Battery monomer, battery and electric equipment

Abstract

The utility model relates to the technical field of battery monomers, and provides a battery monomer, a battery and electric equipment, the battery monomer comprises an electrode assembly and a buffer member, the electrode assembly comprises a first pole piece, a second pole piece and a separator located between the first pole piece and the second pole piece; the first pole piece, the second pole piece and the separator are wound along the winding direction to form a winding body, and a center hole is formed in the center of the winding body along the winding axial direction; the winding direction is perpendicular to the winding axial direction; the buffering piece is at least partially arranged in the center hole, and the buffering piece is wound in the winding direction to form a multi-layer structure; according to the battery monomer provided by the embodiment of the invention, the first pole piece and the second pole piece can be supported in the central hole by utilizing the buffer piece, so that the problem that the first pole piece and the second pole piece are loosened is solved.

Description

Technical Field

[0001] This application relates to the technical field of battery cells, and particularly provides a battery cell, a battery and an electrical device. Background Art

[0002] Energy conservation and emission reduction are the keys to the sustainable development of the automotive industry. Electric vehicles have become an important part of the sustainable development of the automotive industry due to their advantages of energy conservation and environmental protection. For electric vehicles, battery technology is an important factor related to their development.

[0003] A battery cell usually includes a housing, an electrode assembly and an electrolyte. The electrolyte and the electrode assembly are both sealed in the housing. In the design of the electrode assembly, the winding form is a commonly used form; by placing the cathode electrode sheet, the anode electrode sheet and the separator at intervals and winding them around a winding needle to form a wound body. However, after the winding is completed and the winding core is removed from the wound body, since there is no support inside the wound body, the cathode electrode sheet and the anode electrode sheet in the inner circle of the wound body will become loose, resulting in an increase in the distance between the cathode electrode sheet and the anode electrode sheet, and further causing the problem of lithium deposition. Summary of the Utility Model

[0004] The purpose of the embodiments of this application is to provide a battery cell, a battery and an electrical device, aiming to solve the problem that the electrode sheets in the wound body are prone to looseness, resulting in lithium deposition.

[0005] To achieve the above purpose, the technical solution adopted in the embodiments of this application is:

[0006] In a first aspect, the embodiments of this application provide a battery cell, including an electrode assembly and a buffer member. The electrode assembly includes a first electrode sheet, a second electrode sheet and a separator located between the first electrode sheet and the second electrode sheet; the first electrode sheet, the second electrode sheet and the separator are wound along the winding direction to form a wound body, and a central hole is formed along the winding axis at the center of the wound body; the winding direction is perpendicular to the winding axis; at least part of the buffer member is disposed in the central hole, and the buffer member is wound along the winding direction to form a multi-layer structure.

[0007] Advantageous effects of the embodiments of this application: For the battery cell provided by the embodiments of this application, at least part of the buffer member is disposed in the central hole of the wound body, and the buffer member is used to support the first electrode sheet and / or the second electrode sheet in the central hole. Thus, the buffer member can balance the expansion force generated during the charge and discharge process of the battery cell due to expansion, effectively improve the problem that the first electrode sheet and the second electrode sheet become loose at the central hole of the wound body, and reduce the probability of lithium deposition; and the buffer member can be wound to form a multi-layer structure, and the buffer support performance of the buffer member in the multi-layer structure is relatively good, which can further improve the problem of looseness.

[0008] In some embodiments, the buffer member is connected to the first electrode sheet and / or the second electrode sheet.

[0009] By adopting the above technical solution, the buffer member can be connected to the first pole piece and / or the second pole piece, so that the stability of the buffer member is better, and the probability of the buffer member slipping or falling off is lower.

[0010] In some embodiments, the buffer member abuts against the first pole piece and / or the second pole piece.

[0011] By adopting the above technical solution, the buffer member abuts against and supports the first pole piece and / or the second pole piece in the central hole, so that the probability of the first pole piece and / or the second pole piece forming a looseness into the central hole is lower; and the buffer member with a multi-layer structure has a better balancing effect on the expansion force generated due to expansion during the charge and discharge process of the battery cell.

[0012] In some embodiments, the first pole piece is a cathode pole piece and the second pole piece is an anode pole piece.

[0013] By adopting the above technical solution, the buffer member can be connected to or abut against the cathode pole piece and / or the anode pole piece and achieve a supporting effect.

[0014] In some embodiments, the first pole piece is an anode pole piece and the second pole piece is a cathode pole piece.

[0015] By adopting the above technical solution, the buffer member can be connected to or abut against the cathode pole piece and / or the anode pole piece and achieve a supporting effect.

[0016] In some embodiments, the first pole piece includes a single-sided coating area and a double-sided coating area arranged in sequence along the winding direction, and the buffer member is arranged inside the single-sided coating area; in the direction opposite to the winding direction, at least a part of the single-sided coating area extends beyond the second pole piece.

[0017] By adopting the above technical solution, the buffer member is arranged inside the single-sided coating area to achieve a supporting effect, and at the same time, an active material layer can be coated on the outside of the single-sided coating area. Thus, the active material layer on the single-sided coating area can be fully utilized to improve the energy density of the battery cell.

[0018] In some embodiments, the single-sided coating area is wound along the winding direction to form at least one bending portion; the buffer member is arranged inside the bending portion.

[0019] By adopting the above technical solution, the buffer member can be inside the bending portion and support the first pole piece and the second pole piece to increase the corner gap at the bending portion of the first pole piece and the second pole piece, thereby reducing the probability of brittle fracture of the first pole piece and the second pole piece.

[0020] In some embodiments, the single-sided coating area is wound along the winding direction and alternately forms at least one flat portion and at least one bent portion; the buffer member is disposed inside the flat portion and inside the bent portion.

[0021] By adopting the above technical solution, the buffer member can be disposed inside the flat portion and inside the bent portion at the same time. Under the action of the buffer member to support the first pole piece and the second pole piece, the stability of the buffer member is better.

[0022] In some embodiments, at least one flat portion is formed along the winding direction in the single-sided coating area; the buffer member is disposed inside the flat portion.

