Battery cell, battery device, and electric device

Abstract

The present application provides a battery cell, a battery device, and an electric device. The battery cell comprises: a casing comprising a bottom wall, a side wall, and a cavity enclosed by the bottom wall and the side wall and having an opening at one end in a first direction; an electrode assembly arranged in the cavity; an end cover assembly covering the opening, the end cover assembly being connected to the electrode assembly; and thermally conductive assemblies each comprising a first thermally conductive portion and a second thermally conductive portion connected to each other, wherein the first thermally conductive portion is arranged on the side surface of the end cover assembly away from the electrode assembly, and the second thermally conductive portion is arranged on the side wall. By means of the first thermally conductive portions arranged on the side surface of the end cover assembly away from the electrode assembly, an external thermal conduction path for the battery cell is established, so as to reduce the thermal resistance at the end cover assembly; and by means of the second thermally conductive portions arranged on the side wall, the total area of the thermally conductive assemblies is increased, so as to increase the rate of heat exchange between the battery cell and the external environment, thereby mitigating the problem of adverse effects on the performance and service life of the battery cell caused by an excessively high or low temperature.

Description

Battery cells, battery packs and electrical devices Technical Field

[0001] This application relates to the field of batteries, and in particular to a battery cell, a battery device, and an electrical device. Background Technology

[0002] Battery cells are widely used in electronic devices such as mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and power tools, etc.

[0003] However, in actual operation, excessively high or low internal temperatures of a battery cell can adversely affect its lifespan and performance. Summary of the Invention

[0004] In view of the above problems, this application provides a battery cell, a battery device, and an electrical device that can enhance the thermal conductivity of the battery cell, thereby enhancing the performance and service life of the battery cell.

[0005] In a first aspect, this application provides a battery cell, comprising: a housing, including a bottom wall, a side wall, and a cavity enclosed by the bottom wall and the side wall and open at one end in a first direction; an electrode assembly disposed in the cavity; an end cap assembly covering the opening, the end cap assembly and the electrode assembly being connected; and a thermally conductive assembly, including a first thermally conductive portion and a second thermally conductive portion connected to each other, the first thermally conductive portion being disposed on the side surface of the end cap assembly away from the electrode assembly, the second thermally conductive portion being disposed on the side wall, and the thermal conductivity of the thermally conductive assembly being greater than the thermal conductivity of the end cap assembly and the housing.

[0006] In the embodiments of this application, the battery cell includes a housing, an end cap assembly, and an electrode assembly. The housing includes a bottom wall, side walls, and a cavity enclosed by the bottom wall and side walls, with one end open in a first direction. The electrode assembly is housed within the housing. The end cap assembly covers the opening of the housing and connects to the electrode assembly, enabling the electrode assembly to form a circuit with external devices through the end cap assembly. The heat-conducting assembly includes a first heat-conducting part and a second heat-conducting part. The thermal conductivity of the heat-conducting assembly is greater than that of the end cap assembly and the housing. By providing the first heat-conducting part on the side surface of the end cap assembly away from the electrode assembly, an external heat-conducting channel for the battery cell is established to reduce the thermal resistance at the end cap assembly. By providing the second heat-conducting part on the side wall, the total area of ​​the heat-conducting assembly is increased, thereby increasing the rate of heat exchange between the battery cell and the external environment and mitigating the adverse effects on the performance and service life of the battery cell due to excessively high or low temperatures.

[0007] In some embodiments, the sidewall includes two first sidewalls and two second sidewalls, the two first sidewalls are disposed opposite each other in a second direction, the two second sidewalls are disposed opposite each other in a third direction, the first direction, the second direction and the third direction intersect each other, the area of ​​the first sidewall is larger than the area of ​​the second sidewall, a second heat-conducting part is disposed on the first sidewall, and / or the second heat-conducting part is disposed on the second sidewall.

[0008] In the embodiments of this application, the second heat-conducting part is disposed on at least one of the first sidewall and the second sidewall, so that when the battery cell is placed in the housing, the second heat-conducting part can be close to the heat exchange mechanism to improve the heat exchange rate between the heat exchange mechanism and the battery cell, so as to better balance the temperature of the battery cell and improve the performance of the battery device.

[0009] In some embodiments, the second heat-conducting portion covers the entire first sidewall, or the second heat-conducting portion covers the entire second sidewall.

[0010] In the embodiments of this application, the second heat-conducting part covers the entire first sidewall, or the second heat-conducting part covers the entire second sidewall, so as to increase the contact area between the second heat-conducting part and the external environment and improve the heat conduction performance of the heat-conducting component.

[0011] In some embodiments, the sidewall and end cap assemblies are connected with rounded corners, and the rounded corners and thermal conductive components are spaced apart.

[0012] In the embodiment of this application, the sidewall and end cap assembly are connected with rounded corners, and the rounded corners and the heat-conducting assembly are spaced apart, so that there is a gap between the housing and the heat-conducting assembly that can accommodate the expansion and deformation of the housing, thereby reducing the risk of the heat-conducting assembly being burst due to the expansion of the battery cell.

[0013] In some embodiments, the thermally conductive component further includes an adhesive layer, which includes a first adhesive layer, and the second thermally conductive portion is bonded to the sidewall through the first adhesive layer.

[0014] In the embodiment of this application, the second heat-conducting part is bonded to the sidewall through the first adhesive layer, which can reduce the difficulty of connecting the second heat-conducting part and the sidewall, and improve the stability of the second heat-conducting part.

[0015] In some embodiments, the thickness L1 of the adhesive layer satisfies L1≥0.5mm.

[0016] In these embodiments, when the thickness of the adhesive layer meets the above conditions, the adhesive layer creates a sufficient gap between the second thermally conductive part and the sidewall to accommodate the expansion deformation of the housing, thereby reducing the risk of the thermally conductive component bursting due to the expansion of the battery cell.

[0017] In some embodiments, the first adhesive layer is spaced apart from one end of the first heat-conducting portion and the edge of the sidewall in a first direction.

[0018] In the embodiment of this application, the first adhesive layer is spaced apart from the edge of the sidewall at one end facing the first heat-conducting part, so as to facilitate the deformation of the second heat-conducting part together with the shell during the expansion of the battery cell, thereby reducing the risk of the heat-conducting component being burst during the expansion of the battery cell.

[0019] In some embodiments, the minimum distance between the end of the first adhesive layer facing the first heat-conducting part in the first direction and the edge of the sidewall is greater than or equal to 10 mm.

[0020] In the embodiment of this application, when the minimum distance between the end of the first adhesive layer facing the first heat-conducting part in the first direction and the edge of the sidewall satisfies the above conditions, it can facilitate the deformation of the second heat-conducting part together with the shell during the expansion of the battery cell, reduce the risk of the heat-conducting component being burst during the expansion of the battery cell, and reduce the processing cost of the battery cell.

[0021] In some embodiments, the sidewall includes two first sidewalls and two second sidewalls. The two first sidewalls are disposed opposite each other in a second direction, and the two second sidewalls are disposed opposite each other in a third direction. The first direction, the second direction, and the third direction intersect each other. The area of ​​the first sidewall is larger than the area of ​​the second sidewall. At least two second heat-conducting portions are disposed on the first sidewall and the second sidewall, wherein each of the second heat-conducting portions disposed on the first sidewall and the second sidewall is independent of each other.

[0022] In the embodiment of this application, at least two second heat-conducting parts are disposed on the first sidewall and the second sidewall, and each second heat-conducting part disposed on the first sidewall and the second sidewall is independent of each other, so that during the expansion of the battery cell, the two second heat-conducting parts disposed on the first sidewall and the second sidewall move independently of each other, thereby reducing the risk of the heat-conducting component bursting.

[0023] In some embodiments, the minimum distance L2 between the second heat-conducting portion disposed on the first sidewall and the adjacent second sidewall in the third direction satisfies L2≥10mm; and / or the minimum distance L3 between the second heat-conducting portion disposed on the second sidewall and the adjacent first sidewall in the second direction satisfies L3≥10mm.

[0024] In the embodiments of this application, when the minimum distance between the second heat-conducting part disposed on the first sidewall and the adjacent second sidewall in the third direction, and / or the minimum distance between the second heat-conducting part disposed on the second sidewall and the adjacent first sidewall in the second direction satisfies the above conditions, it is convenient for the second heat-conducting part and the shell to deform together during the expansion of the battery cell, so as to reduce the risk of the heat-conducting component bursting. Increasing the distance between the second heat-conducting parts disposed on the first sidewall and the second sidewall can reduce the risk of the two second heat-conducting parts being squeezed and damaged during the deformation of the second heat-conducting part caused by the expansion of the shell, and improve the service life of the heat-conducting component.

[0025] In some embodiments, the heat-conducting component further includes a third heat-conducting part, which is connected to the second heat-conducting part and is disposed on the bottom wall.

[0026] In the embodiment of this application, the heat-conducting component further includes a third heat-conducting component connected to the second heat-conducting component. The third heat-conducting component is disposed on the bottom wall. Through the third heat-conducting component, the heat at the end cap assembly can be transferred to the bottom wall and conducted to the external environment through the first and second heat-conducting components. The third heat-conducting component can increase the contact area between the heat-conducting component and the external environment, improve the heat conduction performance of the heat-conducting component, enhance the heat exchange efficiency between the end cap assembly and the external environment, and enhance the heat conduction performance at the bottom wall of the battery cell. The heat-conducting component can better balance the temperature of the battery cell and improve the performance of the battery device.

[0027] In some embodiments, the bottom wall includes a first part and a second part, a third heat-conducting part is disposed in the first part, and the second part is used to connect with other components.

[0028] In the embodiment of this application, the bottom wall includes a first part and a second part. A third heat-conducting part disposed in the first part is used to conduct heat. The battery cell is connected to the mounting position through the second part to fix the battery cell.

[0029] In some embodiments, the sidewalls and bottom wall are connected with rounded corners, and the rounded corners and thermal conductive components are spaced apart.

[0030] In the embodiments of this application, the sidewalls and bottomwalls are connected with rounded corners, and the rounded corners and the heat-conducting components are spaced apart, so that there is a gap between the shell and the heat-conducting components that can accommodate the expansion and deformation of the shell, thereby reducing the risk of the heat-conducting components bursting due to the expansion of the battery cells.

[0031] In some embodiments, the thermally conductive component further includes an adhesive layer, which includes a second adhesive layer, and the third thermally conductive portion is bonded to the bottom wall through the second adhesive layer.

[0032] In the embodiment of this application, the third heat-conducting part is bonded to the bottom wall through the second adhesive layer to improve the stability of the third heat-conducting part.

[0033] In some embodiments, the second adhesive layer is spaced apart from one end of the second heat-conducting portion and the edge of the bottom wall.

[0034] In the embodiment of this application, the second adhesive layer is spaced apart from the edge of the bottom wall at one end facing the second heat-conducting part, so as to facilitate the movement of the second heat-conducting part together with the casing during the expansion of the battery cell, thereby reducing the risk of the heat-conducting component being burst during the expansion of the battery cell.

[0035] In some embodiments, the minimum distance between the end of the second adhesive layer facing the second heat-conducting part and the edge of the bottom wall is greater than or equal to 10 mm.

[0036] In the embodiments of this application, when the minimum distance between the end of the second adhesive layer facing the second heat-conducting part and the edge of the bottom wall satisfies the above conditions, it is convenient for the second heat-conducting part and the shell to deform synchronously during the expansion of the battery cell, so as to reduce the risk of the heat-conducting component bursting, and also reduce the processing cost of the battery cell.

[0037] In some embodiments, the thermally conductive component further includes an adhesive layer, which includes a third adhesive layer, and the first thermally conductive portion is bonded to the end cap component through the third adhesive layer.

[0038] In the embodiment of this application, the first heat-conducting part is bonded to the end cap assembly through a third adhesive layer to improve the stability of the first heat-conducting part.

[0039] In some embodiments, the third adhesive layer is spaced apart from one end of the second thermally conductive portion and the edge of the end cap assembly.

[0040] In the embodiment of this application, the third adhesive layer is spaced apart from the edge of the end cap assembly at one end facing the second heat-conducting part, so as to facilitate the movement of the second heat-conducting part together with the casing during the expansion of the battery cell and reduce the risk of the heat-conducting component being burst during the expansion of the battery cell.

[0041] In some embodiments, the minimum distance between the end of the third adhesive layer facing the second thermal conductive part and the edge of the end cap assembly is greater than or equal to 10 mm.

[0042] In the embodiment of this application, when the minimum distance between the end of the third adhesive layer facing the second heat-conducting part and the edge of the end cap assembly satisfies the above conditions, it not only facilitates the synchronous deformation of the second heat-conducting part and the shell during the expansion of the battery cell, thereby reducing the risk of the heat-conducting component bursting, but also reduces the processing cost of the battery cell.

[0043] In some embodiments, the end cap assembly includes a cover plate and electrode terminals disposed on the cover plate, the electrode terminals being connected to an electrode assembly, and a first heat-conducting portion being connected to the electrode terminals.

[0044] In the embodiment of this application, the electrode terminals and the electrode assembly are connected. The temperature of the electrode terminals is higher than that of the cover plate. Therefore, the connection between the first heat-conducting part and the electrode terminals can improve the heat conduction rate between the end cover assembly and the heat-conducting assembly, so as to better balance the internal temperature of the battery device and improve the performance of the battery device.

[0045] In some embodiments, the battery cell further includes a first insulating layer disposed on the outer surface of the housing and end cap assembly, and a thermal conductive component disposed on the side of the first insulating layer away from the housing and end cap assembly.

[0046] In the embodiments of this application, the battery cell further includes a first insulating layer disposed on the outer surface of the housing and end cap assembly, and a heat-conducting component disposed on the side of the first insulating layer away from the housing and end cap assembly, so as to insulate the battery cell, the housing and the heat-conducting component from each other.

[0047] In some embodiments, the thermally conductive assembly includes an insulating element and a thermally conductive element. The insulating element forms a receiving cavity in at least a portion of its area. The thermally conductive element is disposed within the receiving cavity. The thermally conductive element includes a first thermally conductive sheet and a second thermally conductive sheet that are interconnected. The first thermally conductive sheet is disposed on the end cap assembly, and the second thermally conductive sheet is disposed on the sidewall. The first thermally conductive portion is composed of the first thermally conductive sheet and the insulating element, and the second thermally conductive portion is composed of the second thermally conductive sheet and the insulating element.

[0048] In the embodiment of this application, the heat-conducting component includes an insulating component and a heat-conducting component. At least a portion of the insulating component forms a receiving cavity, and the heat-conducting component is disposed within the receiving cavity. The heat-conducting component includes a first heat-conducting sheet and a second heat-conducting sheet that are interconnected. The first heat-conducting sheet is disposed on the end cap assembly to conduct heat from the end cap assembly, and the second heat-conducting sheet is disposed on the side wall to conduct heat from the first heat-conducting sheet and the housing. The first heat-conducting part is composed of the first heat-conducting sheet and the insulating component, and the second heat-conducting part is composed of the second heat-conducting sheet and the insulating component. In this way, the insulating component can insulate the heat-conducting component and the electrode body, and the heat-conducting component can improve the heat conduction rate between the end cap assembly and the external environment.

[0049] In some embodiments, an insulating element is disposed on the outer surface of the end cap assembly and the housing.

[0050] In the embodiments of this application, insulating components are disposed on the outer surfaces of the end cap assembly and the housing to insulate the battery cells and the housing, as well as adjacent battery cells, from each other, eliminating the need for additional insulating blue film and reducing the manufacturing cost of the battery cells.

[0051] In some embodiments, the battery cell further includes a second insulating layer, which is connected to an insulating element, and the insulating element and the second insulating layer together cover the outer surface of the housing and end cap assembly.

