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 monomer comprises a shell, an electrode unit and a buffer part, the electrode unit is contained in the shell and comprises two first surfaces oppositely arranged in the first direction and two second surfaces oppositely arranged in the second direction, the first surfaces are connected with the two second surfaces, and the second surfaces are cambered surfaces. The buffering piece is contained in the shell. In the first direction, at least part of the buffer piece is arranged between the connecting position of the first surface and the second surface and the shell. The reliability of the battery monomer can be 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] Battery cells are widely used in electronic devices such as mobile phones, laptops, electric bicycles, electric cars, electric airplanes, electric boats, electric toy cars, electric toy boats, electric toy airplanes, and power tools. Battery cells can include nickel-cadmium battery cells, nickel-metal hydride battery cells, lithium-ion battery cells, and secondary alkaline zinc-manganese battery cells.

[0003] In the development of battery technology, how to improve the reliability of battery cells has always been a research direction in battery technology. Utility Model Content

[0004] In view of the above problems, the present application provides a battery cell, a battery device and an electrical device, which can improve the reliability of the battery cell.

[0005] In a first aspect, the present application provides a battery cell. The battery cell includes a housing, an electrode unit, and a buffer. The electrode unit is housed within the housing and includes two first surfaces disposed opposite each other along a first direction and two second surfaces disposed opposite each other along a second direction. The first surface connects the two second surfaces, and the second surfaces are curved surfaces. The buffer is housed within the housing. In the first direction, at least a portion of the buffer is disposed between the junction of the first and second surfaces and the housing.

[0006] In the above scheme, by providing a buffer, when the electrode assembly contacts the outer shell, the buffer can disperse the stress perpendicular to the direction of the electrode sheet to other directions, thereby reducing the possibility of extrusion between the connection between the first surface and the second surface of the electrode assembly and the outer shell, reducing the risk of the electrode assembly being broken due to extrusion between the electrode assembly and the outer shell, and improving the reliability of the battery cell.

[0007] In some embodiments, in the third direction, the buffer is disposed at least in the middle of the electrode unit, and the first direction, the second direction, and the third direction are perpendicular to each other.

[0008] In the above solution, the above arrangement is helpful to reduce the space occupied by the buffer component in the housing, increase the arrangement space of the electrode unit, and improve the energy density of the battery cell.

[0009] In some embodiments, a dimension of the buffer along the third direction is H, a dimension of the electrode unit along the third direction is h, 0.05h≤H≤0.2h, and the first direction, the second direction, and the third direction are perpendicular to each other.

[0010] In the above solution, it is beneficial to reduce the space occupied by the buffer component in the shell, improve the adaptability of the buffer component and the electrode unit, further reduce the risk of fracture of the electrode piece in the electrode unit due to compression between the electrode unit and the shell, and improve the reliability of the battery cell.

[0011] In some embodiments, the electrode unit includes a plurality of electrode assemblies stacked along a first direction, which is beneficial for increasing the energy density of the battery cell.

[0012] In some embodiments, in the first direction, at least a portion of the buffer is disposed between the first surface and the housing. In the second direction, at least a portion of the buffer is disposed between the second surface and the housing.

[0013] In the above scheme, it is beneficial to reduce the contact area between the electrode unit and the shell when it expands, further improve the buffering effect of the buffer component on the electrode unit, reduce the risk of fracture of the electrode sheet in the electrode unit due to compression between the electrode unit and the shell, and improve the reliability of the battery cell.

[0014] In some embodiments, the battery cell further includes an insulating member connected to the housing and having a receiving cavity, and the electrode unit is received in the receiving cavity.

[0015] In the above solution, the above arrangement is helpful to reduce the possibility of short circuit between the electrode unit and the shell, and improve the reliability of the battery cell.

[0016] In some embodiments, the insulating member includes two first wall portions oppositely arranged along a first direction and two second wall portions oppositely arranged along a second direction, and the buffer member includes a first buffer member, and a first buffer member is provided between the connection between the first wall portion and the second wall portion and the second surface.

[0017] In the above scheme, during the cycle operation of the battery cell, the second surface of the electrode unit will expand toward the connection between the first wall portion and the second wall portion. Disposing the first buffer component in the area between the second surface and the connection between the first wall portion and the second wall portion is beneficial to improving the buffering effect of the first buffer component on the second surface, reducing the space occupied by the first buffer component in the shell, improving space utilization, and increasing the energy density of the battery cell.

[0018] In some embodiments, a gap is provided between at least one of the first surface and the second surface and the first buffer.

[0019] In the above solution, by providing a gap, the expansion space of the electrode unit is increased, the wetting effect of the electrolyte on the electrode sheet in the electrode unit is improved, the deformation of the electrode unit is increased, and the reliability of the battery cell is further improved.

[0020] In some embodiments, the buffer member further includes a second buffer member, which is arranged on the side of the insulating member facing away from the electrode unit, and the orthographic projection of the second buffer member and the orthographic projection of the first buffer member at least partially overlap along the first direction and / or along the second direction.

[0021] In the above scheme, the second buffer component can further increase the buffer area of the electrode unit, reduce the risk of the electrode piece in the electrode unit being broken due to compression between the electrode unit and the shell, and the second buffer component can protect the insulating component, reducing the risk of short circuit between the electrode unit and the shell after the insulating component is broken due to expansion of the electrode unit.

[0022] In some embodiments, an orthographic projection of the first buffer is located within an orthographic projection of the second buffer along the first direction and along the second direction.

[0023] In the above solution, it is beneficial to reduce the space occupied by the first buffer component in the accommodating cavity while improving the buffer performance of the buffer component on the electrode unit, thereby improving the energy density and reliability of the battery cell.