[0023] By adopting the above technical solution, the buffer member can support the first pole piece and the second pole piece inside the flat portion to balance the acting force of the expansion force.

[0024] In some embodiments, in the winding axial direction, the width of the buffer member is less than or equal to the width of the winding body, and the buffer member does not extend outside the central hole.

[0025] By adopting the above technical solution, the buffer member is arranged not to extend outside the central hole in the winding axial direction, which can effectively reduce the influence of the buffer member on the winding operation.

[0026] In some embodiments, in the winding axial direction, the winding body has a width a, and the buffer member has a width b, where 0 ≤ a - b ≤ 2 mm.

[0027] By adopting the above technical solution, in the direction perpendicular to the winding direction, the width of the buffer member can be set to be the same as the width of the winding body to within 2 mm narrower than the width of the winding body; if the width of the buffer member is too wide, it may cause an impact on the winding process, and if the width of the buffer member is too narrow, it may cause stress streaks to form on the first pole piece and the second pole piece.

[0028] In some embodiments, 0 ≤ a - b ≤ 1 mm.

[0029] By adopting the above technical solution, by further limiting the difference between the width of the winding body and the width of the buffer member to be greater than or equal to zero and less than or equal to 1 mm, the probability of stress streaks forming on the first pole piece and the second pole piece can be further reduced.

[0030] In some embodiments, the buffer member has a compression ratio c, 30% ≤ c ≤ 90%.

[0031] By adopting the above technical solution, the compression ratio of the buffer member is limited to be greater than or equal to 30% and less than or equal to 90%, so that within this range, the buffer member has a better supporting effect.

[0032] In some embodiments, 50% ≤ c ≤ 70%.

[0033] By adopting the above technical solution, the compression ratio of the buffer is further limited to be greater than or equal to 50% and less than or equal to 70%. Thus, within this range, the supporting effect of the buffer can be further improved.

[0034] In some embodiments, a chamfer structure is formed at at least one end of the buffer in the winding direction.

[0035] By adopting the above technical solution, by providing a chamfer structure on the buffer, the probability of the end of the buffer causing indentation due to extrusion of the cathode plate and the anode plate during the cold pressing and shaping process of the winding body can be effectively reduced.

[0036] In some embodiments, the buffer includes any one of a polypropylene buffer structure, a polyethylene buffer structure, a plexiglass buffer structure, a polyester buffer structure, and a polycarbonate buffer structure.

[0037] By adopting the above technical solution, using any one of a polypropylene buffer structure, a polyethylene buffer structure, a plexiglass buffer structure, a polyester buffer structure, and a polycarbonate buffer structure as the buffer can achieve the supporting effect on the first plate and the second plate.

[0038] In a second aspect, an embodiment of the present application further provides a battery, including a box body and the battery cell as described above, and the battery cell is accommodated in the box body.

[0039] Advantageous effects of the embodiments of the present application: The battery provided by the embodiments of the present application includes the above battery cell. On the basis of the relatively good reliability of the above battery cell, the battery also has relatively good reliability.

[0040] In a third aspect, an embodiment of the present application further provides an electrical device, including the battery as described above, and the battery is used to provide electrical energy.

[0041] Advantageous effects of the embodiments of the present application: The electrical device provided by the embodiments of the present application includes the above battery. On the basis of the relatively good reliability of the above battery, the electrical device also has relatively good reliability. Description of the Drawings

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required to be used in the embodiments or related technical descriptions. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0043] Figure 1 It is a schematic structural diagram of a vehicle provided by an embodiment of the present application;

[0044] Figure 2 An exploded view of the battery provided by the embodiment of the present application;

[0045] Figure 3 A schematic diagram of the decomposition structure of the battery cell provided by the embodiment of the present application;

[0046] Figure 4 A schematic diagram of the structure of a winding body provided by the embodiment of the present application;

[0047] Figure 5 is Figure 4 A partial enlarged view of part A of

[0048] Figure 6 is Figure 4 A partial enlarged view of part B of

[0049] Figure 7 A schematic diagram of the structure when the buffer member is connected to the first pole piece provided by the embodiment of the present application.

[0050] Among them, the reference numerals in the figure:

[0051] 1000, vehicle;

[0052] 100, battery; 200, controller; 300, motor;

[0053] 10, box body; 11, first part; 12, second part;

[0054] 20, battery cell; 21, end cover; 21a, electrode terminal; 22, housing;

[0055] 23, electrode assembly; 23a, tab; 23b, winding body; 23b1, central hole;

[0056] 231, first pole piece; 2311, single-sided coating area; 2311a, bent portion; 2311b, straight portion; 2312, double-sided coating area;

[0057] 232, second pole piece; 233, separator;

[0058] 24, buffer member; 241, chamfer structure;

[0059] X, winding direction; Y, winding axial direction. Detailed implementation manners

[0060] Embodiments of the present application will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where like or similar reference numerals denote like or similar elements or elements having like or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present application, and should not be construed as limiting the present application.

[0061] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present application.

[0062] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, "a plurality of" means two or more unless otherwise specifically defined.

[0063] In the present application, unless otherwise clearly specified and defined, the terms "mounted", "connected", "coupled", "fixed", etc. should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral body; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0064] Currently, from the perspective of the development of the market situation, the application of power batteries is becoming more and more extensive. Power batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power, and solar power plants, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in many fields such as military equipment and aerospace. With the continuous expansion of the application fields of power batteries, the market demand is also continuously increasing.

[0065] A battery cell generally includes a housing, an electrode assembly, and an electrolyte. The electrolyte and the electrode assembly are both sealed inside the housing. In the design of the electrode assembly, the winding form is a commonly used form; a winding body is formed by arranging a cathode electrode sheet, an anode electrode sheet, and a separator at intervals and winding them around a winding pin. However, after the winding is completed and the winding pin is withdrawn from the winding body, since there is no support inside the winding body, the cathode electrode sheet and the anode electrode sheet in the inner circle of the winding body will become loose, resulting in an increase in the distance between the cathode electrode sheet and the anode electrode sheet, and further causing the problem of lithium deposition.

