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, provided with a pressure relief mechanism; electrode assemblies, located in the casing; and a heat conduction assembly, comprising a first heat conduction portion, the first heat conduction portion being connected to the electrode assemblies in a thermally conductive manner, wherein the first heat conduction portion is disposed between the electrode assemblies and the pressure relief mechanism in a first direction, and the first heat conduction portion is provided with a pressure relief hole passing through the first heat conduction portion in the first direction. In the first direction, the orthographic projection of the pressure relief mechanism at least partially overlaps with the orthographic projection of the pressure relief hole, so that during thermal runaway of the battery cell, pressure inside the casing can act on the pressure relief mechanism by means of the pressure relief hole, causing the pressure relief mechanism to be smoothly activated, thereby enhancing the reliability of the pressure relief mechanism of the battery cell.

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] Lithium-ion power batteries possess advantages such as high operating voltage, high specific energy, small size, light weight, long cycle life, low self-discharge rate, no memory effect, and no pollution, making them widely used by many power equipment manufacturers. However, with the rapid development of lithium batteries, battery safety has also received widespread attention.

[0003] In battery production, a pressure relief mechanism is usually installed in the battery cell to relieve pressure when the battery cell experiences thermal runaway. However, improving the reliability of the pressure relief mechanism is an urgent problem to be solved.

[0004] Summary of the Invention

[0005] In view of the above problems, this application provides a battery cell, a battery device, and an electrical device that can enhance the reliability of the pressure relief mechanism of the battery cell.

[0006] In a first aspect, this application provides a battery cell, comprising: a housing having a pressure relief mechanism; an electrode assembly located within the housing; and a heat-conducting assembly including a first heat-conducting part, the first heat-conducting part and the electrode assembly being thermally connected, wherein the first heat-conducting part is disposed between the electrode assembly and the pressure relief mechanism along a first direction, the first heat-conducting part having a pressure relief hole penetrating through the first heat-conducting part along the first direction, and along the first direction, the orthographic projection of the pressure relief mechanism and the orthographic projection of the pressure relief hole at least partially overlap.

[0007] In the embodiments of this application, the battery cell includes a housing, an electrode assembly, and a heat-conducting assembly. The housing is provided with a pressure relief mechanism for releasing internal pressure. The electrode assembly is disposed inside the housing. The heat-conducting assembly includes a first heat-conducting part, which is thermally connected to the electrode assembly to increase the rate of heat exchange between the electrode assembly and the external environment. The first heat-conducting part is disposed between the electrode assembly and the pressure relief mechanism. The first heat-conducting part has a pressure relief hole that penetrates the first heat-conducting part along a first direction. Along the first direction, the orthographic projection of the pressure relief mechanism and the orthographic projection of the pressure relief hole at least partially overlap, so that at least part of the pressure relief mechanism is exposed through the pressure relief hole. This allows the internal pressure of the housing to act on the pressure relief mechanism through the pressure relief hole when the battery cell experiences thermal runaway, prompting the pressure relief mechanism to start smoothly and improving the reliability of the battery cell's pressure relief mechanism.

[0008] In some embodiments, multiple electrode assemblies are provided, and the multiple electrode assemblies are arranged along a second direction. The first direction and the second direction intersect. The heat-conducting assembly further includes a second heat-conducting part. The first heat-conducting part and the second heat-conducting part are connected. The second heat-conducting part is disposed between two adjacent electrode assemblies. The two side surfaces of the second heat-conducting part along the second direction and the first heat-conducting part form two receiving spaces for accommodating the electrode assemblies. Both receiving spaces are connected to the pressure relief hole.

[0009] In the embodiment of this application, multiple electrode assemblies are arranged along a second direction to increase the capacity of a single battery cell. The heat-conducting assembly also includes a second heat-conducting part disposed between two adjacent electrode assemblies. The first heat-conducting part and the second heat-conducting part are connected. The second heat-conducting part is used to conduct heat from adjacent electrode assemblies and transfer it to the first heat-conducting part. The two side surfaces of the second heat-conducting part along the second direction and the first heat-conducting part form two receiving spaces for accommodating electrode assemblies. Both receiving spaces are connected to the pressure relief hole to improve the problem that when a single battery cell experiences thermal runaway, the pressure in the two receiving spaces is blocked by the first heat-conducting part and cannot be transferred to the pressure relief mechanism, resulting in a slow pressure relief rate and insufficient reliability of the single battery cell.

[0010] In some embodiments, the second heat-conducting part is provided with a through hole along the second direction.

[0011] In the embodiment of this application, the second heat-conducting part is provided with a through hole along the second direction, and the gas in the two accommodating cavities can flow through the through hole to balance the pressure acting on the pressure relief mechanism and improve the reliability of the pressure relief mechanism.

[0012] In some embodiments, a connecting hole is disposed at one end of the second heat-conducting part near the first heat-conducting part.

[0013] In the embodiment of this application, the central region of the electrode assembly generates more heat than the edge region. Therefore, the connecting hole is set at the end of the second heat-conducting part near the first heat-conducting part to avoid the central region of the electrode assembly. While the connecting hole connects the two accommodating spaces, the heat conduction efficiency of the heat-conducting component is improved.

[0014] In some embodiments, the connecting hole and the pressure relief hole are connected.

[0015] In the embodiments of this application, the connecting hole and the pressure relief hole are connected to reduce the processing difficulty of the heat-conducting component.

[0016] In some embodiments, the battery cell further includes a support assembly disposed between the housing and the electrode assembly to allow a pressure relief space to be formed between the electrode assembly and the housing.

[0017] In the embodiments of this application, the battery cell further includes a support component disposed between the casing and the electrode assembly. The support component forms a pressure relief space between the electrode assembly and the casing. The pressure relief space is used to buffer the internal pressure of the casing when the battery cell experiences thermal runaway, so as to reduce the risk of the battery cell exploding or deflagrizing in a short period of time.

[0018] In some embodiments, the support assembly is disposed between the first heat-conducting part and the housing, or between the first heat-conducting part and the electrode assembly.

[0019] In the embodiments of this application, the support component is disposed between the first heat-conducting part and the housing, so that the first heat-conducting part is close to the electrode component, thereby improving the heat conduction rate between the electrode component and the heat-conducting component; or the support component is disposed between the first heat-conducting part and the electrode component, so that the first heat-conducting part is close to the housing, thereby improving the heat conduction rate between the housing and the heat-conducting component.

[0020] In some embodiments, multiple electrode assemblies are provided, and the multiple electrode assemblies are arranged along a second direction, with the first direction and the second direction intersecting. The heat-conducting assembly further includes a second heat-conducting part, and the first heat-conducting part and the second heat-conducting part are connected. A support assembly is disposed between the first heat-conducting part and the electrode assembly, and there are two support assemblies, which are respectively disposed on both sides of the second heat-conducting part in the second direction.

[0021] In the embodiment of this application, a support component is disposed between the first heat-conducting part and the electrode component. There are two support components, which are respectively disposed on both sides of the second heat-conducting part in the second direction, so as to reduce the risk of mutual interference between the support component and the second heat-conducting part, which could lead to damage to the heat-conducting component.

[0022] In some embodiments, multiple electrode assemblies are provided, and the multiple electrode assemblies are stacked along the second direction. The first direction and the second direction intersect. The heat-conducting assembly further includes a second heat-conducting part. The first heat-conducting part and the second heat-conducting part are connected. A support assembly is disposed between the first heat-conducting part and the housing. The orthographic projection of the second heat-conducting part in the first direction is located on the support assembly.

[0023] In the embodiment of this application, the support component is disposed between the first heat-conducting part and the shell, and the orthographic projection of the second heat-conducting part in the first direction is located on the support component, so that a single support component can support the first heat-conducting part that forms two accommodating spaces, thereby reducing the difficulty of matching the support component and the heat-conducting component.

[0024] In some embodiments, the support assembly includes an insulating portion and at least two raised portions connected to each other, the insulating portion being located between the electrode assembly and the raised portions, and each raised portion being spaced apart on the side of the insulating portion away from the electrode assembly.

[0025] In the embodiments of this application, the support component includes an insulating part and at least two raised parts that are interconnected. The insulating part is located between the electrode component and the raised parts. The raised parts are used to support the insulating part and the insulating part is used to support the electrode component. Each raised part is spaced apart on the side of the insulating part away from the electrode component. The cross-sectional area of ​​the insulating part in the first direction is greater than the total cross-sectional area of ​​each raised part in the first direction, so as to increase the contact area between the support component and the electrode component, so that the support component provides a stable support effect for the electrode component.

[0026] In some embodiments, the orthogonal projection of the pressure relief hole in the first direction is at least partially located on the insulating portion, which is configured to melt when the internal pressure or temperature of the battery cell reaches a threshold.

[0027] In the embodiment of this application, the pressure relief hole is at least partially located on the insulating part in the first direction to increase the contact area between the insulating part and the electrode assembly. The insulating part is configured to melt when the internal pressure or temperature of the battery cell reaches a threshold, so that when the battery cell is thermally runaway, the gas inside the casing can smoothly pass through the support assembly and the pressure relief hole to act on the pressure relief mechanism, thereby improving the reliability of the pressure relief mechanism.

[0028] In some embodiments, the dimension L2 of the support component in the first direction satisfies 5mm < L2 ≤ 15mm.

[0029] In the embodiment of this application, when the dimension L2 of the support component in the first direction satisfies the above conditions, a pressure relief space of sufficient volume is formed between the second end face and the housing to improve the reliability of the battery cell.

[0030] In some embodiments, along the first direction, the orthographic projection of the pressure relief hole is completely within the orthographic projection range of the pressure relief mechanism.

[0031] In the embodiment of this application, the orthographic projection of the pressure relief hole is completely located within the orthographic projection range of the pressure relief mechanism along the first direction, so that the internal pressure of the housing can be uniformly applied to the entire pressure relief mechanism through the pressure relief hole, thereby improving the reliability of the pressure relief mechanism.

[0032] In some embodiments, the thermally conductive component includes an insulating element and a thermally conductive element. At least a portion of the insulating element forms a receiving cavity, and the thermally conductive element is disposed within the receiving cavity. The insulating element includes a first insulating portion disposed between the housing and the electrode assembly along a first direction. The thermally conductive element includes a first thermally conductive sheet thermally connected to the electrode assembly. The first thermally conductive portion is composed of the first thermally conductive sheet and the first insulating portion. A first clearance hole is provided through the first thermally conductive sheet, and at least a portion of the first insulating portion covers the inner wall of the first clearance hole. A pressure relief hole is provided through the first insulating portion. The pressure relief hole is located within the first clearance hole, or the pressure relief hole is provided through the first insulating portion, and the pressure relief hole and the receiving cavity are spaced apart.

