Battery monomer, battery device and electric device

Abstract

The utility model provides a battery monomer, a battery device and a power utilization device. The battery cell includes: a case; the electrode assembly is located in the shell and comprises an electrode main body and a tab, the electrode main body comprises a first end face and a second end face which are oppositely arranged in the first direction and a side face connected between the first end face and the second end face, and the tab is connected to the electrode main body and extends out of at least one of the first end face and the second end face; the heat conduction assembly comprises a first heat conduction part which is in heat conduction connection with the side face, and the heat conductivity of the heat conduction assembly is larger than that of the shell.

Description

Technical Field

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

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

[0003] However, during actual operation of a battery cell, if its internal temperature is too high or too low, it will have an adverse effect on the service life and performance of the battery cell. Utility Model Content

[0004] In view of the above problems, the present application provides a battery cell, a battery device and an electrical device, which can enhance the thermal conductivity between the electrode assembly inside the battery cell and the external environment to balance the internal temperature of the battery cell and improve the performance and service life of the battery cell.

[0005] In a first aspect, the present application provides a battery cell, comprising: a shell; an electrode assembly, located in the shell, the electrode assembly comprising an electrode body and a tab, the electrode body comprising a first end face and a second end face arranged opposite to each other in a first direction, and a side face connected between the first end face and the second end face, the tab being connected to the electrode body and extending beyond at least one of the first end face and the second end face; a heat-conducting assembly, comprising a first heat-conducting portion, the first heat-conducting portion being heat-conductingly connected to the side face, and the thermal conductivity of the heat-conducting assembly being greater than the thermal conductivity of the shell.

[0006] In the solution of the embodiment of the present application, the battery cell includes a shell, an electrode assembly and a heat-conducting assembly. The electrode assembly is located inside the shell, and the shell provides accommodation and protection for the electrode assembly. The electrode assembly includes an electrode body and a pole ear. The electrode body includes a first end face and a second end face arranged opposite to each other in a first direction, and a side surface connected between the first end face and the second end face. The electrode body forms a loop with the pole ear extending from the first end face and / or the second end face and an external component. The thermal conductivity of the heat-conducting assembly is greater than the thermal conductivity of the shell. The heat-conducting assembly includes a first heat-conducting part. The first heat-conducting part is heat-conductedly connected to the side surface of the electrode body, so as to reduce the thermal resistance of the electrode body at its side surface, improve the temperature uniformity of the electrode body at its side surface, and improve the rate of heat exchange between the electrode body at its side surface and the external environment, so as to balance the internal temperature of the battery cell and improve the problem of adverse effects on the performance and service life of the battery cell due to excessively high or low internal temperature of the battery cell.

[0007] In some embodiments, the side surfaces include two first side surfaces and two second side surfaces, the two first side surfaces are arranged opposite to each other in the second direction, the two second side surfaces are arranged opposite to each other in the third direction, the first direction, the second direction and the third direction intersect with each other, the area of ​​the first side surface is greater than the area of ​​the second side surface, and the first heat conducting portion is arranged on at least one of the two first side surfaces.

[0008] In the technical solution of the embodiment of the present application, the side surface includes two first side surfaces and two second side surfaces, the area of ​​the first side surface is larger than the area of ​​the second side surface, and the first heat-conducting portion is arranged on at least one of the two first side surfaces, which not only helps to increase the contact area between the first heat-conducting portion and the electrode body to enhance the thermal conductivity rate of the electrode assembly; but also can better match the large-surface water cooling solution, shorten the thermal conductivity path of the first heat-conducting portion and the heat exchange mechanism, and improve the thermal conductivity rate of the electrode assembly to better balance the internal temperature of the battery cell.

[0009] In some embodiments, at least a portion of the first heat conducting portion is disposed between the first side surface of the electrode assembly and the housing along the second direction.

[0010] In the technical solution of the embodiment of the present application, at least a portion of the first heat-conducting portion is arranged between the first side surface of the electrode assembly and the shell along the second direction to shorten the distance between the first heat-conducting portion and the shell. The electrode assembly can achieve heat exchange with the external environment through the first heat-conducting portion and the shell more quickly, thereby improving the thermal conductivity rate of the electrode assembly.

[0011] In some embodiments, a first through hole is provided on the first heat conducting portion.

[0012] In the technical solution of the embodiment of the present application, a first through hole is provided in the first heat conducting portion to facilitate the flow of electrolyte to the electrode assembly, thereby improving the infiltration efficiency of the electrolyte into the electrode assembly.

[0013] In some embodiments, the first heat-conducting part includes a side heat-conducting member and two end heat-conducting members, the two end heat-conducting members are respectively arranged between the shell and the two adjacent first side surfaces, the side heat-conducting member is arranged on at least one second side surface, and the side heat-conducting member is respectively connected to the two end heat-conducting members on both sides along the second direction.

[0014] In the technical solution of the embodiment of the present application, the two end heat conductive parts are respectively arranged between the shell and the two adjacent first side surfaces, the side heat conductive parts are arranged on the second side surface, and the side heat conductive parts are respectively connected to the two end heat conductive parts on both sides along the second direction. The side heat conductive parts are used to allow heat to be conducted between the two end heat conductive parts to balance the heat of the two end heat conductive parts and improve the thermal conductivity efficiency of the first heat conductive part; and it can better match the solution of arranging the heat exchange mechanism on a single large surface of the battery cell or arranging the heat exchange mechanism on both large surfaces, shortening the thermal conduction path of the first heat conductive part and the heat exchange mechanism, and improving the thermal conductivity efficiency of the electrode assembly.

[0015] In some embodiments, a plurality of electrode assemblies are provided, and the plurality of electrode assemblies are stacked along the second direction, and at least a portion of the first heat conducting portion is provided between two adjacent first side surfaces of two adjacent electrode assemblies.

[0016] In the technical solution of the embodiment of the present application, multiple electrode assemblies are stacked along the second direction, and at least part of the first heat-conducting portion is arranged between two adjacent first side surfaces of two adjacent electrode assemblies. The first heat-conducting portion can be used to equalize the temperature of the electrode assemblies in the first direction, thereby improving the performance of the battery cell.

[0017] In some embodiments, the first heat conductive part includes a middle heat conductive part and a side heat conductive part, the middle heat conductive part is arranged between two adjacent first side surfaces of two adjacent electrode assemblies, and the side heat conductive part is arranged on at least one second side surface and connected to the middle heat conductive part.

[0018] In the technical solution of the embodiment of the present application, the middle heat conductive member located between adjacent electrode assemblies helps to extract heat between two adjacent first side surfaces. The side heat conductive members are arranged on at least one second side surface and connected to the middle heat conductive member. The heat of the middle heat conductive member is transferred to the side heat conductive member, and heat exchange is performed at the side heat conductive member and the external environment to balance the internal temperature of the battery cell.

[0019] In some embodiments, the first heat conducting part further includes an end heat conducting member, which is arranged between the shell and an adjacent first side surface, and the side heat conducting member is respectively connected to the middle heat conducting member and the end heat conducting member on both sides along the second direction.

[0020] In the technical solution of the embodiment of the present application, the first heat-conducting part also includes an end heat-conducting part, which is arranged between the shell and an adjacent first side surface, and the side heat-conducting part is respectively connected to the middle heat-conducting part and the end heat-conducting part on both sides along the second direction, so that the heat between adjacent electrode assemblies can be transferred to the end heat-conducting part through the middle heat-conducting part and the side heat-conducting part, and heat exchange is performed between the end heat-conducting part and the external environment to balance the internal temperature of the battery cell.

[0021] In some embodiments, two side heat conductive members are provided, the first heat conductive part further includes two end heat conductive members, the two end heat conductive members are respectively provided between the shell and the two adjacent first side surfaces, the two side heat conductive members are respectively provided on the second side surfaces of different electrode assemblies, one of the side heat conductive members is respectively connected to the middle heat conductive member and an end heat conductive member on both sides along the second direction, and the other side heat conductive member is respectively connected to the middle heat conductive member and the other end heat conductive member on both sides along the second direction.

[0022] In the technical solution of the embodiment of the present application, the first heat-conducting part also includes two end heat-conducting parts. The heat between adjacent electrode assemblies can be transferred to the middle heat-conducting part. The two end heat-conducting parts are respectively arranged between the shell and the two adjacent first side surfaces. The two side heat-conducting parts are respectively arranged on the second side surfaces of different electrode assemblies and are respectively connected to the middle heat-conducting part and an end heat-conducting part, so that the heat of the middle heat-conducting part can be transferred to the end heat-conducting part through the side heat-conducting part, and heat exchange is performed between the end heat-conducting part and the external environment to balance the internal temperature of the battery cell.

[0023] In some embodiments, the two side heat conducting members are respectively disposed on both sides of the plurality of electrode assemblies along the third direction.

[0024] In the technical solution of the embodiment of the present application, two side heat conductive members are respectively arranged on both sides of multiple electrode assemblies along the third direction, and the two side heat conductive members are connected to both sides of the middle heat conductive member in the third direction to improve the heat conduction efficiency between the middle heat conductive member and the side heat conductive member.

[0025] In some embodiments, the two side heat conductive members are disposed on the same side of the plurality of electrode assemblies along the third direction.

[0026] In the technical solution of the embodiment of the present application, two side heat conductive members are arranged on the same side of multiple electrode assemblies along the third direction to reduce the overall size of the heat conductive assembly in the third direction, thereby improving the energy density of the battery cell.

[0027] In some embodiments, the electrode assembly is wound or laminated.

[0028] In the technical solution of the embodiment of the present application, the electrode assembly is of a wound or laminated type. Through the first heat-conducting portion connected to the side of the electrode assembly by heat conduction, the thermal resistance of the electrode body at its side can be reduced, and the rate of heat exchange between the electrode body at its side and the external environment can be increased to balance the internal temperature of the battery cell and improve the problem of adverse effects on the performance and service life of the battery cell due to excessively high or low internal temperature of the battery cell.

[0029] In some embodiments, the first heat conducting portion is disposed around a circumference of the electrode body.

[0030] In the technical solution of the embodiment of the present application, the first heat-conducting portion is arranged around the circumference of the electrode body to increase the side contact area between the heat-conducting component and the electrode body, further increasing the heat exchange rate between the electrode body at its side and the external environment, so as to balance the internal temperature of the battery cell and improve the problem of adverse effects on the performance and service life of the battery cell due to excessively high or low internal temperature of the battery cell.

[0031] In some embodiments, a gap extending along the first direction and penetrating the first heat conducting portion is formed between two ends of the first heat conducting portion along the circumference of the electrode body.

[0032] In the technical solution of the embodiment of the present application, a gap extending along the first direction and penetrating the first heat-conducting portion is formed between the two ends of the first heat-conducting portion along the circumferential side of the electrode body. By setting the gap, the first heat-conducting portion can be deformed synchronously during the expansion process of the electrode assembly, thereby reducing the risk of the first heat-conducting portion being expanded by the electrode body, improving the service life of the heat-conducting assembly, and improving the reliability of the battery cell.

[0033] In some embodiments, a gap is provided at at least one of the two first side surfaces.

[0034] In the technical solution of the embodiment of the present application, during the expansion process of the electrode assembly, the expansion amplitude at the first side surface is greater, so a gap is set at at least one of the two first side surfaces to make it easier for the first heat-conducting part to absorb the expansion of the electrode assembly through the gap, further reducing the risk of the first heat-conducting part being expanded by the electrode body, thereby improving the service life of the heat-conducting assembly and the reliability of the battery cell.

[0035] In some embodiments, the gap is provided at both first sides.

[0036] In the technical solution of the embodiment of the present application, gaps are provided at the two first side surfaces so that the first heat conducting portion can be more easily deformed synchronously during the expansion of the electrode assembly, thereby reducing the risk of the first heat conducting portion being expanded by the electrode body.

[0037] In some embodiments, a plurality of electrode assemblies are provided, and the plurality of electrode assemblies are stacked along the second direction, and the first heat conducting portion is provided around the outer periphery of the entire structure formed by the plurality of electrode assemblies.

[0038] In the technical solution of the embodiment of the present application, a plurality of electrode assemblies are provided, and the plurality of electrode assemblies are stacked along the second direction. The first heat-conducting part is arranged around the overall periphery formed by the plurality of electrode assemblies to shorten the heat-conducting path between the first heat-conducting part and the shell, so that the first heat-conducting part can transfer heat more easily between the electrode assembly and the external environment.

[0039] In some embodiments, the tab extends from the first end surface, and the heat-conducting assembly further includes a second heat-conducting portion, which is disposed along the first direction between the housing and at least a portion of the second end surface.

[0040] In the technical solution of the embodiment of the present application, the heat-conducting assembly also includes a second heat-conducting portion arranged between the shell and at least part of the second end surface along the first direction. The second heat-conducting portion can improve the heat exchange rate between the electrode body at its second end surface and the external environment.

[0041] In some embodiments, the first heat conducting portion and the second heat conducting portion are connected.

[0042] In the technical solution of the embodiment of the present application, the first heat-conducting part and the second heat-conducting part are connected to increase the contact area between the heat-conducting component and the electrode assembly, further increase the heat exchange rate between the electrode assembly and the external environment, so as to balance the internal temperature of the battery cell and improve the problem of adverse effects on the performance and service life of the battery cell due to excessively high or low internal temperature of the battery cell.

[0043] In some embodiments, a second through hole is provided on the second heat conducting portion.

[0044] In the technical solution of the embodiment of the present application, the second through hole is provided in the second heat conducting portion to facilitate the flow of electrolyte to the electrode assembly, thereby improving the infiltration efficiency of the electrolyte into the electrode assembly.

[0045] In some embodiments, the side surfaces include two first side surfaces and two second side surfaces, the two first side surfaces are arranged opposite to each other in the second direction, the two second side surfaces are arranged opposite to each other in the third direction, the first direction, the second direction and the third direction intersect with each other, the area of ​​the first side surface is greater than the area of ​​the second side surface, the first heat conducting portion is arranged on at least one of the two first side surfaces, and the second heat conducting portion is connected to the first heat conducting portion arranged on the first side surface.

[0046] In the technical solution of the embodiment of the present application, the second heat conducting part is connected to the first heat conducting part arranged on the first side surface, which can increase the contact area between the first heat conducting part and the second heat conducting part, thereby improving the heat conduction efficiency between the first heat conducting part and the second heat conducting part, and improving the connection reliability between the first heat conducting part and the second heat conducting part.

[0047] In some embodiments, a plurality of electrode assemblies are provided, and the plurality of electrode assemblies are stacked along the second direction. The first heat conducting portion is provided on at least one of the two first side surfaces of at least two electrode assemblies. A plurality of second heat conducting portions are provided independently of each other, and the plurality of second heat conducting portions are provided corresponding to at least one electrode assembly.