[0066] Based on the above considerations, in order to solve the problem of lithium deposition caused by the easy loosening of the electrode sheets in the winding body, a battery cell is designed. A winding body is formed by winding a cathode electrode sheet, an anode electrode sheet, and a separator along the winding direction, and a central hole is formed along the winding axis in the center of the winding body. At least a part of a buffer member is arranged in the central hole, and the buffer member is connected to the cathode electrode sheet and / or the anode electrode sheet. Thus, the buffer member can support the cathode electrode sheet and the anode electrode sheet in the central hole of the winding body, effectively improving the problem of loosening of the cathode electrode sheet and the anode electrode sheet. At the same time, it can also balance the expansion force generated during the charge and discharge process of the battery cell due to expansion, so as to effectively reduce the probability of lithium deposition.

[0067] The battery cell disclosed in the embodiments of the present application can be used in electrical equipment using a battery as a power source or various energy storage systems using a battery as an energy storage element. The electrical equipment can be, but is not limited to, mobile phones, tablets, laptop computers, electric toys, power tools, battery cars, electric vehicles, ships, spacecraft, etc. Among them, the electric toy can include fixed or mobile electric toys, such as game consoles, electric vehicle toys, electric ship toys, and electric plane toys, etc. The spacecraft can include airplanes, rockets, space shuttles, and spaceships, etc.

[0068] For the convenience of description in the following embodiments, a vehicle 1000, which is an electrical equipment in an embodiment of the present application, is taken as an example for description.

[0069] Please refer to Figure 1 , Figure 1 , which is a schematic structural diagram of the vehicle 1000 provided in some embodiments of the present application. The vehicle 1000 can be a fuel vehicle, a gas vehicle, or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle, or an extended-range vehicle, etc. A battery 100 is arranged inside the vehicle 1000, and the battery 100 can be arranged at the bottom, the head, or the tail of the vehicle 1000. The battery 100 can be used for power supply of the vehicle 1000. For example, the battery 100 can be used as the operating power source of the vehicle 1000. The vehicle 1000 can also include a controller 200 and a motor 300. The controller 200 is used to control the battery 100 to supply power to the motor 300. For example, it is used for the working power requirements during the start, navigation, and driving of the vehicle 1000.

[0070] In some embodiments of the present application, the battery 100 can not only serve as the operating power source of the vehicle 1000, but also 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.

[0071] Please refer to Figure 2 , Figure 2 which is an exploded view of the battery 100 provided in some embodiments of the present application. The battery 100 includes a box body 10 and battery cells 20, and the battery cells 20 are accommodated in the box body 10. Among them, the box body 10 is used to provide an accommodation space for the battery cells 20, and the box body 10 can adopt various structures. In some embodiments, the box body 10 may include a first part 11 and a second part 12, the first part 11 and the second part 12 cover each other, and the first part 11 and the second part 12 jointly define an accommodation space for accommodating the battery cells 20. The second part 12 may be a hollow structure with one end open, and the first part 11 may be a plate-like structure. The first part 11 covers the open side of the second part 12 so that the first part 11 and the second part 12 jointly define the accommodation space; the first part 11 and the second part 12 may also both be hollow structures with one side open, and the open side of the first part 11 covers the open side of the second part 12. Of course, the box body 10 formed by the first part 11 and the second part 12 can be of various shapes, such as a cylinder, a cuboid, etc.

[0072] In the battery 100, there may be multiple battery cells 20, and the multiple battery cells 20 can be connected in series, parallel or in a hybrid connection. A hybrid connection means that there are both series and parallel connections among the multiple battery cells 20. The multiple battery cells 20 can be directly connected in series, parallel or in a hybrid connection together, and then the whole formed by the multiple battery cells 20 is accommodated in the box body 10; of course, the battery 100 can also be in the form that multiple battery cells 20 are first connected in series, parallel or in a hybrid connection to form battery modules, and then the multiple battery modules are connected in series, parallel or in a hybrid connection to form a whole and are accommodated in the box body 10. The battery 100 may further include other structures. For example, the battery 100 may further include a busbar component for realizing the electrical connection among the multiple battery cells 20.

[0073] Among them, each battery cell 20 can be a secondary battery or a primary battery; it can also be a lithium-sulfur battery, a sodium-ion battery or a magnesium-ion battery, but is not limited thereto. The battery cell 20 can be in the shape of a cylinder, a flat body, a cuboid or other shapes, etc.

[0074] Please refer to Figure 3 , Figure 3 which is a schematic exploded view of the battery cell 20 provided in some embodiments of the present application. The battery cell 20 refers to the smallest unit that makes up the battery 100. As Figure 3, the battery cell 20 includes a housing (including an end cap 21 and a housing body 22), an electrode assembly 23, and other functional components.

[0075] The end cap 21 refers to a component that covers the opening of the housing body 22 to isolate the internal environment of the battery cell 20 from the external environment. Without limitation, the shape of the end cap 21 can be adapted to the shape of the housing body 22 to cooperate with the housing body 22. Optionally, the end cap 21 can be made of a material with a certain hardness and strength (such as aluminum alloy). In this way, the end cap 21 is not easily deformed when subjected to extrusion and collision, enabling the battery cell 20 to have higher structural strength and improved reliability. Functional components such as electrode terminals 21a can be provided on the end cap 21. The electrode terminals 21a can be used to electrically connect with the electrode assembly 23 for outputting or inputting the electrical energy of the battery cell 20. In some embodiments, a pressure relief mechanism for releasing the internal pressure when the internal pressure or temperature of the battery cell 20 reaches a threshold can also be provided on the end cap 21. The material of the end cap 21 can also be various. For example, the material of the end cap 21 can be but is not limited to copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc. In some embodiments, an insulating member can also be provided on the inner side of the end cap 21. The insulating member can be used to isolate the electrical connection components in the housing body 22 from the end cap 21 to reduce the risk of short circuit. Exemplarily, the insulating member can be plastic, rubber, etc.