[0024] In some embodiments, the second buffer comprises a first sub-portion and a second sub-portion connected to each other, the first sub-portion being located on a side of the first wall facing away from the first surface, and the second sub-portion being located on a side of the second wall facing away from the second surface. The orthographic projection of the junction of the first and second surfaces along the first direction lies within the orthographic projection of the first sub-portion along the first direction; and / or the orthographic projection of the minimum distance between the second surface and the second wall along the second direction lies within the orthographic projection of the second sub-portion along the second direction.

[0025] In the above solution, by locating the orthographic projection of the point of minimum distance between the second surface and the second wall along the second direction within the orthographic projection of the second sub-section along the second direction, the second sub-section acts as a buffer for the point where the second surface is closest to the second wall, thereby reducing the risk of fracture of the electrode piece within the electrode unit due to compression between the second surface and the housing. By locating the orthographic projection of the junction of the first and second surfaces along the first direction within the orthographic projection of the first sub-section along the first direction, the first sub-section acts as a buffer for the junction of the first and second surfaces, thereby reducing the risk of fracture of the electrode piece within the electrode unit due to compression at the junction of the first and second surfaces.

[0026] In some embodiments, the insulating member is provided with a mounting hole, and the first buffer member and the second buffer member are connected through the mounting hole to reduce the risk of relative displacement between the buffer member and the insulating member due to movement of the electrode unit or external vibration, thereby causing the buffer member and the electrode unit to be unable to effectively buffer the electrode unit after relative displacement, thereby improving the reliability of the battery cell.

[0027] In some embodiments, the number of buffer members includes multiple, and the multiple buffer members are arranged at intervals along the third direction to improve the flexibility of buffer member arrangement, further improve the buffering effect on the electrode unit, and improve the reliability of the battery cell.

[0028] In some embodiments, the buffer is made of sponge, aerogel, or microporous foamed polypropylene to reduce the manufacturing cost of the buffer, increase the channels for the electrolyte to penetrate into the electrode unit through the buffer, and reduce the manufacturing cost of the battery cell.

[0029] In a second aspect, an embodiment of the present application provides a battery device comprising a battery cell according to any of the aforementioned embodiments.

[0030] In a third aspect, an embodiment of the present application provides an electrical device, comprising a battery device according to any of the aforementioned embodiments, and the battery device is used to provide electrical energy.

[0031] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0033] Figure 1 This is a schematic structural diagram of a vehicle provided in an embodiment of the present application;

[0034] Figure 2 This is a schematic diagram of the explosion structure of a battery provided in an embodiment of the present application;

[0035] Figure 3 This is a schematic structural diagram of a battery module provided in an embodiment of the present application;

[0036] Figure 4 This is a schematic diagram of the explosion structure of a battery cell provided in an embodiment of the present application;

[0037] Figure 5 is a schematic cross-sectional structure diagram of a battery cell provided in an embodiment of the present application;

[0038] Figure 6 is a schematic diagram of a battery cell provided in an embodiment of the present application;

[0039] Figure 7 is a schematic cross-sectional structure diagram of another battery cell provided in an embodiment of the present application;

[0040] Figure 8 is a schematic cross-sectional structure diagram of another battery cell provided in an embodiment of the present application;

[0041] Figure 9 yes Figure 8 A schematic diagram of an enlarged structure of P in the figure;

[0042] Figure 10 yes Figure 8 Another enlarged structural diagram of P in the middle;

[0043] Figure 11 This is a schematic diagram of another battery cell provided in an embodiment of the present application.

[0044] Marking Description

[0045] 1000. Vehicle;

[0046] 100, battery device; 200, controller; 300, motor; 400, housing; 410, first housing portion; 420, second housing portion; 430, storage portion; 500, battery module;

[0047] 110. Battery cell;

[0048] 10. Shell;

[0049] 20. Electrode unit; 21. First surface; 22. Second surface; 23. Electrode assembly;

[0050] 30. Buffer; 31. First buffer; 32. Second buffer; 321. First sub-section; 322. Second sub-section;

[0051] 40. Insulator; 41. First wall portion; 42. Second wall portion; 43. Mounting hole;

[0052] MIN, minimum distance; X, first direction; Y, second direction; Z, third direction. DETAILED DESCRIPTION

[0053] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0054] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments 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 figure descriptions are intended to cover non-exclusive inclusions.

[0055] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0056] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present 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. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0057] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0058] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0059] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0060] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0061] 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.

[0062] The battery cells can be 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., which are not limited in the embodiments of the present application.

[0063] 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 of a battery cell, active ions (such as lithium ions) are inserted and removed between the positive and negative electrodes. The separator, placed between the positive and negative electrodes, prevents short circuits between the positive and negative electrodes while allowing the active ions to pass through.

[0064] 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.

[0065] 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.

[0066] As an example, the positive electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium with a silver surface treatment may be used. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0067] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0068] As an example, the negative electrode current collector may be a metal foil, a metal foam, a carbon foam, or a composite current collector. For example, as the metal foil, stainless steel, copper, aluminum, nickel, a carbon electrode, carbon, nickel, or titanium with a silver surface treatment may be used. The metal foam may be a nickel foam, a copper foam, an aluminum foam, or an alloy foam. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector may 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 polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0069] 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.

[0070] 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.

[0071] As an example, the negative electrode active material may be a negative electrode active material known in the art for use in battery cells. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate.

[0072] 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.

[0073] In some embodiments, the electrode assembly further includes a separator disposed between the positive electrode and the negative electrode.

[0074] In some embodiments, the separator is a separator. The present application has no particular limitation on the type of separator, and any known separator with a porous structure having good chemical and mechanical stability can be selected.

[0075] As an example, the main material of the isolation membrane can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramics.

[0076] In some embodiments, the separator is a solid electrolyte, which is disposed between the positive electrode and the negative electrode and serves to transport ions and isolate the positive and negative electrodes.

