provided by the present application is as Figure 1 shown. The all-solid-state battery includes at least two stacked all-solid-state battery cells, and each all-solid-state battery cell includes a positive electrode sheet 103, a negative electrode sheet 105, and an electrolyte sheet 107.

[0053] In a possible implementation manner, an elastic insulating material 102 is coated on the root of the positive ear tab 104 in the positive electrode sheet 103, and a soft conductive material 101 is coated on the surface of the positive ear tab 104.

[0054] The positive electrode sheet 103 generally includes a positive electrode active material and a positive electrode current collector, and is used for storing and releasing the positive charge of the battery. The negative electrode sheet 105 generally includes a negative electrode active material and a negative electrode current collector, and is used for storing and releasing the negative charge. The electrolyte sheet 107 is located between the positive electrode sheet 103 and the negative electrode sheet 105, and allows ions to move between the two electrodes, thereby completing the charge and discharge process of the battery.

[0055] The positive ear tab 104 is a part extending from the positive electrode current collector in the positive electrode sheet 103, and is used for connecting the positive electrode inside the battery to the external circuit. The elastic insulating material 102 coated on its root is used to isolate the contact between the positive ear tab 104 and the negative electrode, preventing the all-solid-state battery from short-circuiting; the soft conductive material 101 coated on its surface is used to improve the conductivity and connection reliability between the positive ear tabs 104 and between the ear tab and the external circuit, and achieve more efficient current transmission.

[0056] The soft conductive material 101 has good electrical conductivity and flexibility, focusing on electrical conduction and adapting to deformation, and providing necessary mechanical buffering without affecting the battery performance. On the one hand, the soft conductive material 101 can closely adhere to the surface of the positive electrode tab 104, reducing the contact resistance and ensuring efficient transmission of current between the positive electrode tabs 104 and between the tab and the external circuit. On the other hand, the flexibility of the soft conductive material 101 can buffer and absorb the mechanical stress suffered by the positive electrode tab 104 during the isostatic pressing process, avoiding breakage or contact failure between the positive electrode tab 104 and the conductive coating, and maintaining a long-term stable electrical connection.

[0057] The elastic insulating material 102 has good insulation and flexibility, focusing on stress buffering and insulation protection. On the one hand, when the mechanical stress suffered by the positive electrode tab 104 during the isostatic pressing process causes the positive electrode tab 104 to deform, the elastic insulating material 102 coated on the root of the positive electrode tab 104 can disperse and absorb the mechanical stress through its own deformation, thereby reducing the stress concentration directly acting on the root of the positive electrode tab 104 and avoiding breakage of the root of the positive electrode tab 104. On the other hand, due to its insulating properties, the elastic insulating material 102 can isolate the contact between the positive electrode tab 104 and the negative electrode, preventing the all-solid-state battery from short-circuiting.

[0058] In a possible implementation, the surface of the negative electrode tab 106 in the negative electrode sheet 105 is coated with the soft conductive material 101.

[0059] The negative electrode tab 106 is a part extending from the negative electrode current collector in the negative electrode sheet 105, used to connect the negative electrode inside the battery to the external circuit. The technical effects of the soft conductive material 101 coated on its surface are similar to those of the soft conductive material 101 coated on the surface of the positive electrode tab 104, and will not be elaborated here.

[0060] Since the elastic moduli of the elastic insulating material 102 and the soft conductive material 101 are lower than that of the solid electrolyte, the thickness difference between the all-solid-state battery unit and the tab can be effectively reduced during the lamination process of at least two all-solid-state battery units, and then the shear stress can be absorbed through plastic deformation during the isostatic pressing process, avoiding tab breakage and optimizing the performance of the all-solid-state battery.

[0061] The all-solid-state battery provided by the embodiment of the present application is composed of at least two stacked all-solid-state battery units. Each all-solid-state battery unit includes a positive electrode sheet, a negative electrode sheet, and an electrolyte sheet. The positive electrode sheet and the negative electrode sheet are respectively composed of a positive electrode active material and a positive electrode current collector, and a negative electrode active material and a negative electrode current collector, which are used to store and release charges. The electrolyte sheet is located between the positive electrode sheet and the negative electrode sheet, allowing ions to move between the two electrodes, thereby realizing the charge and discharge process of the battery. In this all-solid-state battery, the root of the positive electrode tab is coated with an elastic insulating material to prevent direct contact between the positive electrode tab and the negative electrode and avoid the risk of short circuit. The surfaces of the positive electrode tab and the negative electrode tab are coated with a soft conductive material, which improves the conductivity and connection reliability between the tabs and between the tabs and the external circuit. Through the above all-solid-state battery, by utilizing the good flexibility of the soft conductive material and the elastic insulating material, the thickness difference between the all-solid-state battery unit and the tab is effectively reduced during the stacking process of at least two all-solid-state battery units, and then the shear stress is absorbed through plastic deformation during the isostatic pressing process, avoiding tab fracture and optimizing the performance of the all-solid-state battery.

[0062] Based on Figure 1 In an embodiment, in an alternative embodiment, the root of the negative electrode tab 106 in the negative electrode sheet 105 is coated with an elastic insulating material 102.

