Battery device and electric device

Abstract

The embodiment of the utility model provides a battery device and a power utilization device, and relates to the technical field of batteries. The battery device comprises a plurality of single batteries and a bus piece, wherein each single battery comprises an electrode terminal; the confluence piece is arranged opposite to the electrode terminals in the first direction and comprises a first connecting area, a buffer area and a second connecting area, the first connecting area and the second connecting area are arranged in the second direction, the buffer area is located between the first connecting area and the second connecting area, and the first connecting area and the second connecting area are connected with the electrode terminals of the two single batteries respectively; the second direction is perpendicular to the first direction; in the first direction, the buffer area does not exceed the two opposite surfaces of the first connection area and the two opposite surfaces of the second connection area; the buffering area comprises a buffering part which is arranged in a bent mode, and the buffering part is connected with the first connecting area and the second connecting area. Based on the arrangement, the buffer area can absorb the drawing force borne by the confluence piece, and meanwhile, the occupied space of the confluence piece in the first direction can be reduced.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to 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. In this context, electric vehicles, due to their energy-saving and environmentally friendly advantages, have become a crucial component of the industry's sustainable development. Battery technology, in turn, is a crucial factor in the development of electric vehicles.

[0003] In the development of battery device technology, in addition to improving the reliability of battery devices, improving the energy density of battery devices is also an issue that needs to be considered. How to improve the energy density of battery devices is an urgent problem to be solved in battery technology. Utility Model Content

[0004] The present application provides a battery device and an electrical device, which can improve the energy density of the battery device.

[0005] This application is achieved through the following technical solutions:

[0006] In a first aspect, an embodiment of the present application provides a battery device comprising a plurality of battery cells and a busbar, the battery cells comprising electrode terminals; the busbar is arranged opposite to the electrode terminals along a first direction, the busbar comprises a first connection area, a buffer area, and a second connection area, the first connection area and the second connection area are arranged along a second direction, the buffer area is located between the first connection area and the second connection area, the first connection area and the second connection area are respectively connected to the electrode terminals of two battery cells, and the second direction is perpendicular to the first direction; wherein, along the first direction, the buffer area does not exceed the two opposite surfaces of the first connection area and the two opposite surfaces of the second connection area; the buffer area includes a curved buffer portion, the buffer portion connecting the first connection area and the second connection area.

[0007] In the above embodiment, due to the curved configuration of the buffer portion, as the first and second connection areas move away from each other, the buffer portion connected between the first and second connection areas can gradually transition to a straightened state. During this transition, the buffer portion absorbs tensile forces applied to the buffer portion, thereby reducing the risk of the connection area between the battery cell and the current busbar becoming detached, and the risk of the current busbar being at least partially severed at the connection area between the two battery cells. Furthermore, the buffer portion does not extend beyond the two opposing surfaces of the first connection area or the two opposing surfaces of the second connection area along the first direction. This reduces the additional space occupied in the first direction by the curved buffer portion, thereby effectively improving the energy density of the battery device.

[0008] In some embodiments, the buffer portion is at least partially curved along a third direction, with the first, second, and third directions being perpendicular to each other. Curving the buffer portion at least partially along the third direction can mitigate the increased processing difficulty and poor connection reliability associated with curving the buffer portion along the first direction. Compared to curving the buffer portion only along the first direction, this embodiment reduces the processing difficulty of the buffer portion and improves its connection reliability.

[0009] In some embodiments, the buffer portion is arc-shaped. The arc-shaped buffer portion has the advantages of good tensile force absorption and easy processing and manufacturing.

[0010] In some embodiments, the buffer portion is at least partially curved along the first direction. The buffer portion is at least partially curved along the first direction and does not extend beyond two opposing surfaces of the first connection area and two opposing surfaces of the second connection area. This can reduce the space in the first direction additionally occupied by the curved buffer portion, thereby effectively improving the energy density of the battery device.

[0011] In some embodiments, the buffer zone is provided with a plurality of hollow portions, which are arranged alternately with the buffer portions along the third direction, with the first, second, and third directions being perpendicular to each other. The hollow portions provided in the buffer zone can reduce the connection area between the buffer zone and the first and second connection areas. When a battery cell expands, the curved buffer portion of the current collector is more likely to deform when stretched, thereby reducing the risk of disconnection between the battery cell and the current collector due to the poor deformation capacity of the buffer zone.

[0012] In some embodiments, along the third direction, the minimum distance between adjacent hollow portions is d1, where d1 is ≥ 2 mm. By setting the minimum distance between adjacent hollow portions in the third direction, the impact on the strength of the current busbar can be reduced.

[0013] In some embodiments, the plurality of hollow portions have the same size along the second direction. When the buffer zone is subjected to a tensile force from the first connection area and / or the second connection area, the force is more evenly applied to the buffer zone, thereby improving the overall stability of the current collector.

[0014] In some embodiments, along the second direction, the size of the current collector is d2, the size of the hollow portion is d3, and 0.1≤d3 / d2≤0.5. When the technical solution of this embodiment is adopted, the strength of the current collector and the tensile force absorption performance of the buffer portion can be taken into account at the same time.

[0015] In some embodiments, the first connection area is provided with a first through hole, and in a projection plane perpendicular to the first direction, the orthographic projection of the electrode terminal connected to the first connection area at least partially overlaps with the orthographic projection of the first through hole; the minimum distance between the center of the first through hole and the edge of the hollow portion is d4, d4 ≥ 15 mm.

[0016] In some embodiments, the second connection area is provided with a second through hole, and in a projection plane perpendicular to the first direction, the orthographic projection of the electrode terminal connected to the second connection area at least partially overlaps with the orthographic projection of the second through hole; the minimum distance between the center of the second through hole and the edge of the hollow portion is d5, d5 ≥ 15 mm.

[0017] When the minimum distance between the center of the first through hole and / or the second through hole and the edge of the hollow portion is greater than or equal to 15 mm, the influence of the hollow portion on the connection between the electrode terminal and the busbar can be reduced, thereby improving the reliability of the connection between the electrode terminal and the busbar.

[0018] In some embodiments, along the first direction, the first connection region has a first surface facing the battery cell, the second connection region has a second surface facing the battery cell, and the buffer region has a third surface facing the battery cell, with the first, second, and third surfaces being coplanar; and / or, along the first direction, the first connection region has a fourth surface facing away from the battery cell, the second connection region has a fifth surface facing away from the battery cell, and the buffer region has a sixth surface facing away from the battery cell, with the fourth, fifth, and sixth surfaces being coplanar. In the above embodiments, based on the above configuration, the provision of the buffer region does not increase the space occupied in the first direction, and the size of the buffer region along the first direction can be as large as possible, thereby reducing the risk of the buffer portion being broken due to its small size in the first direction, as well as the difficulty in processing.

[0019] In some embodiments, the battery cell further includes a housing, and the electrode terminals are disposed in the housing. At least a portion of the electrode terminals protrude from the outer surface of the housing along a first direction. Along the first direction, the electrode terminals protrude by a dimension d6, where d6 is ≤ 1 mm. In the first direction, the buffer portion does not extend beyond the two opposing surfaces of the first connection area and the two opposing surfaces of the second connection area. This effectively reduces the space occupied by the current busbar in the first direction by the buffer portion, thereby increasing the overall energy density of the battery device. It also reduces the risk of a short circuit between the buffer portion and the housing, which could affect the reliability of the battery device.