[0033] In the embodiments of this application, the thermally conductive component includes an insulating component and a thermally conductive component. At least a portion of the insulating component forms a receiving cavity, and the thermally conductive component is disposed within the receiving cavity. The insulating component includes a first insulating portion disposed along a first direction between the housing and the electrode assembly. The thermally conductive component includes a first thermally conductive sheet, which is thermally connected to the electrode assembly. The first thermally conductive portion is composed of the first thermally conductive sheet and the first insulating portion. This design allows for both insulation between the thermally conductive component and the electrode body, and also isolation between the thermally conductive component and the electrolyte, thereby mitigating incompatibility between the thermally conductive component and the electrolyte. Regarding the issue affecting the performance of a single battery cell, a first clearance hole is provided through the first heat-conducting sheet, and a pressure relief hole is provided through the first insulating part and located inside the first clearance hole, so that the internal pressure of the casing can be applied to the pressure relief mechanism through the pressure relief hole. At least part of the first insulating part covers the inner wall of the first clearance hole, so as to isolate the first heat-conducting sheet and the electrolyte through the first insulating part. The pressure relief hole is provided through the first insulating part, and the pressure relief hole and the receiving cavity are spaced apart, so that when the internal pressure of the casing can be applied to the pressure relief mechanism through the pressure relief hole, the electrolyte and the first heat-conducting sheet are prevented from contacting.

[0034] In some embodiments, multiple electrode assemblies are provided, and the multiple electrode assemblies are arranged along a second direction. The first direction and the second direction intersect. The heat-conducting assembly further includes a second heat-conducting portion, which is disposed between two adjacent electrode assemblies. The insulating member further includes a second insulating portion, which is connected to the first insulating portion. The second insulating portion is disposed between adjacent electrode assemblies along the second direction. The heat-conducting member includes a second heat-conducting sheet, which is disposed within the second insulating portion. The second heat-conducting portion is composed of the second heat-conducting sheet and the second insulating portion. The two side surfaces of the second insulating portion along the second direction and the first insulating portion form two receiving spaces for accommodating the electrode assemblies. Both receiving spaces are connected to the pressure relief hole.

[0035] In the embodiment of this application, the second insulating part forms two receiving spaces for accommodating the electrode assembly on both sides of its second direction and the first insulating part. Both receiving spaces are connected to the pressure relief hole to improve the problem that when the battery cell is thermally runaway, the pressure in the two receiving spaces is blocked by the first insulating part and cannot be transmitted to the pressure relief mechanism, resulting in a slow pressure relief rate of the battery cell and insufficient reliability of the battery cell.

[0036] In some embodiments, a through hole is provided on the second heat-conducting part, a second clearance hole is provided on the second heat-conducting sheet, at least a portion of the second insulating part covers the inner wall of the second clearance hole, the through hole is provided through the second insulating part, the through hole is located inside the second clearance hole, or the through hole is provided through the second insulating part, and the through hole and the receiving cavity are spaced apart.

[0037] In the embodiment of this application, a through hole is provided on the second heat-conducting part, and a second clearance hole is provided on the second heat-conducting sheet. The through hole is provided through the second insulating part and located inside the second clearance hole, so that the gas in the two accommodating spaces can flow through the through hole. At least part of the second insulating part covers the inner wall of the second clearance hole, so as to isolate the second heat-conducting sheet and the electrolyte through the second insulating part. The through hole is provided through the second insulating part, and the through hole and the accommodating cavity are spaced apart, so that the gas in the two accommodating spaces can flow through the through hole, while avoiding contact between the electrolyte and the first heat-conducting sheet.

[0038] In some embodiments, the electrode assembly includes a first end face, a second end face, and a side face. The first end face and the second end face are disposed opposite to each other along a first direction. The side face is connected between the first end face and the second end face. The side face includes two first side faces disposed opposite to each other in a second direction and two second side faces disposed opposite to each other in a third direction. The first direction, the second direction, and the third direction intersect each other. The insulating member also includes two third insulating portions. The third insulating portions include a body portion and a bent portion that are connected to each other. The body portions of the two third insulating portions are respectively disposed on the two first side faces, and the two bent portions are respectively disposed on the two second side faces. The heat-conducting member includes a third heat-conducting sheet. The third heat-conducting sheet is disposed on at least one of the body portion and the bent portion.

[0039] In the embodiment of this application, the third insulating part includes a body part and a bent part that are connected to each other. The body parts of the two third insulating parts are respectively disposed on two first side surfaces, and the two bent parts are respectively disposed on two second side surfaces to achieve insulation between the electrode assembly on its peripheral surface and the housing. The third heat-conducting sheet is disposed on at least one of the body part and the bent part to improve the heat conduction rate at the first side surface and / or the second side surface of the electrode assembly.

[0040] In some embodiments, the body portion is connected to a bend on each side in the third direction, and the two bends of the two third insulating portions, which are located on the same side of the electrode assembly, extend toward each other in the second direction.

[0041] In the embodiment of this application, the main body is connected to a bent portion on each of the two sides in the third direction. The two bent portions of the two third insulating portions, which are located on the same side of the electrode assembly, extend towards each other in the second direction. The splice of the two bent portions is located on the second side surface. The first side surface with a larger area can be provided with a third heat-conducting sheet with a larger area to improve the heat conduction capacity of the heat-conducting assembly.

[0042] In some embodiments, the thickness D1 of the thermally conductive element satisfies 40μm≤D1≤180μm.

[0043] 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.

[0044] In some embodiments, the insulating element comprises polyethylene, polypropylene, polyimide, or polyester resin.

[0045] 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.

[0046] In some embodiments, the thermally conductive element comprises graphite, graphene, or carbon nanotubes.

[0047] 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.

[0048] In some embodiments, the thermal conductivity k of the heat-conducting element satisfies k≥500W / (m·K).

[0049] 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.

[0050] Secondly, embodiments of this application provide a battery device including a battery cell from any of the embodiments of the first aspect described above.

[0051] 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

[0052] 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:

[0053] Figure 1 is a structural schematic diagram of a vehicle provided in an embodiment of this application;

[0054] Figure 2 is a schematic diagram of the structure of a battery device provided in an embodiment of this application;

[0055] Figure 3 is a schematic diagram of the structure of a battery module provided in one embodiment of the application;

[0056] Figure 4 is an exploded view of a single battery cell provided in an embodiment of this application;

[0057] Figure 5 is a schematic diagram of the structure of the electrode assembly of a battery cell provided in an embodiment of this application;

[0058] Figure 6 is a schematic diagram of the structure of the housing of a battery cell provided in an embodiment of this application;

[0059] Figure 7 is a schematic diagram of the structure of the thermal conductive assembly of a battery cell provided in an embodiment of this application;

[0060] Figure 8 is a partial structural schematic diagram of a battery cell provided in an embodiment of this application;

[0061] Figure 9 is a partial structural schematic diagram of a battery cell provided in an embodiment of this application;

[0062] Figure 10 is an exploded view of a single battery cell provided in an embodiment of this application;

[0063] Figure 11 is a partial structural schematic diagram of a battery cell provided in an embodiment of this application;

[0064] Figure 12 is a cross-sectional view at point AA in Figure 11;

[0065] Figure 13 is a partial structural schematic diagram of a battery cell provided in an embodiment of this application;

[0066] Figure 14 is a schematic diagram of the structure of a support assembly for a battery cell provided in an embodiment of this application;

[0067] Figure 15 is a cross-sectional view of a thermally conductive assembly for a battery cell provided in an embodiment of this application;

[0068] Figure 16 is a schematic diagram of the structure of the heat-conducting assembly of a battery cell provided in an embodiment of this application;

[0069] Figure 17 is a schematic diagram of the structure of the first heat-conducting part of a battery cell provided in an embodiment of this application;

[0070] Figure 18 is a schematic diagram of the structure of the first heat-conducting part of a battery cell provided in another embodiment of this application;

[0071] Figure 19 is an enlarged structural diagram of point B in Figure 16;

[0072] Figure 20 is a schematic diagram of the structure of the second heat-conducting part of a battery cell provided in an embodiment of this application;

[0073] Figure 21 is a schematic diagram of the structure of the second heat-conducting part of a battery cell provided in another embodiment of this application.

[0074] Reference numerals: 1. Vehicle; 101. Motor; 102. Controller; 2. Battery assembly; 201. Battery module; 202. Housing; 2021. First housing; 2022. Second housing; 3. Battery cell; 4. Housing; 41. Pressure relief mechanism; 5. Electrode assembly; 51. Tab; 52. Electrode body; 521. First end face; 522. Second end face; 523. Side face; 5231. First side face; 5232. Second side face; 6. Top cover assembly; 7. Adapter mechanism; 8. Heat conduction assembly; 81. First heat conduction part; 82. Second heat conduction part; 83. Third heat conduction part; 811. Pressure relief hole; 821. Accommodation space; 822. Connecting hole; 84. Heat-conducting component; 85. Insulating component; 851. Receiving cavity; 852. First insulating part; 853. Second insulating part; 841. First heat-conducting plate; 842. Second heat-conducting plate; 843. Third heat-conducting plate; 8414. First clearance hole; 8421. Second clearance hole; 854. Third insulating part; 8541. Body part; 8542. Bending part; 9. Support assembly; 91. Insulating part; 92. Elevating part; X, First direction; Y, Second direction; Z, Third direction. Detailed Implementation

[0075] 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.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] In battery production, a pressure relief mechanism is usually installed in the battery cell to relieve pressure when the battery cell experiences thermal runaway. However, the reliability of the pressure relief mechanism still needs to be improved.

[0083] The reason for the above problem is that, in order to improve the heat dissipation efficiency of the electrode assembly, a conductive component is installed inside the housing. The conductive component includes a first heat-conducting part disposed between the second end face of the electrode assembly and the pressure relief mechanism. When the battery cell experiences thermal runaway, some of the gas inside the housing will be blocked by the first heat-conducting part and cannot directly act on the pressure relief mechanism, resulting in insufficient reliability of the pressure relief mechanism.

[0084] To address the aforementioned issues, this application provides a battery cell comprising a housing, an electrode assembly, and a heat-conducting assembly. The housing is provided with a pressure relief mechanism for releasing internal pressure. The electrode assembly is disposed within the housing. The heat-conducting assembly includes a first heat-conducting part, which is thermally connected to the electrode assembly to increase the rate of heat exchange between the electrode assembly and the external environment. The first heat-conducting part is disposed between the electrode assembly and the pressure relief mechanism. A pressure relief hole is provided on the first heat-conducting part, extending through it in a first direction. Along the first direction, the orthographic projection of the pressure relief mechanism and the orthographic projection of the pressure relief hole at least partially overlap, so that at least part of the pressure relief mechanism is exposed through the pressure relief hole. This allows the internal pressure of the housing to act on the pressure relief mechanism through the pressure relief hole when the battery cell experiences thermal runaway, facilitating the smooth activation of the pressure relief mechanism and improving the reliability of the battery cell's pressure relief mechanism.

[0085] The technical solutions described in the embodiments of this application are applicable to battery devices and electrical devices using battery devices.

[0086] 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.

[0087] 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.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] 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.

[0092] 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.

[0093] 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.

[0094] Figure 2 shows a schematic diagram of the structure of a battery device according to an embodiment of this application.

[0095] 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.

[0096] In some embodiments, the battery cell assembly is typically formed by arranging a plurality of battery cells 3.

[0097] 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.

[0098] 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.

[0099] As an example, the battery cell assembly can be a battery module 201, which can be housed in a housing 202 by fixing the battery module 201 in the housing.

[0100] 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.

[0101] 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.

