Battery monomer, battery device and electric device

Abstract

The utility model 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] The present application relates to the field of battery technology, and in particular to a battery cell, a battery device, and an electrical device. Background Art

[0002] Energy conservation and emission reduction are key to the sustainable development of the automotive industry. Electric vehicles, due to their energy-saving and environmentally friendly advantages, have become an important component of the sustainable development of the automotive industry. For electric vehicles, battery technology is a key 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 battery cells, the reliability of battery cells is also a critical issue. Therefore, improving the reliability of battery cells is a pressing technical challenge in battery technology. Utility Model Content

[0004] The embodiments of the present application provide a battery cell, a battery device, and an electrical device, which can improve the reliability of the battery cell.

[0005] In a first aspect, an embodiment of the present application provides a battery cell comprising a housing and an electrode assembly. The housing comprises a first wall portion. The electrode assembly is housed within the housing, and the electrode assembly comprises a first pole piece, a solid electrolyte layer, and a second pole piece. The first pole piece and the second pole piece have opposite polarities, and the solid electrolyte layer is disposed between the first pole piece and the second pole piece. At least a portion of the first pole piece, at least a portion of the solid electrolyte layer, and at least a portion of the second pole piece are stacked along a first direction. Along the first direction, a large surface of the electrode assembly is disposed opposite to the first wall portion. A recess is provided at a position of the first wall portion opposite to the electrode assembly along the first direction, and the recess is configured to provide expansion space for the electrode assembly.

[0006] In the above technical solution, since the first direction is set parallel to the thickness direction of the first wall portion, and at least a portion of the first electrode sheet, at least a portion of the solid electrolyte layer, and at least a portion of the second electrode sheet are stacked along the first direction, the expansion force of the electrode assembly along the first direction is greater. By providing a recessed portion at a position opposite to the electrode assembly in the first wall portion, the recessed portion can provide expansion space for the electrode assembly, thereby reducing the internal stress of the battery cell. When other components are provided on the side of the first wall portion facing away from the electrode assembly, the electrode assembly is likely to squeeze other components when it expands. The recessed portion can provide expansion space for the electrode assembly, thereby 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 by the 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 facing away from the electrode assembly along the first direction. In this way, when the electrode assembly expands to compress the first wall, the recess can expand outward to provide deformation space for the first wall, thereby reducing internal stress of the battery cell.

[0008] In some embodiments, along the first direction, the first wall portion has a first outer surface facing away from the electrode assembly, and the recess is a groove provided on the first outer surface, the groove 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 provided on the first outer surface, and the groove extending to at least one end of the first wall portion along the second direction, heat dissipation from the battery cell is facilitated through the end portion of the first wall portion extending from the groove, and further facilitates processing of the recess, thereby reducing processing costs.

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

[0010] In some embodiments, the battery cell further includes an electrode terminal, disposed at at least one end of the housing along the third direction, with the electrode terminal being disposed perpendicular to each other in the first, second, and third directions. By disposing the electrode terminal 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 along the second direction, thereby reducing the risk of interference between the groove and the electrode terminal and improving the reliability of the battery cell.

[0011] In some embodiments, along the third direction, the maximum dimension of the groove is L1, the maximum dimension of the outer shell is L2, 0.9≤L1 / L2≤0.98, and the first, second, and third directions are perpendicular to each other. When L1 / L2≥0.9, the deformation space provided by the groove for the first wall portion can be increased, reducing the impact of 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 collapse of the first wall portion due to an overly large groove; therefore, when 0.9≤L1 / L2≤0.98, both increasing the deformation space provided by the groove for 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 size along the third direction, thereby making the groove have a larger size along the third direction. The groove can provide a larger deformation space for the first wall portion, reducing the impact of the expansion of the electrode assembly 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 excessively restrain the expansion of the electrode assembly, causing damage to the electrode assembly, L2≤180mm can reduce the risk of damage to the electrode assembly and improve the reliability of the battery cell. Therefore, when 90mm≤L2≤180mm, it is possible to take into account both the groove's ability to provide a larger deformation space for the first wall portion and its ability to reduce the risk of damage to the electrode assembly, thereby improving the reliability of the battery cell.

[0013] In some embodiments, along the 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 collapse of the first wall 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 for the groove, resulting in a smaller deformation of the groove during expansion of the electrode assembly, 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 collapse of the first wall 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 squeezes the groove can be taken into account.

[0014] In some embodiments, along the 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 collapse of the first wall 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 for the groove, resulting in a smaller deformation of the groove during expansion of the electrode assembly, 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 collapse of the first wall 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 squeezes the groove can be taken into account.

[0015] In some embodiments, 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, and the minimum distance between the groove and the third outer surface is L4; 0.01≤L3 / L2≤0.05; and 0.01≤L4 / L2≤0.05. This balances the risk of damage due to the small size of the first wall portions on either side of the groove along the third direction and the risk of damage due to excessive stress at the junction of the groove and the first wall portion when the electrode assembly expands and compresses the groove.

[0016] In some embodiments, L3 = L4. This makes the battery cell structure more beautiful, and the first walls on both sides of the groove have similar dimensions, making the strength of the first walls more uniform and reducing 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 can have sufficient space to provide deformation space for the first wall portion, reducing the risk of damage to the battery cell or external components due to expansion of the electrode assembly. When H1 / H2≤0.15, on the one hand, the risk of the strength of the first wall portion being affected by the recess being too deep can be reduced, and on the other hand, the battery cell can have more space to accommodate the electrode assembly, thereby improving 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 damage to the battery cell or external components due to expansion of the electrode assembly, improve the strength of the first wall portion, and improve the volumetric energy density of the battery cell.

[0018] In some embodiments, a convex portion is provided on a side of the first wall portion facing the electrode assembly at a position corresponding to the concave portion along the first direction, thereby facilitating the formation of the concave portion and reducing the processing cost of the concave portion.

[0019] In some embodiments, the maximum dimension of the housing along the first direction is W1, and 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 volume energy density of the battery cell. On the other hand, because the housing can accommodate thicker electrode assemblies, the electrode assembly can expand more, making the effect of the recess providing deformation space for the first wall more obvious; when W1≤75mm, the size of the battery cell can be reduced, reducing the risk of the battery cell being too large to be convenient for use and assembly; therefore, when 25mm≤W1≤75mm, it is possible to achieve both improving the volume energy density of the battery cell and reducing the risk of the battery cell being too large to be convenient for use and assembly.