[0076] The housing body 22 is a component used to cooperate with the end cap 21 to form the internal environment of the battery cell 20. Among them, the formed internal environment can be used to accommodate the electrode assembly 23, electrolyte, and other components. The housing body 22 and the end cap 21 can be independent components. An opening can be provided on the housing body 22, and the end cap 21 is covered on the opening to form the internal environment of the battery cell 20. Without limitation, the end cap 21 and the housing body 22 can also be integrated. Specifically, the end cap 21 and the housing body 22 can first form a common connection surface before other components are put into the housing, and then the end cap 21 is covered on the housing body 22 when the interior of the housing body 22 needs to be encapsulated. The housing body 22 can be of various shapes and sizes, such as cuboid, cylindrical, hexagonal prism, etc. Specifically, the shape of the housing body 22 can be determined according to the specific shape and size of the electrode assembly 23. The material of the housing body 22 can be various. For example, the housing body 22 can be but is not limited to copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0077] The electrode assembly 23 is a component in the battery cell 20 where an electrochemical reaction occurs. The housing 22 can contain one or more electrode assemblies 23. The electrode assembly 23 is mainly formed by winding or laminating an anode electrode sheet and a cathode electrode sheet, and usually an isolation member, such as an isolation film, etc., is provided between the anode electrode sheet and the cathode electrode sheet. The portions of the anode electrode sheet and the cathode electrode sheet having active materials constitute the main body of the electrode assembly 23, and the portions of the anode electrode sheet and the cathode electrode sheet without active materials respectively constitute the electrode tabs 23a. The anode electrode tab and the cathode electrode tab can be located at one end of the main body together or at both ends of the main body respectively. During the charge and discharge process of the battery, the anode active material and the cathode active material react with the electrolyte, and the electrode tab 23a is connected to the electrode terminal 21a to form a current loop.

[0078] According to some embodiments of the present application, referring to Figures 3 to 6 , embodiments of the present application provide a battery cell 20, including an electrode assembly 23 and a buffer member 24. The electrode assembly 23 includes a first electrode sheet 231, a second electrode sheet 232, and an isolation member 233 located between the first electrode sheet 231 and the second electrode sheet 232; the first electrode sheet 231, the second electrode sheet 232, and the isolation member 233 are wound along the winding direction X to form a winding body 23b, and a central hole 23b1 is formed along the winding axis Y at the center of the winding body 23b; the winding direction X is perpendicular to the winding axis Y; the buffer member 24 is at least partially disposed in the central hole 23b1, and the buffer member 24 is wound along the winding direction X to form a multi-layer structure.

[0079] Among them, the first electrode sheet 231 and the second electrode sheet 232 can react in the electrolyte to form a current. It should be understood that one of the first electrode sheet 231 and the second electrode sheet 232 has a cathode active material (such as anions, etc.), and the other of the first electrode sheet 231 and the second electrode sheet 232 has an anode active material (such as cations, etc.). Thus, the cathode active material and the anode active material react in the electrolyte to form a current.

[0080] The winding direction X refers to the direction in which the first electrode sheet 231, the isolation member 233, and the second electrode sheet 232 are stacked in sequence and then wound. In some embodiments, the first electrode sheet 231 and the second electrode sheet 232 can be wound after being aligned at the starting end in the winding direction X, and the central hole 23b1 is formed by the electrode sheets wound into the innermost circle. Or, in some other embodiments, in the direction opposite to the winding direction X, the first electrode sheet 231 can be wound beyond the second electrode sheet 232, or the second electrode sheet 232 can be wound beyond the first electrode sheet 231, and the portion by which the first electrode sheet 231 extends beyond is wound to the innermost circle of the winding body 23b.

[0081] The winding axis Y refers to the direction perpendicular to the winding direction X. After the first pole piece 231, the separator 233, and the second pole piece 232 are stacked in sequence, they are wound along the winding direction X and around the winding axis Y to form a wound body 23b. It can be understood that after the first pole piece 231, the separator 233, and the second pole piece 232 are stacked in sequence, they are wound around a winding core (not shown in the figure) to form a wound body 23b. After the winding operation is completed, the winding core is removed, and thus a hollow central hole 23b1 will be formed in the middle region of the wound body 23b.

[0082] The buffer member 24 is used to support the first pole piece 231 and the second pole piece 232 inside the central hole 23b1 to reduce the probability that the first pole piece 231 and the second pole piece 232 become loose inside the central hole 23b1. It can be understood that the buffer member 24 includes, but is not limited to, buffer pads, buffer layer bodies, buffer sheet bodies and other buffer support structures; the buffer member 24 can be wound along the winding direction X to form a multi-layer structure; the first pole piece 231 and the second pole piece 232 are supported by the buffer member 24 with a multi-layer structure, and the multi-layer structure has better buffer performance and support performance, so as to effectively improve the problem of looseness of the first pole piece 231 and the second pole piece 232.

[0083] Optionally, the buffer member 24 can be connected to the first pole piece 231; or, the buffer member 24 can also be abutted against the first pole piece 231, and there is no connection relationship between the buffer member 24 and the first pole piece 231.

[0084] Or, the buffer member 24 can be connected to the second pole piece 232; or, the buffer member 24 can also be abutted against the second pole piece 232, and there is no connection relationship between the buffer member 24 and the second pole piece 232.

[0085] Or, the buffer member 24 can also be connected to both the second pole piece 232 and the first pole piece 231 at the same time. For example, a part of the buffer member 24 is connected to the surface of the first pole piece 231 at the initial section in the winding direction X, and the buffer member 24 is bent in the direction opposite to the winding direction X, bypasses the separator 233 and is folded to one side of the second pole piece 232, so as to achieve the purpose of connecting the buffer member 24 to both the first pole piece 231 and the second pole piece 232 at the same time.

[0086] Among them, the way the buffer member 24 is arranged inside the central hole 23b1 can be that the buffer member 24 is connected to the surface of the first pole piece 231 at the initial section in the winding direction X. During the process of winding to form the wound body 23b, the buffer member 24 can be wound into the innermost circle, that is, inside the central hole 23b1; or, after the first pole piece 231, the second pole piece 232, and the separator 233 are wound along the winding direction X and around the winding core to form the wound body 23b, the winding core is taken out, and the buffer member 24 is stuffed in for replacement, so that the buffer member 24 is stuffed into the central hole 23b1 and continues to support the first pole piece 231 and the second pole piece 232.

