Battery monomer, battery device and electric device

Abstract

The invention provides a battery monomer, a battery device and a power utilization device. The battery cell includes a housing and an electrode assembly. The housing includes a first wall portion. The electrode assembly is contained in the shell and comprises a first pole piece, a solid electrolyte layer and a second pole piece, and at least one part of the first pole piece, at least one part of the solid electrolyte layer and at least one part of the second pole piece are arranged in a stacked mode in the first direction. Wherein in the first direction, a concave part is formed in the position, opposite to the electrode assembly, of the first wall part, and the concave part is configured to provide an expansion space for the electrode assembly. The concave part can deform towards the outside of the battery monomer under the expansion action of the electrode assembly, and when other parts are arranged at the positions, opposite to the electrode assembly, of the concave part, the concave part can provide a deformation space for the first wall part, so that the influence of expansion of the electrode assembly on the external part is reduced; therefore, the risk that the battery monomers or external parts are damaged under the action of expansion force is reduced, and the reliability of the battery monomers is improved.

Description

Technical Field

[0001] This application relates to the field of battery technology, and more specifically, to a battery cell, a battery device, and an electrical device. Background Technology

[0002] Energy conservation and emission reduction are key to the sustainable development of the automotive industry, and electric vehicles, due to their energy-saving and environmentally friendly advantages, have become an important component of this sustainable development. For electric vehicles, battery technology is a crucial factor in their development.

[0003] Battery devices are widely used in portable electronic devices, electric vehicles, power tools, drones, energy storage devices, and other fields. Besides considering the performance of individual battery cells, their reliability is also a crucial issue. Therefore, improving the reliability of individual battery cells is a pressing technical problem that needs to be solved in battery technology. Summary of the Invention

[0004] This application provides a battery cell, a battery device, and an electrical device, which can improve the reliability of the battery cell.

[0005] In a first aspect, embodiments of this application provide a battery cell, including a casing and an electrode assembly. The casing includes a first wall. The electrode assembly is housed within the casing and includes a first electrode, a solid electrolyte layer, and a second electrode. The first and second electrodes have opposite polarities. The solid electrolyte layer is disposed between the first and second electrodes. At least a portion of the first electrode, at least a portion of the solid electrolyte layer, and at least a portion of the second electrode are stacked along a first direction. Along the first direction, the large surface of the electrode assembly is positioned opposite the first wall. A recess is provided along the first direction at a position opposite the electrode assembly, and the recess is configured to provide expansion space for the electrode assembly.

[0006] In the above technical solution, because the first direction is parallel to the thickness direction of the first wall, and at least a portion of the first electrode, at least a portion of the solid electrolyte layer, and at least a portion of the second electrode are stacked along the first direction, the expansion force of the electrode assembly expanding along the first direction is greater. By providing a recess at the position opposite to the electrode assembly on the first wall, the recess can provide expansion space for the electrode assembly, reducing the internal stress of the battery cell. When other components are provided on the side of the first wall away from the electrode assembly, the expansion of the electrode assembly can easily squeeze other components. The recess can provide expansion space for the electrode assembly, reducing the internal stress of the battery cell when the expansion force of the electrode assembly squeezes other components, thereby reducing the risk of the battery cell being damaged under the action of expansion force and improving the reliability of the battery cell.

[0007] In some embodiments, a recess is provided on the side of the first wall portion opposite to the electrode assembly along a first direction. Thus, when the electrode assembly expands to compress the first wall portion, the recess can expand outward to provide deformation space for the first wall portion, reducing the internal stress of the battery cell.

[0008] In some embodiments, along a first direction, the first wall portion has a first outer surface facing away from the electrode assembly, and the recess is a groove disposed on the first outer surface, extending to at least one end of the first wall portion along a second direction, the second direction being perpendicular to the first direction. By providing the recess as a groove disposed on the first outer surface, and the groove extending to at least one end of the first wall portion along the second direction, on the one hand, it is beneficial for the battery cell to dissipate heat through the end of the first wall portion extending through the groove; on the other hand, it makes the processing of the recess more convenient and reduces the processing cost of the recess.

[0009] In some embodiments, along the second direction, the opposite ends of the groove extend to the two ends of the first wall portion. This allows the battery cell to dissipate heat through the opposite ends of the groove, and also makes the processing of the first wall portion easier, reducing the forming difficulty and saving processing costs.

[0010] In some embodiments, the battery cell further includes electrode terminals. The electrode terminals are disposed at at least one end of the housing along a third direction, with the first direction, second direction, and third direction being perpendicular to each other. By disposing of the electrode terminals at at least one end of the housing along the third direction, the groove can extend to at least one end of the first wall portion along the second direction, reducing the risk of interference between the groove and the electrode terminals and improving the reliability of the battery cell.

[0011] In some embodiments, along the third direction, the maximum size of the groove is L1, the maximum size of the outer shell is L2, and 0.9 ≤ L1 / L2 ≤ 0.98, with the first direction, the second direction, and the third direction being perpendicular to each other. When L1 / L2 ≥ 0.9, the deformation space provided by the groove to the first wall portion can be increased, reducing the impact of the expansion of the electrode assembly on external components; when L1 / L2 ≤ 0.98, the structural strength of the first wall portion can be improved, reducing the risk of the first wall portion collapsing due to an excessively large groove; therefore, when 0.9 ≤ L1 / L2 ≤ 0.98, both increasing the deformation space provided by the groove to the first wall portion and improving the structural strength of the first wall portion can be achieved.

[0012] In some embodiments, 90mm ≤ L2 ≤ 180mm. When L2 ≥ 90mm, the battery cell can have a larger dimension along the third direction, thereby allowing the groove to have a larger dimension along the third direction as well. The groove can provide a larger deformation space for the first wall portion, reducing the impact of electrode assembly expansion on external components. When L2 ≤ 180mm, the strength requirement of the first wall portion can be reduced. Since excessive strength of the first wall portion can easily over-restrain the expansion of the electrode assembly, causing damage to the electrode assembly, L2 ≤ 180mm can reduce the risk of electrode assembly damage and improve the reliability of the battery cell. Therefore, when 90mm ≤ L2 ≤ 180mm, it is possible to balance the ability of the groove to provide a larger deformation space for the first wall portion and the ability to reduce the risk of electrode assembly damage, thereby improving the reliability of the battery cell.

[0013] In some embodiments, along a third direction, the housing has opposing second and third outer surfaces, and the minimum distance between the groove and the second outer surface is L3, where 0.01 ≤ L3 / L2 ≤ 0.05. When L3 / L2 ≥ 0.01, the structural strength of the groove can be improved, reducing the risk of the first wall collapsing due to the small distance between the groove and the second outer surface. When L3 / L2 ≤ 0.05, the first wall can have more space to accommodate the groove, resulting in smaller deformation of the groove when the electrode assembly expands, reducing the risk of damage at the connection between the groove and the first wall due to excessive stress. Therefore, when 0.01 ≤ L3 / L2 ≤ 0.05, both the risk of the first wall collapsing due to the small distance between the groove and the second outer surface and the risk of damage at the connection between the groove and the first wall due to excessive stress when the electrode assembly expands and compresses the groove can be balanced.

[0014] In some embodiments, along a third direction, the housing has opposing second and third outer surfaces, and the minimum distance between the groove and the third outer surface is L4, where 0.01 ≤ L4 / L2 ≤ 0.05. When L4 / L2 ≥ 0.01, the structural strength of the groove can be improved, reducing the risk of the first wall collapsing due to the small distance between the groove and the third outer surface. When L4 / L2 ≤ 0.05, the first wall can have more space to accommodate the groove, resulting in smaller deformation of the groove when the electrode assembly expands, reducing the risk of damage at the connection between the groove and the first wall due to excessive stress. Therefore, when 0.01 ≤ L4 / L2 ≤ 0.05, both the risk of the first wall collapsing due to the small distance between the groove and the third outer surface and the risk of damage at the connection between the groove and the first wall due to excessive stress when the electrode assembly expands and compresses the groove can be balanced.

[0015] In some embodiments, along a third direction, the housing has opposing second and third outer surfaces, with the minimum distance between the groove and the second outer surface being L3, and the minimum distance between the groove and the third outer surface being L4; 0.01≤L3 / L2≤0.05; 0.01≤L4 / L2≤0.05. This approach balances reducing the risk of damage to the smaller dimensions of the first wall portions located on both sides of the groove along the third direction, and reducing the risk of damage due to excessive stress at the connection between the groove and the first wall portions when the electrode assembly expands and compresses the groove.

[0016] In some embodiments, L3 = L4. This makes the structure of the battery cell more aesthetically pleasing, and the fact that the dimensions of the first walls on both sides of the groove are similar makes the strength of the first walls more uniform and reduces the risk of damage to the first walls.