[0020] In some embodiments, the housing includes two first walls that are disposed opposite each other along a first direction, with the electrode assembly located between the two first walls. By arranging the electrode assembly between the two first walls, when the electrode assembly expands toward both sides along the first direction, the recesses in the two first walls can provide deformation space for the first walls in which the recesses are located, 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 of the housing is parallel to the first direction. Thus, the length of the housing corresponds to the length of the first wall, and the height of the housing corresponds to the height of the first wall. This allows the first wall to have a larger size, thereby reducing the risk of damage to the first wall when the electrode assembly expands.

[0022] In some embodiments, the housing includes a shell and an end cap. The shell has an opening. The end cap seals the opening. The shell includes a first wall. By providing the shell as the first wall, on the one hand, it facilitates the insertion of the electrode assembly into the shell through the opening, and on the other hand, it reduces the difficulty of installing the shell and the end cap.

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

[0025] In some embodiments, the electrode assembly is a laminated structure. This allows the electrode assembly to expand more easily in the first direction. The recessed portion provided on the side of the first wall facing away from the electrode assembly facilitates deformation of the first wall, thereby reducing the impact of electrode assembly expansion on the reliability of the battery cell.

[0026] In a second aspect, embodiments of the present application provide a battery device comprising a plurality of battery cells according to any one of the embodiments of the first aspect, wherein the plurality of battery cells are arranged along a first direction. Thus, the recessed portion can reduce the risk of damage to adjacent battery cells caused by the first wall portion squeezing them when the electrode assembly expands, thereby improving the reliability of the battery device.

[0027] In some embodiments, a recess is provided on a side of the first wall facing away from the electrode assembly along a first direction. The battery device further includes a buffer disposed between two adjacent battery cells along the first direction, with at least a portion of the buffer being accommodated within the recess. The provision of the buffer can mitigate deformation of the recess, reducing the risk of damage due to excessive deformation.

[0028] In some embodiments, between two adjacent battery cells, a portion of the buffer member is housed within a recessed portion of the first wall portion of one battery cell, while another portion of the buffer member is housed within a recessed portion of the first wall portion of the other battery cell. This allows deformation of the recessed portions of both first wall portions to be cushioned by the buffer member, reducing the risk of damage from direct contact between the two recessed portions.

[0029] In some embodiments, the buffer is made of an insulating material, so that the buffer can insulate part of the outer shells of the two battery cells, thereby improving the insulation performance of the two battery cells.

[0030] In some embodiments, the battery device further includes a busbar assembly that connects at least two adjacent battery cells to achieve electrical connection between the at least two adjacent battery cells. Thus, when the electrode assembly of the battery cell expands, the recessed portion can provide deformation space for the first wall portion, thereby reducing the risk of deformation of the electrode assembly squeezing the two adjacent battery cells, thereby reducing the risk of the busbar assembly being broken, and improving the structural stability of the battery device.

[0031] In a third aspect, an embodiment of the present application provides an electrical device, comprising a battery cell provided by any embodiment of the first aspect or a battery device provided by any embodiment of the second aspect, wherein the battery cell is used to provide electrical energy to the electrical device. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0033] Figure 1 A schematic structural diagram of a vehicle provided in some embodiments of the present application;

[0034] Figure 2 An exploded view of a battery device provided in some embodiments of the present application;

[0035] Figure 3 An exploded view of a battery cell provided in some embodiments of the present application;

[0036] Figure 4 A schematic structural diagram of a battery cell provided in some embodiments of the present application;

[0037] Figure 5 for Figure 4 AA cross-sectional view;

[0038] Figure 6 for Figure 5 A partial enlarged view of area A in the middle;

[0039] Figure 7 for Figure 5 A partial enlarged view of the middle B area;

[0040] Figure 8 A schematic structural diagram of a battery cell provided in some other embodiments of the present application;

[0041] Figure 9 for Figure 8 BB cross-sectional view;

[0042] Figure 10 A schematic structural diagram of a battery device provided in some other embodiments of the present application;

[0043] Figure 11 A schematic structural diagram of a battery device provided in some further embodiments of the present application;

[0044] Figure 12 A schematic structural diagram of a battery device provided in some other embodiments of the present application;

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

[0046] Icons: 1-housing; 1a-shell; 1b-end cap; 11-first wall; 111-recess; 111a-groove; 112-first outer surface; 113-first inner surface; 114-convex portion; 12-second outer surface; 13-third outer surface; 14-second wall; 2-electrode assembly; 21-first pole piece; 22-solid electrolyte layer; 23-second pole piece; 3-electrode terminal;

[0047] 10-battery cell; 20-box; 201-first box; 202-second box; 30-buffer; 40-collecting component;

[0048] 100 - battery device; 200 - controller; 300 - motor; 1000 - vehicle; X - first direction; Y - second direction; Z - third direction. DETAILED DESCRIPTION

[0049] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts 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 meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary-secondary relationship.

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

[0052] The term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

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

[0054] The term "plurality" used in this application refers to two or more (including two).

[0055] In the embodiment of the present application, the battery cell may be a secondary battery. A secondary battery refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0056] The battery cell includes, but is not limited to, a lithium-ion battery, a sodium-ion battery, a sodium-lithium-ion battery, a lithium-metal battery, a sodium-metal battery, a lithium-sulfur battery, a magnesium-ion battery, a nickel-hydrogen battery, a nickel-cadmium battery, a lead-acid battery, and the like.

[0057] The battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During charging and discharging of the battery cell, active ions (e.g., lithium ions) are intercalated and deintercalated between the positive electrode and the negative electrode. The separator is disposed between the positive electrode and the negative electrode and can serve to reduce the risk of short circuiting between the positive electrode and the negative electrode while allowing the active ions to pass through.

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

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

[0060] As an example, the positive electrode current collector can be a metal foil or a composite current collector. For example, as the metal foil, aluminum with silver plating on the surface, stainless steel with silver plating on the surface, stainless steel, copper, aluminum, nickel, a carbon electrode, carbon, nickel, or titanium, and the like can be used. The composite current collector can include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, and the like) on a polymer material base material (e.g., a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, and the like).

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

[0062] In some embodiments, a positive electrode may utilize a metal foam. The metal foam may include nickel foam, copper foam, aluminum foam, alloy foam, or the like. When a metal foam is used as the positive electrode, the surface of the metal foam may or may not include a positive electrode active material. For example, a lithium source material, potassium metal, or sodium metal may be filled or / and deposited within the metal foam, where the lithium source material is lithium metal and / or a lithium-rich material.