[0087] The buffer member 24 is disposed at least partially within the central hole 23b1; optionally, the buffer member 24 may be completely received within the central hole 23b1; or, a portion of the buffer member 24 may extend outside the central hole 23b1.

[0088] In the battery cell 20 provided by the embodiment of the present application, by disposing at least a portion of the buffer member 24 within the central hole 23b1 of the wound body 23b, the buffer member 24 is used to support the first electrode tab 231 and / or the second electrode tab 232 within the central hole 23b1, so that the buffer member 24 can balance the expansion force generated due to expansion during the charging and discharging process of the battery cell 20, effectively improving the problem that the first electrode tab 231 and the second electrode tab 232 become loose at the central hole 23b1 of the wound body 23b, and reducing the probability of lithium plating; and the buffer member 24 can be wound to form a multi-layer structure, and the buffer support performance of the buffer member 24 in the multi-layer structure is relatively good, which can further improve the problem of becoming loose.

[0089] Exemplarily, in some embodiments, a single-layer buffer member 24 (for example, a buffer pad structure) may be connected to the surface of the initial segment of the first electrode tab 231 or the second electrode tab 232 in the winding direction X, and the single-layer buffer member 24 can extend beyond the first electrode tab 231 and the second electrode tab 232 in the direction opposite to the winding direction X, and then the first electrode tab 231, the second electrode tab 232, and the separator 233 are wound along the winding direction X; during the winding process, the buffer member 24 extending beyond the first electrode tab 231 and the second electrode tab 232 in the direction opposite to the winding direction X can be wound first and stacked to form a multi-layer structure; after the winding is completed and the wound body 23b is formed, the winding core is removed, and the buffer member 24 located in the innermost layer forms a multi-layer structure and can be filled within the central hole 23b1 to achieve the support of the first electrode tab 231 and the second electrode tab 232.

[0090] Please refer to Figures 4 to 6 , in some embodiments, the buffer member 24 is connected to the first electrode tab 231 and / or the second electrode tab 232.

[0091] Optionally, the buffer member 24 may be connected to the first electrode tab 231, for example, by means of adhesion, thermal compounding, etc. to form a connection with the surface of the first electrode tab 231, as Figure 5 shown.

[0092] Exemplarily, in some embodiments, the buffer member 24 may be connected to the surface of the initial segment of the first pole piece 231 in the winding direction X. During the process of winding the first pole piece 231, the second pole piece 232, and the separator 233 along the winding direction X, the initial segment of the first pole piece 231 may be wound into the innermost circle of the winding body 23b and enclose to form a central hole 23b1. Thus, the buffer member 24 can support the first pole piece 231 and the second pole piece 232 in the central hole 23b1 to reduce the probability of loosening.

[0093] Alternatively, the buffer member 24 may also be connected to the second pole piece 232, for example, by gluing, thermal lamination, etc. to form a connection with the surface of the second pole piece 232 (the scheme of connecting the buffer member 24 to the second pole piece 232 is not shown in the figure, and can be analogized to the scheme of connecting the buffer member 24 to the first pole piece 231).

[0094] Exemplarily, in some embodiments, the buffer member 24 may be connected to the surface of the initial segment of the second pole piece 232 in the winding direction X. During the process of winding the first pole piece 231, the second pole piece 232, and the separator 233 along the winding direction X, the initial segment of the second pole piece 232 may be wound into the innermost circle of the winding body 23b and enclose to form a central hole 23b1. Thus, the buffer member 24 can support the first pole piece 231 and the second pole piece 232 in the central hole 23b1 to reduce the probability of loosening.

[0095] Alternatively, the buffer member 24 may also be connected to both the first pole piece 231 and the second pole piece 232, for example, by gluing, thermal lamination, etc. to form a connection with the surfaces of the first pole piece 231 and the second pole piece 232 (the scheme of connecting the buffer member 24 to both the first pole piece 231 and the second pole piece 232 is not shown in the figure).

[0096] Exemplarily, in some embodiments, before the winding operation, the buffer member 24 may be connected to the surface of the initial segment of the first pole piece 231 in the winding direction X, and the buffer member 24 may be bent so that it can bypass the separator 233 and be able to fit on the surface of the initial segment of the second pole piece 232 in the winding direction X. Thus, during the process of winding the first pole piece 231, the second pole piece 232, and the separator 233 along the winding direction X, a part of the buffer member 24 can be wound first and form a multi-layer structure, and this part of the buffer member 24 with a multi-layer structure is located in the central hole 23b1 and supports the first pole piece 231 and the second pole piece 232 to reduce the probability of loosening.

[0097] With such a setting, the buffer member 24 can be connected to the first pole piece 231 and / or the second pole piece 232, so that the stability of the buffer member 24 is better, and the probability of the buffer member 24 sliding or falling off is lower.

[0098] Please refer to Figures 4 to 6 , in some embodiments, the buffer member 24 abuts against the first pole piece 231 and / or the second pole piece 232.

[0099] Optionally, the buffer member 24 can be arranged to abut against the first pole piece 231 within the central hole 23b1. Exemplarily, in some embodiments, the buffer member 24 can be placed on the inner side of the first pole piece 231 (i.e., in the direction towards the center of the central hole 23b1, which is the direction towards the core during the winding operation), and at least part of the buffer member 24 extends beyond the first pole piece 231 in the direction opposite to the winding direction X. During the process of winding the buffer member 24, the first pole piece 231, the second pole piece 232, and the separator 233 along the winding direction X, at least part of the buffer member 24 can be wound first and form a multi-layer structure; after the winding operation is completed and the winding body 23b is formed, the core is pulled out, and at least part of the buffer member 24 forming the multi-layer structure will be located within the central hole 23b1 and can abut against and support the first pole piece 231 and the second pole piece 232.

[0100] With such an arrangement, the buffer member 24 abuts against and supports the first pole piece 231 and / or the second pole piece 232 within the central hole 23b1, so that the probability of the first pole piece 231 and / or the second pole piece 232 forming looseness towards the central hole 23b1 is relatively low; and the buffer member 24 in the multi-layer structure has a better balancing effect on the expansion force generated during the charge and discharge process of the battery cell 20 due to expansion.