[0063] The negative electrode tab 106 is a part extending from the negative electrode current collector in the negative electrode sheet 105, which is used to connect the negative electrode inside the battery to the external circuit. The root of the negative electrode tab 106 is coated with the elastic insulating material 102, which is Figure 1 similar to the technical effect of the elastic insulating material 102 coated on the root of the positive electrode tab 104 in the embodiment, and will not be elaborated here.

[0064] In another alternative embodiment, in some all-solid-state battery units, the root of the negative electrode tab 106 may not be coated with the elastic insulating material 102.

[0065] This is because the area of the negative electrode sheet 105 is generally larger than that of the positive electrode sheet 103, and the probability of contact between the negative electrode tab 106 and the positive electrode is small, and the risk of accidental short circuit is low. In this case, even if the root of the negative electrode tab 106 is not coated with the elastic insulating material 102, the technical effect of isolating the contact between the negative electrode tab 106 and the positive electrode can still be achieved. The soft conductive material 101 coated on the surface of the negative electrode tab 106 is connected to the negative electrode active material coating. The soft conductive material 101 coated on the surface of the negative electrode tab 106 buffers and absorbs the mechanical stress received by the negative electrode tab 106 during the isostatic pressing process, avoiding fracture or contact failure between the negative electrode tab 106 and the conductive coating and maintaining a long-term stable connection.

[0066] Based on the above embodiments, the soft conductive material 101 coated on the surfaces of the positive electrode tab 104 and the negative electrode tab 106, and the elastic insulating material 102 coated on the roots of the positive electrode tab 104 and the negative electrode tab 106 specifically include:

[0067] In a possible implementation manner, the elastic insulating material 102 is at least one of silicone, polyurethane, fluororubber, acrylic foam, modified rubber, thermoplastic elastomer, polyimide;

[0068] And / or,

[0069] The soft conductive material 101 is at least one of silver-based conductive adhesive, carbon nanotube conductive adhesive, graphene conductive adhesive.

[0070] Taking silicone in the elastic insulating material 102 as an example, silicone is a synthetic polymer material composed of silicon-oxygen chains, with excellent thermal stability and weather resistance, and can maintain its physical properties at extreme temperatures. Its excellent electrical insulation can effectively prevent current leakage and short circuits. In addition, silicone also has good elasticity and flexibility, and can return to its original state under mechanical stress. As the elastic insulating material 102 at the root of the tab in the all-solid-state battery, silicone can effectively improve the safety and reliability of the battery, and at the same time extend its service life.

[0071] Taking the silver-based conductive adhesive in the soft conductive material 101 as an example, the silver-based conductive adhesive is made by dispersing silver powder or silver nanoparticles in a polymer matrix. The high conductivity of silver enables the silver-based conductive adhesive to effectively conduct current and ensure the reliability of electrical connection. Its soft polymer matrix provides good flexibility and adhesion, and can adapt to the deformation and thermal expansion of different material surfaces without affecting the electrical performance. The silver-based conductive adhesive also has excellent oxidation resistance and chemical stability, and can maintain its conductive performance under harsh environmental conditions. As the soft conductive material 101 on the surface of the tab in the all-solid-state battery, the silver-based conductive adhesive can effectively reduce the contact resistance, improve the overall conductivity and efficiency of the battery, and at the same time provide mechanical buffering to reduce contact failure caused by thermal cycling or mechanical stress.

[0072] In a possible implementation manner, the surface area of the soft conductive material 101 coated on the tab in each all-solid-state unit is less than or equal to the surface area of the tab.

[0073] Since the solid electrolyte in the all-solid-state battery lacks the fluidity of the liquid electrolyte, the expansion and contraction of the electrode material are likely to cause interface contact failure, which in turn leads to battery capacity attenuation or even open circuit. Coating the elastic insulating material 102 and the soft conductive material 101 can absorb the shear stress at the root of the tab during the isostatic pressing process through their plastic deformation and can effectively relieve the stress at the tab caused by the volume strain during the battery operation, thereby avoiding tab fracture.

[0074] The surface area of the soft conductive material 101 coated on the tab is less than or equal to the surface area of the tab, which avoids the coating area of the soft conductive material 101 exceeding the tab body, prevents uneven accumulation of the excess soft conductive material 101 due to lack of physical support, generates local stress concentration under the battery stacking pressure, causes the coating to crack or peel off, and may also cause a short circuit due to the overflow of the soft conductive material 101 into the adjacent electrolyte layer or separator area. Therefore, by controlling the surface area of the soft conductive material 101 coated on the tab in each all-solid-state cell to be less than or equal to the surface area of the tab, the effective conductive area of the tab is ensured.