[0017] In some embodiments, along the first direction, the maximum dimension of the recess is H1, the minimum dimension of the electrode assembly is H2, and 0.01 ≤ H1 / H2 ≤ 0.15. When H1 / H2 ≥ 0.01, the recess has sufficient space to provide deformation space for the first wall, reducing the risk of the electrode assembly expanding and damaging the battery cell or external components. When H1 / H2 ≤ 0.15, on the one hand, the risk of the recess being too deep affecting the strength of the first wall can be reduced; on the other hand, the battery cell has more space to accommodate the electrode assembly, increasing the volumetric energy density of the battery cell. Therefore, when 0.01 ≤ H1 / H2 ≤ 0.15, it is possible to simultaneously reduce the risk of the electrode assembly expanding and damaging the battery cell or external components, improve the strength of the first wall, and increase the volumetric energy density of the battery cell.

[0018] In some embodiments, a protrusion is provided on the side of the first wall portion facing the electrode assembly along the first direction, corresponding to the recess. This makes it easier to form the recess and reduces the processing cost of the recess.

[0019] In some embodiments, the maximum dimension of the housing along the first direction is W1, where 25mm ≤ W1 ≤ 75mm. When W1 ≥ 25mm, on the one hand, the housing can have more space to accommodate the electrode assembly, which is beneficial to improving the volumetric energy density of the battery cell. On the other hand, since the housing can accommodate thicker electrode assemblies, the expansion of the electrode assemblies is greater, making the effect of the recess providing deformation space to the first wall more obvious. When W1 ≤ 75mm, the size of the battery cell can be reduced, reducing the risk that the battery cell is too large to be convenient to use and assemble. Therefore, when 25mm ≤ W1 ≤ 75mm, it is possible to balance improving the volumetric energy density of the battery cell and reducing the risk that the battery cell is too large to be convenient to use and assemble.

[0020] In some embodiments, the housing includes two first walls disposed opposite each other along a first direction, with the electrode assembly located between the two first walls. By positioning the electrode assembly between the two first walls, when the electrode assembly expands to both sides along the first direction, the recesses of both first walls can provide deformation space for the first wall containing the recesses, further reducing the impact of electrode assembly expansion on the reliability of the battery cell.

[0021] In some embodiments, the length and height of the housing are both greater than the width of the housing, and the width direction of the housing is parallel to the first direction. Thus, the length direction of the housing is the length direction of the first wall portion, and the height direction of the housing is the height direction of the first wall portion, allowing the first wall portion to have a larger dimension, thereby reducing the risk of damage to the first wall portion when the electrode assembly expands.

[0022] In some embodiments, the housing includes a housing and an end cap. The housing has an opening. The end cap closes the opening. The housing includes a first wall. By providing the housing with a first wall, it facilitates the entry of the electrode assembly into the housing through the opening, and also reduces the difficulty of installing the housing and the end cap.

[0023] In some embodiments, the housing includes two first wall portions disposed opposite each other along a first direction and two second wall portions disposed opposite each other along a second direction. The housing has an opening at at least one end along a third direction, and the first direction, the second direction, and the third direction are perpendicular to each other. The maximum dimension of the first wall portion along the second direction is greater than the maximum dimension of the second wall portion along the first direction.

[0024] In this embodiment, the first wall portion has a larger size than the second wall portion, thereby reducing the risk of damage to the first wall portion when the electrode assembly expands.

[0025] In some embodiments, the electrode assembly has a stacked structure. This allows the electrode assembly to expand more easily along the first direction. A recess is provided on the side of the first wall facing away from the electrode assembly, which helps provide deformation space for the first wall and reduces the impact of the electrode assembly's expansion on the reliability of the battery cell.

[0026] Secondly, embodiments of this application provide a battery device including a plurality of battery cells provided in any of the embodiments of the first aspect, wherein the plurality of battery cells are arranged along a first direction. In this way, the recess can reduce the risk of damage to the battery cells caused by the first wall portion compressing adjacent battery cells when the electrode assembly expands, thereby improving the reliability of the battery device.

[0027] In some embodiments, a recess is provided on the side of the first wall portion opposite to the electrode assembly along a first direction; the battery device further includes a buffer member, which is provided between two adjacent battery cells along the first direction, and at least a portion of the buffer member is accommodated within the recess. By providing the buffer member, the buffer member can buffer the deformation of the recess, reducing the risk of damage due to excessive deformation of the recess.

[0028] In some embodiments, in two adjacent battery cells, a portion of the buffer is housed within a recess in the first wall of one battery cell, and another portion of the buffer is housed within a recess in the first wall of the other battery cell. In this way, deformation of the recesses in both first walls can be buffered, reducing the risk of damage from direct contact between the two recesses.

[0029] In some embodiments, the buffer is made of an insulating material. In this way, the buffer can insulate part of the outer casing of the two battery cells, improving the insulation performance of the two battery cells.

[0030] In some embodiments, the battery device further includes a busbar connecting at least two adjacent battery cells to achieve electrical connection between the two adjacent battery cells. Thus, when the electrode assemblies of the battery cells expand, the recess can provide deformation space for the first wall portion, thereby reducing the risk of deformation of the electrode assemblies compressing the two adjacent battery cells, thereby reducing the risk of the busbar breaking and improving the structural stability of the battery device.

[0031] Thirdly, embodiments of this application provide an electrical device, including a battery cell provided in any one of the embodiments of the first aspect or a battery device provided in any one of the embodiments of the second aspect, wherein the battery cell is used to provide electrical energy to the electrical device. Attached Figure Description

[0032] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This application provides structural schematic diagrams of vehicles for some embodiments;

[0034] Figure 2 Exploded views of battery devices provided in some embodiments of this application;

[0035] Figure 3 Exploded views of a single battery cell provided in some embodiments of this application;

[0036] Figure 4 This is a schematic diagram of the structure of a battery cell provided in some embodiments of this application;

[0037] Figure 5 for Figure 4 AA section view;

[0038] Figure 6 for Figure 5 A magnified view of a portion of region A in the middle;

[0039] Figure 7 for Figure 5 A magnified view of a portion of region B in the middle;

[0040] Figure 8 This is a schematic diagram of the structure of a battery cell provided in some embodiments of this application;

[0041] Figure 9 for Figure 8 BB section view;

[0042] Figure 10 Schematic diagrams of the structure of the battery device provided in some embodiments of this application;

[0043] Figure 11 This is a schematic diagram of the structure of a battery device provided in some embodiments of this application;

[0044] Figure 12 This is a schematic diagram of the structure of a battery device provided in other embodiments of this application;

[0045] Figure 13 A schematic diagram of the structure of a battery device provided for some embodiments of this application (showing a busbar component).

[0046] Icons: 1-Outer shell; 1a-Housing shell; 1b-End cap; 11-First wall portion; 111-Recess; 111a-Groove; 112-First outer surface; 113-First inner surface; 114-Protrusion; 12-Second outer surface; 13-Third outer surface; 14-Second wall portion; 2-Electrode assembly; 21-First electrode; 22-Solid electrolyte layer; 23-Second electrode; 3-Electrode terminal;

[0047] 10 - Battery cell; 20 - Housing; 201 - First housing; 202 - Second housing; 30 - Buffer component; 40 - Busbar component;

[0048] 100 - Battery device; 200 - Controller; 300 - Motor; 1000 - Vehicle; X - First direction; Y - Second direction; Z - Third direction. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0050] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0051] In this application, the reference to "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0052] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0053] In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0054] In this application, "multiple" means two or more (including two).

[0055] In this embodiment of the application, the battery cell can be a secondary battery, which refers to a battery cell that can be recharged to activate the active materials and continue to be used after the battery cell has been discharged.

[0056] Battery cells include, but are not limited to, lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-metal hydride batteries, nickel-cadmium batteries, lead-acid batteries, etc.

[0057] A single battery cell typically includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charging and discharging process of a single battery cell, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative electrodes. The separator, positioned between the positive and negative electrodes, reduces the risk of short circuits while allowing active ions to pass through.

[0058] In some embodiments, the positive electrode can be a positive electrode sheet, which may include a positive current collector and a positive active material disposed on at least one surface of the positive current collector.

[0059] As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive active material is disposed on either or both of the two opposite surfaces of the positive current collector.