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

[0064] As an example, the negative electrode current collector can be a metal foil, a metal foam, or a composite current collector. For example, as the metal foil, aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, or titanium can be used. The metal foam can be nickel foam, copper foam, aluminum foam, alloy foam, etc. The composite current collector can include a polymer material base layer and a metal layer. The composite current collector 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 electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0066] As an example, the negative electrode current collector has two surfaces opposite in the thickness direction thereof, and the negative electrode active material is provided on either one or both of the two surfaces of the negative electrode current collector.

[0067] As an example, the negative electrode active material can employ a negative electrode active material for a battery cell known in the art. As an example, the negative electrode active material can include at least one of artificial graphite, natural graphite, soft carbon, hard carbon, a silicon-based material, a tin-based material, and lithium titanate, etc. The silicon-based material can be selected from at least one of elemental silicon, a silicon oxide compound, a silicon-carbon composite, a silicon-nitrogen composite, and a silicon alloy. The tin-based material can be selected from at least one of elemental tin, a tin oxide compound, and a tin alloy. However, the present application is not limited to these materials, and other conventional materials that can be used as a negative electrode active material for a battery cell can also be used. These negative electrode active materials can be used alone or in combination of two or more.

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

[0069] In some embodiments, the separator is a solid-state electrolyte. The solid-state electrolyte is disposed between the positive electrode and the negative electrode, and functions to transport ions and separate the positive electrode and the negative electrode.

[0070] The solid-state electrolyte includes a polymer solid-state electrolyte, an inorganic solid-state electrolyte, and a composite solid-state electrolyte.

[0071] As an example, the polymer solid-state electrolyte can be a polyether (polyethylene oxide), a polysiloxane, a polycarbonate, a polyacrylonitrile, a polyvinylidene fluoride, a polymethyl methacrylate, a single-ion polymer, a polyionic liquid-lithium salt, cellulose, etc.

[0072] As an example, the inorganic solid-state electrolyte can include one or more of an oxide solid-state electrolyte (crystalline perovskite, sodium superionic conductor, garnet, amorphous LiPON thin film), a sulfide solid-state electrolyte (crystalline lithium superionic conductor (lithium germanium phosphorous sulfide, argyrodite), amorphous sulfide), a halide solid-state electrolyte, a nitride solid-state electrolyte, and a hydride solid-state electrolyte.

[0073] As an example, the composite solid-state electrolyte is formed by adding an inorganic solid-state electrolyte filler to a polymer solid-state electrolyte.

[0074] In some embodiments, the battery cell can include a housing. The housing is used to encapsulate components such as the electrode assembly and the electrolyte. The housing can be a steel case, an aluminum case, a plastic case (e.g., polypropylene), a composite metal case (e.g., a copper-aluminum composite housing), an aluminum-plastic film, etc.

[0075] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes, the prismatic battery cell including a square battery cell, a blade battery cell, a multi-prismatic battery cell, for example, a hexagonal battery cell, etc.

[0076] The battery apparatus mentioned in the embodiments of the present application can include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly can include a plurality of battery cells connected in series, in parallel, or in a mixed connection through a busbar component.

[0077] In some embodiments, the battery cell assembly is generally formed by arranging a plurality of battery cells; as an example, the battery cell assembly can be a battery module formed by arranging and fixing a plurality of battery cells into an independent module.

[0078] As an example, the battery module can be formed by bundling a plurality of battery cells with a cable tie.

[0079] In some embodiments, the battery apparatus can be a battery pack, which can include a box and one or more battery cell assemblies accommodated in the box.

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

[0081] As an example, the battery cell assembly can also be accommodated in the box by directly fixing a plurality of battery cells in the box.

[0082] As an example, the box can include a first box and a second box. The first box and the second box are buckled so that an enclosed space is formed inside the box to accommodate the battery cell assembly. Here, the enclosed means covered or closed, which can be sealed or unsealed. The first box can be a top cover or a bottom plate.

[0083] As an example, the box can include a top cover, a frame, and a bottom plate. The top cover and the bottom plate are respectively connected with the frame so that an enclosed space is formed inside the box to accommodate the battery cell assembly.

[0084] As an example, the box can be part of the chassis structure of a vehicle. For example, the top cover of the box can be at least part of the floor of the vehicle, or the frame of the box can be at least part of the cross beam and the longitudinal beam of the vehicle.

[0085] In some embodiments, the battery device refers to an energy storage device, which includes a box with a door on at least one side. The energy storage device includes an energy storage container, an energy storage cabinet, etc.

[0086] A battery cell may include a housing and an electrode assembly, with the electrode assembly housed within the housing. During the battery cell's electrical cycle, as the number of charge and discharge cycles increases, the electrode assembly tends to expand. The battery cell's housing expands outward under the expansion force of the electrode assembly. This can affect the proper functioning of the battery cell and adjacent components. Furthermore, the housing constrains the expansion of the electrode assembly, potentially damaging the battery cell. This is particularly true for solid-state battery cells, where the electrode assembly includes a stacked first electrode sheet, a solid electrolyte layer, and a second electrode sheet. These first, solid electrolyte, and second electrode sheets are typically relatively thick, and the thickness of the electrode assembly increases the amount of expansion of the electrode assembly along the stacking direction. In such battery cells, the housing deforms more significantly and exerts a greater restraining force on the electrode assembly, making it more susceptible to damage. Furthermore, the outward expansion of the housing compresses adjacent components, increasing the compressive force between the housing and other components, potentially damaging the battery cell and reducing its reliability.

[0087] In view of this, in order to improve the reliability of the battery cell, an embodiment of the present application provides a battery cell, comprising a housing and an electrode assembly. The housing includes a first wall portion. The electrode assembly is accommodated in the housing, and the electrode assembly includes a first pole piece, a solid electrolyte layer, and a second pole piece. The first pole piece and the second pole piece have opposite polarity. The solid electrolyte layer is arranged between the first pole piece and the second pole piece. At least a portion of the first pole piece, at least a portion of the solid electrolyte layer, and at least a portion of the second pole piece are stacked along a first direction. Along the first direction, the large surface of the electrode assembly is arranged opposite to the first wall portion. Wherein, along the first direction, a recess is provided at a position of the first wall portion opposite to the electrode assembly, and the recess is configured to provide expansion space for the electrode assembly.