[0077] In some embodiments, the battery cell also includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. This application does not specifically limit the type of electrolyte, and the electrolyte can be selected based on needs. The electrolyte can be liquid, gel, or solid.

[0078] In some embodiments, the electrode assembly is provided with tabs that can conduct current from the electrode assembly. The tabs include a positive tab and a negative tab.

[0079] The battery device 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.

[0080] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells. For example, the battery cell assembly may be a battery module, which is formed by arranging and securing multiple battery cells to form a single module. For example, a battery module may be formed by bundling multiple battery cells using cable ties.

[0081] In some embodiments, the battery device may be a battery pack, which includes a case and one or more battery cell assemblies, wherein the battery cell assemblies are housed in the case.

[0082] 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.

[0083] 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.

[0084] In some embodiments, the box body can be used as a part of the chassis structure of the vehicle. For example, part of the box body can become at least a part of the floor of the vehicle, or part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0085] In some embodiments, the battery device may be an energy storage device, including an energy storage container, an energy storage cabinet, and the like.

[0086] The development of battery technology must take into account multiple design factors at the same time, such as energy density, cycle life, discharge capacity, charge and discharge rate and other performance parameters. In addition, battery reliability must also be considered.

[0087] The electrode assembly will expand during the cycle. During the expansion process, extrusion will occur between the electrode assembly and the shell, especially the extrusion between the area between the bent area and the straight area of the wound electrode assembly and the shell is particularly prominent. This will cause the electrolyte to be unable to fully infiltrate the electrode sheet and generate stress perpendicular to the direction of the electrode sheet, thereby causing problems such as ion precipitation and electrode sheet breakage, resulting in a decrease in the reliability of the battery cell.

[0088] Based on the above technical problems, the present application provides a technical solution. By setting a buffer part, when the electrode assembly and the shell are in contact, the buffer part can disperse the stress perpendicular to the direction of the electrode sheet to other directions, thereby reducing the possibility of extrusion between the connection between the first surface and the second surface of the electrode assembly and the shell, reducing the risk of the electrode assembly being broken due to extrusion between the electrode assembly and the shell, and improving the reliability of the battery cell.

[0089] The technical solutions described in the embodiments of the present application are applicable to batteries and electrical devices using batteries, such as mobile phones, portable devices, laptops, electric vehicles, electric cars, ships, spacecraft, electric toys and electric tools, etc., among which spacecraft include airplanes, rockets, space shuttles and spacecraft, etc., electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys and electric airplane toys, etc., and electric tools include metal cutting power tools, grinding power tools, assembly power tools and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators and electric planers.

[0090] The battery cells described in the embodiments of the present application are not limited to being applicable to the electrical devices described above, but for the sake of simplicity, the following embodiments are described using electric vehicles as an example.

[0091] See also Figure 1 , Figure 1 It is a structural schematic diagram of a vehicle provided in an embodiment of the present application.

[0092] The vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery device 100 may be provided inside the vehicle 1000. Specifically, for example, the battery device 100 may be provided at the bottom, front or rear of the vehicle 1000. The battery device 100 may be used to power the vehicle 1000. For example, the battery device 100 may serve as an operating power source for the vehicle 1000. The vehicle 1000 may further include a controller 200 and a motor 300. The controller 200 is used, for example, to control the battery to power the motor 300. The battery may be used for starting and navigating the vehicle 1000. Of course, the battery device 100 may also be used to drive the vehicle 1000, replacing or partially replacing fuel or natural gas to provide drive for the vehicle 1000.

[0093] Figure 2 Schematic diagram of the explosion structure of a battery provided in an embodiment of the present application. Figure 2 As shown, the battery device 100 includes a box body 400 and battery cells (not shown in the figure), and the battery cells are accommodated in the box body 400.

[0094] The housing 400 is used to house battery cells and can have various structures. In some embodiments, the housing 400 can include a first housing portion 410 and a second housing portion 420. The first housing portion 410 and the second housing portion 420 overlap each other and together define a receiving portion 430 for accommodating the battery cells. The second housing portion 420 can be a hollow structure with one end open. The first housing portion 410 is a plate-like structure, and the first housing portion 410 overlaps the open side of the second housing portion 420 to form the housing with the receiving portion 430. Alternatively, both the first housing portion 410 and the second housing portion 420 can be hollow structures with one end open. The open side of the first housing portion 410 overlaps the open side of the second housing portion 420 to form the housing 400 with the receiving portion 430. Of course, the first housing portion 410 and the second housing portion 420 can have various shapes, such as a cylinder, a rectangular parallelepiped, etc.

[0095] In the battery device 100, there can be one or more battery cells. If there are multiple battery cells, they can be connected in series, in parallel, or in a hybrid configuration. A hybrid configuration refers to a combination of series and parallel connections. Multiple battery cells can be directly connected in series, in parallel, or in a hybrid configuration, and then the entire battery module can be housed within the housing 400. Alternatively, multiple battery cells can be first connected in series, in parallel, or in a hybrid configuration to form a battery module 500, and then the battery modules 500 can be connected in series, in parallel, or in a hybrid configuration to form a single unit housed within the housing 400.

[0096] Figure 3 It is a structural schematic diagram of a battery module provided in an embodiment of the present application.

[0097] In some embodiments, as Figure 3 As shown, there are multiple battery cells 110, which are first connected in series, in parallel, or in series to form a battery module 500. The multiple battery modules 500 are then connected in series, in parallel, or in series to form a whole, which is then housed in a box.

[0098] Figure 4 This is a schematic diagram of the explosion structure of a battery cell provided in an embodiment of the present application. Figure 5 It is a schematic diagram of the cross-sectional structure of a battery cell provided in an embodiment of the present application.