[0101] Please refer to Figures 4 to 6 , in some embodiments, the first pole piece 231 is a cathode pole piece, and the second pole piece 232 is an anode pole piece.

[0102] In this embodiment, the first pole piece 231 can be a cathode pole piece, that is, the first pole piece 231 has a cathode active material, so that the second pole piece 232 has an anode active material, and the second pole piece 232 is an anode pole piece.

[0103] Thus, the buffer member 24 can be connected to or abut against the cathode pole piece and / or the anode pole piece within the central hole 23b1 and form a support for the cathode pole piece and the anode pole piece.

[0104] Please refer to Figures 4 to 6 , in some embodiments, the first pole piece 231 is an anode pole piece, and the second pole piece 232 is a cathode pole piece.

[0105] In this embodiment, the first pole piece 231 can be an anode pole piece, that is, the first pole piece 231 has an anode active material, so that the second pole piece 232 has a cathode active material, and the second pole piece 232 is a cathode pole piece.

[0106] Thus, the buffer member 24 can be connected to or abutted against the cathode plate and / or the anode plate within the central hole 23b1 to form a support for the cathode plate and the anode plate.

[0107] Please refer to Figures 4 to 6 , in some embodiments, the first pole piece 231 includes a single-sided coating area 2311 and a double-sided coating area 2312 arranged in sequence along the winding direction X, and the buffer member 24 is disposed inside the single-sided coating area 2311; in the direction opposite to the winding direction X, at least a part of the single-sided coating area 2311 extends beyond the second pole piece 232.

[0108] Among them, the single-sided coating area 2311 refers to the part of either the inner surface or the outer surface of the first pole piece 231 coated with the active material layer; the double-sided coating area 2312 refers to the part of both the inner surface and the outer surface of the first pole piece 231 coated with the active material layer.

[0109] The inner side of the single-sided coating area 2311 refers to the side of the single-sided coating area 2311 facing the inside of the central hole 23b1, and the outer side of the single-sided coating area 2311 refers to the opposite side of the single-sided coating area 2311 facing the outside of the winding body 23b. The buffer member 24 is disposed inside the single-sided coating area 2311. Thus, the outer side of the single-sided coating area 2311 is coated with the active material layer.

[0110] The single-sided coating area 2311 and the double-sided coating area 2312 are formed in sequence along the winding direction X, and the single-sided coating area 2311 is formed upstream of the double-sided coating area 2312 in the winding direction X; thus, during the winding operation, the single-sided coating area 2311 can be wound into the innermost side of the winding body 23b, so that at least a part of the single-sided coating area 2311 will be inside the central hole 23b1 or enclose the central hole 23b1.

[0111] Optionally, according to the different lengths of the single-sided coating area 2311 in the winding direction X, the single-sided coating area 2311 can form a winding structure of half a turn, one turn, one and a half turns, etc. inside the central hole 23b1 of the winding body 23b. Exemplarily, in some embodiments, the first pole piece 231, the separator 233, and the second pole piece 232 are stacked in sequence, and in the winding direction X, the starting end of the second pole piece 232 is substantially aligned with the starting end of the double-sided coating area 2312 of the first pole piece 231, or the starting end of the double-sided coating area 2312 extends beyond the starting end of the second pole piece 232 in the direction opposite to the winding direction X; thus, at least a part of the single-sided coating area 2311 can extend into the central hole 23b1 or enclose the central hole 23b1.

[0112] The buffer member 24 is disposed inside the single-sided coating area 2311; optionally, the buffer member 24 can be connected to the single-sided coating area 2311 by means such as gluing or thermal lamination, or the buffer member 24 can abut against the inside of the single-sided coating area 2311.

[0113] With such an arrangement, the buffer member 24 is disposed inside the single-sided coating area 2311 to achieve a supporting effect, and at the same time, an active material layer can be coated on the outside of the single-sided coating area 2311. Thus, the active material layer on the single-sided coating area 2311 can be fully utilized to improve the energy density of the battery cell.

[0114] Please refer to Figures 4 to 6 , in some embodiments, the single-sided coating area 2311 is wound along the winding direction X to form at least one bending portion 2311a; the buffer member 24 is disposed inside the bending portion 2311a.

[0115] It can be understood that when the single-sided coating area 2311 is wound along the winding direction X, one or more bending portions 2311a with a bent surface will be formed. Optionally, when the single-sided coating area 2311 is wound along the winding direction X, a flat structure with a flat surface may also be formed.

[0116] Among them, the buffer member 24 is disposed inside the bending portion 2311a of the single-sided coating area 2311, and the buffer member 24 can be connected or abut against the bending portion 2311a of the single-sided coating area 2311.

[0117] It should be understood that at the location where the single-sided coating area 2311 is wound along the winding direction X to form the bending portion 2311a, the double-sided coating area 2312 of the first pole piece 231 and the second pole piece 232 will also be wound and correspondingly form a bent or even folded structure; there is a risk of brittle fracture at this location for the double-sided coating area 2312 of the first pole piece 231 and the second pole piece 232.

[0118] With such an arrangement, the buffer member 24 is disposed inside the bending portion 2311a, so that the buffer member 24 can support the location where the first pole piece 231 and the second pole piece 232 correspondingly form a bent structure, so as to increase the corner gap between the first pole piece 231 and the second pole piece 232 at this location, and further effectively reduce the probability of brittle fracture of the first pole piece 231 and the second pole piece 232 at this location.

[0119] Please refer to Figures 4 to 6 , in some embodiments, the single-sided coating area 2311 is wound along the winding direction X and alternately forms at least one flat portion 2311b and at least one bending portion 2311a; the buffer member 24 is disposed inside the flat portion 2311b and inside the bending portion 2311a.

[0120] Among them, the buffer member 24 is disposed inside the straight portion 2311b and inside the bent portion 2311a, and the buffer member 24 can be connected to or abutted against the inside of the straight portion 2311b and the inside of the bent portion 2311a.