[0048] In the technical solution of the embodiment of the present application, multiple electrode assemblies are stacked along the second direction, and the first heat-conducting portion is arranged on at least one of the two first side surfaces of at least two electrode assemblies. Heat exchange can be carried out with the first side surfaces of one or two electrode assemblies through one first heat-conducting portion, and multiple second heat-conducting portions are independent of each other and are arranged corresponding to at least one electrode assembly to enhance the thermal conductivity of the electrode assembly at the second end surface.

[0049] In some embodiments, at least two second heat conducting portions among the plurality of second heat conducting portions are stacked along the first direction.

[0050] In the technical solution of the embodiment of the present application, at least two second heat-conducting parts stacked along the first direction help to improve the heat exchange capacity of the electrode assembly at the second end surface.

[0051] In some embodiments, multiple electrode assemblies are provided, and the multiple electrode assemblies are stacked along the second direction. The first heat-conducting part includes a middle heat-conducting part, which is provided between two adjacent first side surfaces of two adjacent electrode assemblies and connected to the second heat-conducting part.

[0052] In the technical solution of the embodiment of the present application, the middle heat conductive member is arranged between two adjacent first side surfaces of two adjacent electrode assemblies and is connected to the second heat conductive part. The heat between the adjacent electrode assemblies can be transferred to the second heat conductive part through the middle heat conductive member, and heat is exchanged between the second heat conductive part and the external environment to balance the internal temperature of the battery cell.

[0053] In some embodiments, two independent middle heat-conducting members are arranged between two adjacent first side surfaces of two adjacent electrode assemblies, and the heat-conducting assembly includes two second heat-conducting portions arranged at intervals, and the two second heat-conducting portions are respectively located on both sides of the two middle heat-conducting members along the second direction, and each middle heat-conducting member is connected to the adjacent second heat-conducting portions.

[0054] In the technical solution of the embodiment of the present application, two independent middle heat-conducting parts are arranged between two adjacent first side surfaces of two adjacent electrode assemblies, and the two second heat-conducting parts are respectively located on both sides of the two middle heat-conducting parts along the second direction. Each middle heat-conducting part is connected to the adjacent second heat-conducting part, so that during the expansion of the electrode assembly, the interconnected middle heat-conducting parts and the second heat-conducting parts can move in the second direction to buffer the extrusion force of the electrode body, improve the problem of extrusion and damage of the heat-conducting assembly during the expansion of the electrode body, and improve the reliability of the battery cell.

[0055] In some embodiments, the two middle heat conductive members between adjacent electrode assemblies are spaced apart in the third direction, or the two middle heat conductive members between adjacent electrode assemblies abut against each other in the third direction.

[0056] In the technical solution of the embodiment of the present application, the two middle heat-conducting parts located between adjacent electrode assemblies are spaced apart or abutted against each other in the third direction, which not only helps to reduce the size of the heat-conducting component, while improving the heat-conducting efficiency of the electrode assembly, but also reduces the processing cost of the battery cell, and also helps to reduce the overall size of the heat-conducting component in the second direction and improve the energy density of the battery cell.

[0057] In some embodiments, the first heat-conducting portion further includes two end heat-conducting members, which are respectively disposed between the housing and two adjacent first side surfaces and are respectively connected to the second heat-conducting portion.

[0058] In the technical solution of the embodiment of the present application, the first heat-conducting part also includes two end heat-conducting parts respectively arranged between the shell and the two adjacent first side surfaces, and respectively connected to the second heat-conducting part. The two end heat-conducting parts can transfer heat through the second heat-conducting part, or the electrode assembly can transfer heat to the external environment through the two end heat-conducting parts and the second heat-conducting part to improve the thermal conductivity efficiency of the heat-conducting assembly.

[0059] In some embodiments, a plurality of electrode assemblies are provided, and the plurality of electrode assemblies are stacked along the second direction. The first heat-conducting portion includes a middle heat-conducting member and an end heat-conducting member. The middle heat-conducting member is provided between two adjacent first side surfaces of two adjacent electrode assemblies, and the end heat-conducting member is provided between the shell and an adjacent first side surface. The middle heat-conducting member and the end heat-conducting member are respectively connected to the second heat-conducting portion.

[0060] In the technical solution of the embodiment of the present application, the first heat-conducting part includes a middle heat-conducting part and an end heat-conducting part. The middle heat-conducting part is arranged between two adjacent first side surfaces of two adjacent electrode assemblies, and the end heat-conducting part is arranged between the shell and an adjacent first side surface. The middle heat-conducting part and the end heat-conducting part are respectively connected to the second heat-conducting part. In this way, the heat between the adjacent electrode assemblies can be transferred to the end heat-conducting part through the middle heat-conducting part and the second heat-conducting part, and heat exchange is carried out between the end heat-conducting part and the external environment to improve the thermal conductivity efficiency of the heat-conducting component.

[0061] In some embodiments, a plurality of electrode assemblies are provided, and the plurality of electrode assemblies are stacked along the second direction. The first heat-conducting part includes a middle heat-conducting part and two end heat-conducting parts. The middle heat-conducting part is provided between two adjacent first side surfaces of two adjacent electrode assemblies. The two end heat-conducting parts are respectively provided between the shell and the two adjacent first side surfaces. The middle heat-conducting part and the two end heat-conducting parts are respectively connected to the second heat-conducting part.

[0062] In the technical solution of the embodiment of the present application, the first heat-conducting part includes a middle heat-conducting part and two end heat-conducting parts. The middle heat-conducting part is arranged between the two adjacent first side surfaces of the two adjacent electrode assemblies. The two end heat-conducting parts are respectively arranged between the shell and the two adjacent first side surfaces. The middle heat-conducting part and the two end heat-conducting parts are respectively connected to the second heat-conducting part. In this way, the heat between the adjacent electrode assemblies can be transferred to the end heat-conducting parts through the middle heat-conducting part and the second heat-conducting part, and heat exchange is carried out between the end heat-conducting parts and the external environment to improve the thermal conductivity efficiency of the heat-conducting assembly.

[0063] In some embodiments, two independent middle heat conductive parts are arranged between two adjacent first side surfaces of two adjacent electrode assemblies, and the heat conductive assembly includes four second heat conductive parts, which are arranged between the two end heat conductive parts at intervals along the second direction. The two outermost second heat conductive parts are respectively connected to the two end heat conductive parts, and the two middle second heat conductive parts are respectively connected to the two middle heat conductive parts.

[0064] In the technical solution of the embodiment of the present application, two independent middle heat-conducting parts are arranged between two adjacent first side surfaces of two adjacent electrode assemblies, the two outermost second heat-conducting parts are respectively connected to the two end heat-conducting parts, and the two middle second heat-conducting parts are respectively connected to the two middle heat-conducting parts, so that when the electrode assembly expands, the combination of the end heat-conducting parts and the second heat-conducting parts and the middle heat-conducting parts can move in the second direction to buffer the extrusion force of the electrode assembly, improve the problem of extrusion and damage of the heat-conducting parts during the expansion of the electrode assembly, and improve the reliability of the battery cell.

[0065] In some embodiments, the thermally conductive assembly and the electrode assembly are adhesively connected.

[0066] In the technical solution of the embodiment of the present application, the thermal conductive component and the electrode component are adhesively connected to improve the connection reliability of the thermal conductive component and the electrode component.

[0067] In some embodiments, the orthographic projection area of ​​the heat conducting component in the second direction is S1, the orthographic projection area of ​​the electrode body in the second direction is S2, 0.1≤S1 / S2≤1 is satisfied, and the first direction and the second direction intersect.

[0068] In the technical solution of the embodiment of the present application, when the above conditions are met, it is possible to improve the problem that the first heat-conducting part does not significantly improve the thermal conductivity efficiency of the electrode assembly due to the small area of ​​the first heat-conducting part, and it is also possible to improve the problem that the first heat-conducting part is too large and interferes with other structures in the battery cell, causing damage to the battery cell.

[0069] In some embodiments, the shell includes an opening in a first direction, the battery cell also includes a top cover assembly, the top cover assembly covers the opening, the top cover assembly has an electrode terminal, the electrode terminal is connected to the tab, the heat conductive assembly also includes a third heat conductive part, the third heat conductive part is heat conductively connected to the tab, and the third heat conductive part is heat conductively connected to the first heat conductive part.

[0070] In the technical solution of the embodiment of the present application, the top cover assembly covers the opening of the shell, the electrode terminal of the pole tab and the top cover assembly are connected to achieve electrical connection, and the heat-conducting assembly also includes a third heat-conducting part heat-conductingly connected to the pole tab, and the third heat-conducting part is heat-conductingly connected to the first heat-conducting part, so that the heat-conducting assembly can increase the heat conduction rate at the pole tab to balance the temperature at the pole tab and the electrode body, thereby improving the problem of affecting the performance of the battery cell due to excessively high temperature at the pole tab.

[0071] In some embodiments, the battery cell further includes a switching mechanism connected between the tab and the electrode terminal, and the switching mechanism is thermally connected to the third heat conducting portion.

[0072] In the technical solution of the embodiment of the present application, the battery cell also includes a transfer mechanism, which is connected between the tab and the electrode terminal. The transfer mechanism and the third heat-conducting part are thermally connected so that the heat-conducting component can increase the heat conduction rate at the transfer mechanism to balance the temperature at the transfer mechanism and improve the problem of affecting the performance of the battery cell due to excessively high temperature at the transfer mechanism.

[0073] In some embodiments, the electrode tab includes a folded section and an extended section, the folded section is connected to the electrode body, one side of the extended section is connected to the folded section, and the other side is connected to the transfer mechanism, the third heat conducting portion is connected to the side of the extended section facing the folded section, or the third heat conducting portion is connected to the side of the extended section facing the transfer mechanism.

[0074] In the technical solution of the embodiment of the present application, the third heat-conducting part is connected to the side of the extension section facing the convergence section, or the third heat-conducting part is connected to the side of the extension section facing the adapter mechanism. The third heat-conducting part is used to improve the heat conduction rate at the pole ear, thereby improving the problem that the temperature at the pole ear is too high, thereby heating the pole piece, causing the electrode body to heat up, and the performance of the battery cell to decrease.

[0075] In some embodiments, the extension section includes a first sub-segment, a second sub-segment, and a third sub-segment connecting the first sub-segment and the second sub-segment, which are spaced apart along the first direction. The first sub-segment is connected to the gathering section, the second sub-segment is connected to the transfer mechanism, and the third heat-conducting portion is connected to the side of the first sub-segment facing the gathering section.

[0076] In the technical solution of the embodiment of the present application, the extension section includes a first sub-segment, a second sub-segment and a third sub-segment connecting the first sub-segment and the second sub-segment, which are arranged at intervals along the first direction. The second sub-segment is connected to the adapter mechanism to increase the contact area between the adapter mechanism and the pole ear. The third heat-conducting part is connected to the side of the first sub-segment toward the convergence section to reduce the difficulty of connecting the third heat-conducting part and the pole ear.

[0077] In some embodiments, the side surfaces include two first side surfaces and two second side surfaces, the two first side surfaces are arranged opposite to each other in the second direction, the two second side surfaces are arranged opposite to each other in the third direction, the first direction, the second direction and the third direction intersect each other, the area of ​​the first side surface is greater than the area of ​​the second side surface, two pole ears are provided, the two pole ears extend from the first end surface and are arranged at intervals along the third direction, two first heat conducting parts and two third heat conducting parts are respectively provided, the two first heat conducting parts are respectively arranged on the two second side surfaces, the two third heat conducting parts are respectively connected to one end of the two first heat conducting parts facing the pole ears, and the two third heat conducting parts are respectively connected to the extension sections of the two pole ears.

[0078] In the technical solution of the embodiment of the present application, the two pole tabs extend out from the first end face and are arranged at intervals along the third direction. The two first heat conducting parts are respectively arranged on the two second side faces. The thickness of the battery cell will not be increased due to the arrangement of the heat conducting component. Since the expansion of the electrode assembly mainly occurs at the first side face, when the first heat conducting part is arranged at the second side face, the interference of the first heat conducting part on the expansion of the electrode assembly can be reduced. The two third heat conducting parts are respectively connected to one end of the two first heat conducting parts facing the pole tabs, and the two third heat conducting parts are respectively connected to the extension sections of the two pole tabs. Each pole tab is connected to a third heat conducting part, so that the heat at the electrode body and each pole tab can be transferred to the first heat conducting part through the third heat conducting part, so as to improve the heat conduction rate at the pole tab, improve the problem that the temperature at the pole tab is too high, thereby heating the pole piece, causing the electrode body to heat up, and reducing the performance of the battery cell.

[0079] In some embodiments, the side surfaces include two first side surfaces and two second side surfaces, the two first side surfaces are arranged opposite to each other in the second direction, the two second side surfaces are arranged opposite to each other in the third direction, the first direction, the second direction and the third direction intersect with each other, the area of ​​the first side surfaces is greater than the area of ​​the second side surfaces, two first heat conducting parts and two third heat conducting parts are respectively provided, the two first heat conducting parts are respectively provided on the two first side surfaces, each third heat conducting part is respectively connected to a first heat conducting part, and the two third heat conducting parts are respectively connected to different positions of the extension section of the same pole ear.

[0080] In the technical solution of the embodiment of the present application, each third heat conducting part is respectively connected to a first heat conducting part, and the two third heat conducting parts are respectively connected to different positions of the extension section of the same pole ear, so as to better improve the heat conduction rate at the pole ear and improve the problem of affecting the performance of the battery cell due to excessive temperature at the pole ear.

[0081] In some embodiments, the extension section includes a first sub-segment, a second sub-segment, and a third sub-segment connecting the first sub-segment and the second sub-segment, which are spaced apart along the first direction. The first sub-segment is connected to the retracting section, and the second sub-segment is connected to the transfer mechanism. One of the two third heat-conducting parts is connected to the first sub-segment, and the other is connected to the second sub-segment.

[0082] In the technical solution of the embodiment of the present application, one of the two third heat conducting parts is connected to the first sub-segment, and the other is connected to the second sub-segment. The connection areas of the two third heat conducting parts and the tabs are reasonably allocated to improve the connection reliability between the third heat conducting parts and the tabs.

[0083] In some embodiments, the side includes two first side surfaces and two second side surfaces, the two first side surfaces are arranged opposite to each other in the second direction, the two second side surfaces are arranged opposite to each other in the third direction, the first direction, the second direction and the third direction intersect with each other, the area of ​​the first side surface is greater than the area of ​​the second side surface, the transfer mechanism includes a first connecting segment and a second connecting segment arranged along the third direction, the tab is connected to the first connecting segment, and the third heat conducting portion is connected to the second connecting segment.