[0099] See also Figure 4 and Figure 5The embodiment of the present application provides a battery cell 110. The battery cell 110 includes a housing 10, an electrode unit 20, and a buffer member 30. The electrode unit 20 is accommodated in the housing 10. The electrode unit 20 includes two first surfaces 21 arranged opposite to each other along a first direction X and two second surfaces 22 arranged opposite to each other along a second direction Y. The first surface 21 connects the two second surfaces 22, and the second surface 22 is a curved surface. The buffer member 30 is accommodated in the housing 10. In the first direction X, at least a portion of the buffer member 30 is disposed between the connection between the first surface 21 and the second surface 22 and the housing 10.

[0100] In some embodiments, the housing 10 is used to encapsulate the electrode unit 20 and electrolyte components. The housing 10 can be a steel shell, an aluminum shell, a plastic shell (such as polypropylene), a composite metal shell (such as a copper-aluminum composite housing 10), or an aluminum-plastic film.

[0101] In some embodiments, functional components such as electrode terminals may be provided on the housing 10. The electrode terminals may be used to electrically connect to the electrode unit 20 to output or input electrical energy of the battery cell 110.

[0102] In some embodiments, a current collecting member may be disposed in the housing 10 , and the electrode unit 20 may be electrically connected to the housing 10 or an electrode terminal disposed on the housing 10 through the current collecting member.

[0103] As an example, the battery cell 110 can be a cylindrical battery cell 110, a prismatic battery cell 110, a soft-pack battery cell 110 or a battery cell 110 of other shapes. The prismatic battery cell 110 includes a square-shell battery cell 110, a blade-shaped battery cell 110, a polygonal battery, and the polygonal battery is, for example, a hexagonal battery.

[0104] In some embodiments, a battery cell may include one or more electrode assemblies 23 .

[0105] In some embodiments, the electrode assembly 23 is a wound structure.

[0106] In some embodiments, the electrode assembly 23 may be flat in shape.

[0107] In some embodiments, the housing 10 includes a shell and an end cap. The shell has an opening, and the end cap covers the opening. The shell and the end cap cover each other in a direction that is consistent with the thickness of the battery cell 110. The first direction X, the second direction Y, and the thickness direction may intersect with each other. Alternatively, the first direction X, the second direction Y, and the thickness direction may be perpendicular to each other.

[0108] The electrode unit 20 includes a first surface 21 and a second surface 22. Optionally, the first surface 21 can be a flat surface. Optionally, the second surface 22 can be a curved surface, which can be a single curved surface or multiple curved surfaces. Optionally, the curved surface can be a circular arc surface.

[0109] Exemplarily, when the electrode unit 20 includes an electrode assembly 23 , the second surface 22 may be an arc surface, that is, the second surface 22 is an outer surface of the electrode assembly 23 along the second direction Y.

[0110] Exemplarily, when the electrode unit 20 includes a plurality of electrode assemblies 23 , the second surface 22 may be a multi-segment arc surface, that is, the second surface 22 is the outer surface of the plurality of electrode assemblies 23 along the second direction Y.

[0111] Optionally, there may be four connections between the first surface 21 and the second surface 22, and a buffer 30 is provided between each connection and the housing 10. Optionally, the buffers 30 between each connection and the housing 10 may be interconnected, or may be independent of each other.

[0112] Optionally, the buffer member 30 may be connected to the inner wall of the housing 10 .

[0113] Optionally, an orthographic projection of a connection point between the first surface 21 and the second surface 22 in the first direction X is located within an orthographic projection of the buffer member 30 in the first direction X.

[0114] It should be understood that, in the first direction X, at least a portion of the buffer member 30 is disposed between the connection between the first surface 21 and the second surface 22 and the housing 10, meaning that, in the first direction X, at least a portion of the buffer member 30 is disposed between the connection and the housing 10. In some examples, in the first direction X, the buffer member 30 is disposed only between the connection between the first surface 21 and the second surface 22 and the housing 10. In other examples, the buffer member 30 includes two portions: in the first direction X, one portion of the buffer member 30 is disposed between the connection between the first surface 21 and the second surface 22 and the housing 10. In the second direction Y, another portion of the buffer member 30 is disposed between the second surface 22 and the housing 10. Alternatively, the buffer member 30 includes two portions: in the first direction X, one portion of the buffer member 30 is disposed between the connection between the first surface 21 and the second surface 22 and the housing 10. In the first direction X, another portion of the buffer member 30 is disposed between the first surface 21 and the housing 10.

[0115] In an embodiment of the present application, by providing a buffer member 30, when the electrode assembly 23 contacts the outer shell 10, the buffer member 30 can disperse the stress perpendicular to the electrode sheet direction to other directions, thereby reducing the possibility of extrusion between the connection between the first surface 21 and the second surface 22 of the electrode assembly 23 and the outer shell 10, reducing the risk of the electrode assembly 23 being broken due to extrusion between the electrode assembly 23 and the outer shell 10, and improving the reliability of the battery cell 110.

[0116] Figure 6 This is a schematic diagram of a battery cell provided in an embodiment of the present application. It should be noted that: Figure 6 and Figure 11 The housing 10 of the battery cell 110 is not shown.

[0117] In some optional embodiments, see Figures 4 to 6 In the third direction Z, the buffer member 30 is at least disposed in the middle of the electrode unit 20 , and the first direction X, the second direction Y, and the third direction Z are perpendicular to each other.

[0118] Illustratively, the electrode unit 20 has a central axis along the third direction Z, the central axis is located in the middle of the electrode unit 20, and the buffer 30 is arranged to overlap the central axis in the third direction Z. Optionally, the buffer 30 is arranged symmetrically about the central axis in the third direction Z.

[0119] In the embodiment of the present application, the above arrangement is advantageous in reducing the space occupied by the buffer member 30 in the housing 10 , increasing the arrangement space of the electrode unit 20 , and improving the energy density of the battery cell 110 .