[0060] As an example, the positive electrode current collector can be a metal foil or a composite current collector. For example, as a metal foil, it can be aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, or titanium, etc. Composite current collectors can include a polymer material base layer and a metal layer. Composite current collectors can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0061] As an example, the positive electrode active material may include at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds. However, this application is not limited to these materials, and other conventional materials that can be used as positive electrode active materials in battery cells may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium phosphate may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (such as LiMnPO4), lithium manganese phosphate and carbon composites, lithium iron manganese phosphate, and lithium iron manganese phosphate and carbon composites. Examples of lithium transition metal oxide may include, but are not limited to, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, and lithium nickel cobalt manganese oxide (such as LiNi). 1 / 3 Co 1 / 3Mn 1 / 3O2 (also known as NCM) 333 LiNi 0.5 Co 0.2 Mn 0.3 O2 (also known as NCM) 523 LiNi 0.5 Co 0.25 Mn 0.25 O2 (also known as NCM) 211 LiNi 0.6 Co 0.2 Mn 0.2 O2 (also known as NCM) 622 LiNi 0.8 Co 0.1 Mn 0.1 O2 (also known as NCM) 811 ), lithium nickel cobalt aluminum oxide (such as LiNi) 0.85 Co 0.15 Al 0.05 At least one of O2 and its modified compounds.

[0062] In some embodiments, the positive electrode can be a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloys, etc. When foamed metal is used as the positive electrode, the surface of the foamed metal may or may not contain a positive electrode active material. As an example, lithium source material, potassium metal, or sodium metal can also be filled and / or deposited within the foamed metal, where the lithium source material is lithium metal and / or a lithium-rich material.

[0063] In some embodiments, the negative electrode can be a negative electrode sheet, and the negative electrode sheet can include a negative current collector.

[0064] As an example, the negative electrode current collector can be a metal foil, a foamed metal, or a composite current collector. For example, as a metal foil, it can be aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrodes, carbon, nickel, or titanium, etc. Foamed metal can be nickel foam, copper foam, aluminum foam, foam alloy, etc. Composite current collectors can include a polymer material base layer and a metal layer. Composite current collectors can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0065] As an example, the negative electrode sheet may include a negative current collector and a negative active material disposed on at least one surface of the negative current collector.

[0066] As an example, the negative electrode current collector has two surfaces opposite each other in its own thickness direction, and the negative electrode active material is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0067] As an example, the negative electrode active material may be a negative electrode active material known in the art for use in battery cells. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, etc. Silicon-based materials may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Tin-based materials may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, this application is not limited to these materials, and other conventional materials that can be used as negative electrode active materials in battery cells may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0068] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0069] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is disposed between the positive and negative electrodes, serving both to transport ions and to isolate the positive and negative electrodes.

[0070] Solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0071] As an example, polymer solid electrolytes can be polyether (polyoxyethylene), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, monoionic polymers, polyionic liquids-lithium salts, cellulose, etc.

[0072] As an example, inorganic solid electrolytes may include one or more of the following: oxide solid electrolytes (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON thin film), sulfide solid electrolytes (crystalline lithium superconducting ion conductor (lithium germanium phosphate sulfide, silver sulfide germanium ore), amorphous sulfides), halide solid electrolytes, nitride solid electrolytes, and hydride solid electrolytes.

[0073] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0074] In some embodiments, the battery cell may include a housing. The housing is used to encapsulate components such as electrode assemblies and electrolytes. The housing may be made of steel, aluminum, plastic (such as polypropylene), composite metal (such as copper-aluminum composite), or aluminum-plastic film, etc.

[0075] As an example, a battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes. Prismatic battery cells include prismatic battery cells, blade-shaped battery cells, and multi-prismatic battery cells, such as hexagonal prismatic battery cells.

[0076] The battery apparatus mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells, which are connected in series, parallel, or mixed connections via a busbar.

[0077] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells; as an example, a battery cell assembly can be a battery module, which is formed by arranging multiple battery cells and fixing them together to form an independent module.

[0078] As an example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0079] In some embodiments, the battery device may be a battery pack, which may include a housing and one or more individual battery cells housed within the housing.

[0080] As an example, the battery cell assembly can be a battery module, which can be housed in a housing by fixing the battery module in the housing.

[0081] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0082] As an example, the enclosure may include a first enclosure and a second enclosure. The first enclosure and the second enclosure are fastened together to form a closed space inside the enclosure to house the individual battery cells. Here, "closed" refers to covering or closing, and can be either sealed or unsealed. The first enclosure may be a top cover or a bottom plate.

[0083] As an example, the enclosure may include a top cover, a frame, and a bottom plate. The top cover and bottom plate are connected to the frame, creating an enclosed space inside the enclosure to house the individual battery cells.

[0084] As an example, the housing can be part of the vehicle's chassis structure. For instance, the housing's roof can be at least part of the vehicle's floor, or the housing's frame can be at least part of the vehicle's crossbeams and longitudinal beams.

[0085] In some embodiments, the battery device refers to an energy storage device, which includes a housing with a door on at least one side. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0086] A battery cell can include a casing and electrode assemblies, with the electrode assemblies housed within the casing. During the battery cell's electrical cycling process, the electrode assemblies tend to expand with increasing charge-discharge cycles. The casing of the battery cell expands outward under the expansion force of the electrode assemblies. On the one hand, this can easily affect the normal operation of the battery cell itself and other adjacent components; on the other hand, the casing restricts the expansion of the electrode assemblies, easily causing damage to the battery cell. This is especially true in solid-state battery cells, where the electrode assemblies consist of a stacked first electrode, a solid electrolyte layer, and a second electrode. Typically, the first electrode, solid electrolyte layer, and second electrode are relatively thick, and the electrode assembly itself is also thick, increasing the expansion of the electrode assembly along the stacking direction of the first electrode, solid electrolyte layer, and second electrode. In such battery cells, the casing deformation is greater, and the constraint force of the casing on the electrode assemblies is greater, making the battery cell more susceptible to damage. Furthermore, the outward expansion of the casing compresses adjacent components, increasing the compressive force between the casing and other components, easily leading to battery cell damage and reducing the battery cell's reliability.

[0087] In view of this, in order to improve the reliability of a single battery cell, this application provides a single battery cell including a casing and an electrode assembly. The casing includes a first wall. The electrode assembly is housed within the casing and includes a first electrode, a solid electrolyte layer, and a second electrode. The first and second electrodes have opposite polarities. The solid electrolyte layer is disposed between the first and second electrodes. At least a portion of the first electrode, at least a portion of the solid electrolyte layer, and at least a portion of the second electrode are stacked along a first direction. Along the first direction, the large surface of the electrode assembly is positioned opposite the first wall. A recess is provided along the first direction at a position opposite the electrode assembly, and the recess is configured to provide expansion space for the electrode assembly.

[0088] In such a battery cell, because the first direction is parallel to the thickness direction of the first wall, and at least a portion of the first electrode, at least a portion of the solid electrolyte layer, and at least a portion of the second electrode are stacked along the first direction, the electrode assembly can easily expand along the first direction to abut against the first wall. By providing a recess at a position opposite to the electrode assembly in the first wall, the recess can provide expansion space for the electrode assembly, reducing the internal stress of the battery cell. When other components are located on the side of the recess of the battery cell away from the electrode assembly, the expansion of the electrode assembly can easily compress these other components. The recess can provide expansion space for the electrode assembly, reducing the internal stress of the battery cell when the expansion force of the electrode assembly compresses these other components, thereby reducing the risk of the battery cell being damaged under the action of expansion force and improving the reliability of the battery cell.

[0089] The technical solutions described in the embodiments of this application are applicable to various electrical devices that use battery cells and battery devices, such as mobile phones, portable devices, laptops, electric vehicles, electric toys, power tools, vehicles, ships and spacecraft, etc. For example, spacecraft include airplanes, rockets, space shuttles and spacecraft.

[0090] For ease of explanation, the following embodiments use a vehicle as an example of electrical equipment.

[0091] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a vehicle 1000 provided in some embodiments of this application. A battery device 100 is disposed inside the vehicle 1000, and the battery device 100 may be located at the bottom, front, or rear of the vehicle 1000. The battery device 100 can be used to power the vehicle 1000; for example, the battery device 100 can serve as the operating power source for the vehicle 1000.

[0092] The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery device 100 to supply power to the motor 300, for example, for the power needs of the vehicle 1000 during startup, navigation and driving.

[0093] In some embodiments of this application, the battery device 100 can not only serve as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0094] Please refer to Figure 2 , Figure 2 This is an exploded view of a battery device 100 provided in some embodiments of this application. The battery device 100 may include a housing 20 and battery cells 10, the housing 20 being used to house the battery cells 10.