[0075] Figure 2(a) is a schematic surface view of the positive electrode tab of an all-solid-state battery provided by the present application, and Figure 2(b) is a schematic cross-sectional view of the positive electrode tab of an all-solid-state battery provided by the present application. On the basis of the Figure 1 embodiment, as shown in Figures 2(a) and 2(b), the positive electrode tab includes a positive electrode tab 104, a positive electrode current collector 201, a positive electrode active material 202, and a positive electrode edge buffer zone 203. Among them, the root of the positive electrode tab 104 is coated with an elastic insulating material 102, the surface of the positive electrode tab 104 is coated with a soft conductive material 101, the positive electrode active material 202 is loaded on the surface of the positive electrode current collector 201, and the positive electrode edge buffer zone 203 is located in a part of the area at the edge of the positive electrode tab, and is used to relieve the edge stress shear problem that may be caused by the size difference between the positive and negative electrode tabs by filling a specific material.

[0076] The structure of the positive electrode tab will be described in detail below:

[0077] In a possible implementation manner, the soft conductive materials 101 coated on the surfaces of the positive electrode tabs 104 in each all-solid-state cell are adhered to each other.

[0078] For the positive electrode tab 104, the soft conductive materials 101 coated on the surface are adhered to each other to form a continuous conduction path for conducting the positive electrodes of at least two all-solid-state cells to form a conduction circuit, which not only improves the current transmission efficiency between the positive electrodes, but also increases the mechanical bonding force between the all-solid-state cells, thereby enhancing the stability of the battery structure.

[0079] In a possible implementation manner, in each all-solid-state cell, the coating thickness of the positive electrode active material 202 is less than or equal to the thickness of the elastic insulating material 102 coated on the root of the positive electrode tab 104, and the coating thickness of the positive electrode active material 202 is less than or equal to the thickness of the soft conductive material 101 coated on the surface of the positive electrode tab 104.

[0080] The coating of the positive electrode active material 202, as the core area for lithium ion insertion and extraction, its thickness determines the capacity and reaction kinetics of the electrode. A thinner coating of the positive electrode active material 202 can reduce the diffusion path of ions inside the battery, thereby improving the charging and discharging speed and efficiency of the battery. It also helps to reduce internal stress and the risk of mechanical failures caused by uneven thickness, thus enhancing the durability of the battery. The thickness of the elastic insulating material 102 needs to be sufficient to provide effective electrical insulation and prevent direct electrical contact between the positive electrode current collector 201 and the negative electrode current collector, avoiding the risk of short circuit. The thickness of the soft conductive material 101, on the other hand, needs to be sufficient to ensure good electrical contact and mechanical flexibility. A thicker soft conductive material 101 can provide a larger contact area and lower contact resistance, thereby improving the current transmission efficiency.

[0081] As shown in Figures 2(a) and 2(b), the thickness h1 of the coating of the positive electrode active material 202, the thickness h2 of the elastic insulating material 102 coated at the root of the positive electrode tab 104, and the thickness h3 of the soft conductive material 101 coated on the surface of the positive electrode tab 104 satisfy that the thickness of the coating of the positive electrode active material 202 is less than or equal to the thickness of the elastic insulating material 102 coated at the root of the positive electrode tab 104, and the thickness of the coating of the positive electrode active material 202 is less than or equal to the thickness of the soft conductive material 101 coated on the surface of the positive electrode tab 104, that is, h1 ≤ h2 and h1 ≤ h3. This not only effectively prevents direct contact between the positive electrode current collector 201 and other battery components, reducing the short circuit risk of the battery, but also improves the current transmission efficiency.

[0082] In a possible implementation, in each all-solid-state battery cell, the elastic insulating material 102 coated at the root of the positive electrode tab 104 is connected to the positive electrode edge buffer zone 203, and the soft conductive material 101 coated on the surface of the positive electrode tab 104 is connected to the elastic insulating material 102 coated at the root of the positive electrode tab 104.

[0083] As shown in Figures 2(a) and 2(b), by connecting the elastic insulating material 102 coated at the root of the positive electrode tab 104 to the positive electrode edge buffer zone 203, direct electrical contact between the positive electrode current collector 201 and other battery components can be effectively prevented, reducing the short circuit risk. In addition, it can also provide additional mechanical support, reducing material delamination or peeling caused by thermal expansion and contraction or mechanical stress, thereby improving the reliability and service life of the battery.

[0084] By connecting the soft conductive material 101 coated on the surface of the positive electrode tab 104 to the elastic insulating material 102 coated on the root of the positive electrode tab 104, it is possible to ensure good electrical conductivity while maintaining the effectiveness of electrical isolation and avoiding breakage of the tabs during battery preparation and use. The flexibility of the elastic insulating material 102 and the soft conductive material 101 allows them to deform under mechanical stress without damage. This connection method can absorb and relieve mechanical stress, reduce the risk of damage at the connection, avoid tab breakage, and thus improve the overall performance and durability of the battery.

[0085] In a possible implementation, in each all-solid-state battery cell, the length of the positive electrode tab 104 is greater than or equal to the sum of the length of the soft conductive material 101 coated on the surface of the positive electrode tab 104 and the length of the elastic insulating material 102 coated on the root of the positive electrode tab 104.