[0088] In such a battery cell, since the first direction is set parallel to the thickness direction of the first wall portion, and at least a portion of the first electrode sheet, at least a portion of the solid electrolyte layer, and at least a portion of the second electrode sheet are stacked along the first direction, the electrode assembly can easily expand along the first direction to abut against the first wall portion. By providing a recessed portion at a position opposite to the electrode assembly in the first wall portion, the recessed portion can provide expansion space for the electrode assembly, thereby reducing the internal stress of the battery cell. When other components are provided on the side of the recessed portion of the battery cell facing away from the electrode assembly, the electrode assembly can easily squeeze the other components when it expands. The recessed portion can provide expansion space for the electrode assembly, thereby reducing the internal stress of the battery cell when the expansion force of the electrode assembly squeezes the other components, thereby reducing the risk of the battery cell being damaged by the expansion force and improving the reliability of the battery cell.

[0089] The technical solutions described in the embodiments of the present 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, electric tools, vehicles, ships and spacecraft, etc. For example, spacecraft include airplanes, rockets, space shuttles and spacecraft, etc.

[0090] For the convenience of description, the following embodiments are described by taking the electric device as a vehicle as an example.

[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 the present application. A battery device 100 is disposed within vehicle 1000. Battery device 100 can be located at the bottom, front, or rear of vehicle 1000. Battery device 100 can be used to power vehicle 1000. For example, battery device 100 can serve as the operating power source of vehicle 1000.

[0092] The vehicle 1000 may further 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, to meet the power requirements of the vehicle 1000 during startup, navigation, and driving.

[0093] In some embodiments of the present application, the battery device 100 can not only serve as the operating power source of the vehicle 1000, but also serve as the driving power source of 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 the present application. The battery device 100 may include a housing 20 and a battery cell 10 , wherein the housing 20 is used to accommodate the battery cell 10 .

[0095] Among them, a closed space for accommodating the battery cells 10 is formed inside the box body 20. The box body 20 can adopt various structures. In some embodiments, the box body 20 may include a first box body 201 and a second box body 202, and the first box body 201 and the second box body 202 are buckled with each other. The first box body 201 and the second box body 202 may be of various shapes, such as a rectangular parallelepiped, a cylinder, etc. The first box body 201 may be a hollow structure with one side open, and the second box body 202 may also be a hollow structure with one side open, and the open side of the second box body 202 is buckled with the open side of the first box body 201 to form a box body 20 with a closed space. The first box body 201 may also be a hollow structure with one side open, and the second box body 202 may be a plate-like structure, and the second box body 202 is buckled with the open side of the first box body 201 to form a box body 20 with a accommodating space.

[0096] In the battery device 100, there can be one or more battery cells 10. If there are multiple battery cells 10, the multiple battery cells 10 can be connected in series, parallel, or in a hybrid connection. A hybrid connection refers to a combination of series and parallel connections among the multiple battery cells 10. Multiple battery cells 10 can be connected in series, parallel, or in a hybrid connection to form a battery module, which is then connected in series, parallel, or in a hybrid connection to form a single unit and housed within the housing 20. Alternatively, all battery cells 10 can be directly connected in series, parallel, or in a hybrid connection, and then the entire unit formed by 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 the present application. The battery cell 10 may include a housing 1 and an electrode assembly 2, wherein the electrode assembly 2 is accommodated in the housing 1.

[0098] In some embodiments, the housing 1 may include a shell 1a and an end cap 1b, wherein the shell 1a has an opening and the end cap 1b closes the opening of the shell 1a. Here, closing means covering or closing, which may be sealed or non-sealed.

[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 opposite ends. The housing 1a can have various shapes, such as a cylinder or a rectangular parallelepiped. The housing 1a can be made of a variety of materials, such as copper, iron, aluminum, steel, and aluminum alloys. The electrode assembly 2 can be partially or completely located within the housing 1a.

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

[0101] In embodiments where the housing 1a is open at one end, one end cap 1b may be provided. In embodiments where the housing 1a is open at two opposite ends, two end caps 1b may be provided, each of which closes the two openings of the housing 1a, and the two end caps 1b and the housing 1a together define a receiving space.

[0102] In some embodiments, the battery cell 10 may further include an electrode terminal 3, which is disposed on the outer casing 1. The electrode terminal 3 is used to electrically connect to the tab of the electrode assembly 2 to input or output electrical energy from the battery cell 10. The electrode terminal 3 may be disposed on the shell 1a of the outer casing 1 or on the end cap 1b of the outer casing 1. The electrode terminal 3 and the tab may be directly connected, for example, by welding the electrode terminal 3 to the tab. The electrode terminal 3 and the tab may also be indirectly connected, for example, by indirectly connecting the electrode terminal 3 and the tab via a current collecting member. The current collecting member may be a metal conductor, such as copper, iron, aluminum, steel, or an aluminum alloy.

[0103] Please refer to Figure 4 and Figure 5 , Figure 4 A schematic structural diagram of a battery cell 10 provided in some embodiments of the present application; Figure 5 for Figure 4 AA cross-sectional view. An embodiment of the present application provides a battery cell 10, comprising a housing 1 and an electrode assembly 2. The housing 1 comprises a first wall portion 11. The electrode assembly 2 is accommodated in the housing 1, and the electrode assembly 2 comprises a first pole piece 21, a solid electrolyte layer 22, and a second pole piece 23. The first pole piece 21 and the second pole piece 23 have opposite polarities. The solid electrolyte layer 22 is arranged between the first pole piece 21 and the second pole piece 23. At least a portion of the first pole piece 21, at least a portion of the solid electrolyte layer 22, and at least a portion of the second pole piece 23 are stacked along a first direction X. Along the first direction X, the large surface of the electrode assembly 2 is arranged opposite to the first wall portion 11. Wherein, a recess 111 is provided at a position where the first wall portion 11 is opposite to the electrode assembly 2 along the first direction X, and the recess 111 is configured to provide expansion space for the electrode assembly 2.

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

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

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

[0107] The electrode assembly 2 can be a laminated structure or a wound structure. In the embodiment of the electrode assembly 2 with a wound structure, there can be only one first electrode piece 21, solid electrolyte layer 22, and second electrode piece 23. The first electrode piece 21, solid electrolyte layer 22, and second electrode piece 23 are stacked and wound to form the electrode assembly 2 with a wound structure. In the embodiment of the electrode assembly 2 with a laminated structure, there can be only one first electrode piece 21, solid electrolyte layer 22, and second electrode piece 23. The first electrode piece 21, solid electrolyte layer 22, and second electrode piece 23 are stacked in sequence to form the electrode assembly 2 with a laminated structure; the first electrode piece 21, solid electrolyte layer 22, and second electrode piece 23 can also be multiple. Multiple first electrode pieces 21, multiple solid electrolyte layers 22, and multiple second electrode pieces 23 are stacked in the order of first electrode piece 21, solid electrolyte layer 22, second electrode piece 23, solid electrolyte layer 22, and first electrode piece 21 to form a multi-layer laminated electrode assembly 2.