[0084] In the technical solution of the embodiment of the present application, the adapter mechanism includes a first connecting section and a second connecting section, the pole ear is connected to the first connecting section, and the third heat conducting part is connected to the second connecting section. The third heat conducting part is used to improve the heat conduction rate at the adapter mechanism, thereby improving the problem that the temperature at the adapter mechanism is too high, thereby heating the pole piece and causing the performance of the battery cell to be reduced.

[0085] In some embodiments, two first heat conducting parts and two third heat conducting parts are respectively provided, the two first heat conducting parts are respectively provided on the two first side surfaces, each third heat conducting part is respectively connected to one first heat conducting part, and the two third heat conducting parts are respectively connected to different positions of the second connecting section of the same adapter mechanism.

[0086] In the technical solution of the embodiment of the present application, two first heat-conducting parts are respectively arranged on the two first side surfaces, each third heat-conducting part is respectively connected to a first heat-conducting part, and the two third heat-conducting parts are respectively connected to different positions of the second connecting section of the same adapter mechanism, so as to better improve the heat conduction rate at the adapter mechanism and improve the problem of affecting the performance of the battery cell due to excessive temperature at the adapter mechanism.

[0087] In some embodiments, two electrode assemblies are provided, and the two electrode assemblies are stacked along the second direction. The adapter mechanism is provided with two first connecting sections, and the two first connecting sections are respectively provided on both sides of the second connecting section in the second direction. The pole ears of the two electrode assemblies are respectively connected to the two first connecting sections. Two first heat conducting parts and two third heat conducting parts are respectively provided, and the two first heat conducting parts are provided on two first side surfaces of the same electrode body. The two third heat conducting parts are respectively connected to one end of the two first heat conducting parts facing the adapter mechanism, and the two third heat conducting parts are respectively connected to the second connecting section and the pole ears of the adapter mechanism.

[0088] In the technical solution of the embodiment of the present application, two first heat-conducting parts are arranged on both sides of an electrode body in the second direction, and two third heat-conducting parts are respectively connected to one end of the two first heat-conducting parts facing the adapter mechanism, and the two third heat-conducting parts are respectively connected to the second connecting section and the pole ear of the adapter mechanism to reduce the difficulty of connecting the third heat-conducting part and the pole ear and the adapter mechanism; and the two third heat-conducting parts are respectively connected to the pole ear and the adapter mechanism to better stabilize the temperature at the pole ear.

[0089] In some embodiments, the tab extends from the first end surface, and the heat-conducting assembly further includes a second heat-conducting portion, which is disposed along the first direction between the housing and at least a portion of the second end surface, and is connected to the first heat-conducting portion.

[0090] In the technical solution of the embodiment of the present application, the heat-conducting component also includes a second heat-conducting portion arranged along the first direction between the shell and at least part of the second end face. The second heat-conducting portion is connected to the first heat-conducting portion to increase the contact area between the heat-conducting component and the shell, so as to increase the heat conduction rate of the heat-conducting component to the pole ear, thereby improving the problem of affecting the performance of the battery cell due to excessively high temperature at the pole ear.

[0091] In some embodiments, the tab extends from the first end face, and the battery cell further includes a first insulating film, which covers the side face and the second end face of the electrode body; wherein the first heat conducting portion is located between the first insulating film and the electrode assembly, or the first heat conducting portion is located between the first insulating film and the shell.

[0092] In the technical solution of the embodiment of the present application, the first insulating film is covered on the side and second end face of the electrode body to insulate the shell and the electrode assembly. The first heat-conducting part is located between the first insulating film and the electrode assembly. The first insulating film plays a role in supporting and protecting the first heat-conducting part, reducing the problem of damage to the first heat-conducting part in the first insulating film under external force impact, or the first heat-conducting part is located between the first insulating film and the shell to improve the insulation reliability between the first heat-conducting part and the electrode assembly, and improve the heat conduction efficiency between the first heat-conducting part and the shell.

[0093] In some embodiments, the heat-conducting component includes an insulating member and a heat-conducting member, at least a portion of the insulating member forms a receiving cavity, the heat-conducting member is arranged in the receiving cavity, the heat-conducting member includes a first heat-conducting plate, the first heat-conducting plate is arranged on the side, and the first heat-conducting part is composed of the first heat-conducting plate and the insulating member.

[0094] In the technical solution of the embodiment of the present application, the heat-conducting component includes an insulating part and a heat-conducting part. At least a partial area of ​​the insulating part forms a receiving cavity. The heat-conducting part is arranged in the receiving cavity. The heat-conducting part includes a first heat-conducting sheet. The first heat-conducting sheet is arranged on the side. The first heat-conducting part is composed of the first heat-conducting sheet and the insulating part. In this way, the insulating part can be used to insulate the heat-conducting part and the electrode body, and the insulating part can be used to isolate the heat-conducting part and the electrolyte, so as to improve the problem of incompatibility between the heat-conducting part and the electrolyte, which affects the performance of the battery cell.

[0095] In some embodiments, the tab extends from the first end surface, and the battery cell further includes a second insulating film, which is connected to the insulating member, and the insulating member and the second insulating film jointly cover the second end surface and side surfaces of the electrode body.

[0096] In the technical solution of the embodiment of the present application, the second insulating film and the insulating part are connected, and the insulating part and the second insulating film are jointly covered on the second end face and side face of the electrode body. The combination of the second insulating film and the insulating part is used to achieve insulation between the electrode body and the shell, which helps to reduce the size of the Mylar film and reduce the preparation cost of the battery cell, and helps to reduce the thickness of the battery cell and improve the energy density of the battery cell.

[0097] In some embodiments, the tab extends from the first end surface, and the insulating member covers the second end surface and side surfaces of the electrode body.

[0098] In the technical solution of the embodiment of the present application, the insulating part covers the second end face and side surface of the electrode body to insulate the shell and the electrode assembly, and there is no need to set a Mylar film, which helps to reduce the cost of segmented preparation of the battery cell, and can reduce the thickness of the battery cell and improve the energy density of the battery cell.

[0099] In some embodiments, the side includes two first side surfaces and two second side surfaces, the two first side surfaces are arranged opposite to each other in the second direction, the two second side surfaces are arranged opposite to each other in the third direction, the first direction, the second direction and the third direction intersect with each other, the area of ​​the first side surface is greater than the area of ​​the second side surface, the insulating member includes a first insulating portion, the first insulating portion includes a main body portion and a bending portion connected to each other, the main body portion and the bending portion are connected, the main bodies of the two first insulating portions are respectively arranged on the two first side surfaces, the two bending portions are respectively arranged on the two second side surfaces, and the first thermal conductive sheet is arranged on at least one of the main body portion and the bending portion.

[0100] In the technical solution of the embodiment of the present application, the first insulating part includes a main body part and a bending part that are connected to each other, the main body part and the bending part are connected, the main bodies of the two first insulating parts are respectively arranged on the two first side surfaces, and the two bending parts are respectively arranged on the two second side surfaces to achieve insulation of the electrode assembly on its circumferential side surface and the shell, and the first thermal conductive sheet is arranged on at least one of the main body part and the bending part to improve the thermal conductivity rate at the first side surface and / or second side surface of the electrode assembly.

[0101] In some embodiments, a first through hole is provided through the first insulating portion, and the first through hole and the accommodating cavity are spaced apart.

[0102] In the technical solution of the embodiment of the present application, a first through hole is provided through the first insulating part so that the electrolyte can infiltrate the electrode assembly through the first through hole. The first through hole and the accommodating cavity are spaced apart to avoid contact between the electrolyte and the first thermal conductive plate.

[0103] In some embodiments, a first avoidance hole is provided through the first heat conducting plate, the first insulating portion covers the inner wall of the first avoidance hole, a first through hole is provided through the first insulating portion, and the first through hole is located in the first avoidance hole.

[0104] In the technical solution of the embodiment of the present application, a first avoidance hole is provided through the first thermal conductive sheet, and a first through hole is provided through the first insulating portion. The first through hole is located in the first avoidance hole so that the electrolyte can penetrate into the electrode assembly through the first through hole and the first avoidance hole. The first insulating portion covers the inner wall of the first avoidance hole to avoid contact between the electrolyte and the first thermal conductive sheet and to keep the first thermal conductive sheet and the electrode assembly insulated.

[0105] In some embodiments, the electrode tab extends from the first end face, and the insulating member also includes a second insulating portion, which is arranged between the second end face of the electrode body and the shell, and the second insulating portion is insulated from the shell and the second end face of the electrode assembly, and the main bodies of the two first insulating portions are respectively connected to the two sides of the second insulating portion.

[0106] In the technical solution of the embodiment of the present application, the insulating part also includes a second insulating part arranged between the second end face of the electrode body and the shell, and the main bodies of the two first insulating parts are respectively connected to the two sides of the second insulating part, thereby reducing the difficulty of aligning the second insulating part and the first insulating part, and reducing the difficulty of matching the insulating part and the electrode assembly.

[0107] In some embodiments, the heat conducting member includes a second heat conducting sheet, and the second heat conducting sheet is disposed on the second insulating portion.

[0108] In the technical solution of the embodiment of the present application, the heat conducting member includes a second heat conducting sheet arranged on the second insulating portion to improve the heat conduction rate at the second end surface.

[0109] In some embodiments, a second through hole is provided through the second insulating portion, and the second through hole and the accommodating cavity are spaced apart.

[0110] In the technical solution of the embodiment of the present application, a second through hole is provided through the second insulating part so that the electrolyte can infiltrate the electrode assembly through the second through hole. The second through hole and the accommodating cavity are spaced apart to avoid contact between the electrolyte and the second thermal conductive plate.

[0111] In some embodiments, a second avoidance hole is provided through the second heat conducting plate, the second insulating portion covers the inner wall of the second avoidance hole, a second through hole is provided through the second insulating portion, and the second through hole is located in the second avoidance hole.

[0112] In the technical solution of the embodiment of the present application, a second avoidance hole is provided through the second thermal conductive sheet, and a second through hole is provided through the second insulating portion. The second through hole is located in the second avoidance hole so that the electrolyte can penetrate into the electrode assembly through the second through hole and the second avoidance hole. The second insulating portion covers the inner wall of the second avoidance hole to prevent the electrolyte from contacting the second thermal conductive sheet and to keep the second thermal conductive sheet and the electrode assembly insulated.

[0113] In some embodiments, a plurality of electrode assemblies are provided, and the plurality of electrode assemblies are stacked along the second direction. The insulating member further includes a middle insulating portion, which is provided between the electrode bodies of adjacent electrode assemblies. The middle insulating portion and the second insulating portion are connected to each other. The first thermal conductive plate includes an intermediate thermal conductive plate, which is provided in the middle insulating portion.

[0114] In the technical solution of the embodiment of the present application, the middle insulating part is arranged between adjacent electrode bodies to insulate the adjacent electrode bodies, the middle insulating part and the second insulating part are connected to each other to improve the insulation reliability of the middle insulating part, and the intermediate thermal conductive plate is arranged in the middle insulating part to improve the thermal conductivity between adjacent electrode bodies.

[0115] In some embodiments, a bending portion is connected to both sides of the main body in the third direction, and the two bending portions of the two first insulating portions and located on the same side of the electrode assembly extend toward each other in the second direction.

[0116] In the technical solution of the embodiment of the present application, the main body is connected to a bending portion on both sides of the third direction, and the two bending portions of the two first insulating portions and located on the same side of the electrode assembly extend toward each other in the second direction. The joint of the two bending portions is located on the second side surface, and the first side surface with a larger area can be provided with a larger area of ​​a thermal conductive layer to improve the thermal conductivity of the thermal conductive assembly.

[0117] In some embodiments, the two bending portions extend toward each other in the second direction, and the two bending portions at least partially overlap in the third direction.

[0118] In the technical solution of the embodiment of the present application, the two bent portions extend toward each other in the second direction, and the two bent portions at least partially overlap in the third direction to improve the insulation reliability of the first insulating portion between the electrode assembly and the shell.

[0119] In some embodiments, the shell includes an opening in a first direction, the battery cell also includes a top cover assembly, the top cover assembly covers the opening and is connected to the tab, and at least one main body extends from the first end surface in the first direction and is connected to the top cover assembly.

[0120] In the technical solution of the embodiment of the present application, at least one main body portion extends from the first end surface in a first direction and is connected to the top cover assembly. The top cover assembly plays a role in positioning and fixing the heat-conducting assembly, thereby improving the stability of the heat-conducting assembly in the shell.

[0121] In some embodiments, a dimension L3 of the main body extending from the first end surface in the first direction is ≥2 mm.

[0122] In the technical solution of the embodiment of the present application, when the above conditions are met, the connection reliability between the heat conducting component and the top cover component is improved.

[0123] In some embodiments, a minimum distance between an orthographic projection of the heat conducting member in the thickness direction of the heat conducting assembly and an edge of an orthographic projection of the insulating member in the thickness direction of the heat conducting assembly is greater than or equal to 2 mm.

[0124] In the technical solution of the embodiment of the present application, the minimum distance from the edge of the orthographic projection of the heat conducting part in the thickness direction of the heat conducting component to the orthographic projection of the insulating part in the thickness direction of the heat conducting component is greater than or equal to 2 mm, so that there is a sufficient plastic sealing area between the heat conducting part and the edge of the insulating part to improve the sealing reliability of the accommodating cavity.

[0125] In some embodiments, the thickness D3 of the thermal conductor satisfies 40 μm≤D3≤180 μm.

[0126] In the technical solution of the embodiment of the present application, 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 heat conductor being too thick, but also improve the problem that the heat conductor is easily damaged due to being too thin.

[0127] In some embodiments, the insulating member includes two sub-insulating layers, which are stacked and connected to each other to form a receiving cavity. The thickness D1 of the sub-insulating layer satisfies 5 μm≤D1≤100 μm.

[0128] In the technical solution of the embodiment of the present application, when the above conditions are met, it can not only improve the problem that the sub-insulating layer is too thick, resulting in a large volume of the battery cell and reduced energy density, but also improve the problem that the sub-insulating layer is too thin and easily damaged.

[0129] In some embodiments, the insulation comprises polyethylene or polypropylene or polyimide or polyester resin.

[0130] In the technical solution of the embodiment of the present application, the insulating member includes polyethylene or polypropylene or polyimide or polyester resin to improve the insulation reliability of the insulating member.

[0131] In some embodiments, the thermal conductor includes graphite or graphene or carbon nanotubes.

[0132] In the technical solution of the embodiment of the present application, the heat conducting member includes graphite, graphene or carbon nanotubes, and the thermal conductivity of the heat conducting component is improved by using the graphite, graphene or carbon nanotube thermal conductive materials.

[0133] In some embodiments, the thermal conductivity k of the heat conducting member satisfies k>500 W / (m·K).