[0086] The soft conductive material 101 is coated along the tab surface and is used to bear the interface stress buffer and electron conduction functions. Its length determines the effective connection range between the positive electrode tabs 104. The elastic insulating material 102 coated on the root needs to completely wrap the transition area between the tab and the electrode body to prevent internal short circuits caused by the growth of lithium dendrites along the metal / electrolyte interface.

[0087] As shown in Figures 2(a) and 2(b), the length l1 of the positive electrode tab 104, the length l2 of the elastic insulating material 102 coated on the root of the positive electrode tab 104, and the length l3 of the soft conductive material 101 coated on the surface of the positive electrode tab 104 satisfy that the length of the positive electrode tab 104 is greater than or equal to the sum of the length of the soft conductive material 101 coated on the surface of the positive electrode tab 104 and the length of the elastic insulating material 102 coated on the root of the positive electrode tab 104, that is, l1 ≥ l2 + l3. This ensures that while providing an effective conduction path, necessary electrical isolation and mechanical support are maintained.

[0088] In a possible implementation, in each all-solid-state battery cell, the width of the positive electrode tab 104 is less than or equal to the width of the elastic insulating material 102 coated on the root of the positive electrode tab 104, and the width of the positive electrode tab 104 is equal to the width of the soft conductive material 101 coated on the surface of the positive electrode tab 104.

[0089] The width of the positive electrode tab 104 refers to the lateral dimension of the tab in its plane. The width of the elastic insulating material 102 coated on the root of the positive electrode tab 104 refers to the lateral dimension of the insulating material covering the root of the tab, which usually needs to be greater than or equal to the width of the positive electrode tab 104 to ensure that the insulating material can completely cover the key area of the tab, provide effective electrical isolation, and prevent short circuits. The width of the soft conductive material 101 coated on the surface of the positive electrode tab 104 refers to the lateral dimension of the conductive material covering the surface of the tab, which is usually equal to the width of the positive electrode tab 104 to ensure that the conductive material can completely cover the surface of the tab, providing good electrical contact and conductivity.

[0090] As shown in Figures 2(a) and 2(b), the width w1 of the positive electrode tab 104, the width w2 of the elastic insulating material 102 coated on the root of the positive electrode tab 104, and the width w3 of the soft conductive material 101 coated on the surface of the positive electrode tab 104 satisfy that the width of the positive electrode tab 104 is less than or equal to the width of the elastic insulating material 102 coated on the root of the positive electrode tab 104, and the width of the positive electrode tab 104 is equal to the width of the soft conductive material 101 coated on the surface of the positive electrode tab 104, that is, w2≥w1 = w3. This ensures effective electrical isolation while also providing good electrical contact and conductivity.

[0091] In the all-solid-state battery provided by the embodiment of the present application, in each all-solid-state battery unit, the soft conductive materials coated on the surfaces of the positive electrode tabs are adhered to each other. The surface area of the soft conductive material on the positive electrode tab is controlled to be less than or equal to the surface area of the tab. The thickness of the positive active material coating is less than or equal to the thickness of the elastic insulating material and the surface soft conductive material at the root of the positive electrode tab. The elastic insulating material at the root of the positive electrode tab is connected to the positive electrode edge buffer area, and the soft conductive material on the surface of the positive electrode tab is connected to the elastic insulating material, which not only effectively prevents electrical short circuits, provides additional mechanical support, but also can absorb and relieve mechanical stress, improving the overall reliability of the battery. In addition, the length of the positive electrode tab is greater than or equal to the sum of the lengths of the soft conductive material and the elastic insulating material, ensuring an effective conduction path and necessary electrical isolation and mechanical support. The width of the positive electrode tab is less than or equal to the width of the root elastic insulating material and is equal to the width of the surface soft conductive material to ensure the effectiveness of electrical isolation and good electrical contact performance. Through the above all-solid-state battery, the breakage or damage of the tab caused by stress concentration at the root of the tab is effectively prevented, the electrochemical performance, safety, and structural stability of the all-solid-state battery are improved, the service life of the battery is extended, and its reliability and durability under various operating conditions are ensured.

[0092] FIG. 3(a) is a schematic surface view of the negative electrode sheet of a all-solid-state battery provided by the present application, and FIG. 3(b) is a schematic cross-sectional view of the negative electrode sheet of a all-solid-state battery provided by the present application. On the basis of the above embodiments, as shown in FIG. 3(a) and FIG. 3(b), the negative electrode sheet includes a negative electrode tab 106, a negative electrode current collector 301, and a negative electrode active material 302. Among them, the root of the negative electrode tab 106 is coated with an elastic insulating material 102, the surface of the negative electrode tab 106 is coated with a soft conductive material 101, and the negative electrode active material 302 is loaded on the surface of the negative electrode current collector 301. The structure of the negative electrode sheet will be described in detail below:

[0093] In a possible implementation manner, the soft conductive materials 101 coated on the surfaces of the negative electrode tabs 106 in each all-solid-state battery cell are adhered to each other.

[0094] For the negative electrode tab 106, the soft conductive materials 101 coated on the surface are adhered to each other to form a continuous conduction path for conducting the negative electrodes of at least two all-solid-state battery cells to form a conduction circuit, ensuring that the current transmission between the negative electrodes is equally efficient.