[0020] In a second aspect, an embodiment of the present application provides an electrical device, comprising the battery device provided by any embodiment of the first aspect.

[0021] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become obvious from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] 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.

[0023] Figure 1 A schematic structural diagram of a vehicle according to some embodiments of the present application;

[0024] Figure 2 Schematic diagram of the exploded structure of a battery device according to some embodiments of the present application;

[0025] Figure 3 A schematic diagram of the connection structure between a battery cell and a busbar in some embodiments of the present application;

[0026] Figure 4 This is a schematic diagram of the exploded structure of a battery cell according to some embodiments of the present application;

[0027] Figure 5 This is a schematic structural diagram of a battery device according to some embodiments of the present application;

[0028] Figure 6 for Figure 5 A schematic diagram of the local structure of the AA cross-sectional view;

[0029] Figure 7 This is a schematic structural diagram of a busbar in some embodiments of the present application;

[0030] Figure 8 Schematic diagrams of the structures of battery devices according to other embodiments of the present application;

[0031] Figure 9 for Figure 8 BB cross-sectional view;

[0032] Figure 10 Schematic diagrams of the structures of the current collectors of other embodiments of the present application;

[0033] Figure 11 Schematic diagrams of the structures of battery devices according to some other embodiments of the present application;

[0034] Figure 12 for Figure 11 CC cross-sectional view;

[0035] Figure 13 for Figure 12 A schematic diagram of the structure of the busbar;

[0036] icon:

[0037] 1000 - vehicle; 100 - battery device; 200 - controller; 300 - motor; 10 - housing; 11 - first housing; 12 - second housing; 20 - battery cell; 201 - electrode terminal; 202 - housing; 2021 - casing; 2022 - end cap; 203 - electrode assembly; 30 - busbar; 301 - first connection area; 3011 - first surface; 3012 - fourth surface; 302 - buffer; 3021 - buffer portion; 3022 - hollow portion; 3023 - third surface; 3024 - sixth surface; 303 - second connection area; 3031 - second surface; 3032 - fifth surface; 304 - first through hole; 305 - second through hole;

[0038] X-first direction; Y-second direction; Z-third direction. DETAILED DESCRIPTION

[0039] 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.

[0040] 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.

[0041] 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.

[0042] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "attached" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0043] 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.

[0044] 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.

[0045] The term "plurality" used in this application refers to two or more (including two).

[0046] 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.

[0047] Battery cells include but are not limited to lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-hydrogen batteries, nickel-cadmium batteries, lead-acid batteries, etc.

[0048] A battery cell typically includes an electrode assembly. This assembly includes a positive electrode, a negative electrode, and a separator. During the charge and discharge process, active ions (such as lithium ions) move back and forth between the positive and negative electrodes. A separator, placed between the positive and negative electrodes, reduces the risk of short circuits while allowing active ions to pass through.

[0049] In some embodiments, the positive electrode may be a positive electrode sheet, which may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0050] As an example, the positive electrode current collector has two surfaces facing each other in its thickness direction, and the positive electrode active material is provided on either or both of the two facing surfaces of the positive electrode current collector.

[0051] As an example, the positive electrode current collector can employ a metal foil or a composite current collector. For example, as the metal foil, aluminum subjected to silver plating on the surface, stainless steel subjected to silver plating on the surface, copper, aluminum, nickel, a carbon electrode, carbon, titanium, or the like can be employed. The composite current collector can include a high molecular 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, or the like) on a high molecular material base material (such as a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, or the like).

[0052] 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 only one or two or more can be used in combination. As an example of the lithium-containing phosphate, at least one of lithium iron phosphate (such as LiFeP04(also referred to simply as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnP04), a composite material of lithium manganese phosphate and carbon, lithium manganese iron phosphate, and a composite material of lithium manganese iron phosphate and carbon can be included, but is not limited thereto. As an example of the lithium transition metal oxide, lithium cobalt oxide (such as LiCo02), lithium nickel oxide (such as LiNi02), lithium manganese oxide (such as LiMn02, LiMn204), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi 1 / 3 Co 1 / 3Mn 1 / 3 O2(also referred to simply as NCM 333 ), LiNi 0.5 Co 0.2 Mn 0.3 O2(also referred to simply as NCM 523 ), LiNi 0.5 Co 0.25 Mn 0.25 O2(also referred to simply as NCM 211 ), LiNi 0.6 Co 0.2 Mn 0.2 O2(also referred to simply as NCM 622 ), LiNi 0.8 Co 0.1 Mn 0.1 O2(also referred to simply as NCM 811 ), lithium nickel cobalt aluminum oxide (such as LiNi 0.85 Co 0.15 Al 0.05O2) and at least one of its modified compounds, etc.

[0053] 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.

[0054] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0055] 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, copper, aluminum, nickel, a carbon electrode, carbon or titanium, etc. 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.).

[0056] 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.

[0057] As an example, the negative electrode current collector has two surfaces facing each other in its thickness direction, and the negative electrode active material is provided on either or both of the two facing surfaces of the negative electrode current collector.

[0058] As an example, the negative electrode active material may adopt the negative electrode active material for battery cells that is well known in the art. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, etc. The silicon-based material may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The tin-based material may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, the present application is not limited to these materials, and other traditional materials that can be used as negative electrode active materials for battery cells may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0059] In some embodiments, the material of the positive electrode current collector may be aluminum, and the material of the negative electrode current collector may be copper.

[0060] In some embodiments, the separator is a separator film. The separator film can be any porous structure separator film known to have good chemical stability and mechanical stability.

[0061] As an example, the separator film can include at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator film can be a single layer film or a multi-layer composite film. When the separator film is a multi-layer composite film, the materials of the layers can be the same or different. The separator can be a separate component between the positive and negative electrodes or can be attached to the surface of the positive and negative electrodes.

[0062] In some embodiments, the separator is a solid-state electrolyte. The solid-state electrolyte is disposed between the positive and negative electrodes and functions to transport ions and separate the positive and negative electrodes.

[0063] In some embodiments, the battery cell further includes an electrolyte that functions to conduct ions between the positive and negative electrodes. The electrolyte can be in a liquid state, a gel state, or a solid state. Among them, the liquid electrolyte includes an electrolyte salt and a solvent.

[0064] In some embodiments, the electrolyte salt can include at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bisfluorosulfonylimide, lithium bis-trifluoromethanesulfonylimide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluoro oxalate borate, lithium di-oxalate borate, lithium difluoro di-oxalate phosphate, and lithium tetrafluoro oxalate phosphate.

[0065] In some embodiments, the solvent can include at least one of ethylene carbonate, propylene carbonate, methyl ethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, butyrosulfone, methyl ethyl sulfone, and diethyl sulfone. The solvent can also be an ether solvent. The ether solvent can include one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyl tetrahydrofuran, diphenyl ether, and crown ether.