[0052] In these embodiments, the second insulating layer and the insulating element are connected, and the insulating element and the second insulating layer together cover the outer surface of the housing and end cap assembly. The combination of the second insulating layer and the insulating element achieves insulation of the battery cell, which also helps to reduce the size of the second insulating layer, reduce the manufacturing cost of the battery cell, and help to reduce the weight of the battery cell and increase the energy density of the battery cell.

[0053] In some embodiments, the end cap assembly includes a cover plate and a pressure relief mechanism disposed on the cover plate, with an insulating member having a first opening through which the pressure relief mechanism is exposed.

[0054] In the embodiment of this application, the insulating member is provided with a first opening through it, so that the pressure relief mechanism can be exposed through the first opening, thereby reducing the risk that the insulating member will hinder the activation of the pressure relief mechanism and improving the reliability of the battery cell.

[0055] In some embodiments, the battery device further includes a heat exchange mechanism disposed within the housing. The housing includes a bottom wall and side walls connected to each other. The bottom wall and an opening are disposed opposite to each other. An insulating member is provided with a second opening through which the heat exchange mechanism is connected to the bottom wall.

[0056] In the embodiment of this application, the insulating member is provided with a second opening through it, so that the heat exchange mechanism can be stably connected to the bottom wall of the battery cell through the second opening.

[0057] In some embodiments, the sidewall includes two first sidewalls and two second sidewalls. The two first sidewalls are disposed opposite each other in a second direction, and the two second sidewalls are disposed opposite each other in a third direction. The first direction, the second direction, and the third direction intersect each other. The area of ​​the first sidewall is larger than the area of ​​the second sidewall. At least two second heat-conducting sheets are disposed on the first sidewall and the second sidewall respectively, wherein each second heat-conducting sheet disposed on the first sidewall and the second sidewall is independent of each other.

[0058] In the embodiment of this application, at least two second heat-conducting sheets are respectively disposed on the first sidewall and the second sidewall, and each second heat-conducting sheet disposed on the first sidewall and the second sidewall is independent of each other, so that during the expansion of the battery cell, the two second heat-conducting sheets disposed on the first sidewall and the second sidewall can move independently of each other, thereby reducing the risk of the heat-conducting component being burst.

[0059] In some embodiments, the heat-conducting element further includes a third heat-conducting sheet, which is connected to the second heat-conducting sheet and is disposed on the bottom wall.

[0060] In the embodiment of this application, the heat-conducting component further includes a third heat-conducting sheet connected to the second heat-conducting sheet. The third heat-conducting sheet is disposed on the bottom wall. By increasing the volume of the heat-conducting component, the heat conduction performance of the heat-conducting component is improved, so as to better conduct the heat at the end cap component through the heat-conducting component.

[0061] In some embodiments, the thickness D1 of the heat-conducting element satisfies 40μm≤D1≤180μm.

[0062] In the solution of this application embodiment, when the above conditions are met, it can not only improve the problem that the battery cell volume is too large and the energy density is reduced due to the excessive thickness of the heat-conducting component, but also improve the problem that the heat-conducting component is easily damaged due to the excessive thinness of the heat-conducting component.

[0063] In some embodiments, the insulating element comprises polyethylene, polypropylene, polyimide, or polyester resin.

[0064] In the embodiments of this application, the insulating component includes polyethylene, polypropylene, polyimide, or polyester resin to improve the insulation reliability of the insulating component.

[0065] In some embodiments, the thermally conductive element comprises graphite, graphene, or carbon nanotubes.

[0066] In the embodiments of this application, the thermal conductive component includes graphite, graphene, or carbon nanotubes, and the thermal conductivity of the thermal conductive component is improved by using graphite, graphene, or carbon nanotube thermal conductive materials.

[0067] In some embodiments, the thermal conductivity k of the heat-conducting element satisfies k≥500W / (m·K).

[0068] In the embodiments of this application, when the thermal conductivity k of the heat-conducting component satisfies the above conditions, the heat-conducting component has sufficient thermal conductivity to conduct the heat of the electrode body.

[0069] Secondly, embodiments of this application provide a battery device, including a housing and a battery cell as described in the first aspect embodiment, wherein the battery cell is disposed within the housing.

[0070] In the embodiment of this application, the battery cell is disposed in the housing, which serves to accommodate the battery cell. The battery cell includes a heat-conducting component. An external heat-conducting channel for the battery cell is established by a first heat-conducting part disposed on the side surface of the end cap assembly away from the electrode assembly and a second heat-conducting part disposed on the side wall. This reduces the thermal resistance at the end cap assembly and the side wall, increases the rate of heat exchange between the battery cell and the external environment, and improves the problem of adverse effects on the performance and service life of the battery cell due to excessively high or low temperatures, thereby improving the performance of the battery device.

[0071] In some embodiments, the battery device further includes a heat exchange mechanism disposed within the housing, and the heat-conducting components and the heat exchange mechanism are thermally connected.

[0072] In the embodiments of this application, the battery device further includes a heat exchange mechanism disposed inside the housing. The heat conduction component and the heat exchange mechanism are thermally connected to improve the heat exchange rate between the battery cells and the heat exchange mechanism, so as to better balance the temperature of the battery cells and improve the performance of the battery device.

[0073] In some embodiments, the sidewall includes two first sidewalls and two second sidewalls. The two first sidewalls are disposed opposite each other in a second direction, and the two second sidewalls are disposed opposite each other in a third direction. The first direction, the second direction, and the third direction intersect each other. The area of ​​the first sidewall is larger than the area of ​​the second sidewall. The heat exchange mechanism and the first sidewall are spaced apart along the second direction. At least one second heat-conducting part is disposed between the first sidewall and the heat exchange mechanism. Alternatively, the heat exchange mechanism and the second sidewall are spaced apart along the third direction, and at least one second heat-conducting part is disposed between the second sidewall and the heat exchange mechanism.

[0074] In the embodiments of this application, the heat exchange mechanism and the first sidewall are spaced apart along the second direction, and at least one second heat-conducting part is disposed between the first sidewall and the heat exchange mechanism, or the heat exchange mechanism and the second sidewall are spaced apart along the third direction, and at least one second heat-conducting part is disposed between the second sidewall and the heat exchange mechanism, so as to shorten the distance between the heat-conducting component and the heat exchange mechanism, so as to better transfer heat between the heat exchange mechanism and the end cap assembly through the heat-conducting component, so as to better balance the temperature of the battery cell and improve the performance of the battery device.

[0075] In some embodiments, the heat-conducting component further includes a third heat-conducting part, which is connected to the second heat-conducting part. The third heat-conducting part is disposed on the bottom wall, and the heat exchange mechanism is disposed on the side of the third heat-conducting part away from the bottom wall.

[0076] In the embodiments of this application, when the heat exchange mechanism is disposed on the bottom wall of the battery cell, the third heat conduction part can transfer the heat at the end cap assembly to the heat exchange mechanism, so as to better balance the heat at the end cap assembly, balance the internal temperature of the battery device, and improve the performance of the battery device.

[0077] In some embodiments, at least two battery cells are thermally connected to the same thermally conductive component.

[0078] In the embodiments of this application, at least two battery cells are thermally connected to the same thermally conductive component to reduce the difficulty of matching the thermally conductive component and the battery cells.

[0079] Thirdly, embodiments of this application provide an electrical device, including the battery device described in the second aspect of the embodiment above. Attached Figure Description

[0080] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0081] Figure 1 is a structural schematic diagram of a vehicle provided in an embodiment of this application;

[0082] Figure 2 is a schematic diagram of the structure of a battery device provided in an embodiment of this application;

[0083] Figure 3 is a schematic diagram of the structure of a battery module provided in one embodiment of the application;

[0084] Figure 4 is an exploded view of a single battery cell provided in an embodiment of this application;

[0085] Figure 5 is a partial structural schematic diagram of a battery cell provided in an embodiment of this application;

[0086] Figure 6 is a schematic diagram of the structure of a battery cell provided in an embodiment of this application;

[0087] Figure 7 is a schematic diagram of the structure of a battery cell provided in an embodiment of this application;

[0088] Figure 8 is a schematic diagram of the structure of a battery cell provided in an embodiment of this application;

[0089] Figure 9 is a schematic diagram of the structure of a battery cell provided in an embodiment of this application;

[0090] Figure 10 is a partial structural schematic diagram of a battery cell provided in an embodiment of this application;

[0091] Figure 11 is a side view of a battery cell provided in an embodiment of this application;

[0092] Figure 12 is a side view of a battery cell provided in an embodiment of this application;

[0093] Figure 13 is a schematic diagram of the structure of a battery cell provided in an embodiment of this application;

[0094] Figure 14 is a schematic diagram of the structure of a battery cell provided in an embodiment of this application;

[0095] Figure 15 is a bottom view of a battery cell provided in an embodiment of this application;

[0096] Figure 16 is a top view of a battery cell provided in an embodiment of this application;

[0097] Figure 17 is a schematic diagram of the structure of a battery cell provided in an embodiment of this application;

[0098] Figure 18 is a schematic diagram of the structure of a battery cell provided in an embodiment of this application;

[0099] Figure 19 is a cross-sectional view of the thermal conductive assembly of a battery cell provided in an embodiment of this application;

[0100] Figure 20 is a schematic diagram of the structure of a battery cell provided in an embodiment of this application;

[0101] Figure 21 is a schematic diagram of the structure of a battery cell provided in an embodiment of this application;

[0102] Figure 22 is a schematic diagram of the structure of a battery device provided in an embodiment of this application;

[0103] Figure 23 is a schematic diagram of the structure of a battery cell provided in an embodiment of this application;

[0104] Figure 24 is a schematic diagram of the structure of a battery device provided in an embodiment of this application;

[0105] Figure 25 is an enlarged structural diagram of point A in Figure 24;

[0106] Figure 26 is a partial structural schematic diagram of a battery device provided in an embodiment of this application;

[0107] Figure 27 is an enlarged structural diagram of point B in Figure 26;

[0108] Figure 28 is a partial structural schematic diagram of a battery device provided in an embodiment of this application.

[0109] Figure label:

[0110] 1. Vehicle; 101. Motor; 102. Controller; 2. Battery Unit; 201. Battery Module; 202. Housing; 2021. First Housing; 2022. Second Housing;

[0111] 3. Battery cells;

[0112] 4. Shell; 41. Opening; 42. Side wall; 43. Bottom wall; 421. First side wall; 422. Second side wall; 431. First part; 432. Second part;

[0113] 5. Electrode assembly; 51. Electrode tab; 52. Electrode body;

[0114] 6. End cap assembly; 61. Cover plate; 62. Electrode terminal; 63. Pressure relief mechanism;

[0115] 7. Thermally conductive component; 71. First thermally conductive part; 72. Second thermally conductive part; 73. Third thermally conductive part; 74. Adhesive layer; 741. First adhesive layer; 742. Second adhesive layer; 743. Third adhesive layer; 75. Insulating component; 76. Thermally conductive component; 761. First thermally conductive sheet; 762. Second thermally conductive sheet; 763. Third thermally conductive sheet; 751. First opening; 752. Second opening; 77. Receiving cavity;

[0116] 8. Heat exchange mechanism;

[0117] 91. First insulating layer; 92. Second insulating layer;

[0118] X, first direction; Y, second direction; Z, third direction. Detailed Implementation

[0119] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0120] It should be noted that, unless otherwise stated, the technical or scientific terms used in the embodiments of this application should have the ordinary meaning understood by those skilled in the art to which the embodiments of this application pertain.

[0121] In the description of the embodiments of this application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0122] Furthermore, technical terms such as "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. In the description of the embodiments of this application, "a plurality of" means two or more, unless otherwise explicitly defined.

[0123] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0124] In the description of the embodiments of this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0125] Currently, judging from market trends, the application of battery devices is becoming increasingly widespread. Battery devices are not only used in energy storage power systems such as hydropower, thermal power, wind power, and solar power plants, but also widely applied in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. With the continuous expansion of battery device applications, market demand is also constantly increasing.

[0126] During the use of a battery cell, there is a problem where the cell temperature is too high or too low, causing the battery cell performance to fail to meet the expected requirements.

[0127] The reason for the above problem is that during the operation of the battery device, the end cap assembly of the battery cell generates a large amount of heat due to overcurrent. This heat cannot be dissipated to the external environment in time, which causes the electrode assembly to be heated in reverse, resulting in the battery cell reaching the current-limiting temperature too early, thus affecting the performance of the battery cell and consequently having an adverse effect on the performance and service life of the battery device.

[0128] Based on the above problems, this application provides a battery cell, which includes a housing, an end cap assembly, and an electrode assembly. The housing includes a bottom wall, a side wall, and a cavity enclosed by the bottom wall and the side wall, with one end open in a first direction. The electrode assembly is housed within the housing. The end cap assembly covers the opening of the housing and connects to the electrode assembly, enabling the electrode assembly to form a circuit with external devices through the end cap assembly. The heat-conducting assembly includes a first heat-conducting part and a second heat-conducting part. The thermal conductivity of the heat-conducting assembly is greater than that of the end cap assembly and the housing. By providing the first heat-conducting part on the side surface of the end cap assembly away from the electrode assembly, an external heat-conducting channel is established for the battery cell to reduce the thermal resistance at the end cap assembly. By providing the second heat-conducting part on the side wall, the total area of ​​the heat-conducting assembly is increased, thereby increasing the rate of heat exchange between the battery cell and the external environment and improving the problem of adverse effects on the performance and service life of the battery cell due to excessively high or low temperatures.

[0129] The technical solutions described in the embodiments of this application are applicable to battery devices and electrical devices that use battery devices.

[0130] Electrical devices can include vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools, etc. Vehicles can be gasoline-powered cars, natural gas-powered cars, or new energy vehicles; new energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Power 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, etc. This application does not impose any special limitations on the above-mentioned electrical devices.

[0131] In this embodiment of the application, the battery cell can be a secondary battery, which refers to a battery cell that can be recharged to activate the active materials and continue to be used after the battery cell has been discharged.

[0132] The battery cell can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and this application embodiment is not limited to this. The battery cell can be cylindrical, flat, cuboid, or other shapes, and this application embodiment is not limited to this either.

[0133] The battery device mentioned in the embodiments of this application refers to a single physical module comprising one or more battery cells to provide higher voltage and capacity. For example, the battery device mentioned in this application may include a battery module or a battery pack. A battery pack generally includes a housing for encapsulating one or more battery cells. The housing can prevent liquids or other foreign matter from affecting the charging or discharging of the battery cells.

[0134] A single battery cell includes electrode components and an electrolyte. The electrode components include a positive electrode, a negative electrode, and a separator. The battery cell primarily functions by the movement of metal ions between the positive and negative electrode components. The positive electrode includes a positive current collector and a positive active material layer, the latter coated on the surface of the current collector. The current collector includes a positive current-collecting section and a positive electrode tab connected to it. The current-collecting section is coated with the positive active material layer, while the tab is not. Taking a lithium-ion battery as an example, the positive current collector can be made of aluminum, and the positive active material layer includes the positive active material, which can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc. The negative electrode sheet includes a negative current collector and a negative active material layer, the negative active material layer being coated on the surface of the negative current collector. The negative current collector includes a negative current collection section and a negative electrode tab connected to the negative current collection section. The negative current collection section is coated with the negative active material layer, while the negative electrode tab is not coated with the negative active material layer. The material of the negative current collector can be copper, and the negative active material layer includes negative active material, which can be carbon or silicon, etc. The material of the separator can be PP (polypropylene) or PE (polyethylene), etc.

[0135] It should be understood that the technical solutions described in the embodiments of this application are not limited to the battery devices and electrical equipment described above, but can also be applied to all battery devices including housings and electrical equipment using battery devices. However, for the sake of brevity, the following embodiments are all illustrated using electric vehicles as examples.