[0134] In the technical solution of the embodiment of the present application, when the thermal conductivity k of the heat conducting member meets the above conditions, the heat conducting component has sufficient thermal conductivity to conduct the heat of the electrode body.

[0135] In a second aspect, an embodiment of the present application provides a battery device comprising a battery cell according to any one of the embodiments of the first aspect.

[0136] In a third aspect, an embodiment of the present application provides an electrical device, comprising the battery device of the embodiment of the second aspect described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0137] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present application. The same reference symbols are used throughout the drawings to represent the same components. In the drawings:

[0138] Figure 1 is a structural schematic diagram of a vehicle provided in one embodiment of the present application;

[0139] Figure 2 is a structural diagram of a battery device provided in one embodiment of the present application;

[0140] Figure 3 This is a schematic structural diagram of a battery module provided in one embodiment of the application;

[0141] Figure 4 is an exploded view of a battery cell provided in one embodiment of the present application;

[0142] Figure 5 This is a schematic structural diagram of an electrode assembly of a battery cell provided in one embodiment of the present application;

[0143] Figure 6 This is a partial structural diagram of a battery cell provided in one embodiment of the present application;

[0144] Figure 7 is a partial structural diagram of a battery cell provided by another embodiment of the present application;

[0145] Figure 8 This is a partial structural diagram of a battery cell provided in one embodiment of the present application;

[0146] Figure 9 This is a partial structural diagram of a battery cell provided in one embodiment of the present application;

[0147] Figure 10 This is a partial structural diagram of a battery cell provided in one embodiment of the present application;

[0148] Figure 11 This is a partial structural diagram of a battery cell provided in one embodiment of the present application;

[0149] Figure 12 This is a partial structural diagram of a battery cell provided in one embodiment of the present application;

[0150] Figure 13 This is a partial structural diagram of a battery cell provided in one embodiment of the present application;

[0151] Figure 14 This is a partial structural diagram of a battery cell provided in one embodiment of the present application;

[0152] Figure 15 This is a partial structural diagram of a battery cell provided in one embodiment of the present application;

[0153] Figure 16 This is a partial structural diagram of a battery cell provided in one embodiment of the present application;

[0154] Figure 17 This is a partial structural diagram of a battery cell provided in one embodiment of the present application;

[0155] Figure 18 This is a partial structural diagram of a battery cell provided in one embodiment of the present application;

[0156] Figure 19 is a schematic diagram of a heat-conducting component of a battery cell provided in one embodiment of the present application;

[0157] Figure 20 This is a partial structural diagram of a battery cell provided in one embodiment of the present application;

[0158] Figure 21 This is a partial structural diagram of a battery cell provided in one embodiment of the present application;

[0159] Figure 22 This is a partial structural diagram of a battery cell provided in one embodiment of the present application;

[0160] Figure 23 This is a partial structural diagram of a battery cell provided in one embodiment of the present application;

[0161] Figure 24 is a schematic diagram of a heat-conducting component of a battery cell provided in one embodiment of the present application;

[0162] Figure 25 This is a partial structural diagram of a battery cell provided in one embodiment of the present application;

[0163] Figure 26 This is a partial structural diagram of a battery cell provided in one embodiment of the present application;

[0164] Figure 27 This is a partial structural diagram of a battery cell provided in one embodiment of the present application;

[0165] Figure 28 This is a partial structural diagram of a battery cell provided in one embodiment of the present application;

[0166] Figure 29 The battery cell provided in one embodiment of the present application is Figure 28 Enlarged view of point A in the middle;

[0167] Figure 30 Another embodiment of the present invention provides a battery cell. Figure 28 Enlarged view of point A in the middle;

[0168] Figure 31 is an exploded view of a battery cell provided in another embodiment of the present application;

[0169] Figure 32 This is a partial structural diagram of a battery cell provided in one embodiment of the present application;

[0170] Figure 33 This is a partial structural diagram of a battery cell provided in one embodiment of the present application;

[0171] Figure 34 is an exploded view of a battery cell provided in another embodiment of the present application;

[0172] Figure 35 This is a partial structural diagram of a battery cell provided in one embodiment of the present application;

[0173] Figure 36 This is a partial structural diagram of a battery cell provided in one embodiment of the present application;

[0174] Figure 37 This is a partial structural diagram of a battery cell provided in one embodiment of the present application;

[0175] Figure 38 This is a partial structural diagram of a battery cell provided in one embodiment of the present application;

[0176] Figure 39 yes Figure 38 Schematic diagram of the enlarged structure at B in the middle;

[0177] Figure 40 This is a partial structural diagram of a battery cell provided in one embodiment of the present application;

[0178] Figure 41 This is a partial structural diagram of a battery cell provided in one embodiment of the present application;

[0179] Figure 42 This is a partial structural diagram of a battery cell provided in one embodiment of the present application;

[0180] Figure 43 is an exploded view of a battery cell provided in another embodiment of the present application;

[0181] Figure 44 This is a schematic structural diagram of a heat-conducting component of a battery cell provided in one embodiment of the present application;

[0182] Figure 45 yes Figure 44 Cross-section at CC;

[0183] Figure 46 is an exploded view of a battery cell provided in another embodiment of the present application;

[0184] Figure 47 is an exploded view of a battery cell provided in another embodiment of the present application;

[0185] Figure 48 This is a partial structural diagram of a battery cell provided in one embodiment of the present application;

[0186] Figure 49 This is a schematic structural diagram of a heat-conducting component of a battery cell provided in one embodiment of the present application;

[0187] Figure 50 This is an expanded view of a thermally conductive component of a battery cell provided in one embodiment of the present application;

[0188] Figure 51 This is a schematic structural diagram of a heat-conducting component of a battery cell provided in one embodiment of the present application;

[0189] Figure 52 This is a schematic structural diagram of a heat-conducting component of a battery cell provided in one embodiment of the present application;

[0190] Figure 53 This is a partial structural diagram of a heat-conducting component of a battery cell provided in one embodiment of the present application;

[0191] Figure 54 This is a schematic structural diagram of a heat-conducting component of a battery cell provided in one embodiment of the present application;

[0192] Figure 55 This is a partial structural diagram of a heat-conducting component of a battery cell provided in another embodiment of the present application;

[0193] Figure 56 This is a schematic structural diagram of a heat-conducting component of a battery cell provided in one embodiment of the present application;

[0194] Figure 57 This is a schematic structural diagram of a heat-conducting component of a battery cell provided in one embodiment of the present application;

[0195] Figure 58 This is a partial structural diagram of a heat-conducting component of a battery cell provided in one embodiment of the present application;

[0196] Figure 59 This is a schematic structural diagram of a heat-conducting component of a battery cell provided in one embodiment of the present application;

[0197] Figure 60 This is a partial structural diagram of a heat-conducting component of a battery cell provided in another embodiment of the present application;

[0198] Figure 61 This is a schematic structural diagram of a heat-conducting component of a battery cell provided in one embodiment of the present application;

[0199] Figure 62 This is an expanded view of a thermally conductive component of a battery cell provided in one embodiment of the present application.

[0200] Reference numerals:

[0201] 1. Vehicle; 101. Motor; 102. Controller; 2. Battery device; 201. Battery module; 202. Case; 2021. First case; 2022. Second case;

[0202] 3. Battery cells;

[0203] 4. Shell; 41. Opening;

[0204] 5. Electrode assembly; 51. Tab; 52. Electrode body; 521. First end surface; 522. Second end surface; 523. Side surface; 5231. First side surface; 5232. Second side surface; 5241. Positive electrode sheet; 5242. Negative electrode sheet; 511. Retracted section; 512. Extended section; 5121. First subsegment; 5122. Second subsegment; 5123. Third subsegment;

[0205] 6. Top cover assembly; 61. Electrode terminal;

[0206] 7. Transfer mechanism; 71. First connecting section; 72. Second connecting section;

[0207] 8. Heat-conducting assembly; 81. First heat-conducting portion; 82. Second heat-conducting portion; 83. Third heat-conducting portion; 811. Gap; 812. Middle heat-conducting member; 813. End heat-conducting member; 814. Side heat-conducting member; 815. First through hole; 821. Second through hole;

[0208] 84. Thermal conductor; 85. Insulating member; 851. Accommodating cavity; 852. First insulating portion; 8521. Main body; 8522. Bend portion; 853. Second insulating portion; 854. Middle insulating portion; 855. Sub-insulating layer; 841. First thermally conductive sheet; 842. Second thermally conductive sheet; 8414. First avoidance hole; 8421. Second avoidance hole; 856. Plastic sealing area; 8411. Middle thermally conductive sheet; 8412. End thermally conductive sheet; 8413. Side thermally conductive sheet.

[0209] 91. First insulating film; 92. Second insulating film;

[0210] X, first direction; Y, second direction; Z, third direction. DETAILED DESCRIPTION

[0211] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0212] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in the embodiments of the present application should have the common meanings understood by technicians in the field to which the embodiments of the present application belong.

[0213] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they should not be understood as limiting the embodiments of the present application.

[0214] In addition, the technical terms "first," "second," etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. In the description of the embodiments of the present application, the meaning of "plurality" is more than two, unless otherwise specifically defined.

[0215] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0216] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, a first feature being "above," "above," and "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is at a higher level than the second feature. A first feature being "below," "below," and "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0217] Currently, market developments indicate that battery applications are becoming increasingly widespread. They are not only used in energy storage systems such as hydropower, thermal, wind, and solar power plants, but are also widely used in electric vehicles like electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. As battery applications continue to expand, market demand is also growing.

[0218] During the use of battery cells, the temperature difference between the inside and outside is too large, resulting in a decrease in the performance and service life of the battery cells.

[0219] The cause of these issues is that during battery cell operation, the electrode assembly undergoes an electrochemical reaction and generates heat, which needs to be exchanged between the battery housing and the external environment. Limited by the thermal conductivity of the housing, the internal temperature of the battery cell cannot be quickly transferred to the outside world, causing it to accumulate and rise. This excessive temperature can easily lead to lithium deposition in the electrode assembly. Furthermore, in low-temperature environments, the external environment also struggles to heat the electrode assembly, resulting in a decrease in the battery cell's capacity and pulse performance due to the low temperature, impacting the performance of the battery cell.

[0220] Based on the above problems, an embodiment of the present application provides a battery cell, which includes a shell, an electrode assembly and a heat-conducting assembly. The electrode assembly is located inside the shell, and the shell provides accommodation and protection for the electrode assembly. The electrode assembly includes an electrode body and a pole ear. The electrode body includes a first end face and a second end face arranged opposite to each other in a first direction, and a side surface connected between the first end face and the second end face. The electrode body forms a loop with the pole ear extending from the first end face and / or the second end face and an external component. The thermal conductivity of the heat-conducting assembly is greater than the thermal conductivity of the shell. The heat-conducting assembly includes a first heat-conducting portion. The first heat-conducting portion is heat-conductedly connected to the side surface of the electrode body, so as to reduce the thermal resistance of the electrode body at its side surface, improve the temperature uniformity of the electrode body at its side surface, and improve the rate of heat exchange between the electrode body at its side surface and the external environment, so as to balance the internal temperature of the battery cell and improve the problem that the performance and service life of the battery cell are adversely affected by the internal temperature of the battery cell being too high or too low.

[0221] The technical solutions described in the embodiments of the present application are applicable to battery devices and electrical devices using battery devices.

[0222] Electrical devices may include vehicles, mobile phones, portable devices, laptop computers, ships, spacecraft, electric toys, and electric tools, etc. Vehicles may include fuel vehicles, gas vehicles, or new energy vehicles. New energy vehicles may include pure electric vehicles, hybrid vehicles, or extended-range vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools, and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. The embodiments of the present application do not impose any special restrictions on the above-mentioned electrical devices.

[0223] In the embodiment of the present application, the battery cell may be a secondary battery. A secondary battery refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0224] The battery cells may be lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-metal hydride batteries, nickel-cadmium batteries, lead-acid batteries, etc., and the present invention does not limit this. The battery cells may be cylindrical, flat, rectangular, or other shapes, and the present invention does not limit this.

[0225] The battery device referred to in the embodiments of this application refers to a single physical module that includes one or more battery cells to provide higher voltage and capacity. For example, the battery device referred to in this application may include a battery module or battery pack. A battery pack generally includes a casing for enclosing one or more battery cells. The casing prevents liquids or other foreign matter from affecting the charging or discharging of the battery cells.

[0226] A battery cell includes an electrode assembly and an electrolyte. The electrode assembly includes a positive electrode sheet, a negative electrode sheet, and a separator. A battery cell primarily operates by the movement of metal ions between the positive and negative electrode sheets. The positive electrode sheet includes a positive current collector and a positive active material layer, with the positive active material layer coated on the surface of the positive current collector. The positive current collector includes a positive current collector portion and a positive electrode tab connected to the positive current collector portion. The positive current collector portion is coated with the positive active material layer, while the positive electrode tab is not coated with the positive active material layer. Taking a lithium-ion battery as an example, the material of the positive current collector can be aluminum, and the positive active material layer includes a positive active material. The positive active material 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, which is coated on the surface of the current collector. The negative current collector includes a negative current collecting portion and a negative electrode tab connected to the negative current collecting portion. The negative current collecting portion is coated with the negative active material layer, while the negative tab is not coated with the negative active material layer. The negative current collector can be made of copper, and the negative active material layer includes a negative active material, which can be carbon or silicon, for example. The separator can be made of materials such as PP (polypropylene) or PE (polyethylene).

[0227] It should be understood that the technical solutions described in the embodiments of the present application are not limited to the battery devices and electrical equipment described above, but can also be applied to all battery devices including a box and electrical equipment using the battery devices. However, for the sake of simplicity, the following embodiments are explained using electric vehicles as an example.

[0228] Please refer to Figure 1 , Figure 1 A schematic structural diagram of a vehicle 1 provided for some embodiments of the present application. The vehicle 1 may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery device 2 is provided inside the vehicle 1, and the battery device 2 may be provided at the bottom, head or tail of the vehicle 1. The battery device 2 may be used to power the vehicle 1, for example, the battery device 2 may serve as an operating power source for the vehicle 1. The vehicle 1 may further include a controller 102 and a motor 101, and the controller 102 is used to control the battery to power the motor 101, for example, for starting, navigating and operating power requirements of the vehicle 1 during driving.

[0229] In some embodiments of the present application, the battery device 2 can serve not only as an operating power source for the vehicle 1 , but also as a driving power source for the vehicle 1 , replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1 .

[0230] Figure 2 A schematic structural diagram of a battery device according to an embodiment of the present application is shown.

[0231] The battery device 2 mentioned in the embodiment of the present application may include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly may include multiple battery cells 3, and the multiple battery cells 3 are connected in series, parallel or mixed via a busbar.

[0232] In some embodiments, a battery cell assembly is generally formed by arranging a plurality of battery cells 3 .