[0120] In some optional embodiments, see Figure 6 The dimension of the buffer member 30 along the third direction Z is H, the dimension of the electrode unit 20 along the third direction Z is h, 0.05h≤H≤0.2h, and the first direction X, the second direction Y and the third direction Z are perpendicular to each other.

[0121] Illustratively, H=0.05h, H=0.06h, H=0.08h, H=0.12h, H=0.15h, or H=0.2h.

[0122] The above-mentioned arrangement of the embodiment of the present application is conducive to reducing the space occupied by the buffer component 30 in the outer shell 10, while improving the adaptability of the buffer component 30 and the electrode unit 20, further reducing the risk of the electrode unit 20 and the outer shell 10 being squeezed to cause the electrode piece in the electrode unit 20 to break, and improving the reliability of the battery cell 110.

[0123] In some optional embodiments, see Figure 5The electrode unit 20 includes a plurality of electrode assemblies 23 stacked along a first direction X, which is beneficial to increasing the energy density of the battery cell 110 .

[0124] Exemplarily, each electrode assembly 23 includes a flat region and a curved region. The flat region of each electrode assembly 23 includes two flat surfaces opposite each other along a first direction X, and the curved region of each electrode assembly 23 includes two curved surfaces opposite each other along a second direction Y. After multiple electrode assemblies 23 are stacked along the first direction X, the electrode unit 20 includes a first electrode assembly 23 to an Nth electrode assembly 23. The flat surface of the first electrode assembly 23 facing away from the Nth electrode assembly 23 is a first surface 21, and the flat surface of the Nth electrode assembly 23 facing away from the first electrode assembly 23 is another first surface 21. The multiple curved surfaces on one side of the first electrode assembly 23 to the Nth electrode assembly 23 along the second direction Y are connected to form a second surface 22. The connection between the first surface 21 and the second surface 22 includes the connection between the first surface 21 of the first electrode assembly 23 and the curved surface of the first electrode assembly 23, and the connection between the first surface 21 of the Nth electrode assembly 23 and the curved surface of the Nth electrode assembly 23.

[0125] In some optional embodiments, see Figure 5 In the first direction X, at least a portion of the buffer member 30 is disposed between the first surface 21 and the housing 10 . In the second direction Y, at least a portion of the buffer member 30 is disposed between the second surface 22 and the housing 10 .

[0126] Exemplarily, the buffer member 30 includes two parts. In the first direction X, one part of the buffer member 30 is disposed between the first surface 21 and the housing 10 . In the second direction Y, the other part of the buffer member 30 is disposed between the second surface 22 and the housing 10 .

[0127] In these optional embodiments, the above-mentioned arrangement is conducive to reducing the contact area between the electrode unit 20 and the outer shell 10 when it expands, further improving the buffering effect of the buffer member 30 on the electrode unit 20, reducing the risk of fracture of the electrode sheet in the electrode unit 20 due to extrusion between the electrode unit 20 and the outer shell 10, and improving the reliability of the battery cell 110.

[0128] Figure 7 This is a schematic diagram of the cross-sectional structure of another battery cell provided in an embodiment of the present application.

[0129] In some optional embodiments, see Figure 5 and Figure 7 , further comprising an insulating member 40, which is connected to the housing 10 and has a receiving cavity, and the electrode unit 20 is received in the receiving cavity.

[0130] Optionally, the insulating member 40 may cover the entire electrode unit 20. Of course, the insulating member 40 may cover a portion of the electrode unit 20. The insulating member 40 has good insulation performance and its material may be, but is not limited to, mylar or mica, or other insulating materials, which is not particularly limited in this embodiment of the present application.

[0131] Optionally, the shape of the insulating member 40 and the shape of the housing 10 may be matched.

[0132] Optionally, the insulating member 40 includes a first insulating portion and a second insulating portion, the first insulating portion covers the first surface 21 and the second surface 22 of the electrode unit 20, and the second insulating portion is located on one side of the electrode unit 20 along the third direction Z. The first insulating portion and the second insulating portion enclose a accommodating cavity.

[0133] Optionally, the buffer member 30 may be located between the insulating member 40 and the electrode unit 20 . Alternatively, the buffer member 30 may be located on a side of the insulating member 40 facing away from the electrode unit 20 .

[0134] Optionally, the buffer member 30 may be fixedly connected to the insulating member 40 . For example, the buffer member 30 may be fixedly connected to the insulating member 40 by bonding or the like.

[0135] In the embodiment of the present application, the above configuration is helpful to reduce the possibility of short circuit between the electrode unit 20 and the housing 10 and improve the reliability of the battery cell 110.

[0136] In some optional embodiments, see Figure 5 and Figure 7 The insulating member 40 includes two first wall portions 41 arranged opposite to each other along the first direction X and two second wall portions 42 arranged opposite to each other along the second direction Y. The buffer member 30 includes a first buffer member 31. A first buffer member 31 is provided between the connection between the first wall portion 41 and the second wall portion 42 and the second surface 22.

[0137] Optionally, the first wall portion 41 and the second wall portion 42 enclose a rectangular structure. Since the second surface 22 is a curved surface, the gap between the connection between the first wall portion 41 and the second wall portion 42 and the second surface 22 is larger than the gap between the first surface 21 and the first wall portion 41.

[0138] Optionally, when the electrode unit 20 includes the first electrode assembly 23 to the Nth electrode assembly 23, the second surface 22 includes a plurality of arcuate surfaces, and the first buffer member 31 is disposed between the arcuate surface of the first first electrode assembly 23 and the connection between the first wall portion 41 and the second wall portion 42, and the first buffer member 31 is disposed between the arcuate surface of the Nth first electrode assembly 23 and the connection between the first wall portion 41 and the second wall portion 42. It is understood that the arcuate surface may be in the shape of a circular arc, and the arcuate surface may include a first sub-arcd surface connected to the first surface 21 and a second sub-arcd surface connected to the first sub-arcd surface, and the first buffer member 31 is disposed between the connection between the first sub-arcd surface of the first first electrode assembly 23 and the first wall portion 41 and the second wall portion 42, and the first buffer member 31 is disposed between the connection between the first sub-arcd surface of the Nth first electrode assembly 23 and the first wall portion 41 and the second wall portion 42.