[0136] Please refer to Figure 1, which is a schematic diagram of the structure of a vehicle 1 provided in some embodiments of this application. Vehicle 1 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery device 2 is installed inside vehicle 1, and the battery device 2 can be located at the bottom, front, or rear of vehicle 1. The battery device 2 can be used to power vehicle 1; for example, the battery device 2 can serve as the operating power source for vehicle 1. Vehicle 1 may also include a controller 102 and a motor 101. The controller 102 is used to control the battery to supply power to the motor 101, for example, to meet the power needs of vehicle 1 during starting, navigation, and driving.

[0137] In some embodiments of this application, the battery device 2 can not only serve as the operating power source for the vehicle 1, but also as the driving power source for the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0138] Figure 2 shows a schematic diagram of the structure of a battery device according to an embodiment of this application.

[0139] The battery device 2 mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells 3, which are connected in series, parallel, or mixed connections via a busbar.

[0140] In some embodiments, the battery cell assembly is typically formed by arranging a plurality of battery cells 3.

[0141] As an example, the battery cell assembly can be a battery module 201, which is formed by arranging and fixing multiple battery cells 3 to form an independent module. As an example, the battery module 201 can be formed by binding multiple battery cells 3 together with cable ties.

[0142] In some embodiments, the battery device may be a battery pack, which includes a housing 202 and one or more battery cell assemblies housed in the housing 202.

[0143] As an example, the battery cell assembly can be a battery module 201, which can be housed in the housing by fixing the battery module 201 in the housing.

[0144] As an example, the battery cell assembly can also be housed in the housing 202 by directly fixing multiple battery cells 3 to the housing 202.

[0145] As an example, the housing 202 may include a first housing 2021 and a second housing 2022. The first housing 2021 and the second housing 2022 are fastened together, forming a closed space inside the housing 202 to house the battery cell assembly. Here, "closed" refers to covering or closing, which can be sealed or unsealed. The first housing 2021 may be a top cover or a bottom plate.

[0146] As an example, the housing 202 may include a top cover, a frame, and a bottom plate. The top cover and the bottom plate are respectively connected to the frame, so that the interior of the housing 202 forms an enclosed space to accommodate the battery cell assembly.

[0147] In some embodiments, the housing 202 may be part of the vehicle's chassis structure. For example, a portion of the housing 202 may be at least a portion of the vehicle's floor, or a portion of the housing 202 may be at least a portion of the vehicle's crossbeams and longitudinal beams.

[0148] Figure 3 shows a schematic diagram of the structure of a battery module 201 according to an embodiment of this application.

[0149] In some embodiments, as shown in Figures 2 and 3, there are multiple battery cells 3, which are first connected in series, parallel, or mixed to form a battery module 201. The multiple battery modules 201 are then connected in series, parallel, or mixed to form a whole and housed in a housing 202.

[0150] Multiple battery cells 3 in the battery module 201 can be electrically connected through a busbar component to achieve parallel, series, or mixed connection of multiple battery cells 3 in the battery module 201.

[0151] Figure 4 is an exploded view of a battery cell according to an embodiment of this application. The battery cell 3 refers to the smallest unit that makes up the battery device. As shown in Figure 4, the battery cell 3 includes an end cap assembly 6, a housing 4, and an electrode assembly 5.

[0152] Electrode assembly 5 is the component in the battery cell 3 where electrochemical reactions occur. The casing 4 may contain one or more electrode assemblies 5. Electrode assembly 5 is mainly formed by winding or stacking electrode sheets, which are divided into positive and negative electrode sheets, and a separator is usually provided between the positive and negative electrode sheets. The portions of the positive and negative electrode sheets containing active material constitute the electrode body 52, while the portions of the positive and negative electrode sheets without active material each constitute a tab 51. The positive and negative tabs can be located together at one end of the electrode body 52 or separately at both ends of the electrode body 52. ​​During the charging and discharging process of the battery cell 3, the positive and negative active materials react with the electrolyte, and the tabs 51 connect to the electrode terminals to form a current loop.

[0153] The electrode assembly 5 can be a wound structure, a stacked structure, or a hybrid structure of wound and stacked.

[0154] In some embodiments, the electrode assembly 5 is a wound structure. The positive electrode and the negative electrode are wound into a wound structure.

[0155] In some embodiments, the electrode assembly 5 is a stacked structure. As an example, multiple positive and negative electrodes can be provided, with multiple positive and multiple negative electrodes stacked alternately. Multiple spacers can be provided and respectively provided between any adjacent positive or negative electrodes. Alternatively, the spacers can be provided continuously and provided between any adjacent positive or negative electrodes by folding.

[0156] In some embodiments, the electrode assembly 5 may be cylindrical, flat, or polygonal, etc.

[0157] In some embodiments, the electrode assembly 5 is provided with tabs that can conduct current from the electrode assembly. The tabs include a positive tab and a negative tab.

[0158] The battery cell 3 may include a housing 4. The housing 4 is an assembly used to cooperate with the end cap assembly 6 to form the internal environment of the battery cell 3, wherein the formed internal environment can accommodate the electrode assembly 5, electrolyte (not shown in the figure), and other components. The housing 4 can be a steel housing, an aluminum housing, a plastic housing (such as polypropylene), a composite metal housing (such as a copper-aluminum composite housing), or an aluminum-plastic film, etc. In some embodiments, the housing 4 can be a sealed structure or a non-sealed structure. As an example, when the housing 4 is a non-sealed structure, the housing 4 serves to protect the electrode assembly 5, and a sealing bag is also included between the housing 4 and the electrode assembly 5. The sealing bag is used to encapsulate the electrode assembly and electrolyte. Specifically, the sealing bag can be a bag-shaped insulating material or an aluminum-plastic film. When the housing 4 is a sealed structure, it is used to encapsulate the electrode assembly 5 and electrolyte, etc.

[0159] As an example, the battery cell 3 can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes. Prismatic battery cells include prismatic battery cells, blade-shaped battery cells, and multi-prismatic batteries, such as hexagonal prismatic batteries. This application does not have any particular limitations.

[0160] The housing 4 and the end cap assembly 6 can be independent components. One or more openings 41 can be provided on the housing 4, and one or more end cap assemblies 6 can close the openings 41 to form the internal environment of the battery cell 3. Optionally, the end cap assembly 6 and the housing 4 can also be integrated. Optionally, the end cap assembly 6 and the housing 4 can form a common connection surface before other components are inserted into the housing, and the end cap assembly 6 closes the housing 4 when it is necessary to encapsulate the interior of the housing 4.

[0161] In some embodiments, the electrode terminal 62 can be disposed on the end cap assembly 6 or on the housing 4, and the electrode terminal 62 is electrically connected to the electrode tab 51. The electrode terminal 62 can be directly connected to the electrode tab 51 or indirectly connected to the electrode tab 51 through an adapter mechanism.

[0162] Please refer to Figures 5, 6, and 7. Figure 5 is a partial structural schematic diagram of a battery cell provided in an embodiment of this application; Figure 6 is a structural schematic diagram of a battery cell provided in an embodiment of this application; Figure 7 is a structural schematic diagram of a battery cell provided in an embodiment of this application; and Figure 8 is a structural schematic diagram of a battery cell provided in an embodiment of this application.

[0163] In a first aspect, as shown in Figures 4 to 8, this application provides a battery cell 3, which includes a housing 4, an end cap assembly 6, and an electrode assembly 5. The housing 4 includes a bottom wall 43, a side wall 42, and a cavity enclosed by the bottom wall 43 and the side wall 42, which is open at one end in a first direction X. The electrode assembly 5 is disposed in the cavity, and the end cap assembly 6 is closed to the opening 41. The electrode assembly 5 and the end cap assembly 6 are connected. The thermal conductive assembly 7 includes a first thermal conductive part 71 and a second thermal conductive part 72 connected to each other. The first thermal conductive part 71 is disposed on the side surface of the end cap assembly 6 away from the electrode assembly 5, and the second thermal conductive part 72 is disposed on the side wall 42. The thermal conductivity of the thermal conductive assembly 7 is greater than that of the end cap assembly 6 and the housing 4.

[0164] In the embodiment of this application, the battery cell 3 includes a housing 4, an end cap assembly 6, and an electrode assembly 5. The housing 4 includes a bottom wall 43, a side wall 42, and a cavity enclosed by the bottom wall 43 and the side wall 42 with an opening 41 at one end in a first direction X. The electrode assembly 5 is housed within the housing 4. The end cap assembly 6 covers the opening 41 of the housing 4 and is connected to the electrode assembly 5, so that the electrode assembly 5 can form a circuit with external devices through the end cap assembly 6. The heat-conducting assembly 7 includes a first heat-conducting part 71 and a second heat-conducting part 72. The thermal conductivity of the heat-conducting component 7 is greater than that of the end cap assembly 6 and the housing 4. An external heat-conducting channel for the battery cell 3 is established by the first heat-conducting part 71 disposed on the side surface of the end cap assembly 6 away from the electrode assembly 5, so as to reduce the thermal resistance at the end cap assembly 6. The total area of ​​the heat-conducting component 7 is increased by the second heat-conducting part 72 disposed on the side wall 42, thereby increasing the rate of heat exchange between the battery cell 3 and the external environment and improving the problem that the battery cell 3 is adversely affected by excessively high or low temperature.

[0165] The heat-conducting component 7 includes a first heat-conducting part 71, which is disposed on the side surface of the end cap assembly 6 facing away from the electrode assembly 5. This allows the heat-conducting component 7 to transfer the heat from the end cap assembly 6 to the external environment more quickly in high-temperature environments, thereby improving the problem of the end cap assembly 6 heating the electrode assembly 5 in reverse, causing the battery cell 3 to reach the current-limiting temperature too quickly and affecting the performance of the battery cell 3. Alternatively, in low-temperature environments, the heat-conducting component 7 can transfer the heat from the external environment to the end cap assembly 6 more quickly, thereby increasing the temperature of the electrode assembly 5 through the end cap assembly 6, thus improving the problem of the battery cell 3 experiencing a decrease in capacity and pulse performance due to low temperature.

[0166] The thermal conductivity of the thermally conductive component 7 is greater than that of the end cap component 6 and the housing 4. The thermally conductive component 7 may include copper, copper alloy, silver, silver alloy, graphite, graphene, or carbon nanotubes, etc.

[0167] For example, the first direction X is the height direction of the battery cell 3.

[0168] Optionally, the first heat-conducting part 71 and the end cap assembly 6 can be connected by adhesive bonding or abutment.

[0169] The first heat-conducting part 71 is thermally connected to the end cap assembly 6. Specifically, the first heat-conducting part 71 is directly attached to or abuts against the end cap assembly 6; or the first heat-conducting part 71 is a plating layer disposed on the end cap assembly 6; or the first heat-conducting part 71 and the end cap assembly 6 are spaced apart, and the first heat-conducting part 71 is indirectly connected to the end cap assembly 6 through a heat-conducting medium, which can be air, metal, or heat-conducting adhesive, etc.

[0170] The first heat-conducting part 71 can be in the form of a strip, a flat plate, or a mesh, etc. The first heat-conducting part 71 can be rectangular, circular, or rhomboid, etc. The specific shape and size of the first heat-conducting part 71 can be flexibly designed.

[0171] Optionally, multiple first heat-conducting parts 71 are spaced apart on the end cap assembly 6, which can conduct heat from the end cap assembly 6 through the first heat-conducting parts 71, while also reducing the size of the heat-conducting assembly 7 and lowering the manufacturing cost of the battery cell 3.

[0172] Optionally, one end of the first heat-conducting part 71 is connected to the end cap assembly 6, and the other end extends out of the end cap assembly 6, so as to increase the contact area between the heat-conducting component 7 and the external environment and improve the heat conduction rate of the heat-conducting component 7.

[0173] Optionally, the first heat-conducting part 71 is disposed around the peripheral edge of the end cap assembly 6 to increase the contact area between the heat-conducting assembly 7 and the end cap assembly 6, thereby improving the heat exchange efficiency between the heat-conducting assembly 7 and the end cap assembly 6.

[0174] Optionally, a second heat-conducting part is disposed on the side surface of the sidewall 42 opposite to the electrode assembly 5, so that the second heat-conducting part 72 helps to transfer the heat of the housing 4 to the external environment.

[0175] The battery device may also include a heat exchange mechanism 8, which is typically located on the side wall 42 of the housing 4. By connecting to the first heat-conducting part 71 and being located on the side wall 42, the distance between the heat-conducting component 7 and the heat exchange mechanism 8 can be shortened to enhance the heat exchange rate between the end cap assembly 6 and the heat exchange mechanism 8.

[0176] The second heat-conducting part 72 is disposed on the side wall 42, and the second heat-conducting part 72 and the side wall 42 abut against each other or adhere to each other, or the second heat-conducting part 72 and the side wall 42 are disposed at intervals, and the two are connected by a heat-conducting medium, which can be air or a heat-conducting colloid, etc.

[0177] Optionally, the first heat-conducting part 71 and the second heat-conducting part 72 are prepared separately and bonded together to facilitate adjustment of the shape and size of the first heat-conducting part 71 and the second heat-conducting part 72; or the first heat-conducting part 71 and the second heat-conducting part 72 are integrally formed and obtained by bending the same substrate to reduce the processing difficulty of the heat-conducting component 7.

[0178] During the operation of the battery cell 3, the temperature of the end of the housing 4 near the end cap assembly 6 is relatively high, while the temperature of the end away from the end cap assembly 6 is relatively low. The second heat-conducting part 72 provided on the side wall 42 can conduct and equalize the temperature of the battery cell 3 in the first direction X.

[0179] Optionally, in the first direction X, the second heat-conducting part 72 extends to both ends of the sidewall 42.

[0180] Optionally, multiple second heat-conducting parts 72 are spaced apart on the side wall 42, which can conduct heat from the end cap assembly 6 through the second heat-conducting parts 72, and also reduce the size of the heat-conducting assembly 7, thereby reducing the manufacturing cost of the battery cell 3.

[0181] Optionally, the end cap assembly 6 is rectangular, and four independent first heat-conducting parts 71 are respectively disposed on the four edges of the end cap assembly 6 in the second direction Y and the third direction Z. The four first heat-conducting parts 71 are spliced ​​and connected to each other and are disposed without overlapping each other, so as to increase the contact area between the first heat-conducting parts 71 and the end cap assembly 6, without increasing the size of the battery cell 3 in the first direction X due to the setting of the heat-conducting assembly 7.

[0182] In some embodiments, as shown in Figures 5 to 8, the sidewall 42 includes two first sidewalls 421 and two second sidewalls 422. The two first sidewalls 421 are disposed opposite each other in the second direction Y, and the two second sidewalls 422 are disposed opposite each other in the third direction Z. The first direction X, the second direction Y, and the third direction Z intersect each other. The area of ​​the first sidewall 421 is larger than the area of ​​the second sidewall 422. The second heat-conducting part 72 is disposed on the first sidewall 421 and / or the second heat-conducting part 72 is disposed on the second sidewall 422.

[0183] In these embodiments, the second heat-conducting part 72 is disposed on at least one of the first sidewall 421 and the second sidewall 422, so that when the battery cell 3 is placed in the housing 202, the second heat-conducting part 72 can be close to the heat exchange mechanism 8 to improve the heat exchange rate between the heat exchange mechanism 8 and the battery cell 3, so as to better balance the temperature of the battery cell 3 and improve the performance of the battery device 2.

[0184] Optionally, the second direction Y is the width direction of the battery cell 3, the first direction X is the height direction of the battery cell 3, and the third direction Z is the length direction of the battery cell 3.

[0185] If the area of ​​the first sidewall 421 is larger than the area of ​​the second sidewall 422, then a larger area of ​​the second heat-conducting part 72 can be provided on the first sidewall 421 to improve the heat conduction rate of the second heat-conducting part 72 to the shell. The specific areas of the first sidewall 421 and the second sidewall 422 can be designed by the user.