[0066] Among them, the gel-state electrolyte includes a polymer as a skeleton network of the electrolyte, in combination with an ionic liquid-lithium salt.

[0067] Among them, the solid-state electrolyte includes a polymer solid-state electrolyte, an inorganic solid-state electrolyte, and a composite solid-state electrolyte.

[0068] As an example, the polymer solid electrolyte may be polyether (polyethylene oxide), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, a single ion polymer, polyionic liquid-lithium salt, cellulose, or the like.

[0069] As an example, the inorganic solid electrolyte may include an oxide solid electrolyte (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON film), a sulfide solid electrolyte (crystalline lithium superion conductor (lithium germanium phosphosulfide, silver germanium sulfide), amorphous sulfide) and one or more of a halide solid electrolyte, a nitride solid electrolyte and a hydride solid electrolyte.

[0070] As an example, a composite solid electrolyte is formed by adding an inorganic solid electrolyte filler to a polymer solid electrolyte.

[0071] In some embodiments, the electrode assembly is a wound structure, wherein the positive electrode sheet and the negative electrode sheet are wound into a wound structure.

[0072] In some embodiments, the electrode assembly is a laminate structure.

[0073] As an example, multiple positive electrode sheets and multiple negative electrode sheets can be provided respectively, and the multiple positive electrode sheets and the multiple negative electrode sheets can be alternately stacked.

[0074] As an example, multiple positive electrode sheets may be provided, and the negative electrode sheet is folded to form multiple stacked folded segments, with a positive electrode sheet sandwiched between adjacent folded segments.

[0075] As an example, both the positive electrode sheet and the negative electrode sheet are folded to form a plurality of stacked folded segments.

[0076] As an example, multiple separators may be provided, each of which is provided between any adjacent positive electrode sheets or negative electrode sheets.

[0077] As an example, the separator may be provided continuously, and may be provided between any adjacent positive electrode sheets or negative electrode sheets by folding or winding.

[0078] In some embodiments, the shape of the electrode assembly can be cylindrical, flat, or polygonal.

[0079] In some embodiments, the electrode assembly is provided with tabs that can conduct current from the electrode assembly. The tabs include a positive electrode tab and a negative electrode tab.

[0080] In some embodiments, a battery cell may include a housing. The housing is used to encapsulate components such as the electrode assembly and the electrolyte. The housing may be a steel housing, an aluminum housing, a plastic housing (e.g., polypropylene), a composite metal housing (e.g., a copper-aluminum composite housing), or an aluminum-plastic film.

[0081] As an example, the battery cell may be a cylindrical battery cell, a prismatic battery cell, a soft-pack battery cell or a battery cell of other shapes. Prismatic battery cells include square-shell battery cells, blade-shaped battery cells, and polygonal battery cells. Polygonal battery cells are, for example, hexagonal battery cells.

[0082] The battery apparatus mentioned in the embodiments of the present application may include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly may include multiple battery cells, which are connected in series, parallel, or hybrid via a busbar.

[0083] In some embodiments, a battery cell assembly is generally formed by arranging a plurality of battery cells. As an example, the battery cell assembly may be a battery module, which is formed by arranging and fixing a plurality of battery cells to form an independent module.

[0084] As an example, a battery module may be formed by bundling a plurality of battery cells by cable ties.

[0085] In some embodiments, the battery device may be a battery pack, which may include a case and one or more battery cell assemblies, wherein the battery cell assemblies are housed in the case.

[0086] As an example, the battery cell assembly may be a battery module, and the battery cell assembly may be accommodated in the box by fixing the battery module in the box.

[0087] As an example, the battery cell assembly may also be housed in the box by directly fixing the plurality of battery cells to the box.

[0088] As an example, the housing may include a first housing and a second housing. The first housing and the second housing engage to form an enclosed space within the housing to house the battery cell assembly. Enclosed here means covered or closed, and can be either sealed or unsealed. The first housing may be a top cover or a bottom plate.

[0089] As an example, the box body may include a top cover, a frame, and a bottom plate, wherein the top cover and the bottom plate are respectively connected to the frame, so that a closed space is formed inside the box body to accommodate the battery cell assembly.

[0090] As an example, the box body can be used as a part of the chassis structure of the vehicle. For example, the top cover of the box body can become at least a part of the floor of the vehicle, or the frame of the box body can become at least a part of the crossbeam and longitudinal beam of the vehicle.

[0091] 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.

[0092] During use, a battery cell may swell. When a battery cell swells, the current bus connecting multiple battery cells is subjected to tensile force in at least one direction. When subjected to tensile force, the bus may find it difficult to absorb the force, causing the connection area between the battery cell and the bus to gradually separate, affecting the current flow capacity of the battery cell and the bus. Alternatively, the bus may be at least partially severed in the area connecting two battery cells, further affecting the current flow capacity of the bus. A compromised current flow capacity of either the battery cell or the bus, or the bus itself, will ultimately affect the reliability of the battery device.

[0093] Based on the above situation, a buffer portion can be provided on the busbar. This buffer portion is configured to be curved toward or away from the battery cell. When the battery cell expands and the busbar is stretched, the buffer portion deforms, absorbing the tensile force, thereby reducing the impact of battery cell expansion on the reliability of the battery device. However, in the above approach, because the buffer portion protrudes from the side of the busbar facing the battery cell or the side facing away from the battery cell, it occupies a relatively large height space, resulting in a decrease in the energy density of the final battery device.

[0094] In view of this, an embodiment of the present application provides a battery device, comprising a plurality of battery cells and a busbar, the battery cells comprising electrode terminals; the busbar is arranged opposite to the electrode terminals along a first direction, the busbar comprises a first connection area, a buffer area, and a second connection area, the first connection area and the second connection area are arranged along a second direction, the buffer area is located between the first connection area and the second connection area, the first connection area and the second connection area are respectively connected to the electrode terminals of two battery cells, and the second direction is perpendicular to the first direction; along the first direction, the buffer area does not exceed the two opposite surfaces of the first connection area and the two opposite surfaces of the second connection area; the buffer area includes a curved buffer portion, the buffer portion connecting the first connection area and the second connection area.

[0095] In such a battery device, due to the curved setting of the buffer portion, when the first connection area and the second connection area move away from each other, the buffer portion connected between the first connection area and the second connection area can gradually transform into a straightened state to absorb the tensile force exerted on the busbar, and the buffer area does not exceed the two opposite surfaces of the first connection area and the two opposite surfaces of the second connection area along the first direction, which can reduce the additional space in the first direction occupied by the setting of the curved buffer portion, thereby effectively improving the energy density of the battery device.

[0096] 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.

[0097] For the convenience of description, the following embodiments are described by taking a vehicle as an example of an electrical device.

[0098] 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.

[0099] 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.

[0100] 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.

[0101] Please refer to Figure 2 , Figure 2 1 is a schematic diagram of an exploded structure of a battery device 100 according to some embodiments of the present application. The battery device 100 may include a battery cell 20 and a case 10 . The case 10 is used to accommodate the battery cell 20 .