[0121] Exemplarily, in some embodiments, the single-sided coating area 2311 is wound along the winding direction X and can form two straight portions 2311b and two bent portions 2311a. The opposite ends of one of the bent portions 2311a are respectively connected to the two straight portions 2311b, and the opposite ends of the other bent portion 2311a are respectively connected to one of the straight portions 2311b and the double-sided coating area 2312, specifically as Figure 5 and Figure 6 shown.

[0122] With such an arrangement, the buffer member 24 can be simultaneously connected to or abutted against the inside of the straight portion 2311b and the inside of the bent portion 2311a. Under the action of the buffer member 24 supporting the first pole piece 231 and the second pole piece 232, the stability of the buffer member 24 is better.

[0123] Please refer to Figures 4 to 6 , in some embodiments, the single-sided coating area 2311 forms at least one straight portion 2311b along the winding direction X; the buffer member 24 is disposed inside the straight portion 2311b.

[0124] Among them, the buffer member 24 is disposed inside the straight portion 2311b, and the buffer member 24 can be connected to or abutted against the inside of the straight portion 2311b.

[0125] With such an arrangement, the buffer member 24 can support the first pole piece 231 and the second pole piece 232 on the surface of the straight portion 2311b to balance the expansion force.

[0126] Please refer to Figures 4 to 7 , in some embodiments, in the winding axial Y direction, the width of the buffer member 24 is less than or equal to the width of the winding body 23b, and the buffer member 24 does not extend out of the central hole 23b1.

[0127] It can be understood that the first pole piece 231, the second pole piece 232, and the separator 233 are wound to form the winding body 23b. Therefore, the width of the winding body 23b is equal to the width of the first pole piece 231 or the width of the second pole piece 232.

[0128] In the winding axial Y direction, the buffer member 24 does not extend out of the central hole 23b1; thus, in the winding axial Y direction, the end of the buffer member 24 can be flush with the end of the winding body 23b, or a gap can be formed between the end of the buffer member 24 and the end of the winding body 23b.

[0129] With such a setting, the buffer member 24 is set not to protrude outside the central hole 23b1 in the winding axial direction Y, which can effectively reduce the influence of the buffer member 24 on the recognition of the vision system during the winding operation, and at the same time can also reduce the influence of the buffer member 24 protruding outside the central hole 23b1 on the occupied space, thereby reducing the influence on the energy density.

[0130] Please refer to Figures 4 to 7 , in some embodiments, in the winding axial direction Y, the winding body 23b has a width a, and the buffer member 24 has a width b, where 0 ≤ a - b ≤ 2 mm.

[0131] It can be understood that the width a of the winding body 23b can be wider than the width b of the buffer member 24, and the range where the width a of the winding body 23b can be wider than the width b of the buffer member 24 does not exceed 2 millimeters (hereinafter, millimeters are represented by mm). Exemplarily, the width a of the winding body 23b can be, but is not limited to, 0.1 mm, 0.5 mm, 1 mm, 1.5 mm, 2 mm, etc. wider than the width b of the buffer member 24.

[0132] Alternatively, the width a of the winding body 23b can be the same as the width b of the buffer member 24.

[0133] With such a setting, in the direction perpendicular to the winding direction X, the width of the buffer member 24 can be set to be the same as the width of the winding body 23b to within a range of 2 millimeters narrower than the width of the winding body 23b; if the width of the buffer member 24 is too wide, it may cause an impact on the winding process, and if the width of the buffer member 24 is too narrow, it may cause stress streaks to form on the first pole piece 231 and the second pole piece 232.

[0134] Please refer to Figures 4 to 7 , in some embodiments, 0 ≤ a - b ≤ 1 mm.

[0135] With such a setting, by further limiting the difference between the width of the winding body 23b and the width of the buffer member 24 to be greater than or equal to zero and less than or equal to 1 millimeter, the probability of stress streaks forming on the first pole piece 231 and the second pole piece 232 can be further reduced.

[0136] Please refer to Figures 4 to 6 , in some embodiments, the buffer member 24 has a compression ratio c, 30% ≤ c ≤ 90%.

[0137] In this embodiment, the compression ratio of the buffer member 24 is limited to be greater than or equal to 30% and less than or equal to 90%; Exemplarily, the compression ratio of the buffer member 24 can be, but is not limited to, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, etc.

[0138] With such a setting, the compression ratio of the buffer member 24 is limited to be greater than or equal to 30% and less than or equal to 90%. Thus, within this range, the buffer member 24 has a better supporting effect.

[0139] Please refer to Figures 4 to 6 , in some embodiments, 50% ≤ c ≤ 70%.

[0140] In this embodiment, the compression ratio c of the buffer member 24 is limited to be greater than or equal to 50% and less than or equal to 70%; exemplarily, the compression ratio c of the buffer member 24 can be but is not limited to 50%, 52%, 55%, 57%, 60%, 62%, 65%, 67%, 70%, etc.

[0141] With such a setting, the compression ratio of the buffer member 24 is further limited to be greater than or equal to 50% and less than or equal to 70%. Thus, within this range, the supporting effect of the buffer member 24 can be further improved.

[0142] Please refer to Figures 4 to 7 , in some embodiments, on the winding direction X, at least one end of the buffer member 24 is formed with a chamfer structure 241.

[0143] In this embodiment, the chamfer structure 241 can be formed at one end of the buffer member 24 along the winding direction X, or the chamfer structure 241 can be formed at both opposite ends of the buffer member 24 along the winding direction X.

[0144] Optionally, the chamfer structure 241 includes but is not limited to a rounded chamfer structure, an inverted triangular structure, an inverted double triangular structure, an inverted arc structure, an inverted semi - arc structure, etc.

[0145] With such a setting, by providing the chamfer structure 241 on the buffer member 24, the probability of the end of the buffer member 24 generating indentations due to extrusion of the first pole piece 231 and the second pole piece 232 during the cold pressing and shaping process of the winding body 23b can be effectively reduced.

[0146] Please refer to Figure 4 , in some embodiments, the buffer member 24 includes any one of a polypropylene buffer structure, a polyethylene buffer structure, a plexiglass buffer structure, a polyester buffer structure, and a polycarbonate buffer structure.

[0147] With such a setting, using any one of a polypropylene buffer structure, a polyethylene buffer structure, a plexiglass buffer structure, a polyester buffer structure, and a polycarbonate buffer structure as the buffer member 24 can achieve the supporting effect on the first pole piece 231 and the second pole piece 232.