[0186] Optionally, the second heat-conducting part 72 is disposed on one or two first sidewalls 421, or the second heat-conducting part 72 is disposed on one or two second sidewalls 422.

[0187] In some embodiments, as shown in Figures 5 to 8, the second heat-conducting portion 72 covers the entire first sidewall 421, or the second heat-conducting portion 72 covers the entire second sidewall 422.

[0188] In these embodiments, the second heat-conducting part 72 covers the entire first sidewall 421, or the second heat-conducting part 72 covers the entire second sidewall 422, so as to increase the contact area between the second heat-conducting part 72 and the external environment and improve the thermal conductivity of the heat-conducting component 7.

[0189] Optionally, the second heat-conducting part 72 and the first sidewall 421 are bonded together, and / or the second heat-conducting part 72 and the second sidewall 422 are bonded together.

[0190] Optionally, the dimensions of the first heat-conducting part 71 in the third direction Z and the second heat-conducting part 72 in the third direction Z are the same, and / or the dimensions of the first heat-conducting part 71 in the second direction Y and the second heat-conducting part 72 in the second direction Y are the same, so as to increase the contact area of ​​the first heat-conducting part 71 and the second heat-conducting part 72 and improve the heat conduction rate of the heat-conducting component 7.

[0191] Please refer to Figure 9, which is a schematic diagram of the structure of a battery cell provided in an embodiment of this application.

[0192] In some embodiments, as shown in Figures 5 and 9, the sidewall 42 and the end cap assembly 6 are connected with rounded corners, and the rounded corners and the heat-conducting assembly 7 are spaced apart.

[0193] In these embodiments, the sidewall 42 and the end cap assembly 6 are connected with rounded corners, and the rounded corners and the heat-conducting assembly 7 are spaced apart so that there is a gap between the housing 4 and the heat-conducting assembly 7 that can accommodate the expansion and deformation of the housing 4, thereby reducing the risk that the heat-conducting assembly 7 will burst due to the expansion of the battery cell 3.

[0194] The sidewall 42 and the end cap assembly 6 are connected by a rounded corner. The rounded corner helps to relieve stress at the connection between the sidewall 42 and the end cap assembly 6 and reduces the risk of the sharp angle between the sidewall 42 and the end cap assembly 6 puncturing other parts.

[0195] For example, the fillet radius between the sidewall 42 and the end cap assembly 6 is greater than or equal to 0.5 mm. For example, the fillet radius is 0.5 mm, 1 mm, 2 mm, 3 mm or 5 mm, etc.

[0196] The rounded corners and the heat-conducting component 7 are spaced apart, that is, there is a partial gap between the second heat-conducting part 72 and the side wall 42, so that during the expansion of the battery cell 3, this partial gap can accommodate at least part of the expansion deformation of the shell 4, thereby reducing the compressive force of the shell 4 on the second heat-conducting part 72 and reducing the risk of the heat-conducting component 7 bursting.

[0197] Optionally, the second heat-conducting part 72 and the side wall 42 are spaced apart along the second direction Y or the third direction Z. The second heat-conducting part 72 is bonded to the side wall 42, or the second heat-conducting part 72 is connected to the battery cell 3 through the first heat-conducting part 71, so that a gap is formed between the second heat-conducting part 72 and the side wall 42 to accommodate the expansion and deformation of the housing 4.

[0198] Optionally, the first heat-conducting part 71 and the second heat-conducting part 72 are connected by rounded corners to disperse the stress acting between the first heat-conducting part 71 and the second heat-conducting part 72 and reduce the risk of breakage at the connection between the first heat-conducting part 71 and the second heat-conducting part 72.

[0199] Please refer to Figure 10, which is a partial structural schematic diagram of a battery cell provided in an embodiment of this application.

[0200] In some embodiments, as shown in Figures 8 to 10, the thermally conductive component 7 further includes an adhesive layer 74, which includes a first adhesive layer 741, and the second thermally conductive part 72 is bonded to the sidewall 42 through the first adhesive layer 741.

[0201] In these embodiments, the second heat-conducting part 72 is bonded to the sidewall 42 by the first adhesive layer 741, which can reduce the difficulty of connecting the second heat-conducting part 72 and the sidewall 42 and improve the stability of the second heat-conducting part 72.

[0202] Optionally, the first adhesive layer 741 is an insulating adhesive layer, and the second thermally conductive part 72 is connected to the sidewall 42 through the insulating adhesive layer to enhance the insulation performance of the battery cell 3.

[0203] Optionally, the area of ​​the first adhesive layer 741 can be flexibly designed. For example, the first adhesive layer 741 is applied to the entire sidewall 42 to improve the connection reliability of the sidewall 42 and the second heat-conducting part 72.

[0204] Optionally, the shape of the first adhesive layer 741 can be flexibly designed. For example, the first adhesive layer 741 can be any two-dimensional image such as a circle, rectangle, or rhombus.

[0205] In some embodiments, as shown in Figures 8 to 10, the thickness L1 of the adhesive layer 74 satisfies L1≥0.5mm.

[0206] In these embodiments, when the thickness of the adhesive layer 74 meets the above conditions, the adhesive layer 74 creates a sufficient gap between the second heat-conducting part 72 and the sidewall 42 to accommodate the expansion deformation of the housing 4, thereby reducing the risk of the heat-conducting component 7 bursting due to the expansion of the battery cell 3.

[0207] For example, the thickness L1 of the adhesive layer 74 is 0.5 mm, 0.6 mm, 1.0 mm or 2 mm, etc.

[0208] Optionally, an adhesive layer 74 is provided between the second heat-conducting part 72 and the side wall 42 to fix the second heat-conducting part 72 to the side wall 42. The distance between the second heat-conducting part 72 and the side wall 42 can be adjusted by adjusting the thickness of the adhesive layer 74.

[0209] For example, the end cap assembly 6 and the first sidewall 421 are connected by a rounded transition, the second heat-conducting part 72 and the first sidewall 421 are spaced apart along the second direction Y, the distance between the end of the second heat-conducting part 72 and the rounded part near the second heat-conducting part 72 in the second direction Y is greater than or equal to 0.5 mm, and the distance between the end of the second heat-conducting part 72 and the rounded part away from the second heat-conducting part 72 in the second direction Y is greater than or equal to 1.0 mm.

[0210] For example, the expansion size of the battery cell 3 during charging and discharging is less than 0.5 mm, so that the gap between the second heat-conducting part 72 and the side wall 42 can accommodate the expansion of the battery cell 3. Alternatively, the user can set the gap between the second heat-conducting part 72 and the side wall 42 according to the actual expansion size of the battery cell 3.

[0211] In some embodiments, as shown in Figures 8 to 10, the first adhesive layer 741 is spaced apart from one end of the first heat-conducting portion 71 and the edge of the sidewall 42 in the first direction X.

[0212] In these embodiments, the first adhesive layer 741 is spaced apart from one end of the first heat-conducting part 71 and the edge of the sidewall 42 to facilitate the deformation of the second heat-conducting part 72 together with the housing 4 during the expansion of the battery cell 3, thereby reducing the risk of the heat-conducting component 7 being burst during the expansion of the battery cell 3.

[0213] Part of the second heat-conducting part 72 is bonded to the sidewall 42 through the first adhesive layer 741, while part of the second heat-conducting part 72 located in the area between the first adhesive layer 741 in the first direction X and the edge of the sidewall 42 is not fixed, so that during the expansion of the battery cell 3, this part of the second heat-conducting part 72 can easily deform in the second direction Y, and absorb the expansion of the casing 4 through deformation, reducing the risk of the heat-conducting component 7 bursting.

[0214] Optionally, the adhesive layer 74 and the rounded corner area are spaced apart so that the portion of the second heat-conducting part 72 corresponding to the rounded corner area is easy to deform.

[0215] Optionally, multiple first adhesive layers 741 are respectively disposed at the edges of the sidewall 42 in the first direction X and the second direction Y. This allows a gap to be formed between the middle region of the sidewall 42 and the second heat-conducting part 72 to accommodate the expansion of the battery cell 3, while also reducing the material cost of the heat-conducting assembly 7, provided that the first adhesive layers 741 can fix the second heat-conducting part 72 and the sidewall 42. For example, four rectangular first adhesive layers 741 are adjacent to each other and are respectively disposed at the edges of the first sidewall 421 in the first direction X and the second direction Y.

[0216] In some embodiments, as shown in Figures 8 to 10, the minimum distance L4 between the end of the first adhesive layer 741 facing the first heat-conducting part 71 in the first direction X and the edge of the sidewall 42 is greater than or equal to 10 mm.

[0217] In these embodiments, when the minimum distance between the end of the first adhesive layer 741 facing the first heat-conducting part 71 in the first direction X and the edge of the sidewall 42 satisfies the above conditions, it can facilitate the deformation of the second heat-conducting part 72 together with the shell 4 during the expansion of the battery cell 3, reduce the risk of the heat-conducting component 7 being burst during the expansion of the battery cell 3, and reduce the processing cost of the battery cell 3.

[0218] For example, the distance L4 between the end of the first adhesive layer 741 facing the first heat-conducting part 71 and the edge of the sidewall 42 in the first direction X is 10mm, 12mm, or 15mm, etc.

[0219] In some embodiments, as shown in Figures 5 and 8, the sidewall 42 includes two first sidewalls 421 and two second sidewalls 422. The two first sidewalls 421 are disposed opposite each other in the second direction Y, and the two second sidewalls 422 are disposed opposite each other in the third direction Z. The first direction X, the second direction Y, and the third direction Z intersect each other. The area of ​​the first sidewall 421 is larger than the area of ​​the second sidewall 422. At least two second heat-conducting parts 72 are disposed on the first sidewall 421 and the second sidewall 422, wherein each second heat-conducting part 72 disposed on the first sidewall 421 and the second sidewall 422 is independent of each other.

[0220] In these embodiments, at least two second heat-conducting parts 72 are respectively disposed on the first sidewall 421 and the second sidewall 422, and each second heat-conducting part 72 disposed on the first sidewall 421 and the second sidewall 422 is independent of each other, so that during the expansion of the battery cell 3, the two second heat-conducting parts 72 disposed on the first sidewall 421 and the second sidewall 422 can move independently of each other, thereby reducing the risk of the heat-conducting assembly 7 bursting.

[0221] Specifically, a second heat-conducting part 72 is provided on one or two first sidewalls 421, and a second heat-conducting part 72 is provided on one or two second sidewalls 422, and each second heat-conducting part 72 provided on the first sidewall 421 and the second sidewall 422 is independently provided.

[0222] For example, during the expansion of the battery cell 3, the second heat-conducting part 72 disposed on the first sidewall 421 deforms with the first sidewall 421. Since the two first heat-conducting parts 71 disposed on the first sidewall 421 and the second sidewall 422 are independent of each other, the second heat-conducting part 72 disposed on the first sidewall 421 will not be pulled by the second heat-conducting part 72 disposed on the second sidewall 422, thereby reducing the problem of excessive compression between the second heat-conducting part 72 disposed on the first sidewall 421 and the second sidewall 422, and damage to the second heat-conducting part 72.

[0223] Optionally, the second heat-conducting portion 72 disposed on the first sidewall 421 is spaced apart at both ends in the third direction Z and at both sides of the first sidewall 421 in the third direction Z, and / or the second heat-conducting portion 72 disposed on the second sidewall 422 is spaced apart at both ends in the second direction Y and at both sides of the second sidewall 422 in the second direction Y.

[0224] Please refer to Figures 11 and 12. Figure 11 is a side view of a battery cell provided in an embodiment of this application; Figure 12 is a side view of a battery cell provided in an embodiment of this application.

[0225] In some embodiments, as shown in Figures 5, 8, 11 and 12, the minimum distance L2 between the second heat-conducting portion 72 disposed on the first sidewall 421 and the adjacent second sidewall 422 in the third direction Z satisfies L2≥10mm; and / or the minimum distance L3 between the second heat-conducting portion 72 disposed on the second sidewall 422 and the adjacent first sidewall 421 in the second direction Y satisfies L3≥10mm.

[0226] In these embodiments, when the minimum distance L2 between the second heat-conducting part 72 disposed on the first sidewall 421 and the adjacent second sidewall 422 in the third direction Z and / or the minimum distance L3 between the second heat-conducting part 72 disposed on the second sidewall 422 and the adjacent first sidewall 421 in the second direction Y satisfies the above conditions, it is convenient for the second heat-conducting part 72 to move together during the expansion of the battery cell 3, so as to reduce the risk of the heat-conducting assembly 7 bursting. Increasing the distance between the second heat-conducting parts 72 disposed on the first sidewall 421 and the second sidewall 422 can reduce the risk of the two second heat-conducting parts 72 being crushed and damaged during the deformation of the second heat-conducting part 72 caused by the expansion of the shell 4, and improve the service life of the heat-conducting assembly 7.

[0227] For example, the minimum distance L2 between the second heat-conducting part 72 disposed on the first sidewall 421 and the adjacent second sidewall 422 in the third direction Z can be 10mm, 11mm, 12mm or 15mm, etc.

[0228] The minimum distance L3 between the second heat-conducting part 72 disposed on the second sidewall 422 and the adjacent first sidewall 421 in the second direction Y can be 10mm, 11mm, 12mm or 15mm, etc.

[0229] Optionally, the minimum distance between the second heat-conducting part 72 disposed on the first sidewall 421 and the adjacent second sidewall 422 in the third direction Z is the same as the minimum distance between the second heat-conducting part 72 disposed on the second sidewall 422 and the adjacent first sidewall 421 in the second direction Y, thereby reducing the difficulty of fitting the second heat-conducting part and the housing.

[0230] Please refer to Figure 13, which is a schematic diagram of the structure of a battery cell provided in an embodiment of this application.

[0231] In some embodiments, as shown in FIG8 and FIG13, the heat-conducting component 7 further includes a third heat-conducting part 73, which is connected to the second heat-conducting part 72, and the third heat-conducting part 73 is disposed on the bottom wall 43.

[0232] In these embodiments, the heat-conducting component 7 further includes a third heat-conducting part 73 connected to the second heat-conducting part 72. The third heat-conducting part 73 is disposed on the bottom wall 43. Through the third heat-conducting part 73, the heat at the end cap assembly 6 can be transferred to the bottom wall 43 and conducted to the external environment through the first heat-conducting part 71 and the second heat-conducting part 72. The third heat-conducting part 73 can increase the contact area between the heat-conducting component 7 and the external environment, improve the heat conduction performance of the heat-conducting component 7, thereby enhancing the heat exchange efficiency between the end cap assembly 6 and the external environment. It can also enhance the heat conduction performance at the bottom wall 43 of the battery cell 3. The heat-conducting component 7 can better balance the temperature of the battery cell 3 and improve the performance of the battery device 2.

[0233] Specifically, the heat-conducting component 7 includes a first heat-conducting part 71, a second heat-conducting part 72, and a third heat-conducting part 73, with the first heat-conducting part 71 and the third heat-conducting part 73 respectively connected to the two ends of the second heat-conducting part 72 in the first direction X.

[0234] The heat from the end cap assembly 6 is transferred to the third heat-conducting part 73 through the first heat-conducting part 71 and the second heat-conducting part 72, and then transferred to the external environment.

[0235] For example, the heat exchange mechanism 8 is connected to the bottom wall 43 of the housing 4, and the heat from the end cap assembly 6 is transferred to the heat exchange mechanism 8 through the third heat conduction part 73.

[0236] Optionally, the third heat-conducting part 73 and the second heat-conducting part 72 are manufactured separately and then bonded together to facilitate adjustment of the shape and size of the third heat-conducting part 73 and the second heat-conducting part 72; or the third heat-conducting part 73 and the second heat-conducting part 72 are integrally formed and bent from the same substrate to reduce the processing difficulty of the heat-conducting component 7. For example, the first heat-conducting part 71, the second heat-conducting part 72, and the third heat-conducting part 73 are integrally formed and bent from the same substrate.