[0095] In a possible implementation manner, in each all-solid-state battery cell, the coating thickness of the negative electrode active material 302 is less than or equal to the thickness of the elastic insulating material 102 coated on the root of the negative electrode tab 106, and the coating thickness of the negative electrode active material 302 is less than or equal to the thickness of the soft conductive material 101 coated on the surface of the negative electrode tab 106.

[0096] As shown in FIG. 3(a) and FIG. 3(b), the coating thickness h4 of the negative electrode active material 302, the thickness h5 of the elastic insulating material 102 coated on the root of the negative electrode tab 106, and the thickness h6 of the soft conductive material 101 coated on the surface of the negative electrode tab 106 satisfy that the coating thickness of the negative electrode active material 302 is less than or equal to the thickness of the elastic insulating material 102 coated on the root of the negative electrode tab 106, and the coating thickness of the negative electrode active material 302 is less than or equal to the thickness of the soft conductive material 101 coated on the surface of the negative electrode tab 106, that is, h4≤h5 and h4≤h6. Its technical effect is similar to that of the positive electrode sheet and will not be elaborated here.

[0097] In a possible implementation manner, in each all-solid-state battery cell, the elastic insulating material 102 coated on the root of the negative electrode tab 106 is connected to the coating of the negative electrode active material 302, and the soft conductive material 101 coated on the surface of the negative electrode tab 106 is connected to the elastic insulating material 102 coated on the root of the negative electrode tab 106.

[0098] Its technical effect is similar to that of the positive electrode sheet and will not be elaborated here.

[0099] In a possible implementation, in each all-solid-state battery cell, the length of the negative electrode tab 106 is greater than or equal to the sum of the length of the soft conductive material 101 coated on the surface of the negative electrode tab 106 and the length of the elastic insulating material 102 coated on the root of the negative electrode tab 106.

[0100] As shown in FIGS. 3(a) and 3(b), for the length l4 of the negative electrode tab 106, the length l5 of the elastic insulating material 102 coated on the root of the negative electrode tab 106, and the length l6 of the soft conductive material 101 coated on the surface of the negative electrode tab 106, it is satisfied that the length of the negative electrode tab 106 is greater than or equal to the sum of the length of the soft conductive material 101 coated on the surface of the negative electrode tab 106 and the length of the elastic insulating material 102 coated on the root of the negative electrode tab 106, that is, l4≥l5 + l6. Its technical effect is similar to that of the positive electrode plate and will not be elaborated here.

[0101] In a possible implementation, in each all-solid-state battery cell, the width of the negative electrode tab 106 is less than or equal to the width of the elastic insulating material 102 coated on the root of the negative electrode tab 106, and the width of the negative electrode tab 106 is equal to the width of the soft conductive material 101 coated on the surface of the negative electrode tab 106.

[0102] As shown in FIGS. 3(a) and 3(b), for the width w4 of the negative electrode tab 106, the width w5 of the elastic insulating material 102 coated on the root of the negative electrode tab 106, and the width w6 of the soft conductive material 101 coated on the surface of the negative electrode tab 106, it is satisfied that the width of the negative electrode tab 106 is less than or equal to the width of the elastic insulating material 102 coated on the root of the negative electrode tab 106, and the width of the negative electrode tab 106 is equal to the width of the soft conductive material 101 coated on the surface of the negative electrode tab 106, that is, w5≥w4 = w6. Its technical effect is similar to that of the positive electrode plate and will not be elaborated here.

[0103] The all-solid-state battery provided by the embodiments of the present application, in each all-solid-state battery unit, the soft conductive materials coated on the surface of the negative electrode tabs are adhered to each other, the surface area of the soft conductive materials on the negative electrode tabs is controlled to be less than or equal to the surface area of the tabs, and the thickness of the negative electrode active material coating is set to be less than or equal to the thickness of the elastic insulating material and the surface soft conductive material at the root of the negative electrode tab. The elastic insulating material at the root of the negative electrode tab is connected to the negative electrode active material coating, and the soft conductive material on the surface of the negative electrode tab is connected to the elastic insulating material, which not only effectively prevents electrical short circuits, provides additional mechanical support, but also can absorb and relieve mechanical stress, improving the overall reliability of the battery. In addition, the length of the negative electrode tab is greater than or equal to the sum of the lengths of the soft conductive material and the elastic insulating material, ensuring an effective conduction path and necessary electrical isolation and mechanical support. The width of the negative electrode tab is less than or equal to the width of the elastic insulating material at the root and is equal to the width of the surface soft conductive material, to ensure the effectiveness of electrical isolation and good electrical contact performance. Through the above all-solid-state battery, the breakage or damage of the tab caused by stress concentration at the root of the tab is effectively prevented, improving the electrochemical performance, safety and structural stability of the all-solid-state battery, and extending the service life of the battery.

[0104] Figure 4 Schematic flow chart of a method for preparing a solid-state battery provided by the present application, as Figure 4 shown, the method includes:

[0105] S401: Prepare a positive electrode sheet, a negative electrode sheet and an electrolyte sheet.