[0102] 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.

[0103] 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.

[0104] Figure 3 shows a schematic diagram of the structure of a battery module 201 according to an embodiment of this application.

[0105] 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.

[0106] 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.

[0107] 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 a top cover assembly 6, a housing 4, and an electrode assembly 5.

[0108] Electrode assembly 5 is the component in the battery cell 3 where the electrochemical reaction occurs. 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.

[0109] The electrode assembly 5 can be a wound structure, a stacked structure, or a hybrid structure of wound and stacked.

[0110] In some embodiments, the electrode assembly 5 is a wound structure. The positive electrode and the negative electrode are wound into a wound structure.

[0111] 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.

[0112] In some embodiments, the electrode assembly 5 may be cylindrical, flat, or polygonal in shape.

[0113] 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.

[0114] The battery cell 3 may include a housing 4. The housing 4 is an assembly used to cooperate with the top cover 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 component 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.

[0115] 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.

[0116] The housing 4 and the top cover assembly 6 can be independent components. One or more openings can be provided on the housing 4, and one or more top cover assemblies 6 can close the openings to form the internal environment of the battery cell 3. Alternatively, the top cover assembly 6 and the housing 4 can be integrated. Alternatively, the top cover assembly 6 and the housing 4 can form a common connection surface before other components are inserted into the housing, and the top cover assembly 6 closes the housing 4 when it is necessary to encapsulate the interior of the housing 4.

[0117] In some embodiments, the electrode terminals can be disposed on the top cover assembly 6 or on the housing 4, and the electrode terminals are electrically connected to the tabs 51. The electrode terminals can be directly connected to the tabs 51 or indirectly connected to the tabs 51 through the adapter mechanism 7.

[0118] Please refer to Figures 5, 6, 7 and 8. Figure 5 is a schematic diagram of the structure of the electrode assembly of a battery cell provided in an embodiment of this application; Figure 6 is a schematic diagram of the structure of the housing of a battery cell provided in an embodiment of this application; Figure 7 is a schematic diagram of the structure of the heat-conducting assembly of a battery cell provided in an embodiment of this application; and Figure 8 is a partial structural schematic diagram of a battery cell provided in an embodiment of this application.

[0119] In a first aspect, as shown in Figures 4 to 8, this application provides a battery cell 3, which includes a housing 4, an electrode assembly 5, and a heat-conducting assembly 8. The housing 4 is provided with a pressure relief mechanism 41. The electrode assembly 5 is located inside the housing 4. The heat-conducting assembly 8 includes a first heat-conducting part 81, which is thermally connected to the electrode assembly 5. The first heat-conducting part 81 is disposed between the electrode assembly 5 and the pressure relief mechanism 41. The first heat-conducting part 81 is provided with a pressure relief hole 811 that penetrates the first heat-conducting part 81 along a first direction X. Along the first direction X, the orthographic projection of the pressure relief mechanism 41 and the orthographic projection of the pressure relief hole 811 at least partially overlap.

[0120] In the embodiment of this application, the battery cell 3 includes a housing 4, an electrode assembly 5, and a heat-conducting assembly 8. The housing 4 is provided with a pressure relief mechanism 41 for releasing the pressure inside the housing 4. The electrode assembly 5 is disposed inside the housing 4. The heat-conducting assembly 8 includes a first heat-conducting part 81, which is thermally connected to the electrode assembly 5 to increase the rate of heat exchange between the electrode body 52 and the external environment. The first heat-conducting part 81 is disposed between the electrode assembly 5 and the pressure relief mechanism 41. The first heat-conducting part 81 is provided with a pressure relief hole 811 that penetrates the first heat-conducting part 81 along a first direction X. Along the first direction X, the orthographic projection of the pressure relief mechanism 41 and the orthographic projection of the pressure relief hole 811 at least partially overlap, so that at least part of the pressure relief mechanism 41 is exposed through the pressure relief hole 811. This allows the internal pressure of the housing 4 to act on the pressure relief mechanism 41 through the pressure relief hole 811 when the battery cell 3 experiences thermal runaway, thus promoting the smooth activation of the pressure relief mechanism 41 and improving the reliability of the pressure relief mechanism 41 of the battery cell 3.

[0121] The electrode assembly 5 includes an electrode body 52 and tabs 51. The electrode body 52 includes a first end face 521, a second end face 522, and a side surface 523 connected between the first end face 521 and the second end face 522, which are disposed opposite to each other. The tabs 51 are connected to the electrode body 52. ​​The electrode body 52 is formed by winding or stacking a diaphragm, a positive electrode sheet, and a negative electrode sheet. The tabs 51 include a positive tab and a negative tab, both of which extend from the first end face 521 or the second end face 522.

[0122] For example, the battery cell 3 also includes a top cover assembly 6 connected to the tab 51. The housing 4 includes an opening at one end near the first end face 521 in the first direction X. The top cover assembly 6 covers the opening. Electrode terminals can be disposed on the top cover assembly 6. The positive tab and the negative tab extend out of the first end face 521 and are connected to the electrode terminals on the top cover assembly 6.

[0123] For example, the first direction X is the height direction of the electrode assembly 5, the first end face 521 and the second end face 522 are arranged opposite each other in the first direction, the tab 51 extends out of the first end face 521, and the pressure relief hole 811 is disposed between the second end face 522 and the pressure relief mechanism 41. Alternatively, the first direction X is the length or width direction of the electrode assembly 5, the arrangement direction of the first end face 521 and the second end face 522 intersects the first direction, the tab 51 extends out of the first end face 521 or the second end face 522, and the pressure relief hole 811 is disposed between the side face 523 and the pressure relief mechanism 41.

[0124] As an example, the pressure relief mechanism 41 is actuated to release internal pressure or temperature when the internal pressure or temperature of the battery cell 3 reaches a predetermined threshold. When the internal pressure or temperature of the battery cell 3 reaches the predetermined threshold, the pressure relief mechanism 41 performs its action or a weak structure provided in the pressure relief mechanism 41 is damaged, thereby forming an opening or channel for the release of internal pressure or temperature. The threshold design varies depending on design requirements. The threshold may depend on one or more of the materials of the positive electrode, negative electrode, electrolyte, and separator in the battery cell.

[0125] As an example, the pressure relief mechanism 41 can be integrally formed with the housing 4, for example, by making grooves on the housing 4 to form a weak structure, which serves as the pressure relief mechanism 41.

[0126] The pressure relief mechanism 41 can also be separately disposed from and connected to the housing 4, for example, by welding or by connecting it to the housing 4 through other components. As an example, the pressure relief mechanism 41 is provided with grooves to form a weak structure.

[0127] As an example, the pressure relief mechanism 41 can take the form of an explosion-proof valve, a balancing valve, a gas valve, a pressure relief valve, or a safety valve.

[0128] The term "actuation" as used in this application refers to the pressure relief mechanism 41 being activated or undergoing a certain state, thereby releasing the internal pressure and temperature of the battery cell 3. The actions of the pressure relief mechanism 41 may include, but are not limited to: movement of components within the pressure relief mechanism 41 to form an exhaust channel, rupture, breakage, tearing, or opening of at least a portion of the pressure relief mechanism 41, etc. When the pressure relief mechanism 41 is activated, the high-temperature, high-pressure substances inside the battery cell 3 are discharged outwards from the activated portion. This method allows for pressure and temperature relief of the battery cell 3 under controllable pressure or temperature conditions, thereby preventing potentially more serious accidents.

[0129] The emissions from battery cell 3 mentioned in this application include, but are not limited to: electrolyte, dissolved or split positive and negative electrode plates, fragments of separator, high-temperature and high-pressure gases generated by the reaction, flames, etc.

[0130] If the first heat-conducting part 81 is thermally connected to the electrode assembly 5, then the first heat-conducting part 81 is directly attached to or abuts against the electrode body 52; or the first heat-conducting part 81 is a plating layer disposed on the electrode body 52; or the first heat-conducting part 81 and the electrode body 52 are spaced apart, and the first heat-conducting part 81 is connected to the electrode body 52 through a heat-conducting medium, which can be air, metal, or heat-conducting adhesive, etc.

[0131] During the operation of the battery cell 3, the heat generated by the electrode body 52 can be transferred to the external environment through the heat conduction component 8, which can improve the problem of the electrode body 52 being damaged due to excessive temperature; or in a low temperature environment, the heat conduction component 8 can conduct external heat to the electrode body 52 to heat the electrode component 5.

[0132] Optionally, the battery device 2 includes a heat exchange mechanism, the housing 4 of the battery cell 3 is thermally connected to the heat exchange mechanism, the heat conduction component 8 can conduct heat between the heat exchange mechanism and the electrode assembly 5, and the heat exchange mechanism can introduce or export heat to the heat conduction component 8.

[0133] For example, the heat exchange mechanism can be a water-cooled plate or a phase change heat sink plate or a cavity containing a heat exchange medium, which can be disposed on the outer surface of the battery cell 3.

[0134] The first heat-conducting part 81 can be in the form of a strip, a flat plate, or a mesh, etc. The first heat-conducting part 81 can be rectangular, circular, or rhomboid, etc. The specific shape and size of the first heat-conducting part 81 can be flexibly designed.

[0135] A pressure relief hole 811 is provided through the first heat-conducting part 81. The shape and size of the pressure relief hole 811 can be designed by oneself. For example, the pressure relief hole 811 is a circular hole or a rectangular hole, etc.

[0136] At least part of the pressure relief mechanism 41 is exposed through the pressure relief hole 811. The orthographic projection of the pressure relief mechanism 41 on at least part of the first heat-conducting part 81 coincides with the pressure relief hole 811. The gas inside the housing 4 can act directly on the pressure relief mechanism 41 through the pressure relief hole 811 along the first direction X, so that when the battery cell 3 thermally runs away, the gas inside the housing 4 can activate the pressure relief mechanism 41 through the pressure relief hole 811 to release the internal pressure of the housing 4.

[0137] In some embodiments, as shown in Figures 4, 7 and 8, the orthographic projection of the pressure relief hole 811 is completely within the orthographic projection range of the pressure relief mechanism 41 along the first direction X.

[0138] In these embodiments, along the first direction X, the orthographic projection of the pressure relief hole 811 is completely within the orthographic projection range of the pressure relief mechanism 41, and the pressure relief mechanism 41 is completely exposed in the pressure relief hole 811, so that the internal pressure of the housing 4 can be evenly applied to the entire pressure relief mechanism 41 through the pressure relief hole 811, thereby improving the reliability of the pressure relief mechanism 41.

[0139] Optionally, the pressure relief hole 811 and the pressure relief mechanism 41 have the same shape, so that when the orthographic projection of the pressure relief hole 811 is completely within the orthographic projection range of the pressure relief mechanism 41 along the first direction X, the size of the pressure relief hole 811 is reduced, and the heat conduction efficiency of the first heat-conducting part 81 is improved. For example, the pressure relief mechanism 41 is circular, and the pressure relief hole 811 is a circular hole; the pressure relief mechanism 41 is elliptical, and the pressure relief hole 811 is an oblong hole, etc.

[0140] Please refer to Figure 9, which is a partial structural schematic diagram of a battery cell provided in an embodiment of this application.