[0237] Optionally, multiple second heat-conducting parts 72 are spaced apart and all connected to the third heat-conducting part 73 to increase the connection area between the second heat-conducting parts 72 and the third heat-conducting part 73, thereby increasing the heat conduction rate of the heat-conducting component 7. For example, four second heat-conducting parts 72 are respectively disposed on two first sidewalls 421 and two second sidewalls 422, and all four second heat-conducting parts 72 are connected to the third heat-conducting part 73 to increase the connection area between the second heat-conducting parts 72 and the third heat-conducting part 73.

[0238] Optionally, the size and shape of the third heat-conducting part 73 can be designed by the user. For example, the third heat-conducting part 73 can be rectangular, circular, or annular.

[0239] In some embodiments, as shown in FIG13, the bottom wall 43 includes a first portion 431 and a second portion 432, a third heat-conducting portion 73 is disposed on the first portion 431, and the second portion 432 is used to connect with the mounting position.

[0240] In these embodiments, the bottom wall 43 includes a first part 431 and a second part 432. A third heat-conducting part 73 disposed in the first part 431 is used to conduct heat. The battery cell 3 is connected to the mounting position through the second part 432 to fix the battery cell 3.

[0241] For example, the installation location is located at the heat exchange mechanism 8 or the housing 202.

[0242] For example, the installation position can be set at the heat exchange mechanism 8, the third heat conduction part 73 is set at the first part 431, and part of the heat exchange mechanism 8 is set on the side of the third heat conduction part 73 away from the first part 431, so that the heat of the end cap assembly 6 can be transferred to the heat exchange mechanism 8 through the third heat conduction part 73, and another part of the heat exchange mechanism 8 is connected to the second part 432 of the bottom wall 43 so that the battery cell 3 and the heat exchange mechanism 8 are stably connected.

[0243] Optionally, the specific dimensions and shapes of the first part 431 and the second part 432 can be designed by the user.

[0244] Optionally, the first portion 431 surrounds the outside of the second portion 432 to facilitate the connection between the third heat-conducting part 73 and the second heat-conducting part 72 disposed on the side wall 42, thereby reducing the difficulty of setting up the heat-conducting assembly 7; or the first portion 431 and the second portion 432 are spaced apart along the second direction Y to facilitate the connection between the third heat-conducting part 73 and the second heat-conducting part 72 disposed on the first side wall 421; or the first portion 431 and the second portion 432 are spaced apart along the third direction Z to facilitate the connection between the third heat-conducting part 73 and the second heat-conducting part 72 disposed on the second side wall 422.

[0245] Please refer to Figure 14, which is a schematic diagram of the structure of a battery cell provided in an embodiment of this application.

[0246] In some embodiments, as shown in FIG14, the sidewall 42 and the bottom wall 43 are connected by rounded corners, and the rounded corners and the heat-conducting components 7 are spaced apart.

[0247] In the embodiment of this application, the side wall 42 and the bottom wall 43 are connected with rounded corners, and the rounded corners and the heat-conducting component 7 are spaced apart, so that there is a gap between the housing 4 and the heat-conducting component 7 that can accommodate the expansion and deformation of the housing 4, thereby reducing the risk that the heat-conducting component 7 will burst due to the expansion of the battery cell 3.

[0248] The side wall 42 and the bottom wall 43 are connected by rounded corners. The rounded corners help to relieve stress at the connection between the side wall 42 and the bottom wall 43 and reduce the risk of the sharp angle between the side wall 42 and the bottom wall 43 piercing other parts.

[0249] For example, the radius of the fillet between the side wall 42 and the bottom wall 43 is greater than or equal to 0.5 mm. For example, the radius of the fillet is 0.5 mm, 1 mm, 2 mm, 3 mm or 5 mm, etc.

[0250] The rounded corners and the heat-conducting component 7 are spaced apart, that is, there is a gap between the second heat-conducting part 72 and the side wall 42, so that during the expansion of the battery cell 3, this gap can accommodate at least part of the expansion of the shell 4, thereby reducing the compressive force of the shell 4 on the second heat-conducting part 72 and reducing the risk of the heat-conducting component 7 bursting.

[0251] Optionally, the third heat-conducting part 73 and the second heat-conducting part 72 are connected by rounded corners to disperse the stress acting between the third heat-conducting part 73 and the second heat-conducting part 72, thereby reducing the risk of breakage at the connection between the third heat-conducting part 73 and the second heat-conducting part 72.

[0252] Optionally, the sidewall 42 and the bottom wall 43 are connected with rounded corners, and the sidewall 42 and the end cap assembly 6 are connected with rounded corners. The rounded corners and the heat-conducting assembly 7 are spaced apart so that there is a gap between the housing 4 and the heat-conducting assembly 7 that can accommodate the expansion and deformation of the housing 4, thereby reducing the risk that the heat-conducting assembly 7 will burst due to the expansion of the battery cell 3.

[0253] Please refer to Figure 15, which is a bottom view of a battery cell provided in an embodiment of this application.

[0254] In some embodiments, as shown in Figures 13 to 15, the thermally conductive component 7 further includes an adhesive layer 74, which includes a second adhesive layer 742, and the third thermally conductive part 73 is bonded to the bottom wall 43 through the second adhesive layer 742.

[0255] In these embodiments, the third heat-conducting part 73 is bonded to the bottom wall 43 by the second adhesive layer 742 to improve the stability of the third heat-conducting part 73.

[0256] Optionally, the second adhesive layer 742 is an insulating adhesive layer, and the third thermally conductive part 73 is connected to the bottom wall 43 through the insulating adhesive layer to enhance the insulation performance of the battery cell 3.

[0257] Optionally, the area of ​​the second adhesive layer 742 can be flexibly designed. For example, the shape of the second adhesive layer 742 is the same as the shape of the first part 431. The second adhesive layer 742 is applied to the entire first part 431 of the bottom wall 43 to improve the connection reliability between the bottom wall 43 and the third heat-conducting part 73.

[0258] Optionally, the shape of the second adhesive layer 742 can be flexibly designed. For example, the second adhesive layer 742 can be any two-dimensional shape such as a circle, rectangle, or rhombus.

[0259] In some embodiments, as shown in Figures 13 to 15, the second adhesive layer 742 is spaced apart from one end of the second heat-conducting portion 72 and the edge of the bottom wall 43.

[0260] In these embodiments, the second adhesive layer 742 is spaced apart from one end of the second heat-conducting part 72 and the edge of the bottom wall 43 to facilitate the movement of the second heat-conducting part 72 together with the housing 4 during the expansion of the battery cell 3, thereby reducing the risk of the heat-conducting component 7 being burst during the expansion of the battery cell 3.

[0261] Part of the third heat-conducting part 73 is bonded to the bottom wall 43 through the second adhesive layer 742, while part of the third heat-conducting part 73 located in the area between the second adhesive layer 742 and the edge of the bottom wall 43 is not fixed. The second heat-conducting part 72 and the third heat-conducting part 73 are connected so that during the expansion of the battery cell 3, the part of the third heat-conducting part 73 connected to the second heat-conducting part 72 can easily deform to absorb the expansion of the casing 4 and reduce the risk of the heat-conducting component 7 bursting.

[0262] Optionally, the second adhesive layer 742 and the rounded corner area are spaced apart so that the portion of the third heat-conducting part 73 corresponding to the rounded corner area is easy to deform.

[0263] Optionally, the distance between the end of the second adhesive layer 742 facing the second heat-conducting part 72 and the edge of the bottom wall 43 is greater than or equal to 5 mm. For example, the distance between the end of the second adhesive layer 742 facing the second heat-conducting part 72 and the edge of the bottom wall 43 is 5 mm, 6 mm, or 10 mm, etc.

[0264] Optionally, multiple second adhesive layers 742 are respectively disposed at the edge positions of the bottom wall 43 in the second direction Y and / or the third direction Z, so that when the second adhesive layers 742 can fix the third heat-conducting part 73 and the bottom wall 43, a second part 432 connecting the heat exchange mechanism 8 can be formed between the middle region of the side wall 42 and the third heat-conducting part 73. For example, four rectangular second adhesive layers 742 are disposed end-to-end at the edge positions of the bottom wall 43 in the second direction Y and the third direction Z.

[0265] In some embodiments, as shown in Figures 13 to 15, the minimum distance between one end of the second adhesive layer 742 facing the second heat-conducting part 72 and the edge of the bottom wall 43 is greater than or equal to 10 mm.

[0266] In these embodiments, when the minimum distance between the end of the second adhesive layer 742 facing the second heat-conducting part 72 and the edge of the bottom wall 43 satisfies the above conditions, it facilitates the synchronous deformation of the second heat-conducting part 72 and the shell 4 during the expansion of the battery cell 3, thereby reducing the risk of the heat-conducting component 7 bursting, and also reducing the processing cost of the battery cell 3.

[0267] For example, the second heat-conducting part 72 is disposed on the first sidewall 421, and the minimum distance between the end of the second adhesive layer 742 facing the second heat-conducting part 72 and the edge of the bottom wall 43 in the second direction Y is greater than or equal to 10 mm; and / or the second heat-conducting part 72 is disposed on the second sidewall 422, and the minimum distance between the end of the second adhesive layer 742 facing the second heat-conducting part 72 and the edge of the bottom wall 43 in the third direction Z is greater than or equal to 10 mm.

[0268] For example, the minimum distance between the end of the second adhesive layer 742 facing the second heat-conducting part 72 and the edge of the bottom wall 43 can be 10mm, 11mm, 12mm or 15mm, etc.

[0269] Please refer to Figure 16, which is a top view of a battery cell provided in an embodiment of this application.

[0270] In some embodiments, as shown in Figures 14 and 16, the thermally conductive component 7 further includes an adhesive layer 74, which includes a third adhesive layer 743, through which the first thermally conductive portion 71 is bonded to the end cap component 6.

[0271] In these embodiments, the first heat-conducting part 71 is bonded to the end cap assembly 6 by a third adhesive layer 743 to improve the stability of the first heat-conducting part 71.

[0272] Optionally, the third adhesive layer 743 is an insulating adhesive layer, and the first thermally conductive part 71 is connected to the end cap assembly 6 through the insulating adhesive layer to enhance the insulation performance of the battery cell 3.

[0273] Optionally, the shape of the third adhesive layer 743 can be flexibly designed. For example, the third adhesive layer 743 can be rectangular or circular, etc.

[0274] Optionally, four third adhesive layers 743 are connected end to end and are respectively disposed at the edge positions of the end cap assembly 6 in the second direction Y and the third direction Z to improve the connection reliability between the end cap assembly 6 and the first heat-conducting part 71.

[0275] In some embodiments, as shown in Figures 14 and 16, the third adhesive layer 743 is spaced apart from one end of the second heat-conducting portion 72 and the edge of the end cap assembly 6.

[0276] In these embodiments, the third adhesive layer 743 is spaced apart from one end of the second heat-conducting part 72 and the edge of the end cap assembly 6 to facilitate the movement of the second heat-conducting part 72 together with the housing 4 during the expansion of the battery cell 3, thereby reducing the risk of the heat-conducting assembly 7 being burst during the expansion of the battery cell 3.

[0277] A portion of the first thermally conductive part 71 is bonded to the end cap assembly 6 via the third adhesive layer 743, while a portion of the first thermally conductive part 71 located between the third adhesive layer 743 and the edge of the end cap assembly 6 is not fixed. The second thermally conductive part 72 is connected to the first thermally conductive part 71 so that during the expansion of the battery cell 3, the portion of the third thermally conductive part 73 connected to the second thermally conductive part 72 can easily deform to absorb the expansion of the casing 4 and reduce the risk of the thermally conductive assembly 7 bursting.

[0278] Optionally, the third adhesive layer 743 and the rounded corner area are spaced apart so that the portion of the first heat-conducting part 71 corresponding to the rounded corner area is easy to deform.

[0279] Optionally, the distance between the end of the third adhesive layer 743 facing the second heat-conducting part 72 and the edge of the end cap assembly 6 is greater than or equal to 5 mm. For example, the distance between the end of the third adhesive layer 743 facing the second heat-conducting part 72 and the edge of the end cap assembly 6 is 5 mm, 6 mm, or 10 mm, etc.

[0280] In some embodiments, as shown in Figures 14 and 16, the minimum spacing between one end of the third adhesive layer 743 facing the second heat-conducting part 72 and the edge of the end cap assembly 6 is greater than or equal to 10 mm.

[0281] In these embodiments, when the minimum distance between the end of the third adhesive layer 743 facing the second heat-conducting part 72 and the edge of the end cap assembly 6 satisfies the above conditions, it facilitates the synchronous deformation of the second heat-conducting part 72 and the shell 4 during the expansion of the battery cell 3, thereby reducing the risk of the heat-conducting assembly 7 bursting, and also reduces the processing cost of the battery cell 3.

[0282] For example, the second heat-conducting part 72 is disposed on the first sidewall 421, and the minimum distance between one end of the second adhesive layer 742 facing the second heat-conducting part 72 and the edge of the end cap assembly 6 in the second direction Y is greater than or equal to 10 mm; and / or the second heat-conducting part 72 is disposed on the second sidewall 422, and the minimum distance between one end of the second adhesive layer 742 facing the second heat-conducting part 72 and the edge of the end cap assembly 6 in the third direction Z is greater than or equal to 10 mm.

[0283] For example, the minimum spacing between the end of the third adhesive layer facing the second heat-conducting part and the edge of the end cap assembly can be 10mm, 11mm, 12mm or 15mm, etc.

[0284] Optionally, the heat-conducting component 7 includes a first heat-conducting part 71, a second heat-conducting part 72, and a third heat-conducting part 73. The minimum distance between the first adhesive layer 741 and the edge of the sidewall 42 in the first direction X is greater than or equal to 10 mm. The minimum distance between the end of the second adhesive layer 742 facing the second heat-conducting part 72 and the edge of the bottom wall 43 is greater than or equal to 10 mm. The minimum distance between the end of the third adhesive layer 743 facing the second heat-conducting part 72 and the edge of the end cap assembly 6 is greater than or equal to 10 mm.

[0285] Please refer to Figure 17, which is a schematic diagram of the structure of a battery cell provided in an embodiment of this application.

[0286] In some embodiments, as shown in FIG17, the end cap assembly 6 includes a cover plate 61 and an electrode terminal 62 disposed on the cover plate 61. The electrode terminal 62 is connected to the electrode assembly 5, and the first heat-conducting part 71 is connected to the electrode terminal 62.

[0287] In these embodiments, the electrode terminal 62 is connected to the electrode assembly 5. The temperature of the electrode terminal 62 is higher than that of the cover plate 61. Therefore, the connection between the first heat-conducting part 71 and the electrode terminal 62 can improve the heat conduction rate between the end cover assembly 6 and the heat-conducting assembly 7, so as to better balance the internal temperature of the battery cell 3 and improve the performance of the battery cell 3.

[0288] The cover plate 61 covers the housing 4 to form a chamber for accommodating the electrode assembly 5. The electrode terminal 62 is connected to the cover plate 61. One end of the electrode terminal 62 is electrically connected to the electrode assembly 5, and the other end extends out of the cover plate 61 and is used to form a circuit with external components.

[0289] Electrode terminal 62 is the main current-carrying component of end cover assembly 6. During the charging and discharging process of battery cell 3, the heat at electrode terminal 62 is higher than that at cover plate 61. Therefore, the connection between the first heat-conducting part 71 and electrode terminal 62 helps to improve the heat conduction efficiency of the first heat-conducting part 71.