[0233] As an example, the battery cell assembly may be a battery module 201, wherein the battery module 201 is formed by arranging and fixing a plurality of battery cells 3 to form an independent module. As an example, the battery module 201 may be formed by bundling the plurality of battery cells 3 with a cable tie.

[0234] In some embodiments, the battery device may be a battery pack, which includes a case 202 and one or more battery cell assemblies, wherein the battery cell assemblies are housed in the case 202 .

[0235] As an example, the battery cell assembly may be a battery module 201 , and the battery cell assembly may be accommodated in the box by fixing the battery module 201 in the box.

[0236] As an example, the battery cell assembly may also be housed in the box body 202 by directly fixing the plurality of battery cells 3 to the box body 202 .

[0237] As an example, housing 202 may include a first housing 2021 and a second housing 2022. The first housing 2021 and the second housing 2022 engage to form an enclosed space within housing 202 for accommodating battery cell assemblies. Enclosed here means covered or closed, and can be either sealed or unsealed. First housing 2021 may be a top cover or a bottom plate.

[0238] As an example, the box body 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 a closed space is formed inside the box body 202 to accommodate the battery cell assembly.

[0239] In some embodiments, the box 202 can be used as part of the chassis structure of the vehicle. For example, part of the box 202 can become at least a part of the floor of the vehicle, or part of the box 202 can become at least a part of the crossbeam and longitudinal beam of the vehicle.

[0240] Figure 3 A schematic structural diagram of a battery module 201 according to an embodiment of the present application is shown.

[0241] In some embodiments, as Figure 2 and Figure 3 As shown, there are multiple battery cells 3, which are first connected in series, in parallel, or in series to form a battery module 201. The multiple battery modules 201 are then connected in series, in parallel, or in series to form a whole, and are accommodated in a box 202.

[0242] The multiple battery cells 3 in the battery module 201 can be electrically connected via a busbar component to achieve parallel connection, series connection, or mixed connection of the multiple battery cells 3 in the battery module 201 .

[0243] In the present application, the battery cell 3 may include a lithium-ion battery cell, a sodium-ion battery cell, a magnesium-ion battery cell, etc., which is not limited in the embodiments of the present application.

[0244] Figure 4 : is an exploded view of a battery cell provided in one embodiment of the present application. Battery cell 3 refers to the smallest unit that makes up a battery. Figure 4 The battery cell 3 includes a top cover assembly 6, a shell 4 and an electrode assembly 5.

[0245] The electrode assembly 5 is a component in the battery cell 3 where electrochemical reactions occur. One or more electrode assemblies 5 may be contained in the shell 4. The electrode assembly 5 is mainly formed by winding or stacking electrode sheets, which are divided into positive electrode sheets and negative electrode sheets, and a separator is usually provided between the positive electrode sheets and the negative electrode sheets. The parts of the positive electrode sheets and the negative electrode sheets with active materials constitute the electrode body 52, and the parts of the positive electrode sheets and the negative electrode sheets without active materials each constitute the electrode tab 51. The positive electrode tab and the negative electrode tab may be located together at one end of the electrode body 52 or respectively at both ends of the electrode body 52. ​​During the charge and discharge process of the battery cell 3, the positive electrode active material and the negative electrode active material react with the electrolyte, and the tab 51 connects the electrode terminals to form a current loop.

[0246] The electrode assembly 5 may be a wound structure, a laminated structure, or a mixed structure of wound and laminated structures.

[0247] In some embodiments, the electrode assembly 5 is a wound structure in which the positive electrode sheet and the negative electrode sheet are wound into a wound structure.

[0248] In some embodiments, the electrode assembly 5 has a laminated structure. As an example, multiple positive and negative electrode sheets can be provided, and the multiple positive and negative electrode sheets can be alternately stacked. Multiple separators can be provided and respectively disposed between any adjacent positive or negative electrode sheets. Alternatively, the separators can be provided continuously and folded between any adjacent positive or negative electrode sheets.

[0249] In some embodiments, the shape of the electrode assembly 5 can be cylindrical, flat, or polygonal.

[0250] In some embodiments, the electrode assembly 5 is provided with tabs, which can conduct current from the electrode assembly. The tabs include a positive tab and a negative tab.

[0251] The battery cell may include a shell. The shell 4 is a component used to cooperate with the top cover assembly 6 to form an internal environment of the battery cell 3, wherein the internal environment formed can be used to accommodate the electrode assembly 5, the electrolyte (not shown in the figure) and other components. The shell 4 can be a steel shell, an aluminum shell, a plastic shell (such as polypropylene), a composite metal shell (such as a copper-aluminum composite shell) or an aluminum-plastic film, etc. In some embodiments, the shell 4 can be a sealed structure or a non-sealed structure. As an example, when the shell 4 is a non-sealed structure, the shell 4 plays a role in protecting the electrode assembly 5, and a sealing bag is further included between the shell 4 and the electrode assembly 5, which is used to encapsulate the electrode assembly and the electrolyte. Specifically, the sealing bag can be a bag-shaped insulating member or an aluminum-plastic film. When the shell 4 is a sealed structure, it is used to encapsulate components such as the electrode assembly 5 and the electrolyte.

[0252] As an example, the battery cell 3 can be a cylindrical battery cell, a prismatic battery cell, a soft-pack battery cell or a battery cell of other shapes. The prismatic battery cell includes a square-shell battery cell, a blade-shaped battery cell, and a polygonal battery. The polygonal battery is, for example, a hexagonal battery, etc. There is no special limitation in this application.

[0253] The housing 4 and the top cover assembly 6 can be separate components. One or more openings 41 can be provided on the housing 4, and one or more top cover assemblies 6 cover the openings 41 to form the internal environment of the battery cell 3. Alternatively, the top cover assembly 6 and the housing 4 can be integrated. Optionally, the top cover assembly 6 and the housing 4 can form a common connection surface before other components are inserted into the housing. When the interior of the housing 4 needs to be enclosed, the top cover assembly 6 can be used to cover the housing 4.

[0254] In some embodiments, the electrode terminal 61 can be provided on the top cover assembly 6 or on the housing 4, and the electrode terminal 61 is electrically connected to the tab 51. The electrode terminal 61 can be directly connected to the tab 51 or indirectly connected to the tab 51 through the adapter 7.

[0255] See also Figure 5 , Figure 5 Schematic diagram of the structure of an electrode assembly of a battery cell provided in one embodiment of the present application.

[0256] First, as Figure 4 and Figure 5 As shown, the present application provides a battery cell 3, which includes a shell 4, an electrode assembly 5 and a heat-conducting assembly 8. The electrode assembly 5 is located in the shell 4, and the electrode assembly 5 includes an electrode body 52 and a pole ear 51. The electrode body 52 includes a first end face 521 and a second end face 522 arranged opposite to each other in a first direction X, and a side face 523 connected between the first end face 521 and the second end face 522. The pole ear 51 is connected to the electrode body 52 and extends out of at least one of the first end face 521 and the second end face 522; the heat-conducting assembly 8 includes a first heat-conducting portion 81, which is heat-conductingly connected to the side face 523, and the thermal conductivity of the heat-conducting assembly 8 is greater than the thermal conductivity of the shell 4.

[0257] In the embodiment of the present application, the battery cell 3 includes a shell 4, an electrode assembly 5 and a heat-conducting assembly 8. The electrode assembly 5 is located inside the shell 4. The shell 4 provides accommodation and protection for the electrode assembly 5. The electrode assembly 5 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 that are oppositely arranged in a first direction X, and a side face 523 connected between the first end face 521 and the second end face 522. The electrode body 52 forms a loop with external components through the tab 51 extending from the first end face 521 and / or the second end face 522. The thermal conductivity of the heat-conducting component 8 is greater than that of the shell 4. The heat-conducting component 8 includes a first heat-conducting portion 81. The first heat-conducting portion 81 is thermally connected to the side surface 523 of the electrode body 52 through heat conduction. The thermal resistance of the electrode body 52 at its side surface 523 can be reduced, the temperature uniformity of the electrode body 52 at its side surface 523 can be improved, and the rate of heat exchange between the electrode body 52 at its side surface 523 and the external environment can be improved to balance the internal temperature of the battery cell 3 and improve the problem that the performance and service life of the battery cell 3 are adversely affected by the internal temperature of the battery cell 3 being too high or too low.

[0258] The electrode body 52 is formed by winding or stacking a separator, a positive electrode sheet 5241, and a negative electrode sheet 5242. The tabs 51 include a positive tab and a negative tab, each of which extends from the first end face 521 or the second end face 522, or one of which extends from the first end face 521 and the other from the second end face 522.

[0259] Exemplarily, the battery cell 3 also includes a top cover assembly 6 connected to the pole ear 51, the shell 4 includes an end opening 41 close to the first end face 521 or the second end face 522 in the first direction X, the top cover assembly 6 covers the opening 41, the positive pole ear and the negative pole ear extend from the first end face 521 or the second end face 522 and are connected to the top cover assembly 6; or the shell 4 includes two side openings 41 in the first direction X, the two top cover assemblies 6 respectively cover the openings 41, the positive pole ear and the negative pole ear respectively extend from the first end face 521 and the second end face 522 and are connected to the top cover assembly 6.

[0260] Exemplarily, the first direction X is the height direction of the electrode assembly 5 .

[0261] The first heat-conducting portion 81 is thermally connected to the side surface 523 of the electrode body 52, and the first heat-conducting portion 81 is directly attached to or abuts the side surface 523 of the electrode body 52; or the first heat-conducting portion 81 is a plating layer arranged on the side surface 523; or the first heat-conducting portion 81 and the side surface 523 of the electrode body 52 are spaced apart, and the first heat-conducting portion 81 is connected to the side surface 523 through a heat-conducting medium, and the heat-conducting medium can be air, metal, or heat-conducting glue, etc.

[0262] 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-conducting component 8, thereby improving the problem of damage to the electrode body 52 caused by excessive temperature; or in a low-temperature environment, the heat-conducting component 8 can conduct external heat to the electrode body 52 to heat the electrode assembly 5.

[0263] Optionally, the battery device 2 includes a heat exchange mechanism, the outer shell of the battery cell 3 is thermally connected to the heat exchange mechanism, the heat conducting component 8 can conduct heat between the heat exchange mechanism and the electrode assembly 5, and the heat exchange mechanism can import or export heat to the heat conducting component 8.

[0264] For example, the heat exchange mechanism may be provided on a water-cooling plate or a phase-change heat sink on the outer surface of the battery cell 3 or in a cavity containing a heat exchange medium.

[0265] The first heat conducting portion 81 may be in a strip shape, a flat plate shape, a mesh plate shape, etc. The first heat conducting portion 81 may be in a rectangular shape, a circular shape, a diamond shape, etc. The specific shape and size of the first heat conducting portion 81 may be flexibly designed.

[0266] Optionally, multiple first heat conducting parts 81 are spaced apart on the side surface 523 of the electrode body 52 , which can conduct heat of the electrode body 52 through the first heat conducting parts 81 , reduce the size of the heat conducting component 8 , and reduce the production cost of the battery cell 3 .

[0267] During the operation of the electrode assembly 5, the temperature of the end of the electrode body 52 close to the electrode ear 51 is relatively higher, and the temperature of the end away from the electrode ear 51 is relatively lower. The first heat conduction part 81 arranged on the side 523 of the electrode body 52 can conduct and balance the temperature of the electrode assembly 5 in the first direction X.

[0268] Optionally, in the first direction X, the first heat conducting portion 81 extends to both ends of the electrode body 52 .

[0269] Optionally, the first heat conducting portion 81 covers the entire side surface 523 of the electrode body 52 to improve the heat conduction rate of the first heat conducting portion 81 .

[0270] The thermal conductivity of the heat-conducting component 8 is greater than that of the shell 4 . The heat-conducting component 8 may include copper or copper alloy or silver or silver alloy or graphite or graphene or carbon nanotubes or the like.

[0271] See also Figure 6 , Figure 6 This is a partial structural diagram of a battery cell provided in one embodiment of the present application.

[0272] In some embodiments, as Figures 4 to 6 As shown, the side surface 523 includes two first side surfaces 5231 and two second side surfaces 5232. The two first side surfaces 5231 are arranged opposite to each other in the second direction Y, and the two second side surfaces 5232 are arranged opposite to each other in the third direction Z. The first direction X, the second direction Y and the third direction Z intersect with each other. The area of ​​the first side surface 5231 is greater than the area of ​​the second side surface 5232. The first heat conducting portion 81 is arranged on at least one of the two first side surfaces 5231.

[0273] In these embodiments, the side 523 includes two first side surfaces 5231 and two second side surfaces 5232, the area of ​​the first side surface 5231 is larger than the area of ​​the second side surface 5232, and the first heat conducting portion 81 is arranged on at least one of the two first side surfaces 5231, which not only helps to increase the contact area between the first heat conducting portion 81 and the electrode body 52 to enhance the thermal conductivity of the electrode assembly 5; it can also better match the large-surface heat exchange scheme, shorten the heat conduction path between the first heat conducting portion 81 and the heat exchange mechanism, and improve the thermal conductivity of the electrode assembly 5 to better balance the internal temperature of the battery cell 3.

[0274] Optionally, the second direction Y is the thickness direction of the electrode assembly 5, and the first side surface 5231 is the large surface of the electrode assembly 5. The first direction X is the height direction of the electrode assembly 5, and the third direction Z is the length direction of the electrode assembly 5.

[0275] The electrode body 52 includes a first side surface 5231 and a second side surface 5232 with different areas. Exemplarily, the cross section of the electrode body 52 in the first direction X is rectangular or elliptical.

[0276] Since the area of ​​the first side surface 5231 is larger than that of the second side surface 5232, a first heat conducting portion 81 with a relatively larger area can be provided on the first side surface 5231 to increase the heat conduction rate of the first heat conducting portion 81 to the electrode body 52. ​​The specific areas of the first side surface 5231 and the second side surface 5232 can be designed by the user.

[0277] Optionally, the first heat conducting portion 81 covers the entire first side surface 5231 to improve the heat conduction rate of the first heat conducting portion 81 .

[0278] In the large-surface water cooling solution, the heat exchange mechanism is thermally connected to the side wall of the battery cell 3 in the second direction Y. Therefore, the first heat conduction part 81 arranged on the first side surface 5231 and the heat exchange mechanism have a small distance and a large projected overlapping area, which can better transfer heat between the heat exchange mechanism and the electrode assembly 5.

[0279] When heat is transferred within an object by heat conduction, the resistance encountered is called thermal resistance. In a battery cell 3, heat from the electrode assembly 5 is generally conducted along the current collector. Specifically, most of the heat is transferred along the length or width of the first side surface 5231 of the electrode body 52, resulting in a relatively large thermal resistance in the thickness direction of the electrode body 52, that is, in the second direction Y. Therefore, a first heat conducting portion 81 is provided on the first side surface 5231 to accelerate heat exchange between the electrode body 52 and the external environment in the second direction Y.