[0141] In some embodiments, as shown in Figures 4, 7, and 9, multiple electrode assemblies 5 are provided, and the multiple electrode assemblies 5 are arranged along the second direction Y. The first direction X and the second direction Y intersect. The heat-conducting assembly 8 also includes a second heat-conducting part 82. The first heat-conducting part 81 and the second heat-conducting part 82 are connected. The second heat-conducting part 82 is disposed between two adjacent electrode assemblies 5. The two side surfaces of the second heat-conducting part 82 along the second direction Y and the first heat-conducting part 81 form two receiving spaces 821 for accommodating the electrode assemblies 5. Both receiving spaces 821 are connected to the pressure relief hole 811.

[0142] In these embodiments, multiple electrode assemblies 5 are provided, and the multiple electrode assemblies 5 are arranged along the second direction Y to improve the capacity of the battery cell 3. The heat conduction assembly 8 also includes a second heat conduction part 82 disposed between two adjacent electrode assemblies 5. The first heat conduction part 81 and the second heat conduction part 82 are connected. The second heat conduction part 82 is used to conduct heat from the adjacent electrode assemblies 5 and transfer it to the first heat conduction part 81. The two side surfaces of the second heat conduction part 82 along the second direction Y and the first heat conduction part 81 form two receiving spaces 821 for accommodating the electrode assemblies 5. Both receiving spaces 821 are connected to the pressure relief hole 811 to improve the problem that when the battery cell 3 is thermally runaway, the pressure in the two receiving spaces 821 is blocked by the first heat conduction part 81 and cannot be transferred to the pressure relief mechanism 41, resulting in a slow pressure relief rate of the battery cell 3 and insufficient reliability of the battery cell 3.

[0143] Since the heat between adjacent electrode components 5 is not easily exchanged with the outside through the housing 4, in this embodiment, a second heat-conducting part 82 is provided between adjacent electrode components 5. The heat of the two adjacent electrode components 5 is transferred to the second heat-conducting part 82 and then transferred to the first heat-conducting part 81. The heat is exchanged with the external environment at the first heat-conducting part 81.

[0144] Optionally, the heat-conducting component 8 includes a first heat-conducting part 81 and a second heat-conducting part 82. Two electrode components 5 are disposed on the same side of the first heat-conducting part 81, and the second heat-conducting part 82 is disposed between the two electrode components 5 and connected to the middle region of the first heat-conducting part 81. The two side surfaces of the second heat-conducting part 82 and the first heat-conducting part 81 form two receiving spaces 821. A pressure relief hole 811 extends on both sides of the second heat-conducting part 82, reducing the processing difficulty of the pressure relief hole 811 so that both receiving spaces 821 are connected to the pressure relief hole 811. Alternatively, two pressure relief holes 811 are provided at intervals on the first heat-conducting part 81, and the second heat-conducting part 82 is located between the two pressure relief holes 811. The two pressure relief holes 811 are respectively connected to the two receiving spaces 821, thereby reducing the setting area of ​​a single pressure relief hole 811 and improving the structural strength of the first heat-conducting part 81.

[0145] For example, the heat-conducting component 8 includes two second heat-conducting parts 82 and two first heat-conducting parts 81. Two electrode components 5 are respectively disposed on the same side of the two first heat-conducting parts 81. The two second heat-conducting parts 82 are located between the two electrode components 5. Each second heat-conducting part 82 is respectively connected to each first heat-conducting part 81. Alternatively, the first heat-conducting parts 81 and the second heat-conducting parts 82 are formed by bending the same substrate to reduce the processing difficulty of the heat-conducting component 8. Each first heat-conducting part 81 and each second heat-conducting part 82 respectively form a receiving space 821. Each first heat-conducting part 81 is provided with a pressure relief hole 811 so that each receiving space 821 is connected to the pressure relief hole 811.

[0146] Optionally, the pressure relief holes 811 are located in portions of the same area in each receiving space 821 to balance the pressure relief rates of the two receiving spaces 821.

[0147] In some embodiments, as shown in Figures 7 and 9, the second heat-conducting part 82 is provided with a through hole 822 along the second direction Y.

[0148] In these embodiments, the second heat-conducting part 82 is provided with a through hole 822 along the second direction Y, and the gas in the two receiving cavities 851 can flow through the through hole 822 to balance the pressure acting on the pressure relief mechanism 41 and improve the reliability of the pressure relief mechanism 41.

[0149] A through hole 822 is provided on the second heat-conducting part 82, through which the gas in the two containing spaces 821 can flow to balance the pressure in the two containing spaces 821.

[0150] Optionally, the second heat-conducting part 82 is provided with at least two connecting holes 822 to improve the gas flow rate.

[0151] Optionally, the shape and size of the connecting hole 822 can be designed by the user. For example, the connecting hole 822 can be a circular hole or a rectangular hole, etc.

[0152] In some embodiments, as shown in Figures 7 and 9, a connecting hole 822 is disposed at one end of the second heat-conducting part 82 near the first heat-conducting part 81.

[0153] In these embodiments, the central region of the electrode assembly 5 generates more heat than the edge region. Therefore, the connecting hole 822 is disposed at the end of the second heat-conducting part 82 near the first heat-conducting part 81 to avoid the central region of the electrode assembly 5. With the connecting hole 822 connecting the two receiving spaces 821, the heat conduction efficiency of the heat-conducting assembly 8 is improved.

[0154] A connecting hole 822 is disposed at one end of the second heat-conducting part 82 near the first heat-conducting part 81. The size of the connecting hole 822 along the first direction X to the first heat-conducting part 81 is less than half the size of the second heat-conducting part 82 in the first direction X, so that the connecting hole 822 avoids the middle region of the second heat-conducting part 82 in the first direction X.

[0155] During the operation of the electrode assembly 5, the temperature of the end of the electrode body 52 closer to the tab 51 is relatively high, while the temperature of the end farther from the tab 51 is relatively low. The connecting hole 822 is set at the end of the second heat-conducting part 82 closer to the first heat-conducting part 81 to reduce the impact of setting the connecting hole 822 on the heat conduction performance of the heat-conducting assembly 8.

[0156] Optionally, the connecting hole 822 is disposed on one side edge of the second heat-conducting part 82 near the first heat-conducting part 81, so as to reduce the impact of the connecting hole 822 on the heat conduction performance of the heat-conducting component 8.

[0157] In some embodiments, as shown in Figures 7 and 9, the connecting hole 822 and the pressure relief hole 811 are connected.

[0158] In these embodiments, the connecting hole 822 and the pressure relief hole 811 are connected to reduce the processing difficulty of the heat-conducting component 8.

[0159] The connecting hole 822 is disposed on one side edge of the second heat-conducting part 82 near the first heat-conducting part 81, and the orthographic projection of the connecting hole 822 on the first heat-conducting part 81 coincides with the pressure relief hole 811.

[0160] Please refer to Figure 10, which is an exploded view of a single battery cell provided in an embodiment of this application.

[0161] In some embodiments, as shown in Figures 6, 7 and 10, the battery cell 3 further includes a support component 9, which is disposed between the housing 4 and the electrode assembly 5 so that a pressure relief space can be formed between the electrode assembly 5 and the housing 4.

[0162] In these embodiments, the battery cell 3 also includes a support component 9 disposed between the housing 4 and the electrode assembly 5. The support component 9 forms a pressure relief space between the electrode assembly 5 and the housing 4. The pressure relief space is used to buffer the internal pressure of the housing 4 in the event of thermal runaway of the battery cell 3, so as to reduce the risk of the battery cell 3 exploding or deflagrating in a short period of time.

[0163] The support assembly 9 is disposed inside the housing 4 and supports the electrode assembly 5 from the housing 4, thereby forming a pressure relief space between the electrode assembly 5 and the housing 4 to buffer the internal pressure of the housing 4 in the event of thermal runaway of the battery cell 3. The specific dimensions and shape of the support assembly 9 can be designed independently.

[0164] Specifically, the first heat-conducting part 81 is disposed between the support component 9 and the electrode component 5, and the support component 9 is disposed between the pressure relief hole 811 and the pressure relief mechanism 41; or the first heat-conducting part 81 is disposed between the support component 9 and the housing 4, and the support component 9 is disposed between the pressure relief hole 811 and the electrode component 5.

[0165] Optionally, the support component 9 and the electrode component 5 are insulated from each other to reduce the risk of accidental conduction of the electrode component 5 through the support component 9 and the housing 4. For example, the support component 9 is made of insulating material, or the surface of the support component 9 facing the electrode component 5 is provided with an insulating material layer.

[0166] Optionally, the orthographic projection of the support component 9 in the first direction X covers the electrode component 5 to increase the contact area between the support component 9 and the electrode component 5 and improve the support stability of the support component 9.

[0167] Optionally, at least two support components 9 are spaced apart to jointly support the electrode assembly 5, so as to facilitate adjustment of the support position of the support component 9 on the electrode assembly 5 in different battery cells 3.

[0168] Optionally, the support component 9 may be plate-shaped; or the support component 9 may include a number of spaced-apart support blocks.

[0169] Optionally, a pressure relief channel is provided through the support component 9, which is connected to the pressure relief hole 811 to facilitate the passage of gas inside the housing 4 through the pressure relief hole 811.

[0170] Please refer to Figures 11, 12 and 13. Figure 11 is a partial structural schematic diagram of a battery cell provided in an embodiment of this application; Figure 12 is a cross-sectional view at point AA in Figure 11; Figure 13 is a partial structural schematic diagram of a battery cell provided in an embodiment of this application.

[0171] In some embodiments, as shown in Figures 10 to 13, the support component 9 is disposed between the first heat-conducting part 81 and the housing 4, or the support component 9 is disposed between the first heat-conducting part 81 and the electrode component 5.

[0172] In these embodiments, the support component 9 is disposed between the first heat-conducting part 81 and the housing 4 so that the first heat-conducting part 81 is close to the electrode component 5 to improve the heat conduction rate between the electrode component 5 and the heat-conducting component 8; or the support component 9 is disposed between the first heat-conducting part 81 and the electrode component 5 so that the first heat-conducting part 81 is close to the housing 4 to improve the heat conduction rate between the housing 4 and the heat-conducting component 8.

[0173] A support component 9 is disposed between the first heat-conducting part 81 and the housing 4, as shown in Figure 13. The support component 9 is located on the side of the first heat-conducting part 81 away from the electrode assembly 5. The support component 9 supports the heat-conducting part 8 and the electrode assembly 5. Gas inside the housing 4 can act on the pressure relief mechanism 41 through the pressure relief hole 811 and the support component 9. For example, the heat-conducting part 8 also includes a third heat-conducting part 83. The third heat-conducting part 83 is disposed between the electrode assembly 5 and the housing 4 along the second direction Y. The heat exchange mechanism is arranged along the second direction Y and the battery cell 3. The heat from the first heat-conducting part 81 and the second heat-conducting part 82 is transferred to the third heat-conducting part 83 and exchanges heat with the heat exchange mechanism. At this time, the support component 9 is disposed between the first heat-conducting part 81 and the housing 4. The first heat-conducting part 81 is close to the electrode assembly 5 to facilitate the transfer of heat from the electrode assembly 5 to the first heat-conducting part 81 and finally to the heat exchange mechanism.