[0290] Optionally, the first heat-conducting part 71 is sleeved on the electrode terminal 62 to increase the contact area between the first heat-conducting part 71 and the electrode terminal 62, thereby improving the heat conduction efficiency of the first heat-conducting part 71. For example, the electrode terminal 62 is cylindrical, and the first heat-conducting part 71 is provided with a circular hole so that the first heat-conducting part 71 is sleeved on the electrode terminal 62.

[0291] Optionally, the first heat-conducting part 71 and the electrode terminal 62 are connected by a thermally conductive adhesive to improve the connection stability of the first heat-conducting part 71 and the electrode terminal 62.

[0292] Optionally, the outer surface of the cover plate 61 is flush, and the first heat-conducting part 71 is stacked on the outer surface of the cover plate 61 along the first direction X, so that the first heat-conducting part 71 and the end cap assembly 6 are thermally connected, which can reduce the difficulty of setting the first heat-conducting part 71 and the end cap assembly 6.

[0293] Please refer to Figure 18, which is a schematic diagram of the structure of a battery cell provided in an embodiment of this application.

[0294] In some embodiments, as shown in Figures 5 and 18, the battery cell 3 further includes a first insulating layer 91, which is disposed on the outer surface of the housing 4 and the end cap assembly 6, and a heat-conducting assembly 7 is disposed on the side of the first insulating layer 91 away from the housing 4 and the end cap assembly 6.

[0295] In these embodiments, the battery cell 3 further includes a first insulating layer 91 disposed on the outer surface of the housing 4 and the end cap assembly 6, and a heat-conducting component 7 disposed on the side of the first insulating layer 91 away from the housing 4 and the end cap assembly 6, so that the battery cell 3, the housing 202 and the heat-conducting component 7 are mutually insulated.

[0296] For example, the material of the first insulating layer 91 can be PP or PI (polyimide) or PET (polyethylene terephthalate), etc.

[0297] Specifically, the first insulating layer 91 covers the outer surface of the housing 4 and the outer surface of the end cap assembly 6; or the first insulating layer 91 includes an insulating film layer disposed on the outer surface of the housing 4 and an insulating patch disposed on the outer surface of the end cap assembly 6, with the electrode terminal 62 exposed outside the first insulating layer 91.

[0298] The heat-conducting component 7 is located on the side of the first insulating layer 91 away from the housing 4, so as to facilitate the heat-conducting component 7 to transfer the heat of the end cap assembly 6 to the external environment.

[0299] Please refer to Figures 19 and 20. Figure 19 is a cross-sectional view of the thermal conductive component of a battery cell provided in an embodiment of this application; Figure 20 is a structural schematic diagram of a battery cell provided in an embodiment of this application.

[0300] In some embodiments, as shown in Figures 19 and 20, the heat-conducting assembly 7 includes an insulating member 75 and a heat-conducting member 76. The insulating member 75 forms a receiving cavity 77 in at least a portion of its area. The heat-conducting member 76 is disposed within the receiving cavity 77. The heat-conducting member 76 includes a first heat-conducting sheet 761 and a second heat-conducting sheet 762. The first heat-conducting sheet 761 is disposed on the end cap assembly 6, and the second heat-conducting sheet 762 is disposed on the sidewall 42. The first heat-conducting portion 71 is composed of the first heat-conducting sheet 761 and the insulating member 75, and the second heat-conducting portion 72 is composed of the second heat-conducting sheet 762 and the insulating member 75.

[0301] In these embodiments, the heat-conducting component 7 includes an insulator 75 and a heat-conducting component 76. The insulator 75 forms a receiving cavity 77 in at least a portion of its area. The heat-conducting component 76 is disposed within the receiving cavity 77. The heat-conducting component 76 includes a first heat-conducting sheet 761 and a second heat-conducting sheet 762. The first heat-conducting sheet 761 is disposed on the end cap assembly 6 to conduct heat from the end cap assembly 6. The second heat-conducting sheet 762 is disposed on the side wall 42 to conduct heat from the first heat-conducting sheet 761 and the housing 4. The first heat-conducting part 71 is composed of the first heat-conducting sheet 761 and the insulator 75, and the second heat-conducting part 72 is composed of the second heat-conducting sheet 762 and the insulator 75. In this way, the insulator 75 can insulate the heat-conducting component 76 from the electrode body, and the heat-conducting component 76 can improve the heat conduction rate between the end cap assembly 6 and the external environment.

[0302] For example, the insulating component 75 can be PP or PI (polyimide) or PET (polyethylene terephthalate), etc. The thermally conductive component 76 can be made of graphite, graphene, or carbon nanotubes. The thermal conductivity of the thermally conductive component 76 in the thermally conductive assembly 7 is greater than that of the housing 4.

[0303] Optionally, the heat-conducting element 76 may be plate-shaped, strip-shaped, or mesh-shaped. For example, the receiving cavity 77 is provided with a plate-shaped heat-conducting element, a mesh-shaped heat-conducting element, or one or more spaced strip-shaped heat-conducting elements.

[0304] It should be noted that the heat-conducting element 76 is located within the insulating element 75 and is covered by the insulating element 75. However, in the accompanying drawings, the heat-conducting element 76 is represented by a shaded area on the insulating element 75 for ease of illustration. Optionally, the insulating element 75 may have a receiving cavity 77 with an opening 41 at one end. The heat-conducting element 76 is disposed within the receiving cavity 77 and bonded or fused to the opening 41 of the insulating element 75, so that the heat-conducting element 76 is located within a sealed receiving cavity 77; or the insulating element 75 may be folded in half at both ends, with the heat-conducting element 76 located between the two ends of the insulating element 75, and the two ends of the insulating element 75 bonded or fused together, so that the heat-conducting element 76 is located within a sealed receiving cavity 77; or the insulating element 75 may include two opposing sub-insulating layers, the edges of which are bonded or fused together, so that the heat-conducting element 76 is located within a sealed receiving cavity 77.

[0305] Optionally, an adhesive layer 74 is provided on the side surface of the insulating component 75 facing the battery cell 3 to bond the thermal conductive component 7 and the battery cell 3 together.

[0306] At least a portion of the insulating member 75 extends into the end cap assembly 6. A first thermally conductive sheet 761 is disposed on the end cap assembly 6 and is thermally connected to the end cap assembly 6. The first thermally conductive portion 71 is composed of the first thermally conductive sheet 761 and the insulating member 75. For example, the first thermally conductive sheet 761 covers the entire end cap assembly 6 to improve the heat conduction rate of the first thermally conductive portion 71.

[0307] Optionally, the first heat-conducting sheet 761 and the second heat-conducting sheet 762 are prepared separately and bonded together to facilitate adjustment of the shape and size of the first heat-conducting sheet 761 and the second heat-conducting sheet 762; or the first heat-conducting sheet 761 and the second heat-conducting sheet 762 are integrally formed and obtained by bending the same substrate to reduce the processing difficulty of the heat-conducting component 7.

[0308] Optionally, the second heat-conducting sheet 762 covers the entire sidewall 42 to improve the heat conduction effect of the second heat-conducting part 72.

[0309] For example, the size and shape of the second heat-conducting sheet 762 can be designed by the user, and the second heat-conducting sheet 762 can be rectangular or elliptical, etc.

[0310] In some embodiments, as shown in FIG5 and FIG20, the battery cell 3 further includes a second insulating layer 92, which is connected to an insulating element 75. The insulating element 75 and the second insulating layer 92 together cover the outer surface of the housing 4 and the end cap assembly 6.

[0311] In these embodiments, the second insulating layer 92 and the insulating element 75 are connected, and the insulating element 75 and the second insulating layer 92 together cover the outer surface of the housing 4 and the end cap assembly 6. The combination of the second insulating layer 92 and the insulating element 75 achieves insulation of the battery cell 3, which also helps to reduce the size of the second insulating layer 92, reduce the manufacturing cost of the battery cell 3, and help to reduce the weight of the battery cell 3 and improve the energy density of the battery cell 3.

[0312] If the insulating part 75 of the heat-conducting component 7 covers part of the outer surface of the housing 4 of the battery cell 3 or part of the outer surface of the end cap assembly 6, then the insulating part 75 and the second insulating layer 92 of the heat-conducting component 7 are connected, and the combination of the insulating part 75 and the second insulating layer 92 can cover the outer surface of the housing 4 and the end cap assembly 6.

[0313] The connection method for the insulating component 75 and the second insulating layer 92 is bonding or welding. The specific dimensions of the insulating component 75 and the second insulating layer 92 can be flexibly designed.

[0314] For example, four second heat-conducting parts 72 are spaced apart and respectively disposed on the first sidewall 421 and the second sidewall 422, and the second insulating layer 92 is connected between two adjacent second heat-conducting parts 72.

[0315] Please refer to Figures 21 and 22. Figure 21 is a schematic diagram of the structure of a single battery cell provided in an embodiment of this application; Figure 22 is a schematic diagram of the structure of a battery device provided in an embodiment of this application.

[0316] In some embodiments, as shown in FIG5, FIG20 to FIG22, an insulating element 75 is disposed on the outer surface of the end cap assembly 6 and the housing 4.

[0317] In these embodiments, the insulating element 75 is disposed on the outer surface of the end cap assembly 6 and the housing 4 to insulate the battery cell 3 and the housing 202 as well as adjacent battery cells 3 from each other, eliminating the need for an additional insulating film and reducing the manufacturing cost of the battery cell 3.

[0318] In this embodiment, the battery cell 3 and the housing 202 are insulated by the insulating member 75, eliminating the need for the first insulating layer 91, or in other words, the insulating member 75 replaces the first insulating layer 91. The insulating member 75 and the first insulating layer 91 have similar thermal conductivity; therefore, in this embodiment, replacing the first insulating layer 91 with the insulating member 75 does not significantly affect the heat dissipation of the electrode assembly 5. A heat-conducting member 76 is provided within the insulating member 75. The thermal conductivity of the heat-conducting member 76 is greater than that of the first insulating layer 91. Therefore, compared to using either the insulating member 75 or the first insulating layer 91, providing the heat-conducting member 76 within the insulating member 75 can improve the thermal conductivity rate between the battery cell 3 and the external environment. In other words, the thermal conductivity efficiency between the battery cell 3 and the external environment can be improved through the heat-conducting component 76.

[0319] The thermal conductivity of the thermally conductive component 7 can be measured by methods such as the heat flow method, hot plate method, or hot wire method. When testing the thermal conductivity of the thermally conductive component 7, the test sample of the thermally conductive component 7 should include the thermally conductive element 76 and the insulating element 75 covering the outer surface of the thermally conductive element 76.

[0320] By combining the insulating element 75 and the heat-conducting element 76, the insulating element 75 not only achieves insulation between the battery cell 3 and the housing 202, but also achieves insulation between the heat-conducting element 76 and the battery cell 3.

[0321] Optionally, the heat-conducting element 76 is disposed in the receiving cavity 77, the area of ​​the heat-conducting element 76 and the area of ​​the receiving cavity 77 are matched, the area of ​​the receiving cavity 77 can be smaller than the area of ​​the insulating element 75, the heat-conducting element 76 and the cavity wall of the receiving cavity 77 are in contact, and the receiving cavity 77 plays a limiting role for the heat-conducting element 76.

[0322] In some embodiments, as shown in FIG5 and FIG21, the end cap assembly 6 includes a cover plate 61 and a pressure relief mechanism 63 disposed on the cover plate 61, and an insulating member 75 is provided with a first opening 751 through which the pressure relief mechanism 63 is exposed.

[0323] In these embodiments, the insulating member 75 is provided with a first opening 751 so that the pressure relief mechanism 63 can be exposed through the first opening 751, thereby reducing the risk that the insulating member 75 will hinder the activation of the pressure relief mechanism 63 and improving the reliability of the battery cell 3.

[0324] A pressure relief mechanism 63 is provided on the cover plate 61. When the battery cell 3 experiences thermal runaway, the pressure inside the housing 4 rises, and the gas inside the housing 4 is released to the outside through the pressure relief mechanism 63 to equalize the internal pressure of the housing 4 and alleviate the damage to other nearby battery cells 3 caused by the thermal runaway of the battery cell 3. Therefore, when the insulating component 75 covers the end cover assembly 6, the insulating component 75 is provided with a first opening 751 to expose the pressure relief mechanism 63, so that the insulating component 75 will not affect the activation of the pressure relief mechanism 63, so that the pressure relief mechanism 63 can release the internal pressure of the housing 4 in a timely manner when the battery cell 3 experiences thermal runaway.

[0325] Optionally, the shape and size of the first opening 751 match the shape and size of the pressure relief mechanism 63. For example, both the pressure relief mechanism 63 and the first opening 751 are circular or waist-shaped.

[0326] Optionally, the first opening 751 and the receiving cavity 77 are spaced apart to insulate the first heat-conducting sheet 761 and the end cap assembly 6; a first clearance hole is provided through the first heat-conducting sheet 761, the first opening 751 is located in the first clearance hole, and the insulating member 75 covers the inner wall of the first clearance hole to insulate the first heat-conducting sheet 761 and the end cap assembly 6.

[0327] In some embodiments, as shown in Figures 5 and 20, the sidewall 42 includes two first sidewalls 421 and two second sidewalls 422. The two first sidewalls 421 are disposed opposite each other in the second direction Y, and the two second sidewalls 422 are disposed opposite each other in the third direction Z. The first direction X, the second direction Y, and the third direction Z intersect each other. The area of ​​the first sidewall 421 is larger than the area of ​​the second sidewall 422. At least two second heat-conducting plates 762 are disposed on the first sidewall 421 and the second sidewall 422 respectively, wherein each second heat-conducting plate 762 disposed on the first sidewall 421 and the second sidewall 422 is independent of each other.

[0328] In these embodiments, at least two second heat-conducting sheets 762 are disposed on the first sidewall 421 and the second sidewall 422, and each second heat-conducting sheet 762 disposed on the first sidewall 421 and the second sidewall 422 is independent of each other, so that during the expansion of the battery cell 3, the two second heat-conducting sheets 762 disposed on the first sidewall 421 and the second sidewall 422 can move independently of each other, thereby reducing the risk of the heat-conducting component 76 being burst.

[0329] An insulating component 75 covers the outer surface of the battery cell 3 to insulate the battery cell 3 from the housing 202. The insulating component 75 has stronger elasticity than the second heat-conducting sheet 762. When the battery cell 3 expands and deforms during charging and discharging, the insulating component 75 is less likely to burst than the second heat-conducting sheet 762. In this embodiment, the second heat-conducting sheets 762, which are separately disposed on the first sidewall 421 and the second sidewall 422, are independent of each other. When the housing 4 expands in the second direction Y, the second heat-conducting sheet 762 disposed on the first sidewall 421 deforms independently with the first sidewall 421, reducing the compressive force between the second heat-conducting sheet 762 and the first sidewall 421 and reducing the risk of damage to the second heat-conducting sheet 762.

[0330] Optionally, the sum of the minimum spacing between the second heat-conducting sheet 762 disposed on the first sidewall 421 and the second heat-conducting sheet 762 disposed on the second sidewall 422 is greater than or equal to 10mm in the second direction Y and the third direction Z, so as to reduce the risk of the two second heat-conducting sheets 762 being crushed and damaged during the deformation of the second heat-conducting sheet 762 caused by the expansion of the housing 4, and improve the service life of the heat-conducting component 76.

[0331] Please refer to Figure 23, which is a schematic diagram of the structure of a battery cell provided in an embodiment of this application.

[0332] In some embodiments, as shown in FIG5, FIG20 and FIG23, the heat-conducting element 76 further includes a third heat-conducting sheet 763, which is connected to the second heat-conducting sheet 762, and the third heat-conducting sheet 763 is disposed on the bottom wall 43.

[0333] In these embodiments, the heat-conducting element 76 further includes a third heat-conducting element 763 connected to the second heat-conducting element 762. The third heat-conducting element 763 is disposed on the bottom wall 43. By increasing the volume of the heat-conducting element 76, the heat conduction performance of the heat-conducting component 7 is improved, so as to better conduct the heat at the end cap component 6 through the heat-conducting component 7.