[0102] Among them, a closed space for accommodating the battery cells 20 is formed inside the box body 10, and the box body 10 can adopt a variety of structures. In some embodiments, the box body 10 may include a first box body 11 and a second box body 12, and the first box body 11 and the second box body 12 are buckled with each other. The first box body 11 and the second box body 12 can be of various shapes, such as a rectangular parallelepiped, a cylinder, etc. The first box body 11 can be a hollow structure with one side open, and the second box body 12 can also be a hollow structure with one side open. The open side of the second box body 12 is buckled with the open side of the first box body 11 to form a box body 10 with a closed space. The first box body 11 can also be a hollow structure with one side open, and the second box body 12 can be a plate-like structure. The second box body 12 is buckled with the open side of the first box body 11 to form a box body 10 with a accommodating space.

[0103] In the battery device 100, there can be one or more battery cells 20. If there are multiple battery cells 20, the multiple battery cells 20 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 20. Multiple battery cells 20 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 10. Alternatively, all battery cells 20 can be directly connected in series, parallel, or in a hybrid connection, and then the entire unit formed by all battery cells 20 is housed within the housing 10.

[0104] In some embodiments, please refer to Figure 3 , Figure 3 This is a schematic diagram of the connection structure between the battery cells 20 and the busbar 30 in some embodiments of the present application. The battery device 100 may further include a busbar 30. The multiple battery cells 20 may be electrically connected via the busbar 30 to achieve series, parallel, or mixed connection of the multiple battery cells 20. The busbar 30 may be a metal conductor, such as copper, iron, aluminum, stainless steel, or an aluminum alloy.

[0105] In some embodiments, please refer to Figure 4 , Figure 4 This is a schematic diagram of the exploded structure of a battery cell 20 in some embodiments of the present application. The battery cell 20 may include a housing 202 and an electrode assembly 203 , and the electrode assembly 203 is accommodated in the housing 202 .

[0106] In some embodiments, the housing 202 may include a shell 2021 and an end cap 2022, wherein the shell 2021 has an opening and the end cap 2022 closes the opening of the shell 2021. The closing here means covering or closing, which may be sealed or non-sealed.

[0107] The housing 2021 is a component for accommodating the electrode assembly 203. The housing 2021 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 2021 can have various shapes, such as a cylinder or a rectangular parallelepiped. The housing 2021 can be made of various materials, such as copper, iron, aluminum, steel, and aluminum alloys. The electrode assembly 203 can be partially or completely located within the housing 2021.

[0108] The end cap 2022 and the shell 2021 together define a receiving space for accommodating the electrode assembly 203 and other components. The end cap 2022 can be connected to the shell 2021 by welding, crimping, etc. to close the opening of the shell 2021. The shape of the end cap 2022 can be adapted to the shape of the shell 2021. For example, if the shell 2021 is a rectangular parallelepiped structure, the end cap 2022 is a rectangular plate structure adapted to the shell 2021. For another example, if the shell 2021 is a cylindrical structure, the end cap 2022 is a circular plate structure adapted to the shell 2021. The material of the end cap 2022 can also be various, such as copper, iron, aluminum, steel, aluminum alloy, etc. The material of the end cap 2022 and the shell 2021 can be the same or different.

[0109] In an embodiment where the housing 2021 is open at one end, one end cap 2022 may be provided. In an embodiment where the housing 2021 is open at two opposite ends, two end caps 2022 may be provided, each of which closes the two openings of the housing 2021. The two end caps 2022 and the housing 2021 together define a receiving space.

[0110] In some embodiments, the battery cell 20 may further include an electrode terminal 201, which is disposed on the outer casing 202. The electrode terminal 201 is used to electrically connect to the tab of the electrode assembly 203 to input or output electrical energy from the battery cell 20. The electrode terminal 201 may be disposed on the shell 2021 of the outer casing 202 or on the end cap 2022 of the outer casing 202. The electrode terminals 201 of different polarities of a battery cell 20 may be disposed on the same side of the outer casing 202 or on different sides of the outer casing 202. The electrode terminal 201 and the tab may be directly connected, for example, by welding the electrode terminal 201 to the tab. The electrode terminal 201 and the tab may also be indirectly connected, for example, by indirectly connecting the electrode terminal 201 to the tab through a current collecting member. The current collecting member may be a metal conductor, such as copper, iron, aluminum, steel, or an aluminum alloy.

[0111] As an example, in Figure 4 In the illustrated embodiment, an opening is formed at one end of the housing 2021. A single end cap 2022 is provided in the outer shell 202, and each end cap 2022 seals the opening of the housing 2021. Two electrode terminals 201 are provided on the end cap 2022, namely a positive electrode terminal 201 and a negative electrode terminal 201. A positive electrode tab and a negative electrode tab are formed on the end of the electrode assembly 203 facing the end cap 2022. The positive electrode terminal 201 is electrically connected to the positive electrode tab, and the negative electrode terminal 201 is electrically connected to the negative electrode tab.

[0112] See also Figure 5 and Figure 6 , Figure 5Schematic diagram of the structure of the battery device 100 according to some embodiments of the present application; Figure 6 for Figure 5 AA cross-sectional view of a partial structure diagram. Some embodiments of the present application provide a battery device 100, which includes a busbar 30 and a plurality of battery cells 20. The battery cells 20 include electrode terminals 201. The busbar 30 is arranged opposite the electrode terminals 201 along a first direction X. The busbar 30 includes a first connection area 301, a buffer area 302, and a second connection area 303. The first connection area 301 and the second connection area 303 are arranged along a second direction Y. The buffer area 302 is located between the first connection area 301 and the second connection area 303. The first connection area 301 is connected to the electrode terminal 201 of one battery cell 20, and the second connection area 303 is connected to the electrode terminal 201 of another battery cell 20. The second direction Y is perpendicular to the first direction X. In the first direction X, the buffer area 302 does not extend beyond the two opposite surfaces of the first connection area 301, and the buffer area 302 does not extend beyond the two opposite surfaces of the second connection area 303. The buffer zone 302 includes a curved buffer portion 3021 , which connects the first connection area 301 and the second connection area 303 .

[0113] The number of battery cells 20 in the battery device 100 may be two, three, four, or more.

[0114] The busbar 30, also known as a busbar or busbar, is a component used to connect multiple battery cells 20 in series and parallel. The busbar 30 can be made of metal materials such as copper, aluminum, aluminum alloy, nickel, and their composite materials. The battery device 100 can have one or more busbars 30. When there are two battery cells, one busbar can be provided, connecting the two battery cells to form a whole. When there are more than two battery cells, multiple busbars can be provided, connecting the two battery cells to form a whole. The two battery cells 20 electrically connected to the busbar 30 can be arranged adjacent to each other or non-adjacent to each other. For example, multiple battery cells 20 are arranged along a second direction Y, and the multiple battery cells 20 include a first battery cell, a second battery cell, and a third battery cell, each of which is adjacent to each other, with the second battery cell being positioned between the first and third battery cells. A busbar 30 can connect the electrode terminals 201 of the first battery cell and the electrode terminals 201 of the second battery cell to electrically connect the two adjacent battery cells 20. Alternatively, a busbar 30 can connect the electrode terminals 201 of the first battery cell and the electrode terminals 201 of the third battery cell to electrically connect two non-adjacent battery cells 20. The polarity of the electrode terminals 201 of the two battery cells 20 connected to the same busbar 30 can be the same or opposite. If the electrode terminals 201 of the two batteries connected to the same busbar 30 have the same polarity, the busbar 30 can connect the two battery cells 20 in parallel. If the electrode terminals 201 of the two batteries connected to the same busbar 30 have different polarities, the busbar 30 can connect the two battery cells 20 in series.