[0174] A support assembly 9 is disposed between the first heat-conducting part 81 and the electrode assembly 5, as shown in Figures 11 and 12. The support assembly 9 is located on the side of the first heat-conducting part 81 facing the electrode assembly 5. One end of the support assembly 9 supports the first heat-conducting part 81, and the other end supports the electrode assembly 5. Gas inside the housing 4 can act on the pressure relief mechanism 41 through the support assembly 9 and the pressure relief hole 811. For example, the heat exchange mechanism is arranged along the first direction X and the battery cell 3, and the first heat-conducting part 81 is close to the heat exchange mechanism to facilitate the heat exchange of the electrode assembly 5 through the first heat-conducting part 81 and the heat exchange mechanism.

[0175] In some embodiments, as shown in Figures 10 to 12, multiple electrode assemblies 5 are provided, and the multiple electrode assemblies 5 are arranged along the second direction Y. The first direction X and the second direction Y intersect. The heat-conducting assembly 8 also includes a second heat-conducting part 82. The first heat-conducting part 81 and the second heat-conducting part 82 are connected. The support assembly 9 is disposed between the first heat-conducting part 81 and the electrode assembly 5. There are two support assemblies 9, which are respectively disposed on both sides of the second heat-conducting part 82 in the second direction Y.

[0176] In these embodiments, the support component 9 is disposed between the first heat-conducting part 81 and the electrode component 5. There are two support components 9, which are respectively disposed on both sides of the second heat-conducting part 82 in the second direction Y, so as to reduce the risk of mutual interference between the support component 9 and the second heat-conducting part 82, resulting in damage to the heat-conducting component 8.

[0177] Two support components 9 are spaced apart and are respectively disposed in a receiving space 821. Each support component 9 is supported by an electrode component 5 and a first heat-conducting part 81. A second heat-conducting part 82 extends between the two support components 9 so that the support components 9 can avoid the second heat-conducting part 82.

[0178] Optionally, the two support components 9 located in the two accommodating spaces 821 are identical in size and shape to reduce the mold opening and processing costs of the support components 9.

[0179] Optionally, the size of the second heat-conducting part 82 in the third direction Z is smaller than the size of the support component 9 in the third direction Z. A support component 9 is provided inside the housing 4. A through hole extending along the third direction Z is provided through the support component 9. The second heat-conducting part 82 extends out of the through hole to simplify the installation steps of the support component 9. The first direction X, the second direction Y and the third direction Z intersect each other.

[0180] Optionally, the support component 9 is bonded to the first heat-conducting part 81 and the second heat-conducting part 82 to increase the contact area between the support component 9 and the heat-conducting component 8 and improve the connection reliability between the support component 9 and the heat-conducting component 8.

[0181] In some embodiments, as shown in Figures 10 and 13, multiple electrode assemblies 5 are provided, and the multiple electrode assemblies 5 are stacked along the second direction Y. The first direction X and the second direction Y intersect. The heat-conducting assembly 8 also includes a second heat-conducting part 82. The first heat-conducting part 81 and the second heat-conducting part 82 are connected. The support assembly 9 is disposed between the first heat-conducting part 81 and the housing 4. The orthographic projection of the second heat-conducting part 82 in the first direction X is located on the support assembly 9.

[0182] In these embodiments, the support component 9 is disposed between the first heat-conducting part 81 and the housing 4, and the second heat-conducting part 82 is projected onto the support component 9 in the first direction X, so that a single support component 9 can support the first heat-conducting part 81 that forms two receiving spaces 821, reducing the difficulty of fitting the support component 9 and the heat-conducting component 8.

[0183] A support component 9 is provided inside the housing 4. The support component 9 can simultaneously support the electrode components 5 located in the two accommodating spaces 821, thereby reducing the difficulty of setting up the support component 9.

[0184] Optionally, two support components 9 are spaced apart along the second direction Y, and each support component 9 is respectively disposed between the housing 4 and the first heat-conducting part 81, and each support component 9 is respectively supported by an electrode assembly 5 in a receiving space 821.

[0185] Optionally, a support component 9 is provided inside the housing 4, and the orthographic projections of the two electrode components 5 in the two accommodating spaces 821 are both located inside the support component 9 in the first direction X, so as to improve the support effect of the support component 9 on the electrode components 5.

[0186] Please refer to Figure 14, which is a schematic diagram of the structure of a support assembly for a battery cell provided in an embodiment of this application.

[0187] In some embodiments, as shown in Figures 10 and 14, the support assembly 9 includes an insulating portion 91 and at least two raised portions 92 connected to each other. The insulating portion 91 is located between the electrode assembly 5 and the raised portions 92, and each raised portion 92 is spaced apart on the side of the insulating portion 91 away from the electrode assembly 5.

[0188] In these embodiments, the support assembly 9 includes an insulating portion 91 and at least two raised portions 92 connected to each other. The insulating portion 91 is located between the electrode assembly 5 and the raised portions 92. The raised portions 92 are used to support the insulating portion 91. The insulating portion 91 is used to support the electrode assembly 5. Each raised portion 92 is spaced apart on the side of the insulating portion 91 away from the electrode assembly 5. The cross-sectional area of ​​the insulating portion 91 in the first direction X is larger than the total cross-sectional area of ​​each raised portion 92 in the first direction X, so as to increase the contact area between the support assembly 9 and the electrode assembly 5, so that the support assembly 9 provides a stable support effect for the electrode assembly 5.

[0189] The support assembly 9 includes an insulating portion 91 and a plurality of spaced-apart raised portions 92 connected to the insulating portion 91. The insulating portion 91 supports the electrode assembly 5. One end of each raised portion 92 is connected to the side of the insulating portion 91 opposite to the electrode assembly 5, and the other end abuts against or connects to the housing 4. At least two raised portions 92 are spaced apart. The orthographic projection of each raised portion 92 in the first direction X is located within the insulating portion 91. The insulating portion 91 supports the electrode assembly 5 to increase the contact area between the electrode assembly 5 and the support assembly 9. The two or more raised portions 92 provide a stable support effect for the insulating portion 91. The spaced-apart raised portions 92 provide a larger pressure relief space to better buffer the internal pressure of the housing 4.

[0190] For example, four raised portions 92 are respectively connected to the diagonal positions of the insulating portion 91 to improve the stability of the support assembly 9.

[0191] For example, at least two raised portions 92 are spaced apart along the third direction Z to stably support the insulating portion 91 and reduce the processing difficulty of the support assembly 9.

[0192] Optionally, the insulating part 91 and the raised part 92 are integrally formed to reduce the processing difficulty of the support component 9 and improve the structural strength of the support component 9.

[0193] Optionally, the insulating part 91 is provided with a plurality of ventilation holes through the first direction X to facilitate airflow through the support assembly 9.

[0194] In some embodiments, as shown in Figures 10 and 14, the pressure relief hole 811 is at least partially located on the insulating portion 91 in the first direction X, which is configured to melt when the internal pressure or temperature of the battery cell 3 reaches a threshold.

[0195] In these embodiments, the pressure relief hole 811 is at least partially located on the insulating portion 91 in the first direction X, so as to increase the contact area between the insulating portion 91 and the electrode assembly 5. The insulating portion 91 is configured to melt when the internal pressure or temperature of the battery cell 3 reaches a threshold, so that when the battery cell 3 is thermally runaway, the gas inside the casing 4 can smoothly pass through the support assembly 9 and the pressure relief hole 811 to act on the pressure relief mechanism 41, thereby improving the reliability of the pressure relief mechanism 41.

[0196] For example, the melting point of the insulating part 91 is lower than the temperature at which the battery cell 3 thermally runs away, so that the insulating part 91 melts when the battery cell 3 thermally runs away, so as to prevent the insulating part 91 from blocking the gas through the pressure relief hole 811.

[0197] For example, the insulating part 91 is made of PP (Polypropylene), PVC (Polyvinyl chloride), or PE (polyethylene), etc.

[0198] Optionally, the insulating portion 91 and the pressure relief hole 811 are spaced apart in the second direction Y and / or the third direction Z to avoid the insulating portion 91 blocking the pressure relief hole 811 from releasing pressure. For example, the insulating portions 91 of the two support assemblies 9 are spaced apart to form a pressure relief channel, and the pressure relief hole 811 communicates with the pressure relief channel. Alternatively, a pressure relief channel is provided through the insulating portion 91, and the pressure relief hole 811 communicates with the pressure relief channel.

[0199] In some embodiments, as shown in Figures 9 and 12, the dimensions L1 of the connecting hole 822 in the first direction X and the dimension L2 of the support assembly 9 in the first direction X satisfy that L1 > L2, and at least part of the connecting hole 822 can extend out of the support assembly 9 in the first direction X, so as to improve the problem that when the support assembly 9 is disposed between the first heat-conducting part 81 and the electrode assembly 5, the support assembly 9 blocks the connecting hole 822, resulting in obstructed gas exchange in the two accommodating spaces 821.

[0200] For example, the difference between L1 and L2 can be 0.3mm, 0.5mm, 1mm, 2mm or 5mm, etc.

[0201] Optionally, the dimension L1 of the connecting hole 822 in the first direction X satisfies that L1≥6mm. When the dimension L1 of the connecting hole 822 in the first direction X satisfies the above condition, the gas exchange rate in the two accommodating spaces 821 can be improved.

[0202] For example, the dimension L1 of the connecting hole 822 in the first direction X is 6mm or 7mm or 8mm or 10mm or 20mm, etc.

[0203] For example, the connecting hole 822 is a rectangular hole, and the dimension of the rectangular hole in the first direction X is greater than or equal to 6mm.

[0204] In some embodiments, as shown in Figures 10, 12 and 14, the dimension L2 of the support component 9 in the first direction X satisfies 5mm < L2 ≤ 15mm.

[0205] In these embodiments, when the dimension L2 of the first direction X satisfies the above conditions, the support component 9 forms a pressure relief space of sufficient volume between the electrode component 5 and the housing 4 to improve the reliability of the battery cell 3.

[0206] For example, the dimension L2 of the support component 9 in the first direction X is 5.1 mm, 6 mm, 7 mm, 10 mm, or 15 mm, etc.

[0207] Optionally, the support assembly 9 includes an insulating portion 91 and a raised portion 92. The raised portion 92 has a dimension of 5 mm or more in the first direction X, and the insulating portion 91 has a dimension between 1 mm and 10 mm in the first direction X, so that the raised portion 92 stably supports the insulating portion 91. For example, the insulating portion 91 has a dimension of 1 mm, 2 mm, 5 mm, or 10 mm in the first direction X, etc.

[0208] Please refer to Figures 15, 16, 17 and 18. Figure 15 is a cross-sectional view of the heat-conducting assembly of a battery cell provided in one embodiment of this application; Figure 16 is a structural schematic diagram of the heat-conducting assembly of a battery cell provided in one embodiment of this application; Figure 17 is a structural schematic diagram of the first heat-conducting part of a battery cell provided in one embodiment of this application; and Figure 18 is a structural schematic diagram of the first heat-conducting part of a battery cell provided in another embodiment of this application.