[0095] The housing 20 has an enclosed space inside for accommodating the battery cells 10. The housing 20 can have various structures. In some embodiments, the housing 20 may include a first housing 201 and a second housing 202, which are interlocked. The first housing 201 and the second housing 202 can have various shapes, such as cuboids or cylinders. The first housing 201 can be a hollow structure open on one side, and the second housing 202 can also be a hollow structure open on one side. The open side of the second housing 202 interlocks with the open side of the first housing 201, thus forming a housing 20 with an enclosed space. Alternatively, the first housing 201 can be a hollow structure open on one side, and the second housing 202 can be a plate-like structure, with the second housing 202 interlocked with the open side of the first housing 201, thus forming a housing 20 with an accommodating space.

[0096] In the battery device 100, there can be one or more battery cells 10. If there are multiple battery cells 10, they can be connected in series, parallel, or in a mixed manner. A mixed connection means that multiple battery cells 10 are connected in both series and parallel. Alternatively, multiple battery cells 10 can be first connected in series, parallel, or in a mixed manner to form a battery module, and then multiple battery modules can be connected in series, parallel, or in a mixed manner to form a whole, which is then housed within the housing 20. Another option is that all battery cells 10 can be directly connected in series, parallel, or in a mixed manner, and then the whole consisting of all battery cells 10 is housed within the housing 20.

[0097] Please refer to Figure 3 , Figure 3 This is an exploded view of a battery cell 10 provided in some embodiments of this application. The battery cell 10 may include a housing 1 and an electrode assembly 2, the electrode assembly 2 being housed within the housing 1.

[0098] In some embodiments, the housing 1 may include a housing 1a and an end cap 1b, the housing 1a having an opening and the end cap 1b closing the opening of the housing 1a. Here, "closing" refers to covering or shutting off, and can be either sealed or unsealed.

[0099] The housing 1a is a component used to house the electrode assembly 2. The housing 1a can be a hollow structure with an opening at one end, or it can be a hollow structure with openings at both opposite ends. The housing 1a can have various shapes, such as cylindrical or cuboid. The housing 1a can be made of various materials, such as copper, iron, aluminum, steel, or aluminum alloy. The electrode assembly 2 can be partially or completely housed within the housing 1a.

[0100] The end cap 1b and the housing 1a together define a receiving space for accommodating the electrode assembly 2 and other components. The end cap 1b can be connected to the housing 1a by welding, rolling, or other methods to close the opening of the housing 1a. The shape of the end cap 1b can be adapted to the shape of the housing 1a. For example, if the housing 1a is a cuboid structure, the end cap 1b can be a rectangular plate structure adapted to the housing 1a; or if the housing 1a is a cylindrical structure, the end cap 1b can be a circular plate structure adapted to the housing 1a. The end cap 1b can also be made of various materials, such as copper, iron, aluminum, steel, or aluminum alloy. The end cap 1b and the housing 1a can be made of the same or different materials.

[0101] In an embodiment where the housing 1a has an opening at one end, one end cap 1b may be provided accordingly. In an embodiment where the housing 1a has openings at both opposite ends, two end caps 1b may be provided accordingly, with the two end caps 1b respectively closing the two openings of the housing 1a, and the two end caps 1b and the housing 1a together defining the receiving space.

[0102] In some embodiments, the battery cell 10 may further include electrode terminals 3, which are disposed on the housing 1 and are used for electrical connection with the tabs of the electrode assembly 2 to input or output electrical energy of the battery cell 10. The electrode terminals 3 may be disposed on the housing 1a of the housing 1 or on the end cap 1b of the housing 1. The electrode terminals 3 and the tabs may be directly connected, for example, by welding the electrode terminals 3 to the tabs. Alternatively, the electrode terminals 3 and the tabs may be indirectly connected, for example, by a current collector. The current collector may be a metallic conductor, such as copper, iron, aluminum, steel, or aluminum alloy.

[0103] Please refer to Figure 4 and Figure 5 , Figure 4 This is a schematic diagram of the structure of a battery cell 10 provided in some embodiments of this application; Figure 5 for Figure 4 A cross-sectional view (AA). This application provides a battery cell 10, including a housing 1 and an electrode assembly 2. The housing 1 includes a first wall 11. The electrode assembly 2 is housed within the housing 1 and includes a first electrode 21, a solid electrolyte layer 22, and a second electrode 23. The first electrode 21 and the second electrode 23 have opposite polarities. The solid electrolyte layer 22 is disposed between the first electrode 21 and the second electrode 23. At least a portion of the first electrode 21, at least a portion of the solid electrolyte layer 22, and at least a portion of the second electrode 23 are stacked along a first direction X. Along the first direction X, the larger surface of the electrode assembly 2 is positioned opposite the first wall 11. A recess 111 is provided along the first direction X at a position opposite the electrode assembly 2, and the recess 111 is configured to provide expansion space for the electrode assembly 2.

[0104] The first electrode 21 can be the positive electrode, the second electrode 23 can be the negative electrode, and the first active material layer can be the positive active material; or the first electrode 21 can be the negative electrode, the second electrode 23 can be the positive electrode, and the second active material layer can be the negative active material.

[0105] The first electrode 21, the solid electrolyte layer 22, and the second electrode 23 of the electrode assembly 2 have an overlapping area in a projection plane perpendicular to the first direction X.

[0106] The solid electrolyte layer 22 may be disposed along the first direction X between at least a portion of the first electrode 21 and at least a portion of the second electrode 23; or the entire solid electrolyte layer 22 may be disposed along the first direction X between at least a portion of the first electrode 21 and at least a portion of the second electrode 23. For example, the solid electrolyte layer 22 connects the first electrode 21 and the second electrode 23.

[0107] The electrode assembly 2 can be a stacked structure or a wound structure. In an embodiment where the electrode assembly 2 is a wound structure, there can be only one first electrode 21, one solid electrolyte layer 22, and one second electrode 23. The first electrode 21, the solid electrolyte layer 22, and the second electrode 23 are stacked and then wound to form the wound electrode assembly 2. In an embodiment where the electrode assembly 2 is a stacked structure, there can be only one first electrode 21, one solid electrolyte layer 22, and one second electrode 23. The first electrode 21, the solid electrolyte layer 22, and the second electrode 23 are stacked sequentially to form the stacked electrode assembly 2. Alternatively, there can be multiple first electrodes 21, multiple solid electrolyte layers 22, and multiple second electrodes 23. Multiple first electrodes 21, multiple solid electrolyte layers 22, and multiple second electrodes 23 are stacked sequentially in the order of first electrode 21, solid electrolyte layer 22, second electrode 23, and first electrode 21 to form a multi-layer stacked electrode assembly 2.

[0108] The large surface of electrode assembly 2 is the largest surface of its outer surface. For example, when electrode assembly 2 is a stacked structure, the large surface of electrode assembly 2 is the two opposite outer surfaces of the first electrode 21, the solid electrolyte layer 22, and the second electrode 23 in the stacking direction. Alternatively, when electrode assembly 2 is a wound structure, electrode assembly 2 includes a flat region and a bent region. Along the second direction Y, bent regions are provided at opposite ends of the flat region. The portions of the first electrode 21, the second electrode 23, and the solid electrolyte layer 22 located in the flat region are basically flat, while the portions of the first electrode 21, the second electrode 23, and the solid electrolyte layer 22 located in the bent region are roughly arc-shaped. The portions of the first electrode 21, the second electrode 23, and the solid electrolyte layer 22 located in the flat region are stacked along the first direction X. The second direction Y is perpendicular to the first direction X. Along the first direction X, the outermost surface of the flat region is the large surface of electrode assembly 2.

[0109] In some embodiments, the number of first wall portions 11 may be one, and a recess 111 is provided at a position opposite to the electrode assembly 2. In other embodiments, the number of first wall portions 11 may be two, and the two first wall portions 11 are arranged opposite to each other along a first direction X. A recess 111 is provided at a position opposite to the electrode assembly 2, and a recess 111 is also provided at a position opposite to the electrode assembly 2. The position where the first wall portion 11 is opposite to the electrode assembly 2 refers to the area on the first wall portion 11 that overlaps with the projection of the electrode assembly 2 along the first direction X.

[0110] A recess 111 is provided at a position on the first wall portion 11 opposite to the electrode assembly 2 along the first direction X. The first wall portion 11 may be a plate-like structure, having a first outer surface 112 and a first inner surface 113. The recess may be a groove provided on the first outer surface 112, with an expansion space located on the side of the first wall portion 11 away from the electrode assembly 2; or the recess 111 may be a groove provided on the first inner surface 113, with an expansion space located on the side of the first wall portion 11 facing the electrode assembly 2. The first wall portion 11 may also be a bent structure, with a portion of the first wall portion 11 protruding in the direction facing the electrode assembly 2, so that a recess 111 is formed at a position corresponding to the protrusion in the direction away from the electrode assembly 2.