[0108] The large surface of the electrode assembly 2 is the largest surface of the outer surface of the electrode assembly 2. For example, when the electrode assembly 2 is a laminated structure, the large surface of the electrode assembly 2 is the two outer surfaces opposite to each other in the stacking direction of the first electrode sheet 21, the solid electrolyte layer 22, and the second electrode sheet 23. For another example, when the electrode assembly 2 is a wound structure, the electrode assembly 2 includes a straight region and a bent region. Along the second direction Y, the opposite ends of the straight region are provided with a bent region. The portions of the first electrode sheet 21, the second electrode sheet 23, and the solid electrolyte layer 22 located in the straight region are substantially straight, and the portions of the first electrode sheet 21, the second electrode sheet 23, and the solid electrolyte layer 22 located in the bent region are generally arc-shaped. The portions of the first electrode sheet 21, the second electrode sheet 23, and the solid electrolyte layer 22 located in the straight 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 the 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 of the first wall portion 11 opposite 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 each other along the first direction X. The position of the first wall portion 11 opposite the electrode assembly 2 is provided with a recess 111, and the position of the other first wall portion 11 opposite the electrode assembly 2 is also provided with a recess 111. The position of the first wall portion 11 opposite 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] The recess 111 is provided in the first wall portion 11 at a position opposite the electrode assembly 2 along the first direction X. The first wall portion 11 can be a plate-like structure having a first outer surface 112 and a first inner surface 113. The recess can be a groove provided in the first outer surface 112, with the expansion space located on the side of the first wall portion 11 facing away from the electrode assembly 2. Alternatively, the recess 111 can be a groove provided in the first inner surface 113, with the expansion space located on the side of the first wall portion 11 facing the electrode assembly 2. The first wall portion 11 can also be a bent structure, with a portion of the first wall portion 11 protruding toward the electrode assembly 2, forming the recess 111 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 is 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 the embodiment of the present application, by setting the first direction X parallel to the thickness direction of the first wall portion 11, and at least a portion of the first electrode plate 21, at least a portion of the solid electrolyte layer 22, and at least a portion of the second electrode plate 23 are stacked 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, since a thicker electrode assembly 2 is required to increase the capacitance of the battery cell 10, the thicker electrode assembly 2 makes the expansion of the electrode assembly 2 more obvious during the charge and discharge cycle, and the electrode assembly 2 is easy to expand along the stacking direction of the first electrode sheet 21, the solid electrolyte layer 22 and the second electrode sheet 23. By setting a recess 111 on the side of the first wall portion 11 away from the electrode assembly 2, the recess 111 can be deformed toward the outside of the battery cell 10 under the expansion of the electrode assembly 2. When other components are arranged at the position opposite to the recess 111 and the electrode assembly 2, the recess 111 can provide expansion space for the electrode assembly 2, reduce the impact of the expansion of the electrode assembly 2 on external components, thereby reducing the risk of damage to the battery cell 10 or external components under the action of the expansion force, and improving the reliability of the battery cell 10.

[0113] In some embodiments, please refer to Figure 5 Along the first direction X, a recess 111 is provided on a side of the first wall portion 11 facing away from 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. 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 11 away from the electrode assembly 2, when the electrode assembly expands to squeeze the first wall, the recess can expand outward to provide deformation space for the first wall, thereby reducing the internal stress of the battery cell.

[0116] In some embodiments, please 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. 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. The second direction Y 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 the embodiment where the first wall portion 11 has a first surface and a second surface, the first surface is the first outer surface 112. The first direction X may be the width direction of the electrode assembly 2, along which the electrode assembly 2 and the first wall portion 11 are arranged. 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, the recess 111 is provided as a groove 111a provided on the first outer surface 112, and the groove 111a extends to at least one end of the first wall portion 11 along the second direction Y. On the one hand, this is beneficial for heat dissipation of the battery cell 10 through the end portion extending from the groove 111a to the first wall portion 11. On the other hand, it makes the processing of the recess 111 more convenient, thereby reducing the processing cost of the recess 111.

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

[0120] Two opposite ends of the groove 111 a along the second direction Y extend to two ends of the first wall portion 11 , respectively, so that the groove 111 a passes through the outer shell 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, which reduces the difficulty of forming the first wall portion 11 and saves the processing cost of the first wall portion 11.

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

[0123] The housing 1 may be provided with a motor terminal at only one end along the third direction Z. For example, the housing 1 may be provided with two motor terminals at one end along the third direction Z, with the two motor terminals being a positive motor terminal and a negative motor terminal. Alternatively, the housing 1 may be provided with motor terminals at both ends along the third direction Z. For example, the housing 1 may have two walls along the third direction Z, with the positive motor terminal being provided on one wall and the negative motor terminal being provided on the other wall.

[0124] By arranging the 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 refer to Figure 5 Along the third direction Z, the maximum dimension of the groove 111 a is L1, the maximum dimension of the housing 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 point value among 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 point value between any two of them.

[0127] When L1 / L2≥0.9, the deformation space provided by the groove 111a to the first wall portion 11 can be increased, and the influence of the expansion of the electrode assembly 2 on external components can be reduced; when L1 / L2≤0.98, the structural strength of the first wall portion 11 can be improved, and the risk of the first wall portion 11 collapsing due to the excessive size of the groove 111a can be reduced; therefore, when 0.01≤L1 / L2≤0.15, it is possible to take into account both 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, 90 mm ≤ L2 ≤ 180 mm.

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

[0130] When L2≥90 mm, the battery monomer 10 can have a larger size along the third direction Z, so that the groove 111a has a larger size along the third direction Z, and the groove 111a can provide a larger deformation space for the first wall part 11, reducing the influence of the expansion of the electrode assembly 2 on the external components; when L2≤180 mm, the strength requirement of the first wall part 11 can be reduced, because the first wall part 11 is too strong, which can easily over-constrain 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 monomer 10; therefore, when 90 mm≤L2≤180 mm, the groove 111a can provide a larger deformation space for the first wall part 11 and the risk of damage to the electrode assembly 2 can be reduced, and the reliability of the battery monomer 10 can be improved.