[0209] In some embodiments, as shown in Figures 4, 6, and 15 to 18, the heat-conducting assembly 8 includes an insulating member 85 and a heat-conducting member 84. At least a portion of the insulating member 85 forms a receiving cavity 851. The heat-conducting member 84 is disposed within the receiving cavity 851. The insulating member 85 includes a first insulating portion 852, which is disposed between the housing 4 and the electrode assembly 5 along a first direction X. The heat-conducting member 84 includes a first heat-conducting sheet 841, which is thermally connected to the electrode assembly 5. A heat-conducting part 81 is composed of a first heat-conducting plate 841 and a first insulating part 852. A first clearance hole 8414 is provided through the first heat-conducting plate 841. At least part of the first insulating part 852 covers the inner wall of the first clearance hole 8414. A pressure relief hole 811 is provided through the first insulating part 852. The pressure relief hole 811 is located inside the first clearance hole 8414, or the pressure relief hole 811 is provided through the first insulating part 852. The pressure relief hole 811 and the receiving cavity 851 are spaced apart.

[0210] In these embodiments, the heat-conducting assembly 8 includes an insulator 85 and a heat-conducting element 84. At least a portion of the insulator 85 forms a receiving cavity 851. The heat-conducting element 84 is disposed within the receiving cavity 851. The insulator 85 includes a first insulating portion 852, which is disposed along a first direction X between the housing 4 and the electrode assembly 5. The heat-conducting element 84 includes a first heat-conducting sheet 841, which is thermally connected to the electrode assembly 5. The first heat-conducting portion 81 is composed of the first heat-conducting sheet 841 and the first insulating portion 852. The insulator 85 can both insulate the heat-conducting element 84 from the electrode body 52 and isolate the heat-conducting element 84 from the electrolyte, thereby improving the incompatibility between the heat-conducting element 84 and the electrolyte and mitigating its effects. Regarding the performance issues of the battery cell 3, a first clearance hole 8414 is provided through the first heat-conducting sheet 841, and a pressure relief hole 811 is provided through the first insulating part 852 and located inside the first clearance hole 8414, so that the internal pressure of the housing 4 can act on the pressure relief mechanism 41 through the pressure relief hole 811. At least part of the first insulating part 852 covers the inner wall of the first clearance hole 8414, so as to isolate the first heat-conducting sheet 841 and the electrolyte through the first insulating part 852. The pressure relief hole 811 is provided through the first insulating part 852, and the pressure relief hole 811 and the receiving cavity 851 are spaced apart, so that when the internal pressure of the housing 4 can act on the pressure relief mechanism 41 through the pressure relief hole 811, the electrolyte and the first heat-conducting sheet 841 are prevented from contacting.

[0211] For example, the insulating component 85 can be made of PP or PI (polyimide) or PET (polyethylene terephthalate), etc. The thermally conductive component 84 can be made of graphite, graphene, or carbon nanotubes. The thermal conductivity of the thermally conductive component 84 in the thermally conductive assembly 8 is greater than that of the housing 4.

[0212] Optionally, the heat-conducting element 84 may be plate-shaped, strip-shaped, or mesh-shaped. For example, the receiving cavity 851 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.

[0213] It should be noted that the heat-conducting element 84 is located inside the insulating element 85 and is covered by the insulating element 85. In the accompanying drawings, the heat-conducting element 84 is represented by a shadow on the insulating element 85 for the convenience of showing the position of the heat-conducting element 84.

[0214] Optionally, the insulating member 85 is provided with a receiving cavity 851 with one end open, and the heat-conducting member 84 is disposed in the receiving cavity 851 and bonded or fused to the opening of the insulating member 85, so that the heat-conducting member 84 is located in a sealed receiving cavity 851; or the two ends of the insulating member 85 are folded in half, and the heat-conducting member 84 is located between the two ends of the insulating member 85, and the two ends of the insulating member 85 are bonded or fused together, so that the heat-conducting member 84 is located in a sealed receiving cavity 851; or the insulating member 85 includes two sub-insulating layers disposed opposite to each other, and the edges of the two sub-insulating layers are bonded or fused together, so that the heat-conducting member 84 is located in a sealed receiving cavity 851.

[0215] Optionally, an adhesive layer is provided on the surface of the insulating member 85 facing the electrode assembly 5 to bond the thermally conductive assembly 8 and the electrode body 52 together. For example, the adhesive layer may be an insulating colloid to enhance the insulation performance of the thermally conductive assembly 8 and the electrode assembly 5.

[0216] For example, a pressure relief hole 811 is disposed between the second end face 522 and the pressure relief mechanism 41, and a first heat-conducting sheet 841 is disposed on the second end face 522 and is thermally connected to the electrode assembly 5. The first heat-conducting part 81 is composed of the first heat-conducting sheet 841 and a first insulating part 852. For example, the first heat-conducting sheet 841 covers the entire second end face 522 to improve the heat conduction rate of the first heat-conducting part 81.

[0217] A pressure relief hole 811 is provided through the first insulating part 852. The pressure relief hole 811 and the receiving cavity 851 are spaced apart. The receiving cavity 851 is located in a part of the first insulating part 852. The first heat-conducting plate 841 is located in the receiving cavity 851. The pressure relief hole 811 is provided through another part of the first insulating part 852. The pressure relief hole 811 and the receiving cavity 851 are not connected. In this way, the electrolyte will not enter the receiving cavity 851 and come into contact with the first heat-conducting plate 841, and the first insulating part 852 can still keep the first heat-conducting plate 841 and the electrode assembly 5 insulated.

[0218] For example, if the insulating element 85 is molded to form a receiving cavity 851, then the pressure relief hole 811 can be provided in the molded area, or the pressure relief hole 811 can be provided on the side of the molded area away from the receiving cavity 851.

[0219] A first clearance hole 8414 is provided on the first heat-conducting plate 841, and a pressure relief hole 811 is provided on the first insulating part 852. The pressure relief hole 811 is located inside the first clearance hole 8414, or in other words, the orthographic projection of the first clearance hole 8414 in the thickness direction of the first insulating part 852 is located inside the pressure relief hole 811. Gas inside the housing 4 can act on the pressure relief mechanism 41 through the pressure relief hole 811. The first insulating part 852 covers the inner wall of the first clearance hole 8414 and is used to prevent the electrolyte and the inner wall of the first clearance hole 8414 from contacting each other; and the first insulating part 852 insulates the electrode assembly 5 and the inner wall of the first clearance hole 8414.

[0220] For example, the first insulating portion 852 is plastic-encapsulated to form a receiving cavity 851, the first heat-conducting sheet 841 is received in the receiving cavity 851, a portion of the first insulating portion 852 is plastic-encapsulated and connected in the first clearance hole 8414, the pressure relief hole 811 passes through the plastic-encapsulated area, and the inner walls of the pressure relief hole 811 and the first clearance hole 8414 are spaced apart by the plastic-encapsulated area.

[0221] Optionally, the first insulating part 852 is provided with at least two pressure relief holes 811, and the corresponding first heat-conducting plate 841 is provided with at least two first clearance holes 8414.

[0222] Please refer to Figure 19, which is an enlarged structural diagram of point B in Figure 16.

[0223] In some embodiments, as shown in Figures 4, 15, 16, and 19, multiple electrode assemblies 5 are provided, and the multiple electrode assemblies 5 are arranged along the second direction Y. The first direction X and the second direction Y intersect. The heat-conducting assembly 8 also includes a second heat-conducting part 82, which is disposed between two adjacent electrode assemblies 5. The insulating member 85 also includes a second insulating part 853, which is connected to the first insulating part 852. The second insulating part 853 is disposed between adjacent electrode assemblies 5 along the second direction Y. The heat-conducting member 84 includes a second heat-conducting sheet 842, which is disposed within the second insulating part 853. The second heat-conducting part 82 is composed of the second heat-conducting sheet 842 and the second insulating part 853. The two side surfaces of the second insulating part 853 along the second direction Y and the first insulating part 852 form two receiving spaces 821 for accommodating the electrode assemblies 5. Both receiving spaces 821 are connected to the pressure relief hole 811.

[0224] In these embodiments, the second insulating portion 853 forms two receiving spaces 821 on its two side surfaces in the second direction Y and the first insulating portion 852 for accommodating the electrode assembly 5. Both receiving spaces 821 are connected to the pressure relief hole 811 to improve the problem that when the battery cell 3 is thermally runaway, the pressure in the two receiving spaces 821 is blocked by the first insulating portion 852 and cannot be transmitted to the pressure relief mechanism 41, resulting in a slow pressure relief rate of the battery cell 3 and insufficient reliability of the battery cell 3.

[0225] The second heat-conducting part 82 is composed of a second heat-conducting sheet 842 and a second insulating part 853. The second heat-conducting sheet 842 is used to transfer heat between the electrode assembly 5 and the first heat-conducting sheet 841. The second heat-conducting sheet 842 is insulated from the electrode assembly 5 by the second insulating part 853.

[0226] In the above embodiments, the accommodating space 821 is formed by the first heat-conducting part 81 and the second heat-conducting part 82. Specifically, the accommodating space 821 is formed by the first insulating part 852 and the second insulating part 853. The electrode assembly 5 is located in the accommodating space 821 formed by the first insulating part 852 and the second insulating part 853, so that the electrode assembly 5 and the heat-conducting assembly 8 are mutually insulated.

[0227] Two pressure relief holes 811 are provided at intervals on the first insulating part 852, and each pressure relief hole 811 is connected to a receiving space 821. The second insulating part 853 is located between the two pressure relief holes 811; or the first insulating part 852 is provided with one pressure relief hole 811, and the pressure relief hole 811 extends along the second direction Y on both sides of the second insulating part 853, and both receiving spaces 821 are connected to the pressure relief hole 811.

[0228] Please refer to Figures 20 and 21. Figure 20 is a schematic diagram of the structure of the second heat-conducting part of a battery cell provided in one embodiment of this application; Figure 21 is a schematic diagram of the structure of the second heat-conducting part of a battery cell provided in another embodiment of this application.

[0229] In some embodiments, as shown in Figures 4, 15, 16, 20, and 21, a through hole 822 is provided through the second heat-conducting part 82, a second clearance hole 8421 is provided through the second heat-conducting sheet 842, at least a portion of the second insulating part 853 covers the inner wall of the second clearance hole 8421, the through hole 822 is provided through the second insulating part 853, the through hole 822 is located inside the second clearance hole 8421, or the through hole 822 is provided through the second insulating part 853, and the through hole 822 and the receiving cavity 851 are spaced apart.

[0230] In these embodiments, a through hole 822 is provided through the second heat-conducting part 82, and a second clearance hole 8421 is provided through the second heat-conducting plate 842. The through hole 822 is provided through the second insulating part 853 and located inside the second clearance hole 8421, so that the gas in the two accommodating spaces 821 can flow through the through hole 822. At least part of the second insulating part 853 covers the inner wall of the second clearance hole 8421, so as to isolate the second heat-conducting plate 842 and the electrolyte through the second insulating part 853. The through hole 822 is provided through the second insulating part 853, and the through hole 822 and the accommodating cavity 851 are spaced apart, so that the gas in the two accommodating spaces 821 can flow through the through hole 822, while avoiding contact between the electrolyte and the first heat-conducting plate 841.