[0115] The busbar 30 may be disposed on a side of the battery cell 20 where the electrode terminal 201 is disposed along the first direction X, so that the busbar 30 is disposed opposite to the electrode terminal 201 along the first direction X. The first direction X may be parallel to the axial direction of the electrode terminal 201 .

[0116] The first connection area 301, the buffer area 302 and the second connection area 303 are partial areas of the busbar 30 respectively. The first connection area 301 and the second connection area 303 are respectively the parts of the busbar 30 that connect the electrode terminals 201 of the two battery cells 20. The buffer area 302 is the part of the busbar 30 that is connected between the first connection area 301 and the second connection area 303 and has a buffering function.

[0117] The first connection area 301, the second connection area 303 and the buffer area 302 can be flat plate structures. In the first direction X, the first connection area 301 has a first surface 3011 ( Figure 5 and Figure 6 Not shown) and a fourth surface 3012 ( Figure 5and Figure 6 Not shown), the second connection region 303 has a second surface 3031 ( Figure 5 and Figure 6 Not shown) and a fifth surface 3032 ( Figure 5 and Figure 6 The buffer zone 302 has a third surface 3023 (not shown) facing the battery cell 20. Figure 5 and Figure 6 Not shown) and a sixth surface 3024 ( Figure 5 and Figure 6 (not shown). Furthermore, along the first direction X, the distance from the third surface 3023 to the fourth surface 3012 is less than or equal to the distance from the first surface 3011 to the fourth surface 3012; the distance from the third surface 3023 to the fifth surface 3032 is less than or equal to the distance from the second surface 3031 to the fifth surface 3032; the distance from the sixth surface 3024 to the first surface 3011 is less than or equal to the distance from the fourth surface 3012 to the first surface 3011; and the distance from the sixth surface 3024 to the second surface 3031 is less than or equal to the distance from the fifth surface 3032 to the second surface 3031.

[0118] In this embodiment, a portion of the buffer zone 302 may be the buffer portion 3021 , or the buffer zone 302 may be the buffer portion 3021 .

[0119] The fact that the buffer portion 3021 is at least partially curved should be understood as meaning that the buffer portion 3021 is curved. The buffer portion 3021 may be in an arc, wave, or broken line shape. The buffer portion 3021 may be at least partially curved along the first direction X, or at least partially curved along a direction perpendicular to the second direction Y and the first direction X. The buffer portion 3021 in the buffer zone 302 may be one or more.

[0120] In the above embodiment, due to the curved configuration of the buffer portion 3021, when the first connection region 301 and the second connection region 303 move away from each other, the buffer portion 3021 connected between the first connection region 301 and the second connection region 303 can gradually transition to a straightened state. During this transition, the buffer portion 3021 absorbs tensile forces applied to the buffer portion 3021, thereby reducing the risk of the connection region between the battery cells 20 and the current bus 30 becoming detached, and the risk of the current bus 30 being at least partially severed at the connection region between the two battery cells 20. Furthermore, the buffer portion 302 does not extend beyond the two opposing surfaces of the first connection region 301 or the two opposing surfaces of the second connection region 303 along the first direction X. This reduces the additional space occupied in the first direction X by the curved buffer portion 3021, thereby effectively improving the energy density of the battery device 100.

[0121] In some embodiments, see Figure 7 , Figure 7 Schematic diagram of the structure of the current collector 30 in some embodiments of the present application; the buffer portion 3021 is at least partially bent along the third direction Z. The first direction X, the second direction Y and the third direction Z are perpendicular to each other.

[0122] The buffer portion 3021 being at least partially bent means that the buffer portion 3021 may be only partially bent or may be fully bent.

[0123] When the buffer portion 3021 is bent along the first direction X, in order to ensure that the buffer portion 3021 does not extend beyond the two opposing surfaces of the first connection area 301 and the two opposing surfaces of the second connection area 303 in the first direction X, the size of the buffer portion 3021 in the first direction X needs to be reduced. However, the size of the busbar 30 in the first direction X is typically relatively small, and the buffer portion 3021 must also be made very small. This increases manufacturing difficulty and can also lead to excessive reduction in the size of the buffer portion 3021 in the first direction X, making it susceptible to breaking and affecting its connection reliability. In this embodiment, the buffer portion 3021 is at least partially bent along the third direction Z, which reduces the manufacturing difficulty and poor connection reliability caused by the bending of the buffer portion 3021 in the first direction X.

[0124] Compared with the buffer portion 3021 being bent only along the first direction X, this embodiment can reduce the difficulty of processing the buffer portion 3021 and also improve the connection reliability of the buffer portion 3021 .

[0125] In some other embodiments, see Figure 8 and Figure 9 , Figure 8 Schematic diagrams of the structure of the battery device 100 according to other embodiments of the present application; Figure 9 for Figure 8 The buffer portion 3021 may also be at least partially bent along the first direction X, that is, bent toward the battery cell 20, or bent away from the battery cell 20. This is sufficient as long as the bent buffer portion 3021 does not extend beyond the two opposing surfaces of the first connection area 301 or the two opposing surfaces of the second connection area 303 in the first direction X.

[0126] In some other embodiments, the buffer portion 3021 may include both a portion bent along the third direction Z and a portion bent along the first direction X, so as to improve the ability of the buffer portion 3021 to absorb the tensile force.

[0127] In some embodiments, please refer to Figure 7 and Figure 9 , the buffer portion 3021 is arc-shaped.

[0128] exist Figure 7 In the embodiment, the buffer portion 3021 is bent along the third direction Z to form an arc shape.

[0129] exist Figure 9 In the embodiment, the buffer portion 3021 is bent along the first direction X to form an arc shape.

[0130] The arc shape means that two opposite edges of the buffer portion 3021 in the third direction Z are arc-shaped with the same bending direction, thereby making the buffer portion 3021 form an arc shape as a whole.

[0131] The arc-shaped buffer portion 3021 has the advantages of being good at absorbing tensile force and being easy to manufacture.

[0132] In some embodiments, see Figure 10 , Figure 10 Schematic diagram of the structure of the current collector 30 of some other embodiments of the present application. The buffer zone 302 is provided with a plurality of hollow portions 3022 . Along the third direction Z, the hollow portions 3022 and the buffer portions 3021 are alternately provided.

[0133] The hollow portion 3022 may be a hole penetrating two opposite surfaces of the buffer zone 302 along the first direction X.