[0111] The recess 111 may be a recessed area located on the surface of the first wall portion 11, which is spaced apart from the edge of the first wall portion 11. For example, the recess 111 may be a blind hole located on the surface; the recess 111 may also be a groove extending to the edge of the first wall portion 11.

[0112] In this embodiment, by setting the first direction X parallel to the thickness direction of the first wall portion 11, and stacking at least a portion of the first electrode 21, at least a portion of the solid electrolyte layer 22, and at least a portion of the second electrode 23 along the first direction X, the electrode assembly 2 can easily expand along the first direction X to abut against the first wall portion 11. In the solid-state battery cell 10, a thicker electrode assembly 2 is required to increase the capacity of the battery cell 10. The thicker electrode assembly 2 makes the expansion of the electrode assembly 2 during charge and discharge cycles more obvious. The electrode assembly 2 tends to expand along the stacking direction of the first electrode 21, the solid electrolyte layer 22, and the second electrode 23. By providing a recess 111 on the side of the first wall portion 11 away from the electrode assembly 2, the recess 111 can deform outwards from the battery cell 10 under the expansion of the electrode assembly 2. When other components are provided at the position opposite to the electrode assembly 2, the recess 111 can provide expansion space for the electrode assembly 2, reducing the impact of the expansion of the electrode assembly 2 on external components. This reduces the risk of damage to the battery cell 10 or external components under the expansion force, and improves the reliability of the battery cell 10.

[0113] In some embodiments, please continue to refer to Figure 5 Along the first direction X, a recess 111 is provided on the side of the first wall portion 11 opposite to the electrode assembly 2.

[0114] The first wall portion 11 has a first outer surface 112 and a first inner surface 113 disposed opposite to each other along the first direction X, and the first outer surface 112 is provided with a recess 111.

[0115] In this embodiment, by providing a recess 111 on the side of the first wall portion 11 away from the electrode assembly 2, when the electrode assembly expands to compress the first wall portion, the recess can expand outward to provide deformation space for the first wall portion, thereby reducing the internal stress of the battery cell.

[0116] In some embodiments, please continue to refer to Figure 5 Along the first direction X, the first wall portion 11 has a first outer surface 112 facing away from the electrode assembly 2, and the recess 111 is a groove 111a provided on the first outer surface 112. The groove 111a extends to at least one end of the first wall portion 11 along the second direction Y, which is perpendicular to the first direction X.

[0117] The groove 111a may extend to only one end of the first wall portion 11 along the second direction Y; or the groove 111a may extend to both ends of the first wall portion 11 along the second direction Y. In an embodiment where the first wall portion 11 has a first surface and a second surface, the first surface is a first outer surface 112. The first direction X may be the width direction of the electrode assembly 2, and the electrode assembly 2 and the first wall portion 11 are arranged along the first direction X. The second direction Y may be the length direction of the electrode assembly 2 or the height direction of the electrode assembly 2.

[0118] In this embodiment, by setting the recess 111 as a groove 111a on the first outer surface 112, and the groove 111a extending to at least one end of the first wall portion 11 along the second direction Y, on the one hand, it is beneficial for the battery cell 10 to dissipate heat through the end of the first wall portion 11 extending through the groove 111a; on the other hand, it makes the processing of the recess 111 more convenient and reduces the processing cost of the recess 111.

[0119] In some embodiments, please continue to refer to Figure 5 Along the second direction Y, the opposite ends of the groove 111a extend to the two ends of the first wall portion 11, respectively.

[0120] The groove 111a extends to both ends of the first wall portion 11 along the second direction Y, so that the groove 111a penetrates the outer casing 1 of the battery cell 10 along the second direction Y.

[0121] In this embodiment, by extending the opposite ends of the groove 111a to the opposite ends of the first wall portion 11, on the one hand, the battery cell 10 can dissipate heat through the opposite ends of the groove 111a, and on the other hand, the processing of the first wall portion 11 is more convenient, reducing the forming difficulty of the first wall portion 11 and saving the processing cost of the first wall portion 11.

[0122] In some embodiments, please continue to refer to Figure 5The battery cell 10 also includes an electrode terminal 3. The electrode terminal 3 is provided at least one end of the housing 1 along the third direction Z, and the first direction X, the second direction Y and the third direction Z are perpendicular to each other.

[0123] The housing 1 may have a motor terminal at only one end along the third direction Z; for example, the housing 1 may have two motor terminals at one end along the third direction Z, which are a positive motor terminal and a negative motor terminal, respectively. Alternatively, the housing 1 may have motor terminals at both ends along the third direction Z; for example, the housing 1 may have two walls along the third direction Z, one of which may have a positive motor terminal and the other may have a negative motor terminal.

[0124] By providing an electrode terminal 3 at at least one end of the housing 1 along the third direction Z, the groove 111a can extend to at least one end of the first wall portion 11 along the second direction Y, reducing the risk of interference between the groove 111a and the electrode terminal 3 and improving the reliability of the battery cell 10.

[0125] In some embodiments, please continue to refer to Figure 5 Along the third direction Z, the maximum dimension of the groove 111a is L1, the maximum dimension of the outer shell 1 is L2, 0.9≤L1 / L2≤0.98, and the first direction X, the second direction Y and the third direction Z are perpendicular to each other.

[0126] L1 / L2 can be any of the following point values: 0.9, 0.905, 0.91, 0.915, 0.92, 0.925, 0.93, 0.935, 0.94, 0.945, 0.95, 0.955, 0.96, 0.965, 0.97, 0.975, 0.98, or any value between the two.

[0127] When L1 / L2≥0.9, the deformation space provided by the groove 111a to the first wall portion 11 can be increased, reducing the impact of the expansion of the electrode assembly 2 on external components; when L1 / L2≤0.98, the structural strength of the first wall portion 11 can be improved, reducing the risk of the first wall portion 11 collapsing due to the excessive size of the groove 111a; therefore, when 0.01≤L1 / L2≤0.15, it is possible to balance increasing the deformation space provided by the groove 111a to the first wall portion 11 and improving the structural strength of the first wall portion 11.

[0128] In some embodiments, 90mm ≤ L2 ≤ 180mm.

[0129] L2 can be a point value or a range of any two of the following values: 90mm, 95mm, 100mm, 105mm, 110mm, 115mm, 120mm, 125mm, 130mm, 135mm, 140mm, 145mm, 150mm, 155mm, 160mm, 165mm, 170mm, 175mm, and 180mm.

[0130] When L2 ≥ 90 mm, the battery cell 10 can have a larger dimension along the third direction Z, thereby allowing the groove 111a to also have a larger dimension along the third direction Z. The groove 111a can provide a larger deformation space for the first wall portion 11, reducing the impact of the expansion of the electrode assembly 2 on external components. When L2 ≤ 180 mm, the strength requirement of the first wall portion 11 can be reduced. Excessive strength of the first wall portion 11 can easily over-restrain the expansion of the electrode assembly 2, causing damage to the electrode assembly 2. L2 ≤ 180 mm can reduce the risk of damage to the electrode assembly 2 and improve the reliability of the battery cell 10. Therefore, when 90 mm ≤ L2 ≤ 180 mm, the groove 111a can provide a larger deformation space for the first wall portion 11 and reduce the risk of damage to the electrode assembly 2, thus improving the reliability of the battery cell 10.

[0131] In some embodiments, please refer to Figures 5-7 , Figure 6 for Figure 5 A magnified view of a portion of region A in the middle; Figure 7 for Figure 5 A magnified view of region B in the middle. Along the third direction Z, the outer shell 1 has a second outer surface 12 and a third outer surface 13 with opposite sides. The minimum distance between the groove 111a and the second outer surface 12 is L3, where 0.01≤L3 / L2≤0.05.

[0132] L3 / L2 can be any one of the following values: 0.01, 0.012, 0.015, 0.018, 0.02, 0.022, 0.025, 0.028, 0.03, 0.032, 0.035, 0.038, 0.04, 0.042, 0.045, 0.048, 0.05, or any value between the two.

[0133] When L3 / L2≥0.01, the structural strength of the groove 111a can be improved, reducing the risk of the first wall portion 11 collapsing due to the small distance between the groove 111a and the second outer surface 12. When L3 / L2≤0.05, the first wall portion 11 has more space to accommodate the groove 111a, resulting in smaller deformation of the groove 111a when the electrode assembly 2 expands, thus reducing the risk of damage at the connection between the groove 111a and the first wall portion 11 due to excessive stress. Therefore, when 0.01≤L3 / L2≤0.05, both the risk of the first wall portion 11 collapsing due to the small distance between the groove 111a and the second outer surface 12 and the risk of damage at the connection between the groove 111a and the first wall portion 11 due to excessive stress when the electrode assembly 2 expands and compresses the groove 111a can be balanced.