[0139] In the embodiment of the present application, during the cyclic operation of the battery cell 110, the second surface 22 of the electrode unit 20 will expand toward the connection between the first wall portion 41 and the second wall portion 42. Disposing the first buffer member 31 in the area between the second surface 22 and the connection between the first wall portion 41 and the second wall portion 42 is beneficial to improving the buffering effect of the first buffer member 31 on the second surface 22, reducing the space occupied by the first buffer member 31 in the outer shell 10, improving space utilization, and improving the energy density of the battery cell 110.

[0140] In some optional embodiments, see Figure 5 and Figure 7 A gap is provided between at least one of the first surface 21 and the second surface 22 and the first buffer member 31 .

[0141] In some examples, a gap is provided between the first surface 21 and the first buffer 31. In other examples, a gap is provided between the second surface 22 and the first buffer 31. In still other examples, a gap is provided between the first surface 21 and the first buffer 31, and a gap is provided between the second surface 22 and the first buffer 31.

[0142] Optionally, a portion of the first buffer member 31 is disposed in contact with the first surface 21, and a gap is provided between another portion of the first buffer member 31 and the second surface 22. Optionally, the gap between the other portion of the first buffer member 31 and the second surface 22 gradually increases in a direction away from the first surface 21.

[0143] Optionally, a portion of the first buffer member 31 is disposed in contact with the second surface 22, and a gap is provided between another portion of the first buffer member 31 and the first surface 21. Optionally, the gap between the another portion of the first buffer member 31 and the first surface 21 gradually increases as it approaches the first surface 21.

[0144] In the embodiment of the present application, by setting the gap, the expansion space of the electrode unit 20 is increased, the wetting effect of the electrolyte on the electrode sheet in the electrode unit 20 is improved, the deformation of the electrode unit 20 is increased, and the reliability of the battery cell 110 is further improved.

[0145] Figure 8 This is a schematic diagram of the cross-sectional structure of another battery cell provided in an embodiment of the present application.

[0146] In some optional embodiments, see Figure 8 The buffer member 30 further includes a second buffer member 32, which is arranged on the side of the insulating member 40 facing away from the electrode unit 20, and along the first direction X and / or along the second direction Y, the orthographic projection of the second buffer member 32 and the orthographic projection of the first buffer member 31 are at least partially overlapped.

[0147] Optionally, the first buffer member 31 and the second buffer member 32 are made of the same material. Of course, the first buffer member 31 and the second buffer member 32 may also be made of different materials.

[0148] In some examples, the orthographic projection of the first cushioning member 31 along the first direction X and the orthographic projection of the second cushioning member 32 along the first direction X are arranged to at least partially overlap. In other examples, the orthographic projection of the first cushioning member 31 along the second direction Y and the orthographic projection of the second cushioning member 32 along the second direction Y are arranged to at least partially overlap. In still other examples, the orthographic projection of the first cushioning member 31 along the first direction X and the orthographic projection of the second cushioning member 32 along the first direction X are arranged to at least partially overlap. Furthermore, the orthographic projection of the first cushioning member 31 along the second direction Y and the orthographic projection of the second cushioning member 32 along the second direction Y are arranged to at least partially overlap.

[0149] In these optional embodiments, the second buffer member 32 can further increase the buffer area of the electrode unit 20, reducing the risk of fracture of the electrode piece in the electrode unit 20 due to compression between the electrode unit 20 and the outer shell 10. In addition, the second buffer member 32 can protect the insulating member 40, reducing the risk of short circuit between the electrode unit 20 and the outer shell 10 after the insulating member 40 is broken due to expansion of the electrode unit 20.

[0150] In some optional embodiments, see Figure 8 , along the first direction X and along the second direction Y, the orthographic projection of the first buffer 31 is located within the orthographic projection of the second buffer 32 .

[0151] Exemplarily, the orthographic projection of the first buffer member 31 along the first direction X is located within the orthographic projection of the second buffer member 32 along the first direction X, and the orthographic projection of the first buffer member 31 along the second direction Y is located within the orthographic projection of the second buffer member 32 along the second direction Y, thereby reducing the space occupied by the first buffer member 31 in the accommodating cavity while improving the buffering performance of the buffer member 30 on the electrode unit 20, thereby improving the energy density of the battery cell 110 and the reliability of the battery cell 110.

[0152] Figure 9 yes Figure 8 Schematic diagram of an enlarged structure of P.

[0153] In some optional embodiments, see Figure 8 and Figure 9 The second buffer member 32 includes a first sub-portion 321 and a second sub-portion 322, which are connected to each other. The first sub-portion is located on the side of the first wall portion 41 facing away from the first surface 21, and the second sub-portion 322 is located on the side of the second wall portion 42 facing away from the second surface 22. The orthographic projection of the junction of the first surface 21 and the second surface 22 along the first direction X is located within the orthographic projection of the first sub-portion 321 along the first direction X; and / or the orthographic projection of the minimum distance MIN between the second surface 22 and the second wall portion 42 along the second direction Y is located within the orthographic projection of the second sub-portion 322 along the second direction Y.

[0154] Optionally, along the first direction X, the first sub-portion 321 is located between the first wall portion 41 and the housing 10; along the second direction Y, the second sub-portion 322 is located between the second wall portion 42 and the housing 10. Optionally, the projection shape of the first sub-portion 321 and the second sub-portion 322 along the third direction Z may be L-shaped.