[0106] In this step, the composite positive electrode material is roll-pressed into a film by a dry method and then die-cut after being compounded with the positive electrode current collector to prepare the positive electrode sheet; or the composite positive electrode material is wet-coated on the positive electrode current collector and then die-cut to prepare the positive electrode sheet.

[0107] Similarly, the composite negative electrode material is roll-pressed into a film by a dry method and then die-cut after being compounded with the negative electrode current collector to prepare the negative electrode sheet; or the composite negative electrode material is wet-coated on the negative electrode current collector and then die-cut to prepare the negative electrode sheet.

[0108] The composite electrolyte material is roll-pressed by a dry method to prepare the electrolyte sheet; or the composite electrolyte material is wet-coated on a polyethylene terephthalate (PET) film or foil to prepare the electrolyte sheet, and the electrolyte sheet prepared by wet coating also needs to be transferred to the positive electrode sheet or the negative electrode sheet. Through the above method, the positive electrode sheet, the negative electrode sheet and the electrolyte sheet are prepared, providing a raw material basis for the subsequent preparation of the all-solid-state battery.

[0109] S402: Stack the positive electrode sheet, electrolyte sheet, and negative electrode sheet in sequence. Coat an elastic insulating material on the root of the positive electrode tab of the positive electrode sheet, and coat a soft conductive material on the surface of the positive electrode tab. Coat a soft conductive material on the surface of the negative electrode tab of the negative electrode sheet to obtain a all-solid-state battery cell.

[0110] In this step, stack the positive electrode sheet, electrolyte sheet, and negative electrode sheet in sequence. When stacking the positive electrode sheet and the negative electrode sheet, coat a soft conductive material on the surfaces of the positive electrode tab and the negative electrode tab, and coat an elastic insulating material on the root of the positive electrode tab to obtain a all-solid-state battery cell.

[0111] In an optional embodiment, coat an elastic insulating material on the root of the negative electrode tab of the negative electrode sheet, and coat a soft conductive material on the surface of the negative electrode tab.

[0112] In this step, stack the positive electrode sheet, electrolyte sheet, and negative electrode sheet in sequence. When stacking the positive electrode sheet and the negative electrode sheet, coat a soft conductive material on the surfaces of the positive electrode tab and the negative electrode tab, and coat an elastic insulating material on the roots of the positive electrode tab and the negative electrode tab to obtain a all-solid-state battery cell.

[0113] S403: Stack at least two all-solid-state battery cells, then encapsulate and perform isostatic pressing densification treatment to obtain an all-solid-state battery.

[0114] In this step, stack at least two all-solid-state battery cells together to form a complete battery core. The tabs of the positive and negative electrodes of each battery cell will be connected to a conductor for transmitting current from the inside of the battery core to the external terminals of the battery core, forming the positive and negative electrodes of the battery core. Subsequently, vacuum encapsulate at least two all-solid-state battery cells with an aluminum-plastic film and perform isostatic pressing densification treatment to obtain an all-solid-state battery.

[0115] In addition, in order to prevent the stress shear at the edge of the electrode sheet caused by the size difference between the positive electrode sheet and the negative electrode sheet, it is necessary to fill a part of the area located at the edge of the positive electrode sheet, that is, the positive electrode edge buffer area, which can effectively disperse and absorb these stresses, thereby improving the durability and safety of the battery. The positive electrode edge buffer area can be filled with organic materials mainly composed of polypropylene, polyethylene, polyethylene terephthalate, polyamide resin, polytetrafluoroethylene, and polyvinyl chloride, or inorganic materials mainly composed of Al2O3, AlN, γ-AlOOH, oxide solid electrolyte, halide solid electrolyte, and sulfide solid electrolyte. The thickness of the filling area is close to the thickness of the positive electrode active material coating.

[0116] The preparation method of the all-solid-state battery provided by the embodiment of the present application prepares the positive electrode sheet, negative electrode sheet and electrolyte sheet through a dry or wet process, providing the basic materials for the assembly of the all-solid-state battery. Subsequently, the positive electrode sheet, electrolyte sheet and negative electrode sheet are stacked in sequence, and an elastic insulating material is coated at the root of the tab and a soft conductive material is coated on the surface of the tab to form an all-solid-state battery unit. Then, a plurality of battery units are stacked and subjected to encapsulation and isostatic pressing densification treatment to finally obtain a complete all-solid-state battery. Through the above method, the problem of battery open-circuit failure caused by tab fracture or damage due to stress concentration at the root of the tab during the densification process of the all-solid-state battery is solved, the durability and safety of the battery are improved, and its reliability and service life in practical applications are enhanced.

[0117] Based on the Figure 4 embodiment, the elastic insulating material described in S402 is at least one of silica gel, polyurethane, fluororubber, acrylic foam, modified rubber, thermoplastic elastomer, polyimide; and / or, the soft conductive material is at least one of silver-based conductive adhesive, carbon nanotube conductive adhesive, graphene conductive adhesive.