[0231] A connecting hole 822 is disposed through the second insulating part 853. The connecting hole 822 and the receiving cavity 851 are spaced apart. The receiving cavity 851 is disposed in a part of the second insulating part 853. The second heat-conducting sheet 842 is disposed in the receiving cavity 851. The connecting hole 822 is disposed through another part of the second insulating part 853. The connecting hole 822 and the receiving cavity 851 are not connected. In this way, the electrolyte will not enter the receiving cavity 851 and come into contact with the second heat-conducting sheet 842. The second insulating part 853 can still keep the second heat-conducting sheet 842 and the electrode assembly 5 insulated.

[0232] For example, if the insulating element 85 is molded to form a receiving cavity 851, then the connecting hole 822 can be disposed within the molded area, or the connecting hole 822 can be disposed on the side of the molded area away from the receiving cavity 851.

[0233] A second clearance hole 8421 is provided on the second heat-conducting plate 842, and a connecting hole 822 is provided on the second insulating part 853. The connecting hole 822 is located inside the second clearance hole 8421, or in other words, the orthogonal projection of the second clearance hole 8421 in the thickness direction of the second insulating part 853 is located inside the connecting hole 822. Gas inside the housing 4 can flow through the connecting hole 822 in the two receiving spaces 821. The second insulating part 853 covers the inner wall of the second clearance hole 8421 and is used to prevent the electrolyte and the inner wall of the second clearance hole 8421 from contacting each other; and the second insulating part 853 insulates the electrode assembly 5 and the inner wall of the second clearance hole 8421.

[0234] For example, the second insulating portion 853 is plastic-encapsulated to form a receiving cavity 851, the second heat-conducting sheet 842 is received in the receiving cavity 851, a portion of the second insulating portion 853 is plastic-encapsulated and connected to the second clearance hole 8421, the connecting hole 822 passes through the plastic-encapsulated area, and the inner walls of the connecting hole 822 and the second clearance hole 8421 are spaced apart by the plastic-encapsulated area.

[0235] Optionally, the second insulating part 853 is provided with at least two connecting holes 822. For example, the second insulating part 853 is provided with two, three, or four connecting holes 822.

[0236] In some embodiments, as shown in Figures 4, 5, and 16, the electrode assembly 5 includes a first end face 521, a second end face 522, and a side face 523. The first end face 521 and the second end face 522 are disposed opposite to each other along a first direction X. The side face 523 connects the first end face 521 and the second end face 522. The side face 523 includes two first side faces 5231 disposed opposite to each other along a second direction Y, and two second side faces 5232 disposed opposite to each other along a third direction Z. The first direction X, the second direction Y, and the second direction Z are... The third direction Z intersects in pairs. The insulating member 85 also includes two third insulating portions 854. Each third insulating portion 854 includes a body portion 8541 and a bent portion 8542 that are connected to each other. The body portions 8541 of the two third insulating portions 854 are respectively disposed on two first side surfaces 5231, and the two bent portions 8542 are respectively disposed on two second side surfaces 5232. The heat-conducting member 84 includes a third heat-conducting sheet 843. The third heat-conducting sheet 843 is disposed on at least one of the body portion 8541 and the bent portion 8542.

[0237] In these embodiments, the third insulating portion 854 includes a body portion 8541 and a bent portion 8542 connected to each other. The body portions 8541 of the two third insulating portions 854 are respectively disposed on two first side surfaces 5231, and the two bent portions 8542 are respectively disposed on two second side surfaces 5232, so as to achieve insulation between the electrode assembly 5 on its peripheral surface and the housing 4. The third heat-conducting sheet 843 is disposed on at least one of the body portion 8541 and the bent portion 8542 to improve the heat conduction rate at the first side surface 5231 and / or the second side surface 5232 of the electrode assembly 5.

[0238] Specifically, the electrode assembly 5 includes an electrode body 52 and a tab 51. The tab 51 is connected to the electrode body 52. ​​The first end face 521 and the second end face 522 are the two end faces of the electrode body 52 in the first direction X, respectively.

[0239] The third heat-conducting sheet 843 is disposed on the main body portion 8541, or the third heat-conducting sheet 843 is disposed on the bending portion 8542, or the third heat-conducting sheet 843 is disposed on both the main body portion 8541 and the bending portion 8542 to form the third heat-conducting portion 83.

[0240] Within the same housing 4, the insulating member 85 includes two third insulating portions 854, which are disposed opposite to each other and cover at least a portion of the outer peripheral surface of the electrode assembly 5.

[0241] The third insulating part 854 includes a body part 8541 and a bent part 8542 that are connected to each other. The body part 8541 and the bent part 8542 are integrally formed to improve the structural strength of the third insulating part 854. There is a fold line between the body part 8541 and the bent part 8542. The body part 8541 covers the first side 5231, and the bent part 8542 is bent along the fold line and covers the second side 5232. Alternatively, the body part 8541 and the bent part 8542 can be made separately, and the body part 8541 and the bent part 8542 can be bonded or fused together.

[0242] The third insulating portion 854 includes a body portion 8541 and a bent portion 8542 connected to the body portion 8541 at one end in the third direction Z. The body portion 8541 covers a first side 5231 of the electrode assembly 5. One end of the bent portion 8542 is connected to the body portion 8541, and the other end extends along the second direction Y toward the body portion 8541 of another third insulating portion 854. The bent portion 8542 is connected to the two body portions 8541, or the bent portion 8542 and the body portion 8541 are spaced apart and connected by a Mylar film.

[0243] Alternatively, the third insulating portion 854 includes a body portion 8541 and bent portions 8542 connected to the two ends of the body portion 8541 in the third direction Z. The body portion 8541 covers the first side surface 5231 of the electrode assembly 5. The bent portions 8542 of the two oppositely disposed third insulating portions 854 extend relative to each other in the second direction Y and are connected to each other. Alternatively, the bent portions 8542 of the two oppositely disposed third insulating portions 854 extend relative to each other in the second direction Y, and the two bent portions 8542 are connected by a Mylar film.

[0244] Optionally, the body portion 8541 covers the first side 5231 of the electrode assembly 5, and the bent portion 8542 covers the second side 5232 of the electrode assembly 5, thereby the first insulating portion 852 can reliably insulate the electrode assembly 5 and the housing 4.

[0245] Optionally, the heat-conducting element 84 is disposed throughout the entire body portion 8541 or the bent portion 8542; or multiple heat-conducting elements 84 are disposed at intervals in the body portion 8541 or the bent portion 8542.

[0246] Optionally, multiple electrode assemblies 5 are provided, with the main body 8541 disposed between the housing 4 and the first side 5231 closest to the housing 4, and the bent portion 8542 disposed on one or more second side 5232.

[0247] In some embodiments, as shown in Figures 4, 5, 15 and 16, the body portion 8541 is connected to a bent portion 8542 on each side of the third insulating portion 854 in the third direction Z, and the two bent portions 8542 of the two third insulating portions 854, which are located on the same side of the electrode assembly 5, extend toward each other in the second direction Y.

[0248] In these embodiments, the main body 8541 is connected to a bend 8542 on each side of the third direction Z. The two bends 8542 of the two third insulating parts 854, which are located on the same side of the electrode assembly 5, extend towards each other in the second direction Y. The splice of the two bends 8542 is located on the second side 5232. The first side 5231, which has a larger area, can be provided with a third heat-conducting sheet 843 with a larger area to improve the heat conduction capacity of the heat-conducting assembly 8.

[0249] Optionally, the two bent portions 8542 of the two third insulating portions 854 extend toward each other in the second direction Y and are spaced apart or abut against each other in the second direction Y, so that the body portion 8541 can cover the entire first side 5231 and the heat-conducting component 84 can cover the entire first side 5231 to improve the heat conduction efficiency of the heat-conducting component 8; or the two bent portions 8542 of the two first insulating portions 852 extend toward each other in the second direction Y and overlap each other, so that the overlapping part of the bent portions 8542 in the third direction Z will not increase the size of the battery cell 3 in the second direction Y.

[0250] For example, the bends 8542 of the two third insulating portions 854 are bent and connected to each other. The insulating member 85 is encapsulated by two sub-insulating layers, which are connected at the body portion 8541 to form a receiving cavity 851. Each bend 8542 includes two sub-insulating layers. For ease of understanding, some of the sub-insulating layers are folded and some are unfolded in the figure.

[0251] Optionally, the two bent portions 8542 connected to both sides of the main body 8541 have the same size and shape to reduce the processing difficulty of the third insulating portion 854. The specific size and shape of the bent portion 8542 can be designed by the user; for example, the bent portion 8542 is rectangular.

[0252] In some embodiments, as shown in Figures 4 and 15, the thickness D1 of the heat-conducting element 84 satisfies 40μm≤D1≤180μm.

[0253] In these embodiments, when the above conditions are met, the problem of excessively thick heat conductor 84 leading to excessively large battery cell 3 volume and reduced energy density can be improved, and the problem of excessively thin heat conductor 84 being easily damaged can also be improved.

[0254] For example, the thickness D3 of the thermally conductive component 8 is 40μm, 50μm, 110μm, or 180μm, etc.

[0255] In some embodiments, as shown in Figures 4 and 15, the insulating element 85 comprises polyethylene, polypropylene, polyimide, or polyester resin.

[0256] In these embodiments, the insulating element 85 comprises polyethylene, polypropylene, polyimide, or polyester resin to improve the insulation reliability of the insulating element 85.

[0257] Optionally, the insulating component 85 should have insulating and high-temperature resistant properties so that the insulating component 85 can be used to insulate the heat-conducting component 84 and the electrode assembly 5, and to reduce the risk of the insulating component 85 melting and being damaged under high-temperature conditions.

[0258] In some embodiments, as shown in Figures 4 and 15, the thermal conductive element 84 comprises graphite, graphene, or carbon nanotubes.

[0259] 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 curling one or more layers of graphite. The heat-conducting element 84 is made of graphite, graphene, or carbon nanotubes, and the thermal conductivity of the heat-conducting element 84 is improved by using graphite, graphene, or carbon nanotube thermal conductive materials.

[0260] Optionally, the heat-conducting component 84 is made of supercrystalline graphite, which has a larger grain size than ordinary graphite and a significantly improved thermal conductivity compared to ordinary graphite, so that the heat-conducting component 84 has better thermal conductivity.

[0261] Optionally, the heat-conducting component 84 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.

[0262] In some embodiments, as shown in Figures 4 and 15, the thermal conductivity k of the heat-conducting element 84 satisfies k≥500W / (m·K).

[0263] In these embodiments, when the thermal conductivity k of the heat-conducting element 84 meets the above conditions, the heat-conducting component 8 has sufficient thermal conductivity to conduct the heat of the electrode body 52.

[0264] Optionally, the thermal conductivity k of the heat-conducting component 84 satisfies 500W / (m·K)≤k≤1600W / (m·K). For example, the thermal conductivity of the heat-conducting component 84 is 500W / (m·K), 550W / (m·K), 1050W / (m·K), 1550W / (m·K), or 1600W / (m·K), etc.