[0155] Optionally, the thickness of the first sub-portion 321 and the thickness of the second sub-portion 322 may be the same, or may be different.

[0156] Optionally, the extension dimension of the first sub-portion 321 along the first direction X and the extension dimension of the second sub-portion 322 along the second direction Y may be the same, or may be different.

[0157] Optionally, the first sub-portion 321 may be shaped like a plate.

[0158] In some examples, the orthographic projection of the connection between the first surface 21 and the second surface 22 along the first direction X is located within the orthographic projection of the first sub-portion 321 along the first direction X. In other examples, the orthographic projection of the minimum distance MIN between the second surface 22 and the second wall portion 42 along the second direction Y is located within the orthographic projection of the second sub-portion 322 along the second direction Y. In still other examples, the orthographic projection of the connection between the first surface 21 and the second surface 22 along the first direction X is located within the orthographic projection of the first sub-portion 321 along the first direction X. The orthographic projection of the minimum distance MIN between the second surface 22 and the second wall portion 42 along the second direction Y is located within the orthographic projection of the second sub-portion 322 along the second direction Y.

[0159] In some examples, when the electrode unit 20 includes the first electrode assembly 23 to the Nth electrode assembly, the orthographic projection of the minimum distance MIN between the second surface 22 and the second wall portion 42 along the second direction Y is located within the orthographic projection of the second sub-portion 322 along the second direction Y. Here, "the minimum distance MIN between the second surface 22 and the second wall portion 42" may refer to the minimum distance MIN between the arc surface of the first electrode assembly 23 and the second wall portion 42; and / or, the minimum distance MIN between the arc surface of the Nth electrode assembly 23 and the second wall portion 42. Of course, it may also refer to the minimum distance MIN between the arc surface of the first electrode assembly 23 and the arc surface of the i-th electrode assembly 23 and the second wall portion 42; and / or, the minimum distance MIN between the arc surface of the j-th electrode assembly 23 and the arc surface of the M-th electrode assembly 23 and the second wall portion 42, where 2≤i≤j≤M.

[0160] It is understood that the second surface 22 is a curved surface that protrudes toward the housing 10, such that the position where the curved surface is tangent to the first direction X is the minimum distance MIN between the second surface 22 and the second wall portion 42. In this embodiment of the present application, by positioning the orthographic projection of the minimum distance MIN between the second surface 22 and the second wall portion 42 along the second direction Y within the orthographic projection of the second sub-portion 322 along the second direction Y, the second sub-portion 322 acts as a buffer for the area where the second surface 22 and the second wall portion 42 are closest, thereby reducing the risk of fracture of the electrode piece within the electrode unit 20 caused by compression between the second surface 22 and the housing 10. By positioning the orthographic projection of the junction of the first surface 21 and the second surface 22 along the first direction X within the orthographic projection of the first sub-portion 321 along the first direction X, the first sub-portion 321 acts as a buffer for the junction of the first surface 21 and the second surface 22, thereby reducing the risk of fracture of the electrode piece within the electrode unit 20 caused by compression at the junction of the first surface 21 and the second surface 22.

[0161] Figure 10 yes Figure 8 Schematic diagram of another enlarged structure of P.

[0162] In some optional embodiments, see Figure 10 The insulating member 40 is provided with a mounting hole 43, and the first buffer member 31 and the second buffer member 32 are connected through the mounting hole 43 to reduce the risk of relative displacement between the buffer member 30 and the insulating member 40 due to movement of the electrode unit 20 or external vibration, thereby causing the buffer member 30 and the electrode unit 20 to be unable to effectively buffer the electrode unit 20 after relative displacement, thereby improving the reliability of the battery cell 110.

[0163] Illustratively, the mounting hole 43 is provided through the insulating member 40, and a connecting structure may be provided between the first buffer member 31 and the second buffer member 32. The connecting structure passes through the mounting hole 43 to connect the first buffer member 31 and the second buffer member 32. Alternatively, the connecting structure may connect the first sub-section 321 to the first buffer member 31, and / or the connecting structure may connect the second sub-section 322 to the first buffer member 31.

[0164] Figure 11 This is a schematic diagram of another battery cell provided in an embodiment of the present application.

[0165] In some optional embodiments, see Figure 11 The number of the buffer members 30 includes multiple buffer members 30, and the multiple buffer members 30 are arranged at intervals along the third direction Z to improve the flexibility of the arrangement of the buffer members 30, further improve the buffering effect of the electrode unit 20, and improve the reliability of the battery cell 110.

[0166] Exemplarily, the electrode unit 20 includes four corners, each corner includes a connection between the first surface 21 and the second surface 22, and multiple buffers 30 can be provided at each corner. Along the third direction Z, multiple buffers 30 are spaced apart on each corner.

[0167] Optionally, the plurality of buffer members 30 on each corner may be symmetrically arranged about the central axis of the electrode unit 20 .

[0168] In some examples, the buffer member 30 disposed at the middle portion of the electrode unit 20 along the third direction Z at each corner may include a first buffer member 31 and a second buffer member 32, and the buffer member 30 disposed at other regions of the electrode unit 20 along the third direction Z at each corner may include the first buffer member 31 and / or the second buffer member 32. The "other regions" herein refer to regions other than the middle portion of the electrode unit 20 along the third direction Z, such as regions near the upper edge of the electrode unit 20 along the third direction Z.

[0169] In some optional embodiments, the material of the buffer 30 is sponge, aerogel or microporous foamed polypropylene, so as to reduce the preparation cost of the buffer 30, increase the channel for the electrolyte to infiltrate into the electrode unit 20 through the buffer 30, and reduce the preparation cost of the battery cell 110.

[0170] In a second aspect, an embodiment of the present application provides a battery device 100 , comprising a battery cell 110 in any of the aforementioned embodiments.