[0280] In some embodiments, as Figures 4 to 6 As shown, at least a portion of the first heat conducting portion 81 is disposed along the second direction Y between the first side surface 5231 of the electrode assembly 5 and the shell 4 .

[0281] In these embodiments, at least a portion of the first heat-conducting portion 81 is arranged between the first side surface 5231 of the electrode assembly 5 and the shell 4 along the second direction Y to shorten the distance between the first heat-conducting portion 81 and the shell 4. The electrode assembly 5 can achieve heat exchange with the external environment through the first heat-conducting portion 81 and the shell 4 more quickly, thereby improving the thermal conductivity rate of the electrode assembly 5.

[0282] Specifically, when the electrode assembly 5 includes an electrode body 52 in the second direction Y, at least part of the first heat-conducting portion 81 is arranged between at least one first side surface 5231 of the electrode body 52 and the shell 4; when the electrode assembly 5 includes at least two electrode bodies 52 in the second direction Y, the first heat-conducting portion 81 is arranged between the first side surface 5231 of the electrode body 52 on the outermost side of the electrode assembly 5 and the shell 4.

[0283] The electrode assembly 5 exchanges heat with the external environment through the shell 4 and the first heat-conducting part 81. The first heat-conducting part 81 is arranged between the electrode assembly 5 and the shell 4 along the second direction Y, shortening the distance between the shell 4 and the first heat-conducting part 81 to accelerate the heat exchange rate between the first heat-conducting part 81 and the shell 4, so as to balance the temperature of the electrode assembly 5 more quickly.

[0284] See also Figure 7 , Figure 7 It is a partial structural diagram of a battery cell provided in another embodiment of the present application.

[0285] In some embodiments, as Figure 5 and Figure 7 As shown, a first through hole 815 is provided on the first heat conducting portion 81 .

[0286] In these embodiments, the first through hole 815 provided in the first heat conducting portion 81 facilitates the electrolyte to flow to the electrode assembly 5 , thereby improving the infiltration efficiency of the electrolyte into the electrode assembly 5 .

[0287] Inside the shell 4 , the electrolyte can penetrate the electrode assembly 5 through the first through hole 815 .

[0288] One or more first through holes 815 may be provided on the first heat conducting portion 81 . The shape and size of the first through holes 815 may be designed independently. For example, the first through holes 815 are circular holes, rectangular holes, triangular holes, and the like.

[0289] Illustratively, the first heat conducting portion 81 is evenly provided with a plurality of first through holes 815 to form a mesh, so that the first heat conducting portion 81 can provide a uniform heat conducting effect for the side surface 523 and facilitate uniform infiltration of the electrolyte into the electrode assembly 5 .

[0290] See also Figure 8 , Figure 8 This is a partial structural diagram of a battery cell provided in one embodiment of the present application.

[0291] In some embodiments, as Figure 4 、 Figure 5 and Figure 8 As shown, the first heat-conducting part 81 includes a side heat-conducting member 814 and two end heat-conducting members 813. The two end heat-conducting members 813 are respectively arranged between the shell 4 and the two adjacent first side surfaces 5231. The side heat-conducting member 814 is arranged on at least one second side surface 5232, and the side heat-conducting member 814 is respectively connected to the two end heat-conducting members 813 on both sides along the second direction Y.

[0292] In these embodiments, the two end heat conductive members 813 are respectively arranged between the shell 4 and the two adjacent first side surfaces 5231, and the side heat conductive member 814 is arranged on the second side surface 5232. The side heat conductive member 814 is respectively connected to the two end heat conductive members 813 on both sides along the second direction Y. The side heat conductive member 814 allows heat to be conducted between the two end heat conductive members 813 to balance the heat of the two end heat conductive members 813 and improve the thermal conductivity efficiency of the first heat conductive member 81; and it can better match the scheme of arranging the heat exchange mechanism on a single large surface of the battery cell 3 or arranging the heat exchange mechanism on both large surfaces, shorten the thermal conduction path of the first heat conductive member 81 and the heat exchange mechanism, and improve the thermal conductivity efficiency of the electrode assembly 5.

[0293] When the external ambient temperatures on both sides of the shell 4 in the second direction Y are similar, or when the heat exchange performances of the heat exchange mechanisms on both sides of the shell 4 in the second direction Y are similar, the heat on the first side 5231 is transferred to the end heat conductor 813 and then to the heat exchange mechanism, and the heat on the second side 5232 is transferred to the side heat conductor 814 and can be transferred to the heat exchange mechanism through the end heat conductors 813 on both sides, thereby improving the heat exchange rate at the second side 5232.

[0294] When the temperature difference between the external environment and the internal environment on one side of the second direction Y of the shell 4 is greater, or when the heat exchange performance of the heat exchange mechanism on both sides of the shell 4 in the second direction Y is different, for the convenience of description, the two end heat conductors 813 are respectively the first end heat conductor and the second end heat conductor, the first end heat conductor is close to a heat exchange mechanism with higher thermal conductivity efficiency, the second end heat conductor is close to a heat exchange mechanism with lower thermal conductivity efficiency, or no heat exchange mechanism is set, then the heat on the first side 5231 is transferred to the second end heat conductor, part of the heat of the second end heat conductor is transferred to the heat exchange mechanism close to it, and the other part of the heat is transferred to the first end heat conductor through the side heat conductor 814, and transferred to the heat exchange mechanism close to the first end heat conductor, so as to improve the overall thermal conductivity rate of the heat conducting component 8.

[0295] Optionally, the end heat conductor 813 and the side heat conductor 814 are integrally formed to reduce the joint seams of the heat conducting component 8 and improve the structural strength of the heat conducting component 8; or the end heat conductor 813 and the side heat conductor 814 are prepared separately and connected to each other to more conveniently adjust the size of each part to adapt to electrode components 5 of different sizes.

[0296] See also Figure 9 , Figure 9 This is a partial structural diagram of a battery cell provided in one embodiment of the present application.

[0297] In some embodiments, as Figure 4 、 Figure 5 and Figure 9As shown, a plurality of electrode assemblies 5 are provided, and the plurality of electrode assemblies 5 are stacked along the second direction Y, and at least a portion of the first heat conducting portion 81 is provided between two adjacent first side surfaces 5231 of two adjacent electrode assemblies 5 .

[0298] In these embodiments, multiple electrode assemblies 5 are stacked along the second direction Y, and at least a portion of the first heat conducting portion 81 is disposed between two adjacent first side surfaces 5231 of two adjacent electrode assemblies 5. The first heat conducting portion 81 can be used to equalize the temperature of the electrode assemblies 5 in the first direction X, thereby improving the performance of the battery cell 3.

[0299] The electrode assembly 5 is composed of a stack of positive electrode sheets 5241, negative electrode sheets 5242, and separators, with the positive and negative electrode sheets 5241 and 5242 positioned sequentially between adjacent separators. The electrode sheets include current collectors and tabs 51. The current collectors of the positive and negative electrode sheets 5241 and 5242, as well as the separators, are stacked to form the electrode body 52.

[0300] A plurality of electrode assemblies 5 are arranged in the shell 4, and a single electrode assembly includes the same number of positive electrode sheets 5241 and negative electrode sheets 5242. Exemplarily, a single electrode assembly 5 includes one positive electrode sheet 5241 and one negative electrode sheet 5242; or a single electrode assembly 5 includes two positive electrode sheets 5241 and two negative electrode sheets 5242, or a single electrode assembly 5 includes three positive electrode sheets 5241 and three negative electrode sheets 5242, etc.

[0301] At least a portion of the first heat conducting portion 81 is disposed between two adjacent first side surfaces 5231 of two adjacent electrode assemblies 5 , so that the first heat conducting portion 81 does not affect the ion flow between the positive electrode sheet 5241 and the negative electrode sheet 5242 in the electrode assembly 5 .

[0302] Optionally, the first heat conducting portion 81 is in a flat plate shape and covers the entire first side surface 5231 , thereby increasing the contact area between the electrode assembly 5 and the heat conducting assembly 8 and improving the heat conduction rate of the heat conducting assembly 8 .

[0303] Optionally, the first heat conducting portion 81 is in the shape of a mesh plate, or a plurality of first heat conducting portions 81 are arranged at intervals to facilitate the flow of ions between adjacent electrode assemblies 5 .

[0304] Optionally, the first heat conducting portion 81 extends to both ends of the current collector in the first direction X, so that the first heat conducting portion 81 can better balance the pole piece temperature in the first direction X.

[0305] Optionally, the electrode assembly 5 and the first heat-conducting part 81 are insulated from each other, and the first heat-conducting part 81 is made of an insulating material, or an insulating layer is provided between the first heat-conducting part 81 and the electrode assembly 5 to improve the problem of battery cell 3 failure caused by the connection between the electrode assembly 5 and the heat-conducting assembly 8.

[0306] The specific number of electrode assemblies 5 can be designed by oneself. For example, 2, 3, 4, 5, etc. electrode assemblies 5 can be arranged in the shell 4.

[0307] See also Figure 10 、 Figure 11 and Figure 12 , Figure 10 This is a partial structural diagram of a battery cell provided in one embodiment of the present application; Figure 11 This is a partial structural diagram of a battery cell provided in one embodiment of the present application; Figure 12 This is a partial structural diagram of a battery cell provided in one embodiment of the present application.

[0308] In some embodiments, as Figure 4 、 Figure 5 as well as Figures 10 to 12 As shown, the first heat-conducting part 81 includes a middle heat-conducting part 812 and a side heat-conducting part 814. The middle heat-conducting part 812 is arranged between two adjacent first side surfaces 5231 of two adjacent electrode assemblies 5, and the side heat-conducting part 814 is arranged on at least one second side surface 5232 and connected to the middle heat-conducting part 812.

[0309] In these embodiments, the central heat conductor 812 located between adjacent electrode assemblies 5 helps to dissipate heat between two adjacent first side surfaces 5231. The side heat conductor 814 is arranged on at least one second side surface 5232 and is connected to the central heat conductor 812. The heat of the central heat conductor 812 is transferred to the side heat conductor 814, and heat exchange is performed with the external environment at the side heat conductor 814 to balance the internal temperature of the battery cell 3.

[0310] The heat between adjacent electrode assemblies 5 is not easily exchanged with the outside world through the shell 4. Therefore, in this embodiment, a middle heat conductor 812 is set between the first side surfaces 5231 of adjacent electrode assemblies 5. The heat of the two adjacent first side surfaces 5231 is transferred to the middle heat conductor 812, and then transferred from the middle heat conductor 812 to the side heat conductor 814. The heat is exchanged with the external environment at the side heat conductor 814.

[0311] Alternatively, the side heat conducting member 814 is connected to the end heat conducting member 813 , and heat is transferred from the side heat conducting member 814 to the end heat conducting member 813 for heat exchange with the external environment.

[0312] Exemplarily, one end of the side heat conductive member 814 is connected to the middle heat conductive member 812, and the other end thereof extends along the second direction Y, that is, the first heat conductive portion 81 is bent to form the side heat conductive member 814 and the middle heat conductive member 812, thereby reducing the processing difficulty of the heat conductive component 8; or the middle heat conductive member 812 is connected to the middle area of ​​the side heat conductive member 814, and the two ends of the side heat conductive member 814 extend away from each other in the second direction Y, thereby extending the size of the side heat conductive member 814 to improve the heat conduction efficiency at the side heat conductive member 814.

[0313] Optionally, the two middle heat conductive members 812 are independently arranged and located between the adjacent first side surfaces 5231 of the two adjacent electrode assemblies 5, and the two side heat conductive members 814 are respectively located on both sides of the two middle heat conductive members 812 along the second direction Y. Each middle heat conductive member 812 is connected to the adjacent side heat conductive members 814, so that during the expansion of the electrode assembly 5, the interconnected middle heat conductive members 812 and the side heat conductive members 814 can move in the second direction Y to buffer the extrusion force of the electrode body 52, improve the problem of extrusion and damage of the heat conductive member 8 during the expansion of the electrode body 52, and improve the reliability of the battery cell 3.

[0314] In some embodiments, as Figure 4 、 Figure 5 and Figure 10 As shown, the first heat conducting part 81 also includes an end heat conducting member 813, which is arranged between the shell 4 and an adjacent first side surface 5231, and the side heat conducting member 814 is respectively connected to the middle heat conducting member 812 and the end heat conducting member 813 on both sides along the second direction Y.

[0315] In these embodiments, the first heat-conducting part 81 also includes an end heat-conducting part 813, which is arranged between the shell 4 and an adjacent first side surface 5231, and the side heat-conducting part 814 is respectively connected to the middle heat-conducting part 812 and the end heat-conducting part 813 on both sides along the second direction Y, so that the heat between adjacent electrode assemblies 5 can be transferred to the end heat-conducting part 813 through the middle heat-conducting part 812 and the side heat-conducting part 814, and heat exchange is performed between the end heat-conducting part 813 and the external environment to balance the internal temperature of the battery cell 3.

[0316] A middle heat conductor 812 is arranged between the first side surfaces 5231 of adjacent electrode assemblies 5. The heat of the two adjacent first side surfaces 5231 is transferred to the middle heat conductor 812, and is transferred to the end heat conductor 813 through the side heat conductor 814, and is transferred to the outside through the shell 4 at the end heat conductor 813 and / or the side heat conductor 814.

[0317] Illustratively, the heat exchange mechanism is disposed on one side of the shell 4 close to the end heat conductor 813 in the second direction Y. The heat of the middle heat conductor 812 is transferred to the end heat conductor 813 and then to the heat exchange mechanism.

[0318] Exemplarily, two electrode assemblies 5 are provided, and the two electrode assemblies 5 are stacked along the second direction Y. A middle heat conductive member 812 , an end heat conductive member 813 and a side heat conductive member 814 are provided outside each electrode assembly 5 .

[0319] Optionally, the end heat conductive member 813, the side heat conductive member 814 and the middle heat conductive member 812 are integrally formed to reduce the joint seams of the heat conductive component 8 and improve the structural strength of the heat conductive component 8; or the end heat conductive member 813, the side heat conductive member 814 and the middle heat conductive member 812 are prepared separately and connected to each other to more conveniently adjust the size of each part to adapt to electrode assemblies 5 of different sizes.

[0320] In some embodiments, as Figure 4 、 Figure 5 、 Figure 11 and Figure 12 As shown, there are two side heat conductive members 814, and the first heat conductive member 81 also includes two end heat conductive members 813, which are respectively arranged between the shell 4 and the two adjacent first side surfaces 5231, and the two side heat conductive members 814 are respectively arranged on the second side surfaces 5232 of different electrode assemblies 5, wherein one side heat conductive member 814 is respectively connected to the middle heat conductive member 812 and the end heat conductive member 813 on both sides along the second direction Y, and the other side heat conductive member 814 is respectively connected to the middle heat conductive member 812 and the other end heat conductive member 813 on both sides along the second direction Y.