[0118] Based on the Figure 4 embodiment, when preparing the positive electrode sheet, negative electrode sheet and electrolyte sheet in S401, it specifically includes:

[0119] The composite positive electrode material includes a positive electrode active material, an electrolyte material, a conductive agent and a binder. Among them, the positive electrode active material is LiCoO2, LiMnO2, LiNiO2, LiVO2, LiNi x Co y Mn z O2 (x + y + z = 1; 0 ≤ x < 1, 0 ≤ y < 1, 0 ≤ z < 1), LiNi x Co y Al z O2 (x + y + z = 1; 0 ≤ x < 1, 0 ≤ y < 1, 0 ≤ z < 1), xLi2MnO3·(1 - x)LiTMO2 (TM = Ni, Mn, Co, Al; 0 < x < 1), LiMn2O4, Li4Ti5O 12 , Li(Ni 0.5 Mn 1.5 )O4, LiFePO4, LiMnPO4, LiNiPO4, LiCoPO4, LiMn x Fe 1-x PO4 (0 < x < 1), high-entropy positive electrode LiNi x Mn y M zO2 (M includes at least three of Co, Ti, V, Cr, Fe, Zn, Mg, Ca, Ru, Sn, Sb, W, Al, Mo, Y, Nb, La, Ce, Eu or Er, x+y+z=1; 0≤x<1, 0≤y<1, 0≤z<1). The positive electrode current collector is aluminum, nickel, stainless steel, iron, titanium or carbon, and is in the shape of foil or mesh.

[0120] The composite negative electrode material includes a negative electrode active material, an electrolyte material, a conductive agent and a binder, wherein the negative electrode active material is lithium titanate, metal Li, In, Sn and their respective alloys, graphite, hard carbon, soft carbon, mesophase carbon microspheres, carbon-based active materials of highly oriented pyrolytic graphite, Si single substance, Si alloy, silicon oxide, Si-carbon Si-based active materials at least one. The negative electrode current collector is copper, stainless steel, nickel or carbon, and is in the shape of foil or mesh.

[0121] The composite electrolyte material includes an electrolyte material and a binder, and the electrolyte material includes an oxide solid electrolyte, a halide solid electrolyte and a sulfide solid electrolyte. Among them, the electrolyte material is an oxide solid electrolyte Li 1+ x Al x Ti 2-x (PO4)3 (0.1≤x≤0.9), Li7La3Zr2O 12 , Li 6.4 LqCy 1.4 Ta 0.6 O 12 , Li 0.33 La 0.557 TiO3, LiPON, halide solid electrolyte Li3InCl6, Li2ZrCl6, Li3YCl6 or Li3ScCl6 and derivatives of the above compounds, sulfide solid electrolyte Li x MP y S z (M is one or more of Sn, Ge, Si, 0<x, 0<y, 0<z), , (X is at least one of the halogen elements F, Br and I, 0≤x, 0≤y), xLi2S·(100-x)P2S5 (70≤x≤80) and yLiI·zLiBr·(100-yz)(xLi2S·(100-x)P2S5) (70≤x≤80, 0≤y≤30, 0≤z≤30).

[0122] The binder is at least one of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), nitrile butadiene rubber (NBR), styrene-butadiene latex (SBR), polyacrylic acid (PAA), polyisobutylene (PIB), and carboxymethyl cellulose (CMC); the conductive agent is at least one of conductive carbon black, carbon nanotubes (CNT), carbon nanofibers (CNF), and vapor-grown carbon fibers (VGCF).

[0123] Based on the Figure 4 embodiment, when at least two all-solid-state battery units are stacked, encapsulated, and isostatically compacted in S403, the isostatic pressure is 50 MPa - 800 MPa, and the isostatic temperature is 25°C - 250°C. That is to say, during the actual isostatic compaction process, the isostatic pressure can be 50 MPa, 200 MPa, 400 MPa, 600 MPa, or 800 MPa, etc., and the isostatic temperature can be 25°C, 50°C, 80°C, 100°C, 150°C, 200°C, or 250°C, etc. In practical applications, it can be appropriately adjusted according to specific requirements.

[0124] This application also provides an electrical device, including a device main body and the all-solid-state battery described in the foregoing embodiment.

[0125] Exemplarily, the all-solid-state battery can be used as a power battery for vehicles, and is also applicable to the battery fields of computers, communications, and consumer electronics (3C), as well as to aircraft and drones, etc., providing a stable and lasting power source and power support for them.

[0126] Finally, it should be noted that: After considering the specification and practicing the invention disclosed herein, those skilled in the art will easily think of other implementation schemes of the present invention. The present invention aims to cover any variations, uses, or adaptive changes of the present invention, which follow the general principles of the present invention and include the common general knowledge or conventional technical means in the technical field not disclosed in the present invention. It is not limited to the precise structures already described and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of the present invention is only limited by the appended claims.

Claims

1. An all-solid-state battery, characterized in that: Comprising at least two stacked all-solid-state battery cells, each all-solid-state battery cell comprising a positive electrode sheet, a negative electrode sheet and an electrolyte sheet; Wherein, an elastic insulating material is coated on the root of the positive electrode tab in the positive electrode sheet, and a soft conductive material is coated on the surface of the positive electrode tab; A soft conductive material is coated on the surface of the negative electrode tab in the negative electrode sheet.