[0171] In a third aspect, an embodiment of the present application provides an electrical device, comprising the battery device 100 in any of the aforementioned embodiments, and the battery device is used to provide electrical energy.

[0172] According to some embodiments of this application, please refer to Figures 4 to 9 The battery cell 110 includes a housing 10, an electrode unit 20, and a buffer member 30. The electrode unit 20 is housed within the housing 10 and includes two first surfaces 21 disposed opposite each other along a first direction X and two second surfaces 22 disposed opposite each other along a second direction Y. The first surface 21 connects the two second surfaces 22, and the second surfaces are curved surfaces. The buffer member 30 is housed within the housing 10. In the first direction X, at least a portion of the buffer member 30 is disposed between the housing 10 and the junction of the first and second surfaces 21, 22.

[0173] In the third direction Z, the buffer member 30 is disposed at least in the middle of the electrode unit 20. The electrode unit includes a plurality of electrode assemblies 23 stacked along the first direction X.

[0174] The battery cell 110 also includes an insulating member 40, which is connected to the housing 10 and has a receiving cavity. The electrode unit 20 is received in the receiving cavity. The insulating member 40 includes two first walls 41 arranged opposite each other along a first direction X and two second walls 42 arranged opposite each other along a second direction Y. The buffer 30 includes a first buffer 31 and a second buffer 32. The first buffer 31 is provided between the junction of the first wall 41 and the second wall 42 and the second surface 22. A gap is provided between the first buffer 31 and at least one of the first surface 21 and the second surface 22. The second buffer 32 is provided on the side of the insulating member 40 facing away from the electrode unit 20. In the first direction X and the second direction Y, the orthographic projection of the first buffer 31 is located within the orthographic projection of the second buffer 32. The second cushioning member includes a first sub-portion 321 and a second sub-portion 322 connected to each other. The first sub-portion is located on the side of the first wall portion 41 facing away from the first surface 21, and the second sub-portion 322 is located on the side of the second wall portion 42 facing away from the second surface 22. The orthographic projection of the junction of the first surface 21 and the second surface 22 along the first direction X lies within the orthographic projection of the first sub-portion 321 along the first direction X. Furthermore, the orthographic projection of the minimum distance MIN between the second surface 22 and the second wall portion 42 along the second direction Y lies within the orthographic projection of the second sub-portion 322 along the second direction Y. The cushioning member 30 is made of sponge, aerogel, or microporous foamed polypropylene.

[0175] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery cell, characterized in that: include: shell; an electrode unit housed in the housing, the electrode unit comprising two first surfaces disposed opposite to each other along a first direction and two second surfaces disposed opposite to each other along a second direction, the first surface connecting the two second surfaces, and the second surface being an arc surface; A buffer is accommodated in the shell. In the first direction, at least a portion of the buffer is disposed between the shell and a connection between the first surface and the second surface.

2. The battery cell according to claim 1, wherein: In the third direction, the buffer member is at least arranged in the middle of the electrode unit, and the first direction, the second direction and the third direction are perpendicular to each other.

3. The battery cell according to claim 2, characterized in that: The buffer member has a dimension H along the third direction, the electrode unit has a dimension h along the third direction, 0.05h≤H≤0.2h, and the first direction, the second direction, and the third direction are perpendicular to each other.

4. The battery cell according to claim 1, wherein: The electrode unit includes a plurality of electrode assemblies stacked along the first direction.

5. The battery cell according to claim 1, characterized in that In the first direction, at least a portion of the buffer member is disposed between the first surface and the housing; In the second direction, at least a portion of the buffer member is disposed between the second surface and the housing.

6. The battery cell according to claim 1, characterized in that The device further comprises an insulating member connected to the housing and having a receiving cavity, wherein the electrode unit is received in the receiving cavity.

7. The battery cell according to claim 6, characterized in that The insulating member includes two first wall portions oppositely arranged along the first direction and two second wall portions oppositely arranged along the second direction. The buffer member includes a first buffer member provided between the connection between the first wall portion and the second wall portion and the second surface.

8. The battery cell according to claim 7, characterized in that A gap is defined between at least one of the first surface and the second surface and the first buffer member.

9. The battery cell according to claim 7, characterized in that: The buffer member further includes a second buffer member, which is arranged on a side of the insulating member facing away from the electrode unit. Along the first direction and / or along the second direction, the orthographic projection of the second buffer member and the orthographic projection of the first buffer member at least partially overlap.

10. The battery cell according to claim 9, characterized in that: Along the first direction and along the second direction, the orthographic projection of the first buffer member is located within the orthographic projection of the second buffer member.

11. The battery cell according to claim 9, characterized in that The second buffer member includes a first sub-portion and a second sub-portion connected to each other, the first sub-portion is located on a side of the first wall portion facing away from the first surface, and the second sub-portion is located on a side of the second wall portion facing away from the second surface; wherein the orthographic projection of the connection between the first surface and the second surface along the first direction is located within the orthographic projection of the first sub-section along the first direction; and / or, An orthographic projection of the second surface at a minimum distance from the second wall portion along the second direction is located within an orthographic projection of the second sub-portion along the second direction.

12. The battery cell according to claim 9, characterized in that The insulating member is provided with a mounting hole, and the first buffer member and the second buffer member are connected through the mounting hole.

13. The battery cell according to claim 1, characterized in that The number of the buffer members includes multiple, and the multiple buffer members are arranged at intervals along the third direction, and the first direction, the second direction and the third direction are perpendicular to each other.

14. The battery cell according to claim 1, characterized in that The material of the buffer component is sponge, aerogel or microporous foamed polypropylene.

15. A battery device, characterized in that: The battery cell comprises the battery cell according to any one of claims 1 to 14.

16. An electrical device, characterized in that: The battery device according to claim 15 is used to provide electrical energy.

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