[0134] When the buffer zone 302 is provided with a hollow portion 3022, the solid portion at the edge of the hollow portion 3022 along the third direction Z can be considered as the buffer portion 3021. There can be two or more hollow portions 3022. When there are two hollow portions 3022, the solid portion between the two hollow portions 3022 can be considered as the buffer portion 3021. In the third direction Z, the solid portion of the two hollow portions 3022 away from each other can be considered as the buffer portion 3021 or the connecting portion. When there are more than two hollow portions 3022, the solid portion between any two adjacent hollow portions 3022 can be considered as the buffer portion 3021. In the third direction Z, the solid portion of the hollow portions 3022 located on both sides of the edge, along the side away from each other, can be considered as the buffer portion 3021 or the connecting portion. In the third direction Z, the hollow portions 3022 located at both side edges are solid portions arranged along a side away from each other. Whether the solid portion has a curved portion can determine whether the solid portion is considered as the buffer portion 3021.

[0135] In some examples, the hollow portions 3022 located at the edges of both sides are solid portions arranged along a side away from each other, and when they do not have the ability to deform from a bent state, the solid portions can be considered as connecting portions rather than buffer portions 3021; ​​in specific application scenarios, in order to facilitate the processing and manufacturing of the buffer portions 3021, multiple hollow portions 3022 can be optionally provided on a whole busbar 30, and buffer portions 3021 are formed between adjacent hollow portions 3022. At this time, the buffer zone 302 has connecting portions formed at two edge positions opposite to each other in the third direction Z, and the edges of the connecting portions along the third direction Z will be flush with the edges of the first connection area 301 and the second connection area 303, so that the overall connection portion is not curved or is curved on only one side. At this time, the number of hollow portions 3022 in the buffer zone 302 is one more than the buffer portion 3021. In a specific application scenario, although the connecting part cannot change from a bent state to a straight state when being stretched, when it itself adopts a stretchable base material, the connecting part can still undergo ductile deformation when being stretched, and also has the function of supporting and absorbing tensile force.

[0136] In other examples, when the solid portion has the ability to deform from a bent state, the solid portion can also be considered as the buffer portion 3021. When the hollow portions 3022 located at both side edges are disposed along a solid portion on a side away from each other, the number of hollow portions 3022 in the buffer zone 302 is one less than the number of buffer portions 3021.

[0137] In the above embodiment, a hollow portion 3022 is provided on the buffer zone 302, which can reduce the connection area between the buffer zone 302 and the first connection area 301 and the second connection area 303. When the battery cell 20 expands, the buffer zone 302 of the curved arrangement of the busbar 30 is more likely to deform when stretched, thereby reducing the risk of the battery cell 20 and the busbar 30 becoming disconnected due to the poor deformation ability of the buffer zone 302.

[0138] In some embodiments, see Figure 11 and Figure 12 , Figure 11 Schematic diagram of the structure of the battery device 100 according to some other embodiments of the present application. Figure 12 for Figure 11 Along the third direction Z, the minimum distance between adjacent hollow portions 3022 is d1, and d1 ≥ 2 mm.

[0139] In some examples, the distance between adjacent hollow portions 3022 along the third direction Z is the same everywhere, in which case the minimum distance between the two is the distance between them. In other examples, when the distance between adjacent hollow portions 3022 along the third direction Z has multiple different values, the minimum value is used as the minimum distance between them.

[0140] When the busbar 30 is used to connect multiple battery cells 20 in series or parallel, its strength must meet certain requirements. However, the provision of hollow portions 3022 can affect the connection strength of the busbar 30, which is particularly noticeable when multiple hollow portions 3022 are provided. For example, when multiple hollow portions 3022 are provided, the smaller the size of the buffer portion 3021 between two adjacent hollow portions 3022, the weaker the connection strength. Therefore, when providing multiple hollow portions 3022, it is necessary to consider the minimum distance between adjacent hollow portions 3022 to reduce the impact on the connection strength of the busbar 30. In this embodiment, by setting a minimum distance between adjacent hollow portions 3022 in the third direction Z, the impact on the connection strength of the busbar 30 can be reduced.

[0141] In some embodiments, please refer to Figure 11 In this embodiment, the multiple hollow portions 3022 have the same size along the second direction Y. In this embodiment, the multiple hollow portions 3022 have the same size along the second direction Y. When the buffer zone 302 is subjected to the tensile force of the first connection area 301 and / or the second connection area 303, the force applied to the buffer zone 302 is more uniform, and the overall stability of the current collector 30 is improved.

[0142] In other embodiments, please refer to Figure 10 Among the multiple hollow portions 3022, at least two hollow portions 3022 have different sizes along the second direction Y.

[0143] In some examples, it can be set that the sizes of any two hollow portions 3022 along the second direction Y are different; in other examples, it can be set that multiple groups of hollow portions 3022 are provided, each group of hollow portions 3022 includes at least two, the hollow portions 3022 in each group have the same size along the second direction Y, and the sizes of different groups of hollow portions 3022 along the second direction Y are different; in some other examples, it can be set that multiple groups of hollow portions 3022 are provided, at least one group of hollow portions 3022 includes only one, the hollow portions 3022 in the group with multiple hollow portions 3022 have the same size along the third direction Z, and the sizes of different groups of hollow portions 3022 along the second direction Y are different.

[0144] In some examples, when at least two hollow portions 3022 have different sizes along the second direction Y, the sizes of the hollow portions 3022 can be gradually increased along the third direction Z. Based on this arrangement, the force applied to the buffer zone 302 can be controlled as a whole.

[0145] In the above embodiment, to avoid the area where the electrode terminal 201 is located, the length of some hollow portions 3022 needs to be set relatively short, while the length of other hollow portions 3022 can be set longer, thereby enabling better deformation of the buffer zone 302. By providing hollow portions 3022 of different lengths, the deformation ability of the buffer zone 302 and the avoidance of the electrode terminal 201 can be taken into account simultaneously.

[0146] In some embodiments, please refer to Figure 10 and Figure 11 , the hollow portion 3022 is at least partially bent along the third direction Z.

[0147] Regarding the processing of the buffer portion 3021, the curved buffer portion 3021 can be directly manufactured and then connected to the first connection area 301 and the second connection area 303. However, this processing requires the separate steps of manufacturing the buffer portion 3021 and connecting the buffer portion 3021 to the first connection area 301 and the second connection area 303, resulting in a complex process. In this embodiment, the hollow portion 3022 is curved along the third direction Z, which constrains the buffer portion 3021 to be curved along the third direction Z. Based on this arrangement, during manufacturing, the corresponding buffer portion 3021 can be obtained by manufacturing the hollow portion 3022 on the integral current collector 30. Compared to directly manufacturing the curved buffer portion 3021, this embodiment has a simpler process, less difficulty, and lower processing costs.

[0148] In some embodiments, please refer to Figure 10 and Figure 11 The hollow portion 3022 is arc-shaped. By setting the arc-shaped hollow portion 3022, the arc-shaped buffer portion 3021 can be constrained. In other embodiments, the hollow portion 3022 can also be set to a wave shape or a broken line shape.

[0149] In some embodiments, please refer to Figure 11 Along the second direction Y, the size of the busbar 30 is d2, the size of the hollow portion 3022 is d3, and 0.1≤d3 / d2≤0.5.