[0134] In some embodiments, please continue to refer to Figure 7 Along the third direction Z, the outer shell 1 has a second outer surface 12 and a third outer surface 13 opposite to each other, and the minimum distance between the groove 111a and the third outer surface 13 is L4, 0.01≤L4 / L2≤0.05.

[0135] L4 / L2 can be any one of the following values: 0.01, 0.012, 0.015, 0.018, 0.02, 0.022, 0.025, 0.028, 0.03, 0.032, 0.035, 0.038, 0.04, 0.042, 0.045, 0.048, 0.05, or any value between the two.

[0136] When L4 / L2≥0.01, the structural strength of the groove 111a can be improved, reducing the risk of the first wall portion 11 collapsing due to the small distance between the groove 111a and the third outer surface 13. When L4 / L2≤0.05, the first wall portion 11 has more space to accommodate the groove 111a, resulting in smaller deformation of the groove 111a when the electrode assembly 2 expands, thus reducing the risk of damage at the connection between the groove 111a and the first wall portion 11 due to excessive stress. Therefore, when 0.01≤L4 / L2≤0.05, both the risk of the first wall portion 11 collapsing due to the small distance between the groove 111a and the third outer surface 13 and the risk of damage at the connection between the groove 111a and the first wall portion 11 due to excessive stress when the electrode assembly 2 expands and compresses the groove 111a can be balanced.

[0137] In some embodiments, along the third direction Z, the housing 1 has a second outer surface 12 and a third outer surface 13 opposite to each other, the minimum distance between the groove 111a and the second outer surface 12 is L3, and the minimum distance between the groove 111a and the third outer surface 13 is L4; 0.01≤L3 / L2≤0.05; 0.01≤L4 / L2≤0.05.

[0138] In this embodiment, by setting 0.01≤L3 / L2≤0.05 and 0.01≤L4 / L2≤0.05, it is possible to reduce the risk of damage to the first wall portion 11 located on both sides of the groove 111a along the third direction Z due to its small size, and to reduce the risk of damage to the connection between the groove 111a and the first wall portion 11 due to excessive stress when the electrode assembly 2 expands and squeezes the groove 111a.

[0139] In some embodiments, L3 = L4.

[0140] The first wall portion 11 has a first protrusion and a second protrusion on both sides of the groove 111a along the third direction Z. The first protrusion is located between the groove 111a and the second outer surface 12, and the second protrusion is located between the groove 111a and the third outer surface 13. The dimensions of the first protrusion and the second protrusion along the third direction Z are equal.

[0141] In this embodiment, on the one hand, the equal dimensions of the first protrusion and the second protrusion along the third direction Z make the structure of the battery cell 10 more aesthetically pleasing. On the other hand, the equal dimensions of the first wall portions 11 on both sides of the groove 111a make the strength of the first wall portions 11 more uniform and reduce the risk of damage to the first wall portions 11.

[0142] In some embodiments, please continue to refer to Figure 5 and Figure 6 Along the first direction X, the maximum dimension of the recess 111 is H1 ( Figure 6 As shown in the figure, the minimum size of electrode assembly 2 is H2 ( Figure 5 As shown in the figure, 0.01≤H1 / H2≤0.15.

[0143] The recess 111 has a groove depth, and the maximum dimension of the recess 111 along the first direction X is the maximum groove depth of the recess 111, that is, the distance between the deepest part of the recess 111 in the direction from the first wall portion 11 to the electrode assembly 2 and the first outer surface 112.

[0144] The electrode assembly 2 expands during charging and contracts during discharging. The minimum dimension of the electrode assembly 2 along the first direction X is the minimum dimension of the electrode assembly 2 along the first direction X after it has been manufactured and has been charged and discharged less than or equal to 100 times.

[0145] H1 / H2 can be any one of the following point values: 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14, 0.15, or any point value between the two.

[0146] When H1 / H2≥0.01, the recess 111 has sufficient space to provide deformation space for the first wall portion 11, reducing the risk of the electrode assembly 2 expanding and damaging the battery cell 10 or external components. When H1 / H2≤0.15, on the one hand, the risk of the recess 111 being too deep affecting the strength of the first wall portion 11 can be reduced, and on the other hand, the battery cell 10 can have more space to accommodate the electrode assembly 2, increasing the volumetric energy density of the battery cell 10. Therefore, when 0.01≤H1 / H2≤0.15, it is possible to balance reducing the risk of the electrode assembly 2 expanding and damaging the battery cell 10 or external components, increasing the strength of the first wall portion 11, and increasing the volumetric energy density of the battery cell 10.

[0147] In some embodiments, please continue to refer to Figure 5 The maximum dimension of the outer casing 1 along the first direction X is W1, where 25mm ≤ W1 ≤ 75mm.

[0148] W1≥25mm allows the outer casing 1 to accommodate a larger electrode assembly 2. In the solid-state battery cell 10, the thicker electrode assembly 2 has a larger expansion space during charge and discharge cycles. Thus, the recess 111 on the first wall portion 11 can further enhance the effect of providing deformation space for the first wall portion 11.

[0149] In an embodiment where the housing 1 has a first wall portion 11, the housing 1 has a third wall portion disposed opposite to the first wall portion 11, and the distance between the outer surface of the third wall portion and the first outer surface 112 is the maximum dimension of the housing 1 along the first direction X.

[0150] W1 can be a point value of any one of 25mm, 27mm, 30mm, 32mm, 35mm, 37mm, 40mm, 42mm, 45mm, 47mm, 50mm, 52mm, 55mm, 57mm, 60mm, 62mm, 65mm, 67mm, 70mm, 72mm, 75mm or any combination thereof.

[0151] When W1 ≥ 25 mm, on the one hand, the outer casing 1 has more space to accommodate the electrode assembly 2, which is beneficial to improving the volumetric energy density of the battery cell 10. On the other hand, the outer casing 1 can accommodate a thicker electrode assembly 2, and the expansion of the electrode assembly 2 is greater, making the effect of the recess 111 providing deformation space to the first wall portion 11 more obvious. When W1 ≤ 75 mm, the size of the battery cell 10 can be reduced, reducing the risk that the battery cell 10 is too large and inconvenient to use and assemble. Therefore, when 25 mm ≤ W1 ≤ 75 mm, it is possible to balance improving the volumetric energy density of the battery cell 10 and reducing the risk that the battery cell 10 is too large and inconvenient to use and assemble.

[0152] In some embodiments, 0.9 ≤ H2 / W1 < 1.

[0153] H2 / W1 can be any one of the following values: 0.9, 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98, 0.99, or any value between two of them.

[0154] When H2 / W1≥0.9, the electrode assembly 2 can have a larger size along the first direction X, which is beneficial to improving the volumetric energy density of the battery cell 10. When H2 / W1<1, it is beneficial to place the electrode assembly 2 on the outer casing 1, reducing the installation difficulty of the electrode assembly 2. Therefore, when 0.9≤H2 / W1<1, it is possible to balance improving the volumetric energy density of the battery cell 10 and reducing the installation difficulty of the electrode assembly 2.

[0155] In some embodiments, please continue to refer to Figures 4-7 Along the first direction X, a protrusion 114 is provided on the side of the first wall portion 11 facing the electrode assembly 2, corresponding to the recess 111.

[0156] The recess 111 and the convex portion 114 are provided correspondingly. The recess 111 can be formed by stamping and stretching on the first wall portion 11, and the convex portion 114 can be formed on the side of the first wall portion 11 facing the electrode assembly 2 at a position corresponding to the recess 111; or the first wall portion 11 can be cast to form the recess 111 and the convex portion 114.

[0157] The first wall portion 11 has a first outer surface 112 and a first inner surface 113 disposed opposite to each other along the first direction X. Figure 6 As shown in the figure, a recess 111 is provided on the first outer surface 112 and the recess 111 is recessed in the direction of the electrode assembly 2; a convex portion 114 protrudes from the first inner surface 113 in the direction of the first wall portion 11 pointing to the electrode assembly 2, so that the recess 111 corresponds to the convex portion 114.

[0158] In this embodiment, a protrusion 114 is provided on the side of the first wall portion 11 facing the electrode assembly 2, corresponding to the recess 111, which makes it easier to form the recess 111 and reduces the processing cost of the recess 111.

[0159] In some embodiments, the housing 1 includes two first wall portions 11 disposed opposite to each other along a first direction X, and the electrode assembly 2 is located between the two first wall portions 11.

[0160] Both first wall portions 11 are provided with recesses 111, which provide deformation space for the first wall portions 11 when the electrode assembly 2 expands. The outer casing 1 may include a housing 1a and an end cap 1b. Both first wall portions 11 may be walls on the housing 1a, both first wall portions 11 may be end caps 1b, or one first wall portion 11 may be a wall on the housing 1a and the other first wall portion 11 may be an end cap 1b.