2. The all-solid-state battery according to claim 1, characterized in that, The soft conductive materials coated on the surfaces of the positive electrode tabs in each all-solid-state battery cell are adhesively connected to each other; The soft conductive materials coated on the surfaces of the negative electrode tabs in each all-solid-state battery cell are adhesively connected to each other.

3. The all-solid-state battery according to claim 1, characterized in that, The surface area of the soft conductive material coated on the tab in each all-solid-state battery cell is less than or equal to the surface area of the tab.

4. The all-solid-state battery according to claim 1, characterized in that, In each all-solid-state battery cell, the thickness of the positive electrode active material coating is less than or equal to the thickness of the elastic insulating material coated on the root of the positive electrode tab, and the thickness of the positive electrode active material coating is less than or equal to the thickness of the soft conductive material coated on the surface of the positive electrode tab.

5. The all-solid-state battery according to any one of claims 1 to 4, characterized in that, An elastic insulating material is coated on the root of the negative electrode tab in the negative electrode sheet.

6. The all-solid-state battery according to claim 5, wherein In each all-solid-state battery cell, the thickness of the negative electrode active material coating is less than or equal to the thickness of the elastic insulating material coated on the root of the negative electrode tab, and the thickness of the negative electrode active material coating is less than or equal to the thickness of the soft conductive material coated on the surface of the negative electrode tab.

7. The all-solid-state battery according to any one of claims 1 to 4, characterized in that, In each all-solid-state battery cell, the elastic insulating material coated on the root of the positive electrode tab is connected to the positive electrode edge buffer zone, and the soft conductive material coated on the surface of the positive electrode tab is connected to the elastic insulating material coated on the root of the positive electrode tab.

8. The all-solid-state battery according to claim 5, characterized in that, In each all-solid-state battery cell, the elastic insulating material coated on the root of the negative electrode tab is connected to the negative electrode active material coating, and the soft conductive material coated on the surface of the negative electrode tab is connected to the elastic insulating material coated on the root of the negative electrode tab.

9. The all-solid-state battery according to any one of claims 1 to 4, characterized in that, In each all-solid-state battery cell, the length of the positive electrode tab is greater than or equal to the sum of the length of the soft conductive material coated on the surface of the positive electrode tab and the length of the elastic insulating material coated on the root of the positive electrode tab; And / or, In each all-solid-state battery cell, the width of the positive electrode tab is less than or equal to the width of the elastic insulating material coated on the root of the positive electrode tab, and the width of the positive electrode tab is equal to the width of the soft conductive material coated on the surface of the positive electrode tab.

10. The all-solid-state battery according to claim 5, characterized in that, In each all-solid-state battery cell, the length of the negative electrode tab is greater than or equal to the sum of the length of the soft conductive material coated on the surface of the negative electrode tab and the length of the elastic insulating material coated on the root of the negative electrode tab; And / or, In each all-solid-state battery cell, the width of the negative electrode tab is less than or equal to the width of the elastic insulating material coated on the root of the negative electrode tab, and the width of the negative electrode tab is equal to the width of the soft conductive material coated on the surface of the negative electrode tab.

11. The all-solid-state battery according to any one of claims 1 to 4, characterized in that, The elastic insulating material is at least one of silica gel, polyurethane, fluororubber, acrylic foam, modified rubber, thermoplastic elastomer, polyimide; And / or, the soft conductive material is at least one of silver-based conductive adhesive, carbon nanotube conductive adhesive, graphene conductive adhesive.

12. A method for preparing an all-solid-state battery, characterized in that, The method includes: Preparing a positive electrode sheet, a negative electrode sheet and an electrolyte sheet; Stack the positive electrode sheet, the electrolyte sheet, and the negative electrode sheet in sequence. Coat an elastic insulating material on the root of the positive electrode tab of the positive electrode sheet, and coat a soft conductive material on the surface of the positive electrode tab; coat a soft conductive material on the surface of the negative electrode tab of the negative electrode sheet to obtain a all-solid-state battery unit. Stack at least two all-solid-state battery units, encapsulate them, and perform isostatic pressing densification treatment to obtain the all-solid-state battery according to any one of claims 1 to 11.

13. The method according to claim 12, wherein The step of coating a soft conductive material on the surface of the negative electrode tab of the negative electrode sheet includes: Coat a soft conductive material on the surface of the negative electrode tab of the negative electrode sheet, and coat an elastic insulating material on the root of the negative electrode tab.

14. The method according to claim 12 or 13, characterized in that, The elastic insulating material is at least one of silicone, polyurethane, fluororubber, acrylic foam, modified rubber, thermoplastic elastomer, polyimide; And / or, the soft conductive material is at least one of silver-based conductive adhesive, carbon nanotube conductive adhesive, graphene conductive adhesive.

15. An electrical device, characterized in that, It includes a device main body and the all-solid-state battery according to any one of claims 1 to 11.

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