[0150] d3 / d2 can be any value among 0.1, 0.2, 0.3, 0.4, 0.5, etc., or a range of values ​​therebetween. Along the second direction Y, the size of the current collector 30 refers to its maximum size. When multiple hollow portions 3022 are provided, the size ratios of the different hollow portions 3022 to the current collector 30 can be the same or different, as long as the requirement of 0.1≤d3 / d2≤0.5 is satisfied.

[0151] As an example, the busbar 30 is a rectangular plate-shaped structure, the length direction of the busbar 30 is parallel to the second direction Y, and the dimension of the busbar 30 along the second direction Y is the length of the busbar 30 .

[0152] In the second direction Y, the ratio of the hollow portion 3022 to the busbar 30's dimensions affects the overall strength of the busbar 30. If the hollow portion 3022 occupies a large proportion of the busbar 30's dimensions, the overall strength of the busbar 30 will be reduced. If the hollow portion 3022 occupies a small proportion of the busbar 30's dimensions, the size of the buffer portion 3021 formed by the constraint will be too small, resulting in poor tensile force absorption performance. In this embodiment, 0.1 ≤ d3 / d2 ≤ 0.5, which ensures a balanced balance between the strength of the busbar 30 and the tensile force absorption performance of the buffer portion 3021.

[0153] In some embodiments, please refer to Figure 10 and Figure 11 The first connection area 301 is provided with a first through-hole 304. In a projection plane perpendicular to the first direction X, the orthographic projection of the electrode terminal 201 connected to the first connection area 301 at least partially overlaps with the orthographic projection of the first through-hole 304. The minimum distance between the center of the first through-hole 304 and the edge of the hollow portion 3022 is d4, and d4 is ≥ 15 mm.

[0154] The second connection area 303 is provided with a second through hole 305. In the projection plane perpendicular to the first direction X, the orthographic projection of the electrode terminal 201 connected to the second connection area 303 at least partially overlaps with the orthographic projection of the second through hole 305; the minimum distance between the center of the second through hole 305 and the edge of the hollow portion 3022 is d5, d5 ≥ 15 mm.

[0155] In the battery device 100 , there may be multiple busbars 30 . To facilitate the arrangement of multiple busbars 30 and multiple battery cells 20 , it is necessary to determine the connection area between the busbars 30 and the battery cells 20 , rather than randomly connecting the battery cells 20 and the busbars 30 .

[0156] The first through hole 304 and the second through hole 305 can be used for connecting and positioning the battery cell 20 and the busbar 30. The center of the first through hole 304 or the second through hole 305 refers to the geometric center of the through hole. In some examples, the first through hole 304 and the second through hole 305 can be set as a circular through hole, an elliptical through hole, a waist-shaped hole, etc., or can be set as a special-shaped hole.

[0157] In some examples, only the minimum distance d4 between the center of the first through hole 304 and the edge of the hollow portion 3022 may be set, where d4 is ≥ 15 mm, or only the minimum distance d5 between the center of the second through hole 305 and the edge of the hollow portion 3022 may be set, where d5 is ≥ 15 mm. Alternatively, both the minimum distance d4 between the center of the first through hole 304 and the edge of the hollow portion 3022 may be set, where d4 is ≥ 15 mm, and the minimum distance d5 between the center of the second through hole 305 and the edge of the hollow portion 3022 may be set, where d5 is ≥ 15 mm. When the minimum distance between the center of the first through hole 304 and / or the center of the second through hole 305 and the edge of the hollow portion 3022 is greater than or equal to 15 mm, the effect of the hollow portion 3022 on the connection between the electrode terminal 201 and the busbar 30 can be reduced, thereby improving the reliability of the connection between the electrode terminal 201 and the busbar 30 and facilitating the arrangement of multiple battery cells 20 and / or multiple busbars 30.

[0158] In some embodiments, please refer to Figure 12 , and see Figure 13 , Figure 13 for Figure 12 Schematic diagram of the structure of the busbar 30 in FIG. Along the first direction X, the first connection area 301 has a first surface 3011 facing the battery cell 20, the second connection area 303 has a second surface 3031 facing the battery cell 20, and the buffer area 302 has a third surface 3023 facing the battery cell 20, and the first surface 3011, the second surface 3031, and the third surface 3023 are coplanar; and / or, along the first direction X, the first connection area 301 has a fourth surface 3012 facing away from the battery cell 20, the second connection area 303 has a fifth surface 3032 facing away from the battery cell 20, and the buffer area 302 has a sixth surface 3024 facing away from the battery cell 20, and the fourth surface 3012, the fifth surface 3032, and the sixth surface 3024 are coplanar.

[0159] In some examples, only the first surface 3011, the second surface 3031 and the third surface 3023 may be coplanar, and the fourth surface 3012, the fifth surface 3032 and the sixth surface 3024 may not be coplanar; only the fourth surface 3012, the fifth surface 3032 and the sixth surface 3024 may be coplanar, and the first surface 3011, the second surface 3031 and the third surface 3023 may not be coplanar; or the first surface 3011, the second surface 3031 and the third surface 3023 may be coplanar, and the fourth surface 3012, the fifth surface 3032 and the sixth surface 3024 may be coplanar.

[0160] In the above embodiment, based on the above configuration, the buffer zone 302 does not increase the space occupied in the first direction X, and the size of the buffer zone 302 along the first direction X can be as large as possible, so as to reduce the risk of the buffer portion 3021 being broken due to the small size of the first direction X, and reduce the occurrence of processing difficulties.

[0161] In some embodiments, please refer to Figure 12 The battery cell 20 further includes a housing 202 , an electrode terminal 201 is disposed in the housing 202 , and at least a portion of the electrode terminal 201 protrudes from the outer surface of the housing 202 along the first direction X. Along the first direction X, the protruding dimension of the electrode terminal 201 is d6, d6≤1mm.

[0162] The electrode terminals 201 are typically connected to the busbar 30. To facilitate connection between the electrode terminals 201 and the busbar 30, the electrode terminals 201 are typically arranged to protrude from the outer surface of the housing 202. A larger protrusion of the electrode terminals 201 from the outer surface of the housing 202 can reduce the risk of contact between the busbar 30 and the housing 202, thereby causing a short circuit between the two. However, a larger protrusion of the electrode terminals 201 from the outer surface of the housing 202 occupies more space in the first direction X, thereby resulting in a lower energy density of the battery device 100.

[0163] In the technical solution of providing the buffer portion 3021 on the busbar 30, when the electrode terminal 201 protrudes significantly from the outer surface of the housing 202, the buffer portion 3021 can be bent toward the battery cell 20. This arrangement reduces the additional space occupied by the buffer portion 3021 in the first direction X and also reduces the probability of a short circuit between the buffer portion 3021 and the housing 202. However, when the electrode terminal 201 protrudes less from the outer surface of the housing 202, if the buffer portion 3021 is still bent toward the battery cell 20, the risk of a short circuit between the buffer portion 3021 and the housing 202 is greatly increased. In this case, for battery reliability reasons, the buffer portion 3021 is typically not bent toward the battery cell 20. In this case, the buffer portion 3021 can be bent away from the battery cell 20. However, when this solution is adopted, the space in the first direction X that would have been reduced by the electrode terminal 201 protruding from the outer surface of the housing 202 is again occupied, resulting in a low energy density of the resulting battery device 100.