[0131] In some embodiments, please refer to Figure 5-Figure 7 , Figure 6 for Figure 5 the local enlarged view of the A area in FIG. 1B; Figure 7 for Figure 5 the local enlarged view of the B area in FIG. 1B. Along the third direction Z, the shell 1 has opposite second and third outer surfaces 12 and 13, and the minimum distance between the groove 111a and the second outer surface 12 is L3, 0.01≤L3 / L2≤0.05.

[0132] L3 / L2 can be a point value of any one of 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 a point value between any two of them.

[0133] When L3 / L2≥0.01, the structural strength of the groove 111a can be improved, and the risk of the first wall portion 11 collapsing due to the small distance between the groove 111a and the second outer surface 12 can be reduced; when L3 / L2≤0.05, the first wall portion 11 can have a larger space to set the groove 111a, and the deformation of the groove 111a is smaller when the electrode assembly 2 expands, thereby reducing the risk of damage due to excessive stress at the connection between the groove 111a and the first wall portion 11; therefore, when 0.01≤L3 / L2≤0.05, it is possible to take into account both 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 and reducing the risk of damage due to excessive stress at the connection between the groove 111a and the first wall portion 11 when the electrode assembly 2 expands and squeezes the groove 111a.

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

[0135] L4 / L2 can be any one of 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 point value between any two of them.

[0136] When L4 / L2≥0.01, the structural strength of the groove 111a can be improved, and the risk of the first wall portion 11 collapsing due to the small distance between the groove 111a and the third outer surface 13 can be reduced; when L4 / L2≤0.05, the first wall portion 11 can have a larger space to set the groove 111a, and the deformation of the groove 111a is smaller when the electrode assembly 2 expands, thereby reducing the risk of damage due to excessive stress at the connection between the groove 111a and the first wall portion 11; therefore, when 0.01≤L4 / L2≤0.05, it is possible to take into account both 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 and reducing the risk of damage due to excessive stress at the connection between the groove 111a and the first wall portion 11 when the electrode assembly 2 expands and squeezes the groove 111a.

[0137] In some embodiments, along the third direction Z, the housing 1 has a second outer surface 12 and a third outer surface 13 relative 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 take into account both reducing the risk of damage due to the small size of the first wall portion 11 on both sides of the groove 111a along the third direction Z and reducing the risk of damage due to excessive stress at the connection between the groove 111a and the first wall portion 11 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 at positions 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 first protrusion and the second protrusion are equal in size along the third direction Z.

[0141] In this embodiment, on the one hand, the equal sizes of the first protrusion and the second protrusion along the third direction Z can make the structure of the battery cell 10 more beautiful. On the other hand, the sizes of the first wall portions 11 on both sides of the groove 111a are comparable, so that the strength of the first wall portion 11 is more uniform, reducing the risk of damage to the first wall portion 11.

[0142] In some embodiments, please refer to Figure 5 and Figure 6 Along the first direction X, the maximum dimension of the recess 111 is H1 ( Figure 6 ), the minimum size of the electrode assembly 2 is H2 ( Figure 5 ), 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 along the direction of the first wall portion 11 pointing 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 production is completed and the charge and discharge process is less than or equal to 100 times.

[0145] H1 / H2 can be any point value among 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 therebetween.

[0146] When H1 / H2≥0.01, the recess 111 can have sufficient space to provide deformation space for the first wall 11, thereby 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, it can reduce the risk of the strength of the first wall 11 being affected by the recess 111 being too deep, and on the other hand, it can provide the battery cell 10 with more space to accommodate the electrode assembly 2, thereby improving the volume energy density of the battery cell 10; therefore, when 0.01≤H1 / H2≤0.15, it is possible to take into account both reducing the risk of the electrode assembly 2 expanding and damaging the battery cell 10 or external components, improving the strength of the first wall 11, and improving the volume energy density of the battery cell 10.

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

[0148] W1≥25mm allows the housing 1 to accommodate a larger electrode assembly 2. In the solid-state battery cell 10, the electrode assembly 2 with a larger thickness has a larger expansion space during the charge and discharge cycle. Therefore, providing a 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 the embodiment where the housing 1 has a first wall portion 11 , the housing 1 has a third wall portion arranged 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 any point value of 25mm, 27mm, 30mm, 32mm, 35mm, 37mm, 40mm, 42mm, 45mm, 47mm, 50mm, 52mm, 55mm, 57mm, 60mm, 62mm, 65mm, 67mm, 70mm, 72mm, 75mm or any point value between any two of them.

[0151] When W1≥25mm, on the one hand, the housing 1 can have more space to accommodate the electrode assembly 2, which is beneficial to improving the volume energy density of the battery cell 10. On the other hand, the housing 1 can accommodate a thicker electrode assembly 2, and the electrode assembly 2 can expand more, so that the effect of the recess 111 providing deformation space for the first wall portion 11 is more obvious; when W1≤75mm, the size of the battery cell 10 can be reduced, reducing the risk of the battery cell 10 being too large to be inconvenient to use and assemble; therefore, when 25mm≤W1≤75mm, it is possible to take into account both improving the volume energy density of the battery cell 10 and reducing the risk of the battery cell 10 being too large to be inconvenient to use and assemble.

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

[0153] H2 / W1 can be any one of 0.9, 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98, 0.99 or any point value between any 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 volume energy density of the battery cell 10; when H2 / W1<1, it is beneficial to set the electrode assembly 2 in the shell 1, reducing the difficulty of installing the electrode assembly 2; therefore, when 0.9≤H2 / W1<1, it is possible to take into account both improving the volume energy density of the battery cell 10 and reducing the difficulty of installing the electrode assembly 2.

[0155] In some embodiments, please refer to Figure 4-Figure 7 Along the first direction X, a convex portion 114 is provided at a position corresponding to the concave portion 111 on a side of the first wall portion 11 facing the electrode assembly 2 .

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

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

[0158] In this embodiment, a convex portion 114 is provided at a position corresponding to the concave portion 111 on the side of the first wall portion 11 facing the electrode assembly 2 , which makes forming the concave portion 111 more convenient and reduces the processing cost of the concave portion 111 .

[0159] In some embodiments, the housing 1 includes two first walls 11 . The two first walls 11 are arranged opposite to each other along the first direction X, and the electrode assembly 2 is located between the two first walls 11 .

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

[0161] By arranging the electrode assembly 2 between the two first wall portions 11, when the electrode assembly 2 expands toward both sides thereof 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, thereby 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 the height of the housing 1 are both greater than the width of the housing 1 , and the width direction of the housing 1 is parallel to the first direction X.