[0265] Optionally, the thermal conductivity k of the heat-conducting component 84 satisfies k≥1000W / (m·K).

[0266] Optionally, the density of the thermally conductive component 84 is 2.1 ± 0.05 g / cm³. 3 Insulation resistance greater than 1 GΩ, withstand voltage strength 5400V, and withstand bending cycles > 10000 times.

[0267] Secondly, embodiments of this application provide a battery device including a battery cell from any of the embodiments of the first aspect described above.

[0268] Thirdly, embodiments of this application provide an electrical device, including the battery device described in the second aspect of the embodiment above.

[0269] In some embodiments, as shown in Figures 1 to 21, the battery cell 3 includes a housing 4, an electrode assembly 5, a heat-conducting assembly 8, and a support assembly 9. The housing 4 is provided with a pressure relief mechanism 41 for releasing pressure inside the housing 4. The electrode assembly 5 is located inside the housing 4 and includes an electrode body 52 and a tab 51. The electrode body 52 includes a first end face 521 and a second end face 522 disposed opposite to each other in a first direction X. The tab 51 is connected to the electrode body 52 and extends out of the first end face 521. Multiple electrode assemblies 5 are provided, and the multiple electrode assemblies 5 are arranged side by side along a second direction Y, where the first direction X and the second direction Y intersect. The heat-conducting assembly 8 includes a first heat-conducting part 81 and a second heat-conducting part 82, which are thermally connected to the second end face 522. In the first heat-conducting part 81, a pressure-relieving part 81 is disposed between the second end face 522 and the pressure relief mechanism 41. The first heat-conducting part 81 has a pressure relief hole 811 extending through it along the first direction X. Along the first direction X, the orthographic projection of the pressure relief mechanism 41 and the orthographic projection of the pressure relief hole 811 at least partially overlap. The first heat-conducting part 81 and the second heat-conducting part 82 are connected. The second heat-conducting part 82 is disposed between two adjacent electrode assemblies 5. The second heat-conducting part 82 and the first heat-conducting part 81 form two receiving spaces 821 on their two side surfaces in the second direction Y for accommodating the electrode assemblies 5. Both receiving spaces 821 are connected to the pressure relief hole 811. A connecting hole 822 is provided through the second heat-conducting part 82, and the connecting hole 822 is connected to the pressure relief hole 811. The support assembly 9 is disposed on the housing 4. Between the second end face 522 and the housing 4, a pressure relief space can be formed between the second end face 522 and the housing 4. The support assembly 9 is disposed between the first heat-conducting part 81 and the housing 4, or between the first heat-conducting part 81 and the electrode assembly 5. The support assembly 9 includes an insulating part 91 and at least two raised parts 92 connected to each other. The insulating part 91 is located between the electrode assembly 5 and the raised parts 92. Each raised part 92 is spaced apart on the side of the insulating part 91 away from the electrode assembly 5. The insulating part 91 and the pressure relief hole 811 at least partially overlap. The insulating part 91 is configured to melt when the pressure relief mechanism 41 is activated. The dimension L1 of the connecting hole 822 in the first direction X satisfies L1≥6mm. The dimension L2 of the support assembly 9 in the first direction X satisfies 5mm<L2≤15mm.

[0270] In the embodiment of this application, the battery cell 3 includes a housing 4, an electrode assembly 5, and a heat-conducting assembly 8. The housing 4 is provided with a pressure relief mechanism 41 for releasing the pressure inside the housing 4. The electrode assembly 5 is disposed inside the housing 4. The heat-conducting assembly 8 includes a first heat-conducting part 81, which is thermally connected to the electrode assembly 5 to increase the rate of heat exchange between the electrode body 52 and the external environment. The first heat-conducting part 81 is disposed between the electrode assembly 5 and the pressure relief mechanism 41. The first heat-conducting part 81 is provided with a pressure relief hole 811 that penetrates the first heat-conducting part 81 along a first direction X. Along the first direction X, the orthographic projection of the pressure relief mechanism 41 and the orthographic projection of the pressure relief hole 811 at least partially overlap, so that at least part of the pressure relief mechanism 41 is exposed through the pressure relief hole 811. This allows the internal pressure of the housing 4 to act on the pressure relief mechanism 41 through the pressure relief hole 811 when the battery cell 3 experiences thermal runaway, thus promoting the smooth activation of the pressure relief mechanism 41 and improving the reliability of the pressure relief mechanism 41 of the battery cell 3.

[0271] 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 single battery cell, comprising: The casing is equipped with a pressure relief mechanism; The electrode assembly is located within the housing; The thermally conductive assembly includes a first thermally conductive part, which is thermally connected to the electrode assembly. The first heat-conducting part is disposed between the electrode assembly and the pressure relief mechanism along a first direction. The first heat-conducting part is provided with a pressure relief hole that penetrates the first heat-conducting part along the first direction. Along the first direction, the orthographic projection of the pressure relief mechanism and the orthographic projection of the pressure relief hole at least partially overlap.

2. The battery cell according to claim 1, wherein, Along the first direction, the orthographic projection of the pressure relief hole is completely within the orthographic projection range of the pressure relief mechanism.

3. The battery cell according to claim 1 or 2, wherein, The electrode assembly is provided in multiple ways, and the multiple electrode assemblies are arranged along a second direction. The first direction and the second direction intersect. The heat-conducting assembly further includes a second heat-conducting part. The first heat-conducting part and the second heat-conducting part are connected. The second heat-conducting part is disposed between two adjacent electrode assemblies. The two side surfaces of the second heat-conducting part along the second direction and the first heat-conducting part form two receiving spaces for accommodating the electrode assemblies. Both receiving spaces are connected to the pressure relief hole.

4. The battery cell according to claim 3, wherein, The second heat-conducting part is provided with a through hole along the second direction.

5. The battery cell according to claim 4, wherein, The connecting hole is located at one end of the second heat-conducting part near the first heat-conducting part.

6. The battery cell according to claim 5, wherein, The connecting hole and the pressure relief hole are connected.

7. The battery cell according to any one of claims 1 to 6, wherein, The battery cell also includes a support assembly disposed between the housing and the electrode assembly, so that a pressure relief space can be formed between the electrode assembly and the housing.

8. The battery cell according to claim 7, wherein, The support assembly is disposed between the first heat-conducting part and the housing, or the support assembly is disposed between the first heat-conducting part and the electrode assembly.

9. The battery cell according to claim 8, wherein, Multiple electrode assemblies are provided and arranged along a second direction, where the first and second directions intersect. The heat-conducting assembly further includes a second heat-conducting part, and the first and second heat-conducting parts are connected. The support assembly is disposed between the first heat-conducting part and the electrode assembly. There are two support assemblies, which are respectively disposed on both sides of the second heat-conducting part in the second direction.

10. The battery cell according to claim 8, wherein, Multiple electrode assemblies are provided and arranged along a second direction, where the first and second directions intersect. The heat-conducting assembly further includes a second heat-conducting part, and the first and second heat-conducting parts are connected. The support assembly is disposed between the first heat-conducting part and the housing, and the orthographic projection of the second heat-conducting part in the first direction is located on the support assembly.

11. The battery cell according to any one of claims 7 to 10, wherein, The support assembly includes an insulating portion and at least two raised portions connected to each other. The insulating portion is located between the electrode assembly and the raised portions, and each of the raised portions is spaced apart on the side of the insulating portion away from the electrode assembly.

12. The battery cell according to claim 11, wherein, The pressure relief hole's orthogonal projection in the first direction is at least partially located on the insulating portion, which is configured to melt when the internal pressure or temperature of the battery cell reaches a threshold.

13. The battery cell according to any one of claims 7 to 12, wherein, The dimension L2 of the support component in the first direction satisfies 5mm < L2 ≤ 15mm.

14. The battery cell according to any one of claims 1 to 13, wherein, The thermally conductive component includes an insulating element and a thermally conductive element. At least a portion of the insulating element forms a receiving cavity, and the thermally conductive element is disposed within the receiving cavity. The insulating element includes a first insulating portion disposed along the first direction between the housing and the electrode assembly. The thermally conductive element includes a first thermally conductive sheet, which is thermally connected to the electrode assembly. The first thermally conductive portion is composed of the first thermally conductive sheet and the first insulating portion. The first heat-conducting sheet has a first clearance hole through it, and at least part of the first insulating part covers the inner wall of the first clearance hole. The pressure relief hole is through the first insulating part and is located inside the first clearance hole, or the pressure relief hole is through the first insulating part and is spaced apart from the receiving cavity.

15. The battery cell according to claim 14, wherein, The electrode assembly comprises multiple electrode assemblies arranged along a second direction, where the first direction and the second direction intersect. The heat-conducting assembly further includes a second heat-conducting portion disposed between two adjacent electrode assemblies. The insulating component further includes a second insulating portion, the first insulating portion and the second insulating portion are connected, the second insulating portion is disposed between adjacent electrode assemblies along the second direction, the heat-conducting component includes a second heat-conducting sheet disposed within the second insulating portion, the second heat-conducting portion is composed of the second heat-conducting sheet and the second insulating portion, the two side surfaces of the second insulating portion along the second direction and the first insulating portion form two receiving spaces for accommodating the electrode assemblies, both of the receiving spaces are connected to the pressure relief hole.

16. The battery cell according to claim 15, wherein, A through hole is provided on the second heat-conducting part, and a second clearance hole is provided on the second heat-conducting sheet. At least a portion of the second insulating part covers the inner wall of the second clearance hole. The through hole is provided through the second insulating part. The through hole is located inside the second clearance hole, or the through hole is provided through the second insulating part. The through hole and the receiving cavity are spaced apart.

17. The battery cell according to claim 15, wherein, The electrode assembly includes a first end face, a second end face, and a side face. The first end face and the second end face are disposed opposite each other along the first direction. The side face is connected between the first end face and the second end face. The side face includes two first side faces disposed opposite each other in the second direction and two second side faces disposed opposite each other in the third direction. The first direction, the second direction, and the third direction intersect each other. The insulating member also includes two third insulating portions. The third insulating portions include interconnected body portions and bent portions. The body portions of the two third insulating portions are respectively disposed on the two first side faces, and the two bent portions are respectively disposed on the two second side faces. The heat-conducting member includes a third heat-conducting sheet. The third heat-conducting sheet is disposed on at least one of the body portion and the bent portion.

18. The battery cell according to claim 17, wherein, The main body is connected to a bend on each side of the third direction, and the two bends of the two third insulating parts, which are located on the same side of the electrode assembly, extend toward each other in the second direction.

19. The battery cell according to any one of claims 14 to 18, wherein, The thickness D1 of the heat-conducting component satisfies 40μm≤D1≤180μm.

20. The battery cell according to any one of claims 14 to 19, wherein, The insulating component includes polyethylene, polypropylene, polyimide, or polyester resin.

21. The battery cell according to any one of claims 14 to 20, wherein, The thermally conductive component includes graphite, graphene, or carbon nanotubes.

22. The battery cell according to any one of claims 14 to 21, wherein, The thermal conductivity k of the heat-conducting component satisfies k≥500W / (m·K).

23. A battery device comprising a battery cell as described in any one of claims 1-22.

24. An electrical device comprising the battery device as described in claim 23.

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