[0164] In the above-described embodiments, in the first direction X, the adoption of the buffer portion 3021 does not exceed the two opposite surfaces of the first connecting region 301 and the two opposite surfaces of the second connecting region 303, which can effectively reduce the space occupation of the buffer portion 3021 in the first direction X of the busbar 30, and can be applied to a scheme in which the size of the electrode terminal 201 protruding from the outer surface of the shell 202 is small, so as to support the improvement of the energy density of the battery device 100 by reducing the way of the electrode terminal 201 protruding from the outer surface of the shell 202. Further, the purpose of improving the overall energy density of the battery device 100 is achieved, and at the same time, the risk of short circuit between the buffer portion 3021 and the shell 202, which affects the reliability of the battery device 100, can be reduced.

[0165] In some embodiments of the present application, please refer to Figures 5 to 13A battery device 100 is provided, including a busbar 30 and a plurality of battery cells 20. The battery cells 20 include housings 202 and electrode terminals 201 disposed on the housings 202. The busbar 30 is disposed opposite the electrode terminals 201 along a first direction X. The busbar 30 includes a first connection region 301, a buffer region 302, and a second connection region 303. The first connection region 301 and the second connection region 303 are arranged along a second direction Y. The buffer region 302 is located between the first connection region 301 and the second connection region 303. The first connection region 301 and the second connection region 303 respectively connect the two electrode terminals 201 of two battery cells 20. Along the first direction X, the buffer region 302 does not extend beyond the two opposing surfaces of the first connection region 301 and the two opposing surfaces of the second connection region 303. The buffer region 302 includes a buffer portion 3021 curved along a third direction Z, connecting the first connection region 301 and the second connection region 303. The first direction X, the second direction Y, and the third direction Z are perpendicular to each other. The buffer zone 302 is provided with multiple hollow portions 3022, which are arranged alternately with the multiple buffer portions 3021 along the third direction Z. The hollow portions 3022 have the same dimensions along the second direction Y. The hollow portions 3022 are curved along the third direction Z to form an arc, constraining the arc-shaped bending of the buffer portion 3021 between two adjacent hollow portions 3022. Along the second direction Y, the ratio of the dimensions of the hollow portions 3022 to the dimensions of the current bus 30 is greater than or equal to 0.1 and less than or equal to 0.5, and the minimum distance between adjacent hollow portions 3022 is greater than or equal to 2 mm. The first connection area 301 is provided with a first through hole 304, and the second connection area 303 is provided with a second through hole 305. In a projection plane perpendicular to the first direction X, the orthographic projection of the electrode terminal 201 connected to the first connection area 301 at least partially overlaps with the orthographic projection of the first through hole 304, and the orthographic projection of the electrode terminal 201 connected to the second connection area 303 at least partially overlaps with the orthographic projection of the second through hole 305. The minimum distance between the center of the first through hole 304 and the edge of the hollow portion 3022 is greater than or equal to 15 mm, and the minimum distance between the center of the second through hole 305 and the edge of the hollow portion 3022 is greater than or equal to 15 mm. Along the first direction X, the first connection region 301 has a first surface 3011 facing the battery cell 20, the second connection region 303 has a second surface 3031 facing the battery cell 20, and the buffer region 302 has a third surface 3023 facing the battery cell 20. The first surface 3011, second surface 3031, and third surface 3023 are coplanar. Along the first direction X, the first connection region 301 has a fourth surface 3012 facing away from the battery cell 20, the second connection region 303 has a fifth surface 3032 facing away from the battery cell 20, and the buffer region 302 has a sixth surface 3024 facing away from the battery cell 20. The fourth surface 3012, fifth surface 3032, and sixth surface 3024 are coplanar. The electrode terminal 201 protrudes from the outer surface of the housing 202 along the first direction X by less than or equal to 1 mm.

[0166] 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.

[0167] 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 device, characterized in that: include: a plurality of battery cells, each of the battery cells including an electrode terminal; a busbar, disposed opposite to the electrode terminals along a first direction, the busbar comprising a first connection area, a buffer area, and a second connection area, the first connection area and the second connection area being arranged along a second direction, the buffer area being located between the first connection area and the second connection area, the first connection area and the second connection area being respectively connected to the electrode terminals of two battery cells, and the second direction being perpendicular to the first direction; Wherein, along the first direction, the buffer zone does not exceed two opposite surfaces of the first connection area and two opposite surfaces of the second connection area; the buffer zone includes a curved buffer portion connecting the first connection area and the second connection area.

2. The battery device according to claim 1, wherein: The buffer portion is at least partially bent along a third direction, and the first direction, the second direction and the third direction are perpendicular to each other.

3. The battery device according to claim 2, characterized in that The buffer portion is arc-shaped.

4. The battery device according to claim 1, wherein: The buffer portion is at least partially bent along the first direction.

5. The battery device according to claim 1, wherein: The buffer zone is provided with a plurality of hollow portions, and along the third direction, the hollow portions and the buffer portions are alternately arranged, and the first direction, the second direction and the third direction are perpendicular to each other.

6. The battery device according to claim 5, characterized in that Along the third direction, the minimum distance between two adjacent hollow portions is d1, and d1 ≥ 2 mm.

7. The battery device according to claim 5, characterized in that Along the second direction, the sizes of the plurality of hollow portions are all the same.

8. The battery device according to claim 5, characterized in that Along the second direction, the size of the current collector is d2, the size of the hollow portion is d3, and 0.1≤d3 / d2≤0.

5.

9. The battery device according to claim 5, characterized in that The first connection area is provided with a first through hole, and in a projection plane perpendicular to the first direction, an orthographic projection of the electrode terminal connected to the first connection area at least partially overlaps with an orthographic projection of the first through hole; The minimum distance between the center of the first through hole and the edge of the hollow portion is d4, and d4 is ≥ 15 mm.

10. The battery device according to claim 5, characterized in that The second connection area is provided with a second through hole, and in a projection plane perpendicular to the first direction, an orthographic projection of the electrode terminal connected to the second connection area at least partially overlaps with an orthographic projection of the second through hole; The minimum distance between the center of the second through hole and the edge of the hollow portion is d5, and d5 is ≥ 15 mm.

11. The battery device according to any one of claims 1 to 10, characterized in that Along the first direction, the first connection area has a first surface facing the battery cell, the second connection area has a second surface facing the battery cell, and the buffer area has a third surface facing the battery cell, and the first surface, the second surface, and the third surface are coplanar; And / or, along the first direction, the first connection area has a fourth surface facing away from the battery cell, the second connection area has a fifth surface facing away from the battery cell, the buffer zone has a sixth surface facing away from the battery cell, and the fourth surface, the fifth surface and the sixth surface are coplanar.

12. The battery device according to any one of claims 1 to 10, characterized in that The battery cell further includes a shell, the electrode terminal is provided in the shell, at least part of the electrode terminal protrudes from the outer surface of the shell along the first direction, and along the first direction, the size of the part of the electrode terminal protruding from the outer surface of the shell is d6, d6≤1mm.

13. An electrical device, characterized in that: A battery device comprising the battery device according to any one of claims 1 to 12.

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