[0321] In these embodiments, the first heat-conducting part 81 also includes two end heat-conducting parts 813, and the heat between adjacent electrode assemblies 5 can be transferred to the middle heat-conducting part 812. The two end heat-conducting parts 813 are respectively arranged between the shell 4 and the two adjacent first side surfaces 5231. The two side heat-conducting parts 814 are respectively arranged on the second side surfaces 5232 of different electrode assemblies 5, and are respectively connected to the middle heat-conducting part 812 and one end heat-conducting part 813, so that the heat of the middle heat-conducting part 812 can be transferred to the end heat-conducting part 813 through the side heat-conducting parts 814, and heat exchange is performed between the end heat-conducting parts 813 and the external environment to balance the internal temperature of the battery cell 3.

[0322] Through the combination of the middle heat conductive member 812, the end heat conductive members 813, and the side heat conductive members 814, the heat of the two first side surfaces 5231 of the adjacent electrode assemblies 5 can be transferred to the middle heat conductive member 812. Then, the heat of the middle heat conductive member 812 can be transferred to the two end heat conductive members 813 through the side heat conductive members 814 and transferred to the outside through the housing 4.

[0323] Alternatively, the temperature difference between the external environment and the internal environment of the shell 4 on the side of the second direction Y is greater, and the heat of the middle heat conductor 812 and one of the end heat conductors 813 is transferred to the other end heat conductor 813 through the side heat conductor 814, and heat exchange is carried out here with the outside world. Exemplarily, the heat exchange mechanism is arranged at one end of the shell 4 in the second direction Y.

[0324] Alternatively, the temperature difference between the external environment and the internal environment in the third direction Z of the shell 4 is greater, and the heat of the middle heat conductor 812 and the two end heat conductors 813 is transferred to the side heat conductor 814, and heat is exchanged with the external environment here. Exemplarily, the heat exchange mechanism is arranged at at least one end of the shell 4 in the third direction Z.

[0325] In some embodiments, as Figure 4 、 Figure 5 and Figure 11 As shown, the two side heat conducting members 814 are respectively arranged on both sides of the plurality of electrode assemblies 5 along the third direction Z.

[0326] In these embodiments, the two side heat conductive members 814 are respectively arranged on both sides of the plurality of electrode assemblies 5 along the third direction Z, and the two side heat conductive members 814 are connected to both sides of the middle heat conductive member 812 in the third direction Z to improve the heat conduction efficiency between the middle heat conductive member 812 and the side heat conductive member 814.

[0327] The middle heat conducting member 812 , the two side heat conducting members 814 and the two end heat conducting members 813 are integrally manufactured and can be formed by bending and winding a first heat conducting member 81 around the electrode assembly 5 , which has low processing difficulty.

[0328] The two side heat conductive members 814 are respectively arranged on both sides of the multiple electrode assemblies 5 along the third direction Z, so that the temperature of the two adjacent first side surfaces 5231 is transferred to the middle heat conductive member 812, and the heat is transferred from the two ends of the middle heat conductive member 812 to the two side heat conductive members 814, which can better balance the temperature of the two first side surfaces 5231 in the third direction Z and reduce the temperature difference between the two first side surfaces 5231 in the third direction Z.

[0329] Optionally, the two side heat conducting members 814 have the same shape and size, so that the temperature transferred from the middle heat conducting member 812 to the two side heat conducting members 814 is similar.

[0330] In some embodiments, as Figure 4 、 Figure 5 and Figure 12 The two side heat conducting members 814 are arranged on the same side of the plurality of electrode assemblies 5 along the third direction Z.

[0331] In these embodiments, the two side heat conducting members 814 are disposed on the same side of the plurality of electrode assemblies 5 along the third direction Z to reduce the overall size of the heat conducting assembly 8 in the third direction Z, thereby increasing the energy density of the battery cells 3 .

[0332] After the heat between adjacent first side surfaces 5231 is transferred to the middle heat conductor 812, it is transferred to the side heat conductor 814 located at the same end of the third direction Z. Therefore, setting a heat exchange mechanism on one side of the shell 4 along the third direction Z can effectively exchange heat with the heat conducting component 8, and can reduce the difficulty of setting up the heat exchange mechanism in combination with the battery cell 3.

[0333] Optionally, the two side heat conductive members 814 are heat-conductively connected, that is, the heat of the end heat conductive member 813 can be transferred to the middle heat conductive member 812 through the side heat conductive member 814 , and can also be transferred to the other end heat conductive member 813 .

[0334] See also Figure 13 , Figure 13 This is a partial structural diagram of a battery cell provided in one embodiment of the present application.

[0335] In some embodiments, as Figure 9 and Figure 13 As shown, the electrode assembly 5 is of a wound type or a laminated type.

[0336] In these embodiments, the electrode assembly 5 is of a wound or laminated type, and the first heat-conducting portion 81 connected to the side 523 of the electrode assembly 5 by heat conduction can reduce the thermal resistance of the electrode body 52 at its side 523, and increase the rate of heat exchange between the electrode body 52 and the external environment at its side, so as to balance the internal temperature of the battery cell 3 and improve the problem of adverse effects on the performance and service life of the battery cell due to the internal temperature of the battery cell 3 being too high or too low.

[0337] like Figure 13 In the wound electrode assembly shown in FIG. 5 , the electrode assembly 5 is wound by a positive electrode sheet 5241, a negative electrode sheet 5242 and a separator, and the first heat conducting portion 81 is provided between the separators of two adjacent electrode assemblies 5; Figure 9 The laminated electrode assembly shown is formed by stacking a positive electrode sheet 5241 , a negative electrode sheet 5242 and a separator in sequence, and the first heat conducting portion 81 is arranged between the separators of two adjacent electrode assemblies 5 .

[0338] See also Figure 14 and Figure 15 , Figure 14 This is a partial structural diagram of a battery cell provided in one embodiment of the present application; Figure 15 This is a partial structural diagram of a battery cell provided in one embodiment of the present application.

[0339] In some embodiments, as Figure 4 、 Figure 14 and Figure 15 As shown, the first heat conducting portion 81 is provided around the circumference of the electrode body 52 .

[0340] In these embodiments, the first heat-conducting portion 81 is arranged around the circumference of the electrode body 52 to increase the contact area between the heat-conducting component 8 and the side surface 523 of the electrode body 52, further increasing the heat exchange rate between the electrode body 52 at its side surface and the external environment, so as to balance the internal temperature of the battery cell 3 and improve the problem of adverse effects on the performance and service life of the battery cell due to excessively high or low internal temperature of the battery cell 3.

[0341] The electrode body 52 is cylindrical, and the first heat conducting portion 81 surrounds the peripheral surface of the electrode body 52 ; or the electrode body 52 is flat, and the first heat conducting portion 81 surrounds the first side surface 5231 and the second side surface 5232 .

[0342] The first heat conducting portion 81 disposed on the side of the electrode body 52 can transfer heat in the first direction X to balance the temperature of the electrode assembly 5 in the first direction X and reduce the temperature difference of the electrode assembly in the first direction X.

[0343] Optionally, the first heat conducting portion 81 covers the entire side surface 523 of the electrode body 52 to increase the contact area between the first heat conducting portion 81 and the electrode body 52 and improve the heat conduction rate of the first heat conducting portion 81 .

[0344] In some embodiments, as Figure 4 、 Figure 14 and Figure 15 As shown, a gap 811 extending along the first direction X and penetrating the first heat conducting portion 81 is formed between both ends of the first heat conducting portion 81 along the circumference of the electrode body 52 .

[0345] In these embodiments, a gap 811 extending along the first direction X and penetrating the first heat-conducting portion 81 is formed between the two ends of the first heat-conducting portion 81 along the circumferential side of the electrode body 52. ​​By setting the gap 811, the first heat-conducting portion 81 can be deformed synchronously during the expansion of the electrode assembly 5, thereby reducing the risk of the first heat-conducting portion being expanded by the electrode body 52, improving the service life of the heat-conducting assembly 8, and improving the reliability of the battery cell 3.

[0346] A gap 811 is formed between the ends of the first heat conducting portion 81 along the periphery of the electrode body 52, allowing the first heat conducting portion 81 to elastically deform. As the electrode assembly 5 expands during the charge and discharge process of the battery cell 3, the gap between the ends of the first heat conducting portion 81 increases, reducing the risk of the first heat conducting portion 81 being squeezed and damaged by the electrode assembly 5. As the electrode assembly 5 contracts, the gap between the ends of the first heat conducting portion 81 decreases, allowing the first heat conducting portion 81 to adhere to the electrode assembly 5, maintaining good thermal conductivity. The specific size of the gap 811 can be customized.

[0347] Optional, such as Figure 15 As shown, the first side 5231 and the second side 5232 are connected by a rounded transition, and a gap 811 is set at the rounded connection between the first side 5231 and the second side 5232, so that a thermal conductive component 8 as large as possible can be set on the flat part of the first side 5231 and / or the second side 5232.

[0348] Optionally, the gap 811 extends linearly along the first direction X, reducing the size of the gap 811 .

[0349] In some embodiments, as Figure 4 and Figure 14 As shown, the gap 811 is provided at at least one of the two first side surfaces 5231 .

[0350] In these embodiments, during the expansion of the electrode assembly 5, the expansion amplitude at the first side surface 5231 is greater, so the gap 811 is set at at least one of the two first side surfaces 5231 to make it easier for the first heat-conducting portion 81 to absorb the expansion of the electrode assembly 5 through the gap 811, further reducing the risk of the first heat-conducting portion 81 being expanded by the electrode body 52, thereby improving the service life of the heat-conducting assembly 8 and the reliability of the battery cell 3.

[0351] Exemplarily, the first heat-conducting portion 81 is arranged around the circumference of the electrode body 52, and the gap 811 is arranged at the portion corresponding to the first heat-conducting portion 81 and at least one first side surface 5231; or the first heat-conducting portion 81 includes two end heat-conducting parts 813 and two side heat-conducting parts 814 connected to each other, and the gap 811 is arranged on at least one end heat-conducting part 813; or the first heat-conducting portion 81 includes end heat-conducting parts 813, a middle heat-conducting part 812 and two side heat-conducting parts 814 connected to each other, and the gap 811 is arranged on the end heat-conducting part 813 and / or the middle heat-conducting part 812.

[0352] Optionally, the gap 811 is set at the center position of the first side surface 5231 in the third direction Z. The center position of the first side surface 5231 in the third direction Z has a larger amplitude during the expansion process of the electrode assembly 5. Therefore, the gap 811 is set here. The first heat conducting part 81 can better overcome the expansion of the electrode assembly 5 through the gap 811.

[0353] In some embodiments, as Figure 4 and Figure 14 As shown, the gap 811 is provided at the two first side surfaces 5231 .

[0354] In these embodiments, the gap 811 is provided at the two first side surfaces 5231 so that the first heat conducting portion 81 can be more easily deformed synchronously during the expansion of the electrode assembly 5 , thereby reducing the risk of the first heat conducting portion 81 being expanded by the electrode body 52 .

[0355] The gap 811 is set at the two first side surfaces 5231, and the first heat conducting part 81 is divided into two parts spaced apart in the third direction Z to reduce the risk of the first heat conducting part 81 being burst by the raised first side surface 5231 of the electrode assembly 5 during the expansion process of the electrode assembly 5.

[0356] Exemplarily, the first heat-conducting portion 81 is arranged around the circumference of the electrode body 52, and the gap 811 is arranged in two parts corresponding to the first heat-conducting portion 81 and the two first side surfaces 5231; or the first heat-conducting portion 81 includes two end heat-conducting parts 813 and two side heat-conducting parts 814 connected to each other, and the gap 811 is arranged on the two end heat-conducting parts 813; or the first heat-conducting portion 81 includes end heat-conducting parts 813, a middle heat-conducting part 812 and two side heat-conducting parts 814 connected to each other, and the gap 811 is arranged in the end heat-conducting parts 813 and the middle heat-conducting parts 812.

[0357] Optionally, the gap 811 is arranged at the center position of the first side surface 5231 in the third direction Z, so that the two parts of the first heat conducting part 81 on both sides of the gap 81 in the third direction Z have the same shape, and the two parts of the first heat conducting part 81 can be used interchangeably to save the processing cost of the first heat conducting part 81.

[0358] See also Figure 16 , Figure 16 This is a partial structural diagram of a battery cell provided in one embodiment of the present application.

[0359] In some embodiments, as Figure 4 and Figure 16 As shown, a plurality of electrode assemblies 5 are provided, and the plurality of electrode assemblies 5 are stacked along the second direction Y, and the first heat conducting portion 81 is provided around the outer periphery of the entire structure formed by the plurality of electrode assemblies 5 .

[0360] In these embodiments, a plurality of electrode assemblies 5 are provided, and the plurality of electrode assemblies 5 are stacked along the second direction Y, and the first heat-conducting portion 81 is arranged around the periphery of the whole formed by the plurality of electrode assemblies 5 to shorten the heat-conducting path between the first heat-conducting portion 81 and the shell 4, so that the first heat-conducting portion can transfer heat more easily between the electrode assembly 5 and the external environment.

[0361] The first heat conducting portion 81 is disposed around the outer periphery of the entire structure formed by the plurality of electrode assemblies 5 . The first heat conducting portion 81 is disposed on two first side surfaces 5231 close to the housing 4 and on the second side surfaces 5232 of each electrode assembly 5 .

[0362] Optionally, the gap 811 is provided at a rounded corner connection between a first side surface 5231 and a second side surface 5232 close to the housing 4 .

[0363] See also Figure 17 and Figure 18 , Figure 17 This is a partial structural diagram of a battery cell provided in one embodiment of the present application; Figure 18 This is a partial structural diagram of a battery cell provided in one embodiment of the present application.

[0364] In some embodiments, as Figure 5 、 Figure 17 and Figure 18 As shown, the tab 51 extends out of the first end surface 521 , and the heat-conducting assembly 8 further includes a second heat-conducting portion 82 , which is disposed along the first direction X between the housing 4 and at least a portion of the second end surface 522 .

[0365] In these embodiments, the heat conducting assembly 8 further includes a second heat conducting portion 82 arranged between the shell 4 and at least a portion of the second end surface 522 along the first direction X. The second heat conducting portion 82 can improve the heat exchange rate between the electrode body 52 at its second end surface 522 and the external environment.