[0148] Next, the battery cell 20 of the embodiment of the present application will be described in detail according to specific embodiments.

[0149] Please refer toFigures 3 to 6 , in some embodiments, the battery cell 20 includes an electrode assembly 23. The electrode assembly 23 includes a first electrode tab 231, a second electrode tab 232, and a separator 233 located between the first electrode tab 231 and the second electrode tab 232. The first electrode tab 231, the second electrode tab 232, and the separator 233 are wound along the winding direction X to form a wound body 23b, and a central hole 23b1 is formed along the winding axis Y at the center of the wound body 23b. In this embodiment, the first electrode tab 231 may be an anode electrode tab, and the second electrode tab 232 may be a cathode electrode tab.

[0150] The battery cell 20 further includes a buffer member 24. The anode electrode tab sequentially forms a single-sided coating area 2311 and a double-sided coating area 2312 along the winding direction X. Among them, the single-sided coating area 2311 can be rolled into the innermost circle of the wound body 23b and enclose to form the central hole 23b1. The buffer member 24 can be connected to the inner surface of the single-sided coating area 2311 (i.e., the surface facing the central hole 23b1) by means of gluing, thermal lamination, etc., and the buffer member 24 extends beyond the single-sided coating area 2311 in the direction opposite to the winding direction X. During the winding operation, the part of the buffer member 24 that extends beyond the single-sided coating area 2311 can be wound first and form a multi-layer structure. Thus, at least part of the buffer member 24 forming the multi-layer structure can be located within the central hole 23b1 and can abut and support the inner surface of the single-sided coating area 2311 (including the bent inner surface and the flat inner surface of the single-sided coating area 2311). Therefore, the buffer member 24 can not only improve the problem of looseness between the cathode electrode tab and the anode electrode tab, but also increase the corner gap at the bent portion of the wound body 23b and reduce the probability of fracture at the bent portion.

[0151] Please refer to Figures 2 to 4 , in a second aspect, the embodiment of the present application further provides a battery 100, including a box body 10 and the battery cell 20 as described above. The battery cell 20 is accommodated in the box body 10.

[0152] The battery 100 provided by the embodiment of the present application includes the battery cell 20 as described above. On the basis of the relatively good reliability of the battery cell 20 as described above, the battery 100 also has relatively good reliability.

[0153] Please refer to Figures 1 to 4 , in a third aspect, the embodiment of the present application further provides an electrical device, including the battery 100 as described above. The battery 100 is used to provide electrical energy.

[0154] The electrical device provided by the embodiment of the present application is, for example, the vehicle 1000 as described above. The electrical device includes the battery 100 as described above. On the basis of the relatively good reliability of the battery 100 as described above, the electrical device also has relatively good reliability.

[0155] The above are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. A battery cell, characterized in that: including an electrode assembly including a first electrode tab, a second electrode tab, and a separator located between the first electrode tab and the second electrode tab; the first electrode tab, the second electrode tab, and the separator are wound in a winding direction to form a wound body, and a central hole is formed along the winding axis at the center of the wound body; the winding direction is perpendicular to the winding axis; and a buffer member, at least part of which is disposed in the central hole, and the buffer member is wound in the winding direction to form a multi-layer structure.

2. The battery cell according to claim 1, wherein: The buffer member is connected to the first electrode tab and / or the second electrode tab.

3. The battery cell according to claim 1, wherein: The buffer member abuts against the first electrode tab and / or the second electrode tab.

4. The battery cell according to any one of claims 1 to 3, characterized in that: The first electrode tab is a cathode electrode tab, and the second electrode tab is an anode electrode tab.

5. The battery cell according to any one of claims 1 to 3, characterized in that: The first electrode tab is an anode electrode tab, and the second electrode tab is a cathode electrode tab.

6. The battery cell according to any one of claims 1 to 3, characterized in that: The first electrode tab includes a single-sided coating area and a double-sided coating area arranged in sequence along the winding direction, and the buffer member is disposed inside the single-sided coating area; in a direction opposite to the winding direction, at least part of the single-sided coating area extends beyond the second electrode tab.

7. The battery cell according to claim 6, wherein: The single-sided coating area is wound in the winding direction to form at least one bent portion; the buffer member is disposed inside the bent portion.

8. The battery cell according to claim 6, wherein: The single-sided coating area is wound in the winding direction and alternately forms at least one straight portion and at least one bent portion; the buffer member is disposed inside the straight portion and the bent portion.

9. The battery cell according to claim 6, wherein: The single-sided coating area forms at least one straight portion in the winding direction; the buffer member is disposed inside the straight portion.

10. The battery cell according to any one of claims 1 to 3 and 7 to 9, characterized in that: In the winding axis direction, the width of the buffer member is less than or equal to the width of the wound body, and the buffer member does not extend outside the central hole.

11. The battery cell according to claim 10, wherein: In the winding axis direction, the wound body has a width a, and the buffer member has a width b, where 0 ≤ a - b ≤ 2 mm.

12. The battery cell according to claim 11, characterized in that: 0 ≤ a - b ≤ 1 mm.

13. The battery cell according to any one of claims 1 to 3, 7 to 9, 11, and 12, characterized in that: The buffer member has a compression ratio c, and 30% ≤ c ≤ 90%.

14. The battery cell according to claim 13, characterized in that: 50％≤c≤70％。 15. The battery cell according to any one of claims 1 to 3, 7 to 9, 11, 12, and 14, characterized in that: In the winding direction, at least one end of the buffer member is formed with a chamfer structure.

16. The battery cell according to any one of claims 1 to 3, 7 to 9, 11, 12, and 14, characterized in that: The buffer member includes any one of a polypropylene buffer structure, a polyethylene buffer structure, a plexiglass buffer structure, a polyester buffer structure, and a polycarbonate buffer structure.

17. A battery, characterized in that: including a box body and a battery cell according to any one of claims 1 to 16, and the battery cell is accommodated in the box body.

18. An electrical device, characterized in that: including a battery according to claim 17, and the battery is used to provide electrical energy.

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