[0334] The third heat-conducting plate 763 is disposed in the first part 431 of the bottom wall 43, and the partial heat exchange mechanism 8 is connected to the second part 432 of the bottom wall 43.

[0335] The heat-conducting component 76 includes a first heat-conducting sheet 761, a second heat-conducting sheet 762, and a third heat-conducting sheet 763. The heat of the end cap assembly 6 is transferred to the third heat-conducting sheet 763 through the first heat-conducting sheet 761 and the second heat-conducting sheet 762.

[0336] Optionally, the first heat-conducting sheet 761, the second heat-conducting sheet 762, and the third heat-conducting sheet 763 are prepared separately and bonded together to facilitate adjustment of the shape and size of the first heat-conducting sheet 761, the second heat-conducting sheet 762, and the third heat-conducting sheet 763; or the first heat-conducting sheet 761, the second heat-conducting sheet 762, and the third heat-conducting sheet 763 are integrally formed and obtained by bending from the same substrate to reduce the processing difficulty of the heat-conducting component 7.

[0337] For example, the size and shape of the third heat-conducting plate 763 can be designed by the user, and the third heat-conducting plate 763 can be rectangular or elliptical, etc.

[0338] Optionally, the insulating member 75 is provided with a second opening 752 so that a second portion (not shown) of the bottom wall 43 can be exposed through the second opening 752.

[0339] In some embodiments, as shown in FIG19, the thickness D1 of the heat-conducting element 76 satisfies 40μm≤D1≤180μm.

[0340] In these embodiments, when the above conditions are met, the problem of excessively thick heat conductor 76 leading to excessively large battery cell 3 volume and reduced energy density can be improved, and the problem of excessively thin heat conductor 76 being easily damaged can also be improved.

[0341] For example, the thickness D1 of the thermally conductive component 7 is 40μm, 50μm, 110μm, or 180μm, etc.

[0342] In some embodiments, as shown in FIG19, the insulating element 75 comprises polyethylene, polypropylene, polyimide, or polyester resin.

[0343] In these embodiments, the insulating element 75 comprises polyethylene, polypropylene, polyimide, or polyester resin to improve the insulation reliability of the insulating element 75.

[0344] Optionally, the insulating component 75 should have insulating and high-temperature resistant properties so that the insulating component 75 can be used to insulate the heat-conducting component 76 and the electrode assembly 5, and to reduce the risk of the insulating component 75 melting and being damaged under high-temperature conditions.

[0345] In some embodiments, as shown in FIG19, the heat-conducting element 76 includes graphite, graphene, or carbon nanotubes.

[0346] In these embodiments, graphite is typically composed of parallel layers of carbon atoms, exhibiting a planar sheet-like morphology. Graphene is typically a two-dimensional crystal composed of carbon atoms with only one atom thickness on one side, resembling a fiber. Carbon nanotubes are typically tubular structures formed by rolling up one or more layers of graphite. The heat-conducting element 76 is made of graphite, graphene, or carbon nanotubes, and the thermal conductivity of the heat-conducting element 76 is improved by using graphite, graphene, or carbon nanotube thermal conductive materials.

[0347] Optionally, the heat conductor 76 is made of supercrystalline graphite, which has a larger grain size than ordinary graphite and a significantly improved thermal conductivity, so that the heat conductor 76 has better thermal conductivity.

[0348] Optionally, the heat-conducting component 76 employs graphite thermal conductivity technology, which is a thermal conductivity technology based on graphite materials and microporous structures. Its principle is to utilize the high thermal conductivity of graphite materials to rapidly transfer heat to the heat-conducting sheet, and then dissipate the heat to the external environment quickly through the microporous structure, thereby achieving a heat exchange effect.

[0349] In some embodiments, as shown in FIG19, the thermal conductivity k of the heat-conducting element 76 satisfies k≥500W / (m·K).

[0350] In these embodiments, when the thermal conductivity k of the heat-conducting element 76 meets the above conditions, the heat-conducting component 7 has sufficient thermal conductivity to conduct heat from the electrode body.

[0351] Optionally, the thermal conductivity k of the heat-conducting component 76 satisfies 500W / (m·K)≤k≤1600W / (m·K). For example, the thermal conductivity of the heat-conducting component 76 is 500W / (m·K), 550W / (m·K), 1050W / (m·K), 1550W / (m·K), or 1600W / (m·K), etc.

[0352] Optionally, the thermal conductivity k of the heat-conducting component 76 satisfies k≥1000W / (m·K).

[0353] Optionally, the thermally conductive component 76 has a density of 2.1±0.05g / cm3, an insulation resistance greater than 1GΩ, a withstand voltage of 5400V, and a bending resistance of >10000 cycles.

[0354] Please refer to Figures 24 and 25. Figure 24 is a schematic diagram of the structure of a battery device provided in an embodiment of this application; Figure 25 is an enlarged schematic diagram of the structure at point A in Figure 24.

[0355] Secondly, as shown in Figures 8, 24 and 25, this application provides a battery device 2, including a housing 202 and a battery cell 3 as described in the first aspect embodiment, wherein the battery cell 3 is disposed within the housing 202.

[0356] In the embodiment of this application, the battery cell 3 is disposed inside the housing 202, which serves to accommodate the battery cell 3. The battery cell 3 includes a heat-conducting component 7. An external heat-conducting channel for the battery cell 3 is established by a first heat-conducting part 71 disposed on the side surface of the end cap assembly 6 away from the electrode assembly 5 and a second heat-conducting part 72 disposed on the side wall 42. This reduces the thermal resistance at the end cap assembly 6 and the side wall 42, increases the rate of heat exchange between the battery cell 3 and the external environment, and improves the problem of adverse effects on the performance and service life of the battery cell 3 due to excessively high or low temperatures, thereby improving the performance of the battery device 2.

[0357] A number of battery cells 3 are disposed inside the housing 202. For example, one, two, or three battery cells 3 are disposed inside the housing 202.

[0358] Optionally, multiple battery cells are arranged in rows and columns within the housing 202.

[0359] In some embodiments, as shown in Figures 8, 24 and 25, the battery device 2 further includes a heat exchange mechanism 8, which is disposed inside the housing 202, and the heat conduction component 7 and the heat exchange mechanism 8 are thermally connected.

[0360] In these embodiments, the battery device 2 also includes a heat exchange mechanism 8 disposed within the housing 202. The heat conduction component 7 and the heat exchange mechanism 8 are thermally connected to improve the heat exchange rate between the battery cell 3 and the heat exchange mechanism 8, so as to better balance the temperature of the battery cell 3 and improve the performance of the battery device 2.

[0361] In related technologies, a heat exchange mechanism 8 is provided inside the housing 202, and the heat exchange mechanism 8 is thermally connected to the shell 4 of the battery cell 3, so that the heat of the battery cell 3 can be transferred to the outside through the heat exchange mechanism 8. In the embodiment of this application, in order to improve the thermal conductivity of the battery cell 3, a heat-conducting component 7 is provided and thermally connected to the heat exchange mechanism 8. The heat-conducting component 7 is an external cold bridge for the battery cell 3 to improve the thermal conductivity between it and the heat exchange mechanism 8, so as to better balance the temperature of the battery cell 3.

[0362] For example, the heat exchange mechanism 8 can be a liquid cooling plate or a phase change heat dissipation plate or a cavity containing a heat exchange medium, which can be disposed on the outer surface of the battery cell 3.

[0363] For example, the housing 4 includes a bottom wall 43 and a side wall 42 that are connected to each other, and the heat exchange mechanism 8 and the side wall 42 are arranged side by side, or the heat exchange mechanism 8 and the bottom wall 43 are arranged side by side.

[0364] The heat-conducting component 7 and the heat exchange mechanism 8 are thermally connected. Specifically, the heat-conducting component 7 is directly attached to or abuts against the heat exchange mechanism 8; or the heat-conducting component 7 and the heat exchange mechanism 8 are spaced apart, and the heat-conducting component 7 is indirectly connected to the heat exchange mechanism 8 through a heat-conducting medium, which can be air, metal, or heat-conducting adhesive, etc.

[0365] For example, the two sides of the heat-conducting component 7 are respectively bonded to at least one of the housing 4 and the end cap assembly 6 and the heat exchange mechanism 8 to improve the heat exchange efficiency between the end cap assembly 6 and the heat exchange mechanism 8; or the heat-conducting component 7 is bonded to at least one of the housing 4 and the end cap assembly 6, and the heat-conducting component 7 abuts against the heat exchange mechanism to reduce the installation difficulty of the heat-conducting component 7.

[0366] In some embodiments, as shown in Figures 8, 24, and 25, the sidewall 42 includes two first sidewalls 421 and two second sidewalls 422. The two first sidewalls 421 are arranged opposite each other in the second direction Y, and the two second sidewalls 422 are arranged opposite each other in the third direction Z. The first direction X, the second direction Y, and the third direction Z intersect each other. The area of ​​the first sidewall 421 is larger than the area of ​​the second sidewall 422. The heat exchange mechanism 8 and the first sidewall 421 are spaced apart along the second direction Y. At least one second heat-conducting part 72 is disposed between the first sidewall 421 and the heat exchange mechanism 8. Alternatively, the heat exchange mechanism 8 and the second sidewall 422 are spaced apart along the third direction Z, and at least one second heat-conducting part 72 is disposed between the second sidewall 422 and the heat exchange mechanism 8.

[0367] In these embodiments, the heat exchange mechanism 8 and the first sidewall 421 are spaced apart along the second direction Y, and at least one second heat-conducting part 72 is disposed between the first sidewall 421 and the heat exchange mechanism 8. Alternatively, the heat exchange mechanism 8 and the second sidewall 422 are spaced apart along the third direction Z, and at least one second heat-conducting part 72 is disposed between the second sidewall 422 and the heat exchange mechanism 8. This shortens the distance between the heat-conducting component 7 and the heat exchange mechanism 8, allowing the heat-conducting component 7 to better transfer heat between the heat exchange mechanism 8 and the end cap assembly 6, thereby better balancing the temperature of the battery cell 3 and improving the performance of the battery device 2.

[0368] For example, in the large-area water-cooling solution, the heat exchange mechanism 8 and the first sidewall 421 are arranged side by side along the second direction Y. The second heat-conducting part 72 is disposed between the first sidewall 421 and the heat exchange mechanism 8. The second heat-conducting part 72 disposed on the first sidewall 421 and the heat exchange mechanism 8 have a small distance and a large projected overlapping area, so that the second heat-conducting part 72 can better transfer heat between the end cap assembly 6 and the heat exchange mechanism 8. The second heat-conducting part 72 also improves the heat exchange rate between the first sidewall 421 of the battery cell 3 and the heat exchange mechanism 8.

[0369] For example, the heat exchange mechanism 8 and the second sidewall 422 are arranged side by side along the third direction Z. The second heat-conducting part 72 is disposed between the second sidewall 422 and the heat exchange mechanism 8. The second heat-conducting part 72 disposed on the second sidewall 422 and the heat exchange mechanism 8 have a small distance and a large projected overlapping area, so that the second heat-conducting part 72 can better transfer heat between the end cap assembly 6 and the heat exchange mechanism 8. The second heat-conducting part 72 also improves the heat exchange rate between the first sidewall 421 of the battery cell 3 and the heat exchange mechanism 8.

[0370] Please refer to Figures 26 and 27. Figure 26 is a partial structural schematic diagram of a battery device provided in an embodiment of this application; Figure 27 is an enlarged structural schematic diagram of point B in Figure 26.

[0371] In some embodiments, as shown in Figures 13, 26 and 27, the heat-conducting component 7 further includes a third heat-conducting part 73, which is connected to the second heat-conducting part 72. The third heat-conducting part 73 is disposed on the bottom wall 43, and the heat exchange mechanism 8 is disposed on the side of the third heat-conducting part 73 away from the bottom wall 43.

[0372] In these embodiments, when the heat exchange mechanism 8 is disposed on the bottom wall 43 of the battery cell 3, the third heat conduction part 73 can transfer the heat at the end cap assembly 6 to the heat exchange mechanism 8 to better balance the heat at the end cap assembly 6, thereby balancing the internal temperature of the battery device 2 and improving the performance of the battery device 2.

[0373] Specifically, the heat-conducting component 7 includes a first heat-conducting part 71, a second heat-conducting part 72, and a third heat-conducting part 73, with the first heat-conducting part 71 and the third heat-conducting part 73 respectively connected to the two ends of the second heat-conducting part 72 in the first direction X.

[0374] The heat from the end cap assembly 6 is transferred to the third heat-conducting part 73 through the first heat-conducting part 71 and the second heat-conducting part 72, and then transferred to the external environment.

[0375] For example, the heat exchange mechanism 8 is connected to the bottom wall 43 of the housing 4, and the heat from the end cap assembly 6 is transferred to the heat exchange mechanism 8 through the third heat conduction part 73.

[0376] Optionally, the third heat-conducting part 73 and the second heat-conducting part 72 are manufactured separately and then bonded together to facilitate adjustment of the shape and size of the third heat-conducting part 73 and the second heat-conducting part 72; or the third heat-conducting part 73 and the second heat-conducting part 72 are integrally formed and bent from the same substrate to reduce the processing difficulty of the heat-conducting component 7. For example, the first heat-conducting part 71, the second heat-conducting part 72, and the third heat-conducting part 73 are integrally formed and bent from the same substrate.

[0377] Optionally, multiple second heat-conducting parts 72 are spaced apart and all connected to the third heat-conducting part 73 to increase the connection area between the second heat-conducting parts 72 and the third heat-conducting part 73, thereby increasing the heat conduction rate of the heat-conducting component 7. For example, four second heat-conducting parts 72 are respectively disposed on two first sidewalls 421 and two second sidewalls 422, and all four second heat-conducting parts 72 are connected to the third heat-conducting part 73 to increase the connection area between the second heat-conducting parts 72 and the third heat-conducting part 73.

[0378] Optionally, the size and shape of the third heat-conducting part 73 can be designed by the user. For example, the third heat-conducting part 73 can be rectangular, circular, or annular.

[0379] Please refer to Figure 28, which is a partial structural schematic diagram of a battery device provided in an embodiment of this application.

[0380] In some embodiments, as shown in Figures 5, 8, 13 and 28, at least two battery cells 3 are thermally connected to the same thermally conductive assembly 7.

[0381] In these embodiments, at least two battery cells 3 are thermally connected to the same thermally conductive component 7 to reduce the difficulty of fitting the thermally conductive component 7 and the battery cells 3 together.

[0382] The housing 202 includes multiple battery cells 3 arranged in rows and columns along a second direction Y and / or a third direction Z. To reduce the difficulty of fitting the heat-conducting component 7 and the battery cells 3, the multiple battery cells 3 are thermally connected to the same heat-conducting component 7. For example, the heat-conducting component 7 includes a first heat-conducting part 71 and a second heat-conducting part 72. The first heat-conducting part 71 is connected to the end cap assembly 6 of at least two battery cells 3, and the second heat-conducting part 72 is connected to the first side wall 421 or the second side wall 422 of at least two battery cells 3; or the heat-conducting component 7 includes a first heat-conducting part 71, a second heat-conducting part 72 and a third heat-conducting part 73. The first heat-conducting part 71 is connected to the end cap assembly 6 of at least two battery cells 3, the second heat-conducting part 72 is connected to the first side wall 421 or the second side wall 422 of at least two battery cells 3, and the third heat-conducting part 73 is connected to the bottom wall 43 of at least two battery cells 3.