[0161] By positioning the electrode assembly 2 between the two first wall portions 11, when the electrode assembly 2 expands to both sides along the first direction X, the recesses 111 of the two first wall portions 11 can provide deformation space for the first wall portion 11 where the recesses 111 are located, further reducing the impact of the expansion of the electrode assembly 2 on the reliability of the battery cell 10.

[0162] In some embodiments, the length and height of the outer shell 1 are both greater than the width of the outer shell 1, and the width direction of the outer shell 1 is parallel to the first direction X.

[0163] The length, width, and height of the outer shell 1 are the maximum length, maximum width, and maximum height of the outer shell 1, respectively. The width direction of the outer shell 1 is parallel to the first direction X, such that the length and width of the outer shell 1 are the length and width of the first wall portion 11, respectively, that is, the first wall portion 11 is the largest wall portion of the outer shell 1.

[0164] In this embodiment, by setting the length and height of the outer shell 1 to be greater than the width of the outer shell 1, the length direction of the outer shell 1 is the length direction of the first wall portion 11, and the height direction of the outer shell 1 is the height direction of the first wall portion 11, the first wall portion 11 has a larger size, thereby reducing the risk of the first wall portion 11 being damaged when the electrode assembly 2 expands.

[0165] In some embodiments, the housing 1 includes a housing 1a and an end cap 1b. The housing 1a has an opening. The end cap 1b closes the opening. The housing 1a includes a first wall portion 11.

[0166] The first wall portion 11 can be one, and the first wall portion 11 is one wall portion of the housing 1a; or the first wall portion 11 can be two, and the two first wall portions 11 are two wall portions of the housing 1a arranged opposite each other along the first direction X.

[0167] By setting the housing 1a as the first wall portion 11, on the one hand, it is beneficial for the electrode assembly 2 to enter the housing 1a from the opening, and on the other hand, it reduces the installation difficulty of the housing 1a and the end cap 1b.

[0168] In some embodiments, please refer to Figure 8 and Figure 9 , Figure 8This is a schematic diagram of the structure of a battery cell 10 provided in some embodiments of this application; Figure 9 for Figure 8 The BB cross-sectional view shows that the housing 1a includes two first wall portions 11 disposed opposite each other along a first direction X and two second wall portions 14 disposed opposite each other along a second direction Y. At least one end of the housing 1a has an opening along a third direction Z. The first direction X, the second direction Y, and the third direction Z are perpendicular to each other. The maximum dimension of the first wall portion 11 along the second direction Y is greater than the maximum dimension of the second wall portion 14 along the first direction X.

[0169] The housing 1a has two first wall portions 11, and each of the two first wall portions 11 is provided with a recess 111.

[0170] In an embodiment where the housing 1 has two first wall portions 11, the maximum dimension W1 of the housing 1 along the first direction X is the maximum distance between the first outer surfaces 112 of the two first wall portions 11.

[0171] In this embodiment, the first wall portion 11 has a larger size than the second wall portion 14, thereby reducing the risk of damage to the first wall portion 11 when the electrode assembly 2 expands.

[0172] In some embodiments, the electrode assembly 2 has a stacked structure.

[0173] The electrode assembly 2 may have only one first electrode 21, one solid electrolyte layer 22, and one second electrode 23; or the electrode assembly 2 may have multiple first electrode 21, multiple solid electrolyte layers 22, and multiple second electrode 23. Each solid electrolyte layer 22 has a first electrode 21 and a second electrode 23 respectively disposed on both sides along the first direction X. At least one side of any first electrode 21 has a solid electrolyte layer 22, and at least one side of any second electrode 23 has a solid electrolyte layer 22.

[0174] In this embodiment, the electrode assembly 2 is configured as a stacked structure. The electrode assembly 2 expands more easily along the first direction X. A recess 111 is provided on the side of the first wall portion 11 opposite to the electrode assembly 2. This recess 111 provides deformation space for the first wall portion 11, reducing the impact of the expansion of the electrode assembly 2 on the reliability of the battery cell 10.

[0175] Please refer to Figure 10 , Figure 10 This is a schematic diagram of the structure of a battery device 100 provided in some embodiments of this application. Embodiments of this application provide a battery device 100, including a plurality of battery cells 10 provided in any of the above embodiments, the plurality of battery cells 10 being arranged along a first direction X.

[0176] Multiple battery cells 10 are arranged along a first direction X, such that the recesses 111 of the battery cells 10 can face adjacent battery cells 10. When the battery cells 10 of the battery device 100 are in contact with each other, the electrode assembly 2 expands to cause the recesses 111 to expand toward the adjacent battery cells 10, but the recesses 111 do not easily contact the adjacent battery cells 10, so that the distance between two adjacent battery cells 10 does not easily change, thereby improving the structural stability of the battery device 100.

[0177] In this embodiment, by arranging multiple battery cells 10 along the first direction X, the recess 111 can reduce the risk of damage to the battery cells 10 caused by the first wall portion 11 squeezing adjacent battery cells 10 when the electrode assembly 2 expands, thereby improving the reliability of the battery device 100.

[0178] In some embodiments, please refer to Figure 11 , Figure 11 This is a schematic diagram of the structure of a battery device 100 provided in some embodiments of this application. Along the first direction X, a recess 111 is provided on the side of the first wall portion 11 facing away from the electrode assembly 2. The battery device 100 also includes a buffer member 30, which is provided between two adjacent battery cells 10 along the first direction X, and at least a portion of the buffer member 30 is accommodated in the recess 111.

[0179] The buffer 30 may be entirely contained within the recess 111, or only a portion of the buffer 30 may be located within the recess 111.

[0180] By setting the buffer 30, the buffer 30 can buffer the deformation of the recess 111, increase the contact area between two adjacent battery cells 10, and reduce the risk of damage due to excessive deformation of the recess 111.

[0181] In some embodiments, please refer to Figure 12 , Figure 12 This is a schematic diagram of the structure of a battery device 100 provided in some other embodiments of this application. In two adjacent battery cells 10, a portion of the buffer 30 is accommodated in a recess 111 of the first wall portion 11 of one battery cell 10, and another portion of the buffer 30 is accommodated in a recess 111 of the first wall portion 11 of the other battery cell 10.

[0182] Two battery cells 10 have two first wall portions 11 disposed opposite to each other. The recesses 111 of the two first wall portions 11 together define a receiving cavity. The buffer member 30 may be entirely located in the receiving cavity, or only a portion of the buffer member 30 may be located in the receiving cavity.

[0183] In this embodiment, by setting the two parts of the buffer 30 to be respectively accommodated in the recesses 111 of two adjacent battery cells 10, the deformation of the recesses 111 of the two first wall portions 11 can be buffered by the buffer 30, reducing the risk of the two recesses 111 being damaged by direct contact.

[0184] In some embodiments, the buffer 30 is made of insulating material.

[0185] The material of the buffer 30 can be polyurethane foam, silicone rubber, polypropylene, polyethylene, etc.

[0186] In this embodiment, by setting the buffer 30 to be made of insulating material, the buffer 30 can insulate part of the outer shell 1 of the two battery cells 10, thereby improving the insulation performance of the two battery cells 10.

[0187] In some embodiments, please refer to Figure 13 , Figure 13 This is a schematic diagram of the structure of a battery device 100 provided in some embodiments of this application (showing a busbar 40). The battery device 100 also includes a busbar 40, which connects at least two battery cells 10 to achieve electrical connection between at least two battery cells 10.

[0188] The busbar component 40 can connect multiple battery cells 10 to achieve electrical connection between adjacent battery cells 10. The multiple battery cells 10 can be arranged adjacently or spaced apart. The number of battery cells 10 connected to the busbar component 40 can be multiple, such as two, three, or ten. In embodiments where the battery cells 10 have electrode terminals 3, the busbar component 40 can connect to the electrode terminals 3 of multiple battery cells 10 to achieve electrical connection between the multiple battery cells 10; in embodiments where the battery cells 10 input or output electrical energy through the housing 1, the busbar component 40 is connected to the housing 1 of multiple battery cells 10 to achieve electrical connection between the multiple battery cells 10.

[0189] In this embodiment, by setting the busbar component 40 to connect at least two adjacent battery cells 10, when the electrode assembly 2 of the battery cell 10 expands, the recess 111 can provide deformation space for the first wall portion 11, thereby reducing the risk of the deformation of the electrode assembly 2 squeezing the two adjacent battery cells 10, thereby reducing the risk of the busbar component 40 being pulled off and improving the structural stability of the battery device 100.