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

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

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

[0166] There may be one first wall portion 11 , which is a wall portion of the housing 1 a ; or there may be two first walls 11 , which are two walls of the housing 1 a arranged opposite to each other along the first direction X.

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

[0168] In some embodiments, please refer to Figure 8 and Figure 9 , Figure 8A schematic structural diagram of a battery cell 10 provided in some other embodiments of the present application; Figure 9 for Figure 8 Cross-sectional view taken along line BB. The housing 1a includes two first walls 11 arranged opposite each other along a first direction X and two second walls 14 arranged opposite each other along a second direction Y. At least one end of the housing 1a along a third direction Z is open. 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 11 along the second direction Y is greater than the maximum dimension of the second wall 14 along the first direction X.

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

[0170] In the embodiment where the housing 1 has two first walls 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 walls 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 damaging the first wall portion 11 when the electrode assembly 2 expands.

[0172] In some embodiments, the electrode assembly 2 is a laminate structure.

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

[0174] In this embodiment, the electrode assembly 2 is configured as a laminated structure. The electrode assembly 2 is more likely to expand along the first direction X. The recess 111 is provided on the side of the first wall portion 11 facing away from the electrode assembly 2. This facilitates the recess 111 to provide deformation space for the first wall portion 11, thereby 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 Schematic diagram of a battery device 100 provided in some embodiments of the present application. The present application provides a battery device 100, comprising a plurality of battery cells 10 provided in any of the above embodiments, wherein the plurality of battery cells 10 are arranged along a first direction X.

[0176] The plurality of battery cells 10 are arranged along the first direction X such that the recesses 111 of the battery cells 10 can face the adjacent battery cells 10. When the battery cells 10 of the battery device 100 are pressed against each other, the electrode assemblies 2 expand to expand the recesses 111 towards the adjacent battery cells 10, but the recesses 111 are not likely to contact the adjacent battery cells 10, so that the distance between the two adjacent battery cells 10 is not likely to change, improving the structural stability of the battery device 100.

[0177] In the present embodiment, by arranging the plurality of battery cells 10 along the first direction X, the recesses 111 can reduce the risk of the first wall portions 11 pressing the adjacent battery cells 10 to damage the battery cells 10 when the electrode assemblies 2 expand, improving the reliability of the battery device 100.

[0178] In some embodiments, please refer to Figure 11 , Figure 11 A structural schematic diagram of the battery device 100 according to some other embodiments of the present application is provided. Along the first direction X, the side of the first wall portion 11 away from the electrode assembly 2 is provided with a recess 111. The battery device 100 further comprises a buffer 30, and along the first direction X, the buffer 30 is arranged between the two adjacent battery cells 10, and at least part of the buffer 30 is accommodated in the recess 111.

[0179] The buffer 30 can be entirely accommodated in the recess 111, or only part of the buffer 30 can be located in the recess 111.

[0180] By arranging the buffer 30, the buffer 30 can buffer the deformation of the recess 111, increase the contact area between the 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 A structural schematic diagram of the battery device 100 according to some other embodiments of the present application is provided. In the two adjacent battery cells 10, part of the buffer 30 is accommodated in the recess 111 of the first wall portion 11 of one battery cell 10, and another part of the buffer 30 is accommodated in the recess 111 of the first wall portion 11 of the other battery cell 10.

[0182] The two battery cells 10 have two oppositely arranged first wall portions 11, and the recesses 111 of the two first wall portions 11 jointly define an accommodation cavity. The buffer 30 can be entirely located in the accommodation cavity, or only part of the buffer 30 can be located in the accommodation cavity.

[0183] In this embodiment, by arranging the two parts of the buffer 30 to be respectively accommodated in the recesses 111 of the 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 member 30 can be polyurethane foam, silicone rubber, polypropylene, polyethylene, etc.

[0186] In this embodiment, by configuring the buffer member 30 to be made of an insulating material, the buffer member 30 can insulate portions of the outer shells 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 The battery device 100 is a schematic structural diagram of some embodiments of the present application (showing a busbar component 40 ). The battery device 100 further includes a busbar component 40 , which connects at least two battery cells 10 to achieve electrical connection between the at least two battery cells 10 .

[0188] The busbar component 40 can connect multiple battery cells 10 to achieve electrical connection between multiple adjacent battery cells 10. Multiple battery cells 10 can be arranged adjacent to each other or spaced apart. The number of battery cells 10 connected by the busbar component 40 is multiple, for example, two, three, ten, etc. In the embodiment where the battery cells 10 have electrode terminals 3, the busbar component 40 can connect the electrode terminals 3 of multiple battery cells 10 to achieve electrical connection between multiple battery cells 10; in the embodiment where the battery cells 10 input or output electrical energy through the outer casing 1, the busbar component 40 is connected to the outer casing 1 of multiple battery cells 10 to achieve electrical connection between multiple battery cells 10.

[0189] In this embodiment, a busbar component 40 is provided 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 deformation of the electrode assembly 2 squeezing the two adjacent battery cells 10, thereby reducing the risk of the busbar component 40 being pulled apart 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). The end plate is provided on at least one side of the plurality of battery cells 10 along the first direction X. The battery cells 10 adjacent to the end plate have a first wall portion 11 facing the end plate. When the electrode assembly 2 within the battery cell 10 adjacent to the end plate expands, the recessed portion 111 of the battery cell 10 can reduce the squeezing 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] An embodiment of the present application provides an electrical device, including the battery cell 10 provided by any one of the above embodiments or the battery device 100 provided by any one 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 The embodiment of the present application provides a battery cell 10, which includes a housing 1 and an electrode assembly 2. The housing 1 includes two first wall portions 11 arranged opposite to each other along a first direction X. The electrode assembly 2 is accommodated in the housing 1, and includes a first electrode sheet 21, a solid electrolyte layer 22, and a second electrode sheet 23. The first electrode sheet 21 and the second electrode sheet 23 have opposite polarities. The solid electrolyte layer 22 is arranged between the first electrode sheet 21 and the second electrode sheet 23. The first electrode sheet 21, the solid electrolyte layer 22, and the second electrode sheet 23 are stacked along the first direction X. In the first direction X, a groove 111a is provided on the side of the first wall portion 11 facing away from the electrode assembly 2. The groove 111a is configured to provide deformation space for the first wall portion 11 when the electrode assembly 2 expands. Along the first direction X, the maximum dimension of the groove 111a is H1, and the minimum dimension of the electrode assembly 2 is H2, and 0.01≤H1 / H2≤0.15. The maximum dimension of the housing 1 along the first direction X is W1, with 25 mm ≤ W1 ≤ 75 mm. Along the first direction X, the first wall portion 11 has a first outer surface 112 facing away from the electrode assembly 2. The groove 111 a 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 111 a is L1, and the maximum dimension of the housing 1 is L2, with 0.9 ≤ L1 / L2 ≤ 0.98. The first direction X, the second direction Y, and the third direction Z are perpendicular to each other.