[0383] For example, multiple battery cells 3 are arranged in rows and columns along the second direction Y and the third direction Z inside the housing 202. Multiple heat exchange mechanisms 8 are spaced apart along the second direction Y and arranged side by side with the first sidewall 421 of the battery cells 3. Multiple heat conduction components 7 are spaced apart along the second direction Y. The heat conduction components 7 include a first heat conduction part 71 and a second heat conduction part 72. The first heat conduction part 71 is connected to the end cap assembly 6 of the multiple battery cells 3, and the second heat conduction part 72 is connected to the first sidewall 421 of the multiple battery cells 3 and is located between the heat exchange mechanism 8 and the first sidewall 421 of the battery cells 3.

[0384] Thirdly, embodiments of this application provide an electrical device, including the battery device described in the second aspect of the embodiment above.

[0385] In some embodiments, as shown in Figures 1 to 28, this application provides a battery device 2. The battery device 2 includes a housing 202, a battery cell 3, a heat-conducting component 7, and a heat exchange mechanism 8. The battery cell 3 is disposed within the housing 202 and includes a housing 4, an end cap assembly 6, and an electrode assembly 5. The housing 4 has an opening 41 in a first direction X. The electrode assembly 5 is disposed within the housing 4. The end cap assembly 6 covers the opening 41 and includes a cover plate 61 and electrode terminals 62 disposed on the cover plate 61. The electrode terminals 62 and the electrode assembly 5 are connected to the end cap assembly 6. The electrode assembly 5 is connected. The housing 4 includes a bottom wall 43 and a side wall 42 that are interconnected. The bottom wall 43 and the opening 41 are arranged opposite each other. The side wall 42 and the end cap assembly 6 are connected with rounded corners. The bottom wall 43 and the side wall 42 are connected with rounded corners. The rounded corners are spaced apart from the heat-conducting assembly 7. The side wall 42 includes two first side walls 421 and two second side walls 422. The two first side walls 421 are arranged opposite each other in the second direction Y. The two second side walls 422 are arranged opposite each other in the third direction Z. The first direction X, the second direction Y, and the third direction Z intersect each other. The first side walls 421... The area of ​​the first sidewall 421 is larger than the area of ​​the second sidewall 422. The electrode assembly 5 and the end cap assembly 6 are connected. The heat exchange mechanism 8 is disposed inside the housing 202, and the heat exchange mechanism 8 and the battery cell 3 are spaced apart. The heat conduction assembly 7 includes a first heat conduction part 71, a second heat conduction part 72 and a third heat conduction part 73. The first heat conduction part 71 is disposed on the side surface of the end cap assembly 6 away from the electrode assembly 5. The first heat conduction part 71 is connected to the electrode terminal 62. The thermal conductivity of the heat conduction assembly 7 is greater than the thermal conductivity of the end cap assembly 6 and the housing 4. The heat exchange mechanism 8 and the first sidewall 421 are connected along the second sidewall 422. The heat exchange mechanism 8 is provided with at least one second heat-conducting part 72 between the first sidewall 421 and the heat exchange mechanism 8, or the heat exchange mechanism 8 and the second sidewall 422 are provided with at least one second heat-conducting part 72 between the second sidewall 422 and the heat exchange mechanism 8. The bottom wall 43 includes a first part 431 and a second part 432. The third heat-conducting part 73 is provided in the first part 431. The heat exchange mechanism 8 is connected to the second part 432. The heat-conducting component 7 also includes an adhesive layer 74. The thickness L1 of the adhesive layer satisfies L1≥0.The 5mm adhesive layer 74 includes a first adhesive layer 741, a second adhesive layer 742, and a third adhesive layer 743. The second thermally conductive part 72 is bonded to the side wall 42 via the first adhesive layer 741, and the third thermally conductive part 73 is bonded to the bottom wall 43 via the second adhesive layer 742. The first thermally conductive part 71 is bonded to the end cap assembly 6 via the third adhesive layer 743. At least two second thermally conductive parts 72 are respectively disposed on the first side wall 421 and the second side wall 422. The first adhesive layer 741 faces the first direction X. The minimum distance between one end of the first heat-conducting part 71 and the edge of the sidewall 42 is greater than or equal to 10 mm; the minimum distance between one end of the second adhesive layer 742 facing the second heat-conducting part 72 and the edge of the bottom wall 43 is greater than or equal to 10 mm; the minimum distance between one end of the third adhesive layer 743 facing the second heat-conducting part 72 and the edge of the end cap assembly 6 is greater than or equal to 10 mm; the minimum distance L2 between the second heat-conducting part 72 disposed on the first sidewall 421 and the adjacent second sidewall 422 in the third direction Z satisfies L2≥10 mm; and / or the minimum distance L3 between the second heat-conducting part 72 disposed on the second sidewall 422 and the adjacent first sidewall 421 in the second direction Y satisfies L3≥10 mm; the heat-conducting assembly 7 includes an insulating member 75 and a heat-conducting member 76; the insulating member 75 forms a receiving cavity 77 in at least a portion of its area; the heat-conducting member 76 is disposed within the receiving cavity 77; the heat-conducting member 76 includes a first heat-conducting sheet 761 and a second heat-conducting sheet 762 connected to each other; the first heat-conducting sheet 761... A first heat-conducting part 71 is disposed on the end cap assembly 6, and a second heat-conducting sheet 762 is disposed on the side wall 42. The first heat-conducting part 71 is composed of a first heat-conducting sheet 761 and an insulating member 75, and the second heat-conducting part 72 is composed of a second heat-conducting sheet 762 and an insulating member 75. The insulating member 75 is disposed on the outer surface of the end cap assembly 6 and the housing 4. The end cap assembly 6 includes a cover plate 61 and a pressure relief mechanism 63 disposed on the cover plate 61. The insulating member 75 has a through-hole 751, and the pressure relief mechanism 63 protrudes from the first opening 751.

[0386] In these embodiments, the battery cell 3 includes a housing 4, an end cap assembly 6, and an electrode assembly 5. The housing 4 includes a bottom wall 43, a side wall 42, and a cavity enclosed by the bottom wall 43 and the side wall 42 with an opening 41 at one end in a first direction X. The electrode assembly 5 is housed within the housing 4. The end cap assembly 6 covers the opening 41 of the housing 4 and is connected to the electrode assembly 5, so that the electrode assembly 5 can form a circuit with external devices through the end cap assembly 6. The heat-conducting assembly 7 includes a first heat-conducting part 71 and a second heat-conducting part 72. The thermal conductivity of the heat-conducting assembly 7 is greater than that of the end cap assembly 6 and the housing 4. The first heat-conducting part 71, disposed on the side surface of the end cap assembly 6 away from the electrode assembly 5, establishes an external heat-conducting channel for the battery cell 3 to reduce the thermal resistance at the end cap assembly 6. The second heat-conducting part 72, disposed on the side wall 42, increases the total area of ​​the heat-conducting assembly 7 and increases the rate of heat exchange between the battery cell 3 and the external environment, thereby improving the problem of adverse effects on the performance and service life of the battery cell 3 due to excessively high or low temperatures.

[0387] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, wherein, include: The housing includes a bottom wall, side walls, and a cavity enclosed by the bottom wall and the side walls, which opens at one end in a first direction; Electrode assemblies are disposed within the cavity; An end cap assembly that covers the opening, the end cap assembly being connected to the electrode assembly; A thermally conductive component includes a first thermally conductive part and a second thermally conductive part connected to each other. The first thermally conductive part is disposed on the side surface of the end cap assembly away from the electrode assembly, and the second thermally conductive part is disposed on the side wall. The thermal conductivity of the thermally conductive component is greater than that of the end cap assembly and the housing.

2. The battery cell according to claim 1, wherein the sidewall comprises two first sidewalls and two second sidewalls, the two first sidewalls being disposed opposite each other in a second direction, the two second sidewalls being disposed opposite each other in a third direction, the first direction, the second direction, and the third direction intersecting each other, and the area of ​​the first sidewalls being larger than the area of ​​the second sidewalls. The second heat-conducting part is disposed on the first sidewall, and / or the second heat-conducting part is disposed on the second sidewall.

3. The battery cell according to claim 2, wherein the second thermally conductive portion covers the entire first sidewall, or the second thermally conductive portion covers the entire second sidewall.

4. The battery cell according to any one of claims 1-3, wherein the sidewall and the end cap assembly are connected with rounded corners, and the rounded corners and the heat-conducting assembly are spaced apart.

5. The battery cell according to any one of claims 1-4, wherein the thermally conductive assembly further comprises an adhesive layer, the adhesive layer comprising a first adhesive layer, and the second thermally conductive portion is bonded to the sidewall through the first adhesive layer.

6. The battery cell according to claim 5, wherein the thickness L1 of the adhesive layer satisfies L1≥0.5mm.

7. The battery cell according to claim 5 or 6, wherein the first adhesive layer is disposed at a distance between one end of the first thermally conductive portion and the edge of the sidewall in the first direction.

8. The battery cell according to claim 7, wherein the minimum distance between the end of the first adhesive layer facing the first thermally conductive part in the first direction and the edge of the sidewall is greater than or equal to 10 mm.

9. The battery cell according to any one of claims 1-8, wherein the sidewall comprises two first sidewalls and two second sidewalls, the two first sidewalls are disposed opposite each other in a second direction, the two second sidewalls are disposed opposite each other in a third direction, the first direction, the second direction, and the third direction intersect each other, the area of ​​the first sidewall is larger than the area of ​​the second sidewall, and at least two second heat-conducting portions are disposed on the first sidewall and the second sidewall, wherein, The second heat-conducting parts, which are respectively located on the first sidewall and the second sidewall, are independent of each other.

10. The battery cell according to claim 9, wherein the minimum distance L2 between the second heat-conducting portion disposed on the first sidewall and the adjacent second sidewall in the third direction satisfies L2 ≥ 10 mm; and / or The minimum distance L3 between the second heat-conducting part disposed on the second sidewall and the adjacent first sidewall in the second direction satisfies that L3≥10mm.

11. The battery cell according to any one of claims 1-10, wherein the heat-conducting assembly further comprises a third heat-conducting part, the third heat-conducting part being connected to the second heat-conducting part, and the third heat-conducting part being disposed on the bottom wall.

12. The battery cell according to claim 11, wherein the bottom wall comprises a first portion and a second portion, the third heat-conducting portion is disposed in the first portion, and the second portion is used to connect with the mounting position.

13. The battery cell according to claim 11 or 12, wherein the sidewall and the bottom wall are connected with rounded corners, and the rounded corners and the heat-conducting component are spaced apart.

14. The battery cell according to any one of claims 11 to 13, wherein the thermally conductive assembly further comprises an adhesive layer, the adhesive layer comprising a second adhesive layer, and the third thermally conductive portion is bonded to the bottom wall through the second adhesive layer.

15. The battery cell according to claim 14, wherein the end of the second adhesive layer facing the second thermally conductive portion and the edge of the bottom wall are spaced apart.

16. The battery cell according to claim 15, wherein the minimum distance between the end of the second adhesive layer facing the second thermally conductive part and the edge of the bottom wall is greater than or equal to 10 mm.

17. The battery cell according to claim 15 or 16, wherein the thermally conductive assembly further comprises an adhesive layer, the adhesive layer comprising a third adhesive layer, and the first thermally conductive portion is bonded to the end cap assembly through the third adhesive layer.

18. The battery cell according to claim 17, wherein the third adhesive layer is spaced apart from one end of the second thermally conductive portion and the edge of the end cap assembly.

19. The battery cell according to claim 18, wherein the minimum distance between the end of the third adhesive layer facing the second thermally conductive part and the edge of the end cap assembly is greater than or equal to 10 mm.

20. The battery cell according to any one of claims 1-19, wherein the end cap assembly includes a cover plate and an electrode terminal disposed on the cover plate, the electrode terminal being connected to the electrode assembly, and the first heat-conducting portion being connected to the electrode terminal.

21. The battery cell according to any one of claims 1-20, wherein the battery cell further comprises a first insulating layer disposed on the outer surface of the housing and the end cap assembly, and the heat-conducting component is disposed on the side of the first insulating layer opposite to the housing and the end cap assembly.

22. The battery cell according to any one of claims 1-21, wherein the thermally conductive assembly comprises an insulating member and a thermally conductive member, the insulating member forming a receiving cavity in at least a portion thereof, and the thermally conductive member being disposed within the receiving cavity. The heat-conducting component includes a first heat-conducting sheet and a second heat-conducting sheet connected to each other. The first heat-conducting sheet is disposed on the end cap assembly, and the second heat-conducting sheet is disposed on the side wall. The first heat-conducting part is composed of the first heat-conducting sheet and the insulating component, and the second heat-conducting part is composed of the second heat-conducting sheet and the insulating component.

23. The battery cell according to claim 22, wherein the insulating element is disposed on the outer surface of the end cap assembly and the housing.

24. The battery cell according to claim 22, wherein the battery cell further comprises a second insulating layer, the second insulating layer being connected to the insulating element, and the insulating element and the second insulating layer together covering the outer surface of the housing and the end cap assembly.

25. The battery cell according to claim 24, wherein the end cap assembly includes a cover plate and a pressure relief mechanism disposed on the cover plate, the insulating member having a first opening through it, and the pressure relief mechanism being exposed in the first opening.

26. The battery cell according to any one of claims 22-25, wherein the sidewall comprises two first sidewalls and two second sidewalls, the two first sidewalls being disposed opposite each other in a second direction, the two second sidewalls being disposed opposite each other in a third direction, the first direction, the second direction, and the third direction intersecting each other, the area of ​​the first sidewalls being larger than the area of ​​the second sidewalls, and at least two second heat-conducting sheets being disposed on the first sidewalls and the second sidewalls respectively, wherein, The second heat-conducting plates, located on the first sidewall and the second sidewall respectively, are independent of each other.

27. The battery cell according to any one of claims 22-26, wherein the thermal conductive element further comprises a third thermal conductive sheet, the third thermal conductive sheet being connected to the second thermal conductive sheet, and the second thermal conductive sheet being disposed on the bottom wall.

28. The battery cell according to any one of claims 22-27, wherein the thickness D1 of the thermal conductive element satisfies 40μm≤D1≤180μm.

29. The battery cell according to any one of claims 22-28, wherein the insulating element comprises polyethylene, polypropylene, polyimide, or polyester resin.

30. The battery cell according to any one of claims 22-29, wherein the thermal conductive element comprises graphite, graphene, or carbon nanotubes.

31. The battery cell according to any one of claims 22-30, wherein the thermal conductivity k of the thermal conductive element satisfies k≥500W / (m·K).

32. A battery device, wherein, It includes a housing and a battery cell as described in any one of claims 1-31, wherein the battery cell is disposed within the housing.

33. The battery device according to claim 32, the battery device further comprising a heat exchange mechanism disposed within the housing, the heat-conducting component and the heat exchange mechanism being thermally connected.

34. The battery device of claim 33, wherein the sidewall comprises two first sidewalls and two second sidewalls, the two first sidewalls being disposed opposite each other in a second direction, the two second sidewalls being disposed opposite each other in a third direction, the first direction, the second direction, and the third direction intersecting each other, and the area of ​​the first sidewalls being larger than the area of ​​the second sidewalls. The heat exchange mechanism and the first sidewall are spaced apart along the second direction, and at least one second heat-conducting part is disposed between the first sidewall and the heat exchange mechanism; or the heat exchange mechanism and the second sidewall are spaced apart along the third direction, and at least one second heat-conducting part is disposed between the second sidewall and the heat exchange mechanism.

35. The battery device according to claim 33, wherein the heat-conducting component further comprises a third heat-conducting part, the third heat-conducting part being connected to the second heat-conducting part, the third heat-conducting part being disposed on the bottom wall, and the heat exchange mechanism being disposed on the side of the third heat-conducting part away from the bottom wall.

36. The battery device according to claim 33, wherein at least two of the battery cells are thermally connected to the same thermally conductive assembly.

37. An electrical appliance, wherein, The battery device includes any one of claims 32-36 above.

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