[0190] In some embodiments, the battery device 100 may further include an end plate (not shown), with the end plate disposed on at least one side of a plurality of battery cells 10 along a first direction X, and the battery cells 10 adjacent to the end plate having a first wall portion 11 facing the end plate. When the electrode assembly 2 in the battery cell 10 adjacent to the end plate expands, the recess 111 of the battery cell 10 can reduce the compressive force of the first wall portion 11 on the end plate, thereby reducing the risk of damage to the end plate or the battery cell 10.

[0191] This application provides an electrical device, including a battery cell 10 or a battery device 100 provided in any of the above embodiments, wherein the battery cell 10 is used to provide electrical energy to the electrical device.

[0192] Please continue to refer to Figure 8 and Figure 9 This application provides a battery cell 10, which includes a housing 1 and an electrode assembly 2. The housing 1 includes two first walls 11 disposed opposite to each other along a first direction X. The electrode assembly 2 is housed within the housing 1 and includes a first electrode 21, a solid electrolyte layer 22, and a second electrode 23. The first electrode 21 and the second electrode 23 have opposite polarities. The solid electrolyte layer 22 is disposed between the first electrode 21 and the second electrode 23. The first electrode 21, the solid electrolyte layer 22, and the second electrode 23 are stacked along the first direction X. Along the first direction X, a groove 111a is provided on the side of the first wall 11 facing away from the electrode assembly 2. The groove 111a is configured to provide deformation space for the first wall 11 when the electrode assembly 2 expands. Along the first direction X, the maximum size of the groove 111a is H1, and the minimum size of the electrode assembly 2 is H2, where 0.01 ≤ H1 / H2 ≤ 0.15. The maximum dimension of the outer casing 1 along the first direction X is W1, where 25mm ≤ W1 ≤ 75mm. Along the first direction X, the first wall portion 11 has a first outer surface 112 facing away from the electrode assembly 2, and a groove 111a extends to at least one end of the first wall portion 11 along the second direction Y. Along the third direction Z, the maximum dimension of the groove 111a is L1, and the maximum dimension of the outer casing 1 is L2, where 0.9 ≤ L1 / L2 ≤ 0.98. The first direction X, the second direction Y, and the third direction Z are all perpendicular to each other.

[0193] By providing a recess 111 on the side of the first wall portion 11 opposite to the electrode assembly 2, the recess 111 provides deformation space for the first wall portion 11 when the electrode assembly 2 expands to compress the first wall portion 11, reducing the internal stress of the battery cell 10. By providing recesses 111 on both sides of the electrode assembly 2 along the first direction X, more expansion space can be provided for the electrode assembly 2. When other components are provided on the side of the recess 111 of the battery cell 10 opposite to the electrode assembly 2, the expansion of the electrode assembly 2 can easily compress other components. The recess 111 provides deformation space for the first wall portion 11, reducing the internal stress of the battery cell 10 when the expansion force of the electrode assembly 2 compresses other components, thereby reducing the risk of damage to the battery cell 10 under the action of expansion force and improving the reliability of the battery cell 10. The groove 111a extends to at least one end of the first wall portion 11 along the second direction Y. On the one hand, it is beneficial for the battery cell 10 to dissipate heat through the end of the first wall portion 11 extending through the groove 111a. On the other hand, it makes the processing of the groove 111a easier and reduces the processing cost of the groove 111a. When 0.01≤H1 / H2≤0.15, it is possible to balance reducing the risk of damage to the battery cell 10 or external components due to the expansion of the electrode assembly 2, improving the strength of the first wall portion 11, and increasing the volumetric energy density of the battery cell 10. When 25mm≤W1≤75mm, it is possible to balance increasing the volumetric energy density of the battery cell 10 and reducing the risk of the battery cell 10 being too large and inconvenient to use and assemble. When 0.9≤L1 / L2≤0.98, it is possible to balance increasing the deformation space provided by the groove 111a to the first wall portion 11 and improving the structural strength of the first wall portion 11.

[0194] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0195] The above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit this application. For those skilled in the art, this application can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A battery cell, characterized in that, include: The outer casing includes the first wall portion; An electrode assembly is housed within the housing. The electrode assembly includes a first electrode, a solid electrolyte layer, and a second electrode. The first electrode and the second electrode have opposite polarities. The solid electrolyte layer is disposed between the first electrode and the second electrode. At least a portion of the first electrode, at least a portion of the solid electrolyte layer, and at least a portion of the second electrode are stacked along a first direction. Along the first direction, the large surface of the electrode assembly is disposed opposite to the first wall portion. Wherein, along the first direction, a recess is provided at a position opposite to the electrode assembly in the first wall portion, and the recess is configured to provide expansion space for the electrode assembly.

2. The battery cell as described in claim 1, characterized in that, Along the first direction, the recess is provided on the side of the first wall portion opposite to the electrode assembly.

3. The battery cell as described in claim 2, characterized in that, Along the first direction, the first wall portion has a first outer surface facing away from the electrode assembly, the recess is a groove disposed on the first outer surface, the groove extends to at least one end of the first wall portion along a second direction, the second direction being perpendicular to the first direction.

4. The battery cell as described in claim 3, characterized in that, Along the second direction, the opposite ends of the groove extend to the two ends of the first wall portion, respectively.

5. The battery cell as described in claim 3, characterized in that, The battery cell also includes an electrode terminal. The electrode terminal is provided at least one end of the housing along a third direction, and the first direction, the second direction, and the third direction are perpendicular to each other.

6. The battery cell as described in claim 3, characterized in that, Along the third direction, the maximum size of the groove is L1, the maximum size of the outer shell is L2, 0.9≤L1 / L2≤0.98, and the first direction, the second direction and the third direction are perpendicular to each other.

7. The battery cell as described in claim 6, characterized in that, 90mm≤L2≤180mm.

8. The battery cell as described in claim 6, characterized in that, Along the third direction, the housing has opposing second and third outer surfaces, the minimum distance between the groove and the second outer surface is L3, the minimum distance between the groove and the third outer surface is L4; 0.01≤L3 / L2≤0.05; and / or, 0.01≤L4 / L2≤0.

05.

9. The battery cell as described in claim 8, characterized in that, L3 = L4.

10. The battery cell as described in claim 2, characterized in that, Along the first direction, the maximum size of the recess is H1, the minimum size of the electrode assembly is H2, and 0.01≤H1 / H2≤0.

15.

11. The battery cell as described in claim 2, characterized in that, Along the first direction, a protrusion is provided on the side of the first wall portion facing the electrode assembly, corresponding to the recess.

12. The battery cell according to any one of claims 1-11, characterized in that, The maximum dimension of the outer shell along the first direction is W1, where 25mm ≤ W1 ≤ 75mm.

13. The battery cell according to any one of claims 1-11, characterized in that, The housing includes two first wall portions disposed opposite each other along the first direction, and the electrode assembly is located between the two first wall portions.

14. The battery cell according to any one of claims 1-11, characterized in that, The length and height of the outer shell are both greater than the width of the outer shell, and the width direction of the outer shell is parallel to the first direction.

15. The battery cell according to any one of claims 1-11, characterized in that, The outer casing includes: The shell has an opening; End cap, to close the opening; The housing includes the first wall portion.

16. The battery cell as described in claim 15, characterized in that, The housing includes two first wall portions disposed opposite each other along the first direction and two second wall portions disposed opposite each other along the second direction. The housing has the opening at at least one end along a third direction. The first direction, the second direction and the third direction are perpendicular to each other. The maximum dimension of the first wall portion along the second direction is greater than the maximum dimension of the second wall portion along the first direction.

17. The battery cell according to any one of claims 1-11, characterized in that, The electrode assembly has a stacked structure.

18. A battery device, characterized in that, It includes a plurality of battery cells as described in any one of claims 1-17, wherein the plurality of battery cells are arranged along the first direction.

19. The battery device as claimed in claim 18, characterized in that, Along the first direction, the recess is provided on the side of the first wall portion opposite to the electrode assembly; The battery device further includes a buffer member, which is disposed between two adjacent battery cells along the first direction, and at least a portion of the buffer member is accommodated within the recess.

20. The battery device as claimed in claim 19, characterized in that, In two adjacent battery cells, a portion of the buffer is accommodated within a recess in the first wall of one battery cell, and another portion of the buffer is accommodated within a recess in the first wall of the other battery cell.

21. The battery device as claimed in claim 19, characterized in that, The buffer is made of insulating material.

22. The battery device as claimed in claim 18, characterized in that, The battery device further includes a busbar that connects at least two of the battery cells to achieve an electrical connection between the at least two battery cells.

23. An electrical appliance, characterized in that, Includes a battery cell as described in any one of claims 1-17 or a battery device as described in any one of claims 18-22, wherein the battery cell is used to provide electrical energy to the electrical device.

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