[0193] By providing a recess 111 on the side of the first wall 11 facing away from the electrode assembly 2, the recess 111 provides deformation space for the first wall 11 when the electrode assembly 2 expands and compresses the first wall 11, reducing internal stress in the battery cell 10. Providing recesses 111 on both sides of the electrode assembly 2 along the first direction X provides more expansion space for the electrode assembly 2. If other components are located on the side of the battery cell 10 facing away from the recess 111, the electrode assembly 2 may easily compress these components during expansion. The recess 111 provides deformation space for the first wall 11, reducing internal stress in the battery cell 10 when the expansion force of the electrode assembly 2 compresses these components. This reduces the risk of damage to the battery cell 10 caused by the expansion force, thereby improving the reliability of the battery cell 10. The recess 111a extends to at least one end of the first wall 11 along the second direction Y. This facilitates heat dissipation from the battery cell 10 through the end of the recess 111a extending to the first wall 11. Furthermore, it facilitates machining of the recess 111a, reducing processing costs. When 0.01 ≤ H1 / H2 ≤ 0.15, the risk of damage to the battery cell 10 or external components due to expansion of the electrode assembly 2 can be reduced, the strength of the first wall portion 11 can be increased, and the volumetric energy density of the battery cell 10 can be improved. When 25 mm ≤ W1 ≤ 75 mm, the volumetric energy density of the battery cell 10 can be improved while reducing the risk of the battery cell 10 being too large and inconvenient to use and assemble. When 0.9 ≤ L1 / L2 ≤ 0.98, the deformation space provided by the groove 111a for the first wall portion 11 can be increased while improving the structural strength of the first wall portion 11.

[0194] It should be noted that, unless there is any conflict, the embodiments and features in the embodiments of this application can be combined with each other.

[0195] The above embodiments are intended only to illustrate the technical solutions of this application and are not intended to limit this application. Those skilled in the art will appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this application are intended to be within the scope of protection of this application.

Claims

1. A battery cell, characterized in that: include: a housing comprising a first wall portion; an electrode assembly housed in the housing, the electrode assembly comprising a first electrode piece, a solid electrolyte layer, and a second electrode piece, the first electrode piece and the second electrode piece having opposite polarities, the solid electrolyte layer being disposed between the first electrode piece and the second electrode piece, at least a portion of the first electrode piece, at least a portion of the solid electrolyte layer, and at least a portion of the second electrode piece being stacked along a first direction, with a large surface of the electrode assembly being disposed opposite the first wall portion along the first direction; Wherein, along the first direction, a recess is provided at a position of the first wall portion opposite to the electrode assembly, and the recess is configured to provide expansion space for the electrode assembly.

2. The battery cell according to claim 1, wherein Along the first direction, the recess is provided on a side of the first wall portion facing away from the electrode assembly.

3. The battery cell according to claim 2, wherein: Along the first direction, the first wall portion has a first outer surface facing away from the electrode assembly, and the recess is a groove arranged on the first outer surface, and the groove extends to at least one end of the first wall portion along the second direction, and the second direction is perpendicular to the first direction.

4. The battery cell according to claim 3, wherein: Along the second direction, opposite ends of the groove extend to two ends of the first wall portion respectively.

5. The battery cell according to claim 3, wherein: The battery cell further includes an electrode terminal. The electrode terminal is provided at at least one end of the housing along a third direction. The first direction, the second direction, and the third direction are perpendicular to each other.

6. The battery cell according to claim 3, wherein: Along the third direction, the maximum dimension of the groove is L1, the maximum dimension of the 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 according to claim 6, wherein: 90mm≤L2≤180mm.

8. The battery cell according to claim 6, wherein: Along the third direction, the shell has a second outer surface and a third outer surface relative to each other, the minimum distance between the groove and the second outer surface is L3, and 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 according to claim 8, wherein: L3=L4.

10. The battery cell according to claim 2, wherein: 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.

11. The battery cell according to claim 2, wherein: Along the first direction, a convex portion is provided at a position corresponding to the concave portion on a side of the first wall portion facing the electrode assembly.

12. The battery cell according to any one of claims 1 to 11, characterized in that: A maximum dimension of the housing along the first direction is W1, and 25 mm ≤ W1 ≤ 75 mm.

13. The battery cell according to any one of claims 1 to 11, characterized in that: The housing includes two first wall portions, which are arranged opposite to 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 to 11, characterized in that: The length and height of the shell are both greater than the width of the shell, and the width direction of the shell is parallel to the first direction.

15. The battery cell according to any one of claims 1 to 11, characterized in that: The housing comprises: a housing having an opening; an end cap for closing the opening; The housing includes the first wall portion.

16. The battery cell according to claim 15, wherein: The housing includes two first wall portions arranged opposite to each other along the first direction and two second wall portions arranged opposite to each other along the second direction. At least one end of the housing along the third direction has the opening. The first direction, the second direction and the third direction are perpendicular to each other. A maximum dimension of the first wall portion along the second direction is greater than a maximum dimension of the second wall portion along the first direction.

17. The battery cell according to any one of claims 1 to 11, characterized in that: The electrode assembly is a laminated structure.

18. A battery device, characterized in that: The method comprises a plurality of battery cells according to any one of claims 1 to 17, wherein the plurality of battery cells are arranged along the first direction.

19. The battery device according to claim 18, wherein: Along the first direction, the recess is provided on a side of the first wall portion facing away from 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 in the recess.

20. The battery device according to claim 19, wherein: In two adjacent battery cells, a portion of the buffer member is accommodated in the recessed portion of the first wall portion of one battery cell, and another portion of the buffer member is accommodated in the recessed portion of the first wall portion of the other battery cell.

21. The battery device according to claim 19, wherein: The buffer is made of insulating material.

22. The battery device according to claim 18, wherein: The battery device further includes a busbar component, wherein the busbar component connects at least two of the battery cells to achieve electrical connection between the at least two battery cells.

23. An electrical device, characterized in that: The battery cell comprises the battery cell according to any one of claims 1 to 17 or the battery device according to any one of claims 18 to 22, wherein the battery cell is used to provide electrical energy to the electrical device.

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