[0366] The positive and negative tabs of the electrode assembly 5 both extend out of the first end face 521, and the second heat-conducting portion 82 is arranged between the shell 4 and at least part of the second end face 522 along the first direction X. The heat of the second end face 522 can be transferred to the second heat-conducting portion 82 and then transferred to the outside world by the second heat-conducting portion 82.

[0367] Optionally, the heat exchange mechanism is provided along the first direction X at the end of the battery cell 3 where the tab 51 is not provided, and the second heat conducting portion 82 can transfer heat between the heat exchange mechanism and the second end surface 522 .

[0368] Optionally, the second heat conducting portion 82 covers the entire second end surface 522 of the electrode assembly 5 to improve the heat conduction rate of the second heat conducting portion 82 .

[0369] Optionally, the shape and size of the second heat conducting portion 82 can be flexibly designed. For example, the second heat conducting portion 82 is rectangular or circular.

[0370] In some embodiments, as Figure 5 and Figure 18 As shown, the first heat conducting portion 81 and the second heat conducting portion 82 are connected.

[0371] In these embodiments, the first heat conducting portion 81 and the second heat conducting portion 82 are connected to increase the contact area between the heat conducting component 8 and the electrode assembly 5, further increasing the heat exchange rate between the electrode assembly 5 and the external environment, so as to balance the internal temperature of the battery cell 3 and improve the problem of adverse effects on the performance and service life of the battery cell 3 due to excessively high or low internal temperature of the battery cell 3.

[0372] When the first heat-conducting portion 81 is located between the shell 4 and the electrode assembly 5, the first heat-conducting portion and the second heat-conducting portion 82 are connected to each other to increase the contact area between the heat-conducting assembly 8 and the shell 4 and improve the heat conduction rate of the heat-conducting assembly 8; or when the first heat-conducting portion 81 is located between adjacent electrode assemblies 5 and the first heat-conducting portion 81 and the second heat-conducting portion 82 are connected, the heat of the adjacent electrode bodies 52 is transferred to the second heat-conducting portion 82 through the first heat-conducting portion 81 and transferred to the outside through the shell 4.

[0373] Optionally, the first heat conducting part 81 and the second heat conducting part 82 are integrally formed to reduce the connection seam between the first heat conducting part 81 and the second heat conducting part 82, improve the structural strength of the heat conducting component 8, and improve the heat conduction rate of the first heat conducting part 81 and the second heat conducting part 82, or the first heat conducting part 81 and the second heat conducting part 82 are prepared separately and connected by bonding, clamping or welding to facilitate adjustment of the size of the first heat conducting part 81 and the second heat conducting part 82 to adapt to electrode assemblies 5 of different sizes.

[0374] See also Figure 19 , Figure 19 Schematic diagram of a thermally conductive component of a battery cell provided in one embodiment of the present application.

[0375] In some embodiments, as Figure 4 、 Figure 5 and Figure 19 As shown, the second heat conducting portion 82 is provided with a second through hole 821 .

[0376] In these embodiments, the second through hole 821 provided in the second heat conducting portion 82 facilitates the electrolyte to flow toward the electrode assembly 5 after the electrolyte is injected into the housing 4 , thereby improving the electrolyte infiltration efficiency of the electrode assembly 5 .

[0377] The electrolyte in the shell 4 can penetrate the electrode assembly 5 through the second through hole 821 .

[0378] One or more second through holes 821 may be provided on the second heat conducting portion 82 . The shape and size of the second through holes 821 may be designed independently. For example, the second through holes 821 are circular holes, rectangular holes, triangular holes, and the like.

[0379] Illustratively, the second heat conducting portion 82 is evenly provided with a plurality of second through holes 821 to form a mesh, so that the second heat conducting portion 82 can provide a uniform heat conducting effect for the second end surface 522 and facilitate uniform infiltration of the electrolyte into the electrode assembly 5 .

[0380] See also Figure 20 , Figure 20 This is a partial structural diagram of a battery cell provided in one embodiment of the present application.

[0381] In some embodiments, as Figure 5 and Figure 20 As shown, the side surface 523 includes two first side surfaces 5231 and two second side surfaces 5232. The two first side surfaces 5231 are arranged relative to each other in the second direction Y, and the two second side surfaces 5232 are arranged relative to each other in the third direction Z. The first direction X, the second direction Y and the third direction intersect. The area of ​​the first side surface 5231 is larger than the area of ​​the second side surface 5232. The first heat conducting portion 81 is arranged on at least one of the two first side surfaces 5231, and the second heat conducting portion 82 is connected to the first heat conducting portion 81 arranged on the first side surface 5231.

[0382] In these embodiments, the second heat-conducting portion 82 is connected to the first heat-conducting portion 81 provided on the first side surface 5231, which can increase the contact area between the first heat-conducting portion 81 and the second heat-conducting portion 82, thereby improving the heat conduction efficiency between the first heat-conducting portion 81 and the second heat-conducting portion 82 and improving the connection reliability between the first heat-conducting portion 81 and the second heat-conducting portion 82.

[0383] The area of ​​the first side surface 5231 is larger than the area of ​​the second side surface 5232. Compared with the case where the second heat-conducting part 82 is connected to the first heat-conducting part 81 located on the second side surface 523, when the second heat-conducting part 82 is connected to the first heat-conducting part 81 located on the first side surface 5231, the contact range between the two is larger, which is more conducive to heat transfer between the first heat-conducting part 81 and the second heat-conducting part 82.

[0384] The first heat conducting part 81 and the second heat conducting part 82 can be connected by welding. When the second heat conducting part 82 is connected to the first heat conducting part 81 located on the first side surface 5231 , the contact range between the two is larger and the connection strength is higher.

[0385] See also Figure 21 , Figure 21 This is a partial structural diagram of a battery cell provided in one embodiment of the present application.

[0386] In some embodiments, as Figure 5 and Figure 21As shown, there are multiple electrode assemblies 5, and the multiple electrode assemblies 5 are stacked along the second direction Y. The first heat conducting part 81 is arranged on at least one of the two first side surfaces 5231 of at least two electrode assemblies 5, and there are multiple independent second heat conducting parts 82, and the multiple second heat conducting parts 82 are arranged corresponding to at least one electrode assembly 5.

[0387] In these embodiments, multiple electrode assemblies 5 are stacked along the second direction Y, and the first heat-conducting portion 81 is arranged on at least one of the two first side surfaces 5231 of at least two electrode assemblies 5. Heat exchange can be performed with the first side surfaces 5231 of one or two electrode assemblies 5 through one first heat-conducting portion 81. Multiple second heat-conducting portions 82 are independent of each other and are arranged corresponding to at least one electrode assembly 5 to enhance the thermal conductivity of the electrode assembly 5 at the second end surface 522.

[0388] Optionally, the first heat conducting part 81 and each second heat conducting part 82 are arranged at intervals to facilitate adjustment of the positions of the first heat conducting part 81 and the second heat conducting part 82; or the first heat conducting part 81 and the second heat conducting part 82 are connected to each other so that heat can be transferred from the first heat conducting part 81 to the second heat conducting part 82 and exchange heat with the external environment.

[0389] Exemplarily, the first heat-conducting part 81 includes an end heat-conducting part 813, and at least one second heat-conducting part 82 is connected to the end heat-conducting part 813; or the first heat-conducting part 81 includes a middle heat-conducting part 812, and at least one second heat-conducting part 82 is connected to the middle heat-conducting part 812; or the first heat-conducting part 81 includes a middle heat-conducting part 812 and an end heat-conducting part 813, and at least one second heat-conducting part 82 is connected between the middle heat-conducting part 812 and the end heat-conducting part 813.

[0390] The second heat conducting portion 82 and the electrode assembly 5 are provided correspondingly, and the orthographic projection of the second heat conducting portion 82 in the first direction X may be on the electrode assembly 5 .

[0391] Optionally, each second heat-conducting portion 82 is spaced along the second direction Y, and the second heat-conducting portion 82 and the second end face 522 of an electrode assembly 5 are arranged correspondingly, or multiple independent second heat-conducting portions 82 and the second end face 522 of an electrode assembly 5 are arranged correspondingly, and the second heat-conducting portion 82 is used to enhance the thermal conductivity of the electrode assembly 5 at the second end face 522.

[0392] In some embodiments, as Figure 5 and Figure 21 As shown, at least two second heat conducting portions 82 among the plurality of second heat conducting portions 82 are stacked along the first direction X.

[0393] In these embodiments, at least two second heat conducting portions 82 stacked along the first direction X help to improve the heat exchange capability of the electrode assembly 5 at the second end surface 522 .

[0394] For ease of description, among the stacked second heat conducting portions 82, the second heat conducting portion 82 that is farthest from the electrode assembly 5 in the first direction X may be referred to as an outer second heat conducting portion, and the other second heat conducting portions 82 may be referred to as inner second heat conducting portions. For example, two, three, four, or other second heat conducting portions 82 may be stacked in the first direction X.

[0395] Optionally, the area of ​​the outer second heat-conducting portion is larger than the area of ​​the inner second heat-conducting portion, so as to improve the thermal conductivity of the electrode assembly 5 at the second end surface 522 .

[0396] Optionally, multiple independent inner second heat conducting parts are attached to the same outer second heat conducting part to enhance heat conduction between the independent inner second heat conducting parts and improve temperature uniformity between the electrode assemblies 5 .

[0397] Optionally, the inner second heat-conducting part is connected to the middle heat-conducting part 812 or the end heat-conducting part 813, and the inner second heat-conducting part is connected to the outer second heat-conducting part. The contact area between the outer second heat-conducting part and the middle heat-conducting part 812 or the end heat-conducting part 813 is increased through the inner second heat-conducting part to increase the heat exchange rate between the second heat-conducting part 82 and the first heat-conducting part 81.

[0398] Exemplarily, the two electrode assemblies 5 are spaced apart in the second direction Y, and two independent middle heat-conducting parts 812 are arranged between the two adjacent first side surfaces 5231 of the two adjacent electrode assemblies 5. The first side surface 5231 of the electrode assembly 5 away from the other electrode assemblies 5 is provided with an end heat-conducting part 813. The middle heat-conducting part 812 and the end heat-conducting part 813 are connected by an inner second heat-conducting part. The two independent inner second heat-conducting parts in the second direction Y are stacked on the outer second heat-conducting part along the first direction X. The outer second heat-conducting part is used to strengthen heat conduction between the two inner second heat-conducting parts to improve the heat dissipation efficiency of the electrode assembly 5 at the second end surface 522.

[0399] See also Figure 22 , Figure 22 This is a partial structural diagram of a battery cell provided in one embodiment of the present application.

[0400] In some embodiments, as Figure 4 、 Figure 5 and Figure 22 As shown, there are multiple electrode assemblies 5, and the multiple electrode assemblies 5 are stacked along the second direction Y. The first heat-conducting part 81 includes a middle heat-conducting part 812, and the middle heat-conducting part 812 is arranged between two adjacent first side surfaces 5231 of two adjacent electrode assemblies 5 and connected to the second heat-conducting part 82.

[0401] In these embodiments, the middle heat conductive member 812 is arranged between two adjacent first side surfaces 5231 of two adjacent electrode assemblies 5 and is connected to the second heat conductive portion 82. The heat between the adjacent electrode assemblies 5 can be transferred to the second heat conductive portion 82 through the middle heat conductive member 812, and heat is exchanged between the second heat conductive portion 82 and the external environment to balance the internal temperature of the battery cell 3.

[0402] The heat-conducting assembly 8 includes a middle heat-conducting member 812 arranged between adjacent electrode assemblies 5, and a second heat-conducting part 82 connected to the middle heat-conducting member 812. The temperature between the two adjacent first side surfaces 5231 is transferred to the middle heat-conducting member 812 and then transferred to the second heat-conducting part 82 by the middle heat-conducting member 812.

[0403] Exemplarily, the heat exchange mechanism is disposed on one side of the battery cell 3 close to the second heat conducting portion 82 in the first direction X, and the temperature between adjacent first side surfaces 5231 is transferred to the heat exchange mechanism through the middle heat conducting member 812 and the second heat conducting portion 82 .

[0404] Optionally, a plurality of middle heat conducting members 812 may be disposed between adjacent first side surfaces 5231 to improve the heat conduction rate of the heat conducting assembly 8. For example, two, three, five, or other middle heat conducting members 812 may be disposed between adjacent first side surfaces 5231.

[0405] Optionally, the shell 4 includes multiple electrode assemblies 5 , and a middle heat conducting member 812 is provided between the first side surfaces 5231 of adjacent electrode assemblies 5 to improve the heat conduction rate of the heat conducting assembly 8 .

[0406] Optionally, the middle heat conductive member 812 covers the first side surface 5231 to increase the contact area between the middle heat conductive member 812 and the electrode assembly 5 , thereby increasing the heat conduction rate of the heat conductive assembly 8 .

[0407] See also Figure 23 , Figure 23 This is a partial structural diagram of a battery cell provided in one embodiment of the present application.

[0408] In some embodiments, as Figure 4 、 Figure 5 and Figure 23 As shown, two independent middle heat-conducting parts 812 are arranged between the two adjacent first side surfaces 5231 of the two adjacent electrode assemblies 5, and the heat-conducting assembly 8 includes two second heat-conducting parts 82 arranged at intervals. The two second heat-conducting parts 82 are respectively located on both sides of the two middle heat-conducting parts 812 along the second direction Y, and each middle heat-conducting part 812 is connected to the adjacent second heat-conducting part 82.

[0409] In these embodiments, two independent middle heat-conducting members 812 are arranged between two adjacent first side surfaces 5231 of two adjacent electrode assemblies 5, and the two second heat-conducting portions 82 are respectively located on both sides of the two middle heat-conducting members 812 along the second direction Y. Each middle heat-conducting member 812 is connected to the adjacent second heat-conducting portion 82, so that during the expansion of the electrode assembly 5, the interconnected middle heat-conducting members 812 and the second heat-conducting portions can move in the second direction Y to buffer the extrusion force of the electrode body 52, thereby improving the problem of extrusion and damage of the heat-conducting assembly 8 during the expansion of the electrode body 52, and improving the reliability of the battery cell 3.

[0410] The middle heat conducting member 812 and the adjacent second heat conducting portion 82 are integrally formed. The two can be formed by bending the same base material, and the processing difficulty is low.

[0411] Two independent middle heat-conducting parts 812 are stacked between adjacent first side surfaces 5231 of adjacent electrode assemblies 5 along the second direction Y, and each middle heat-conducting part 812 is heat-conductingly connected to a first side surface close to it. The two second heat-conducting parts 82 are spaced apart in the second direction Y. The two middle heat-conducting parts 812 are located between the two second heat-conducting parts 82 along the second direction Y. One end of the second heat-conducting part 82 is connected to a middle heat-conducting part 812 close to it in the second direction Y, and the other end extends along the second direction Y away from the other second heat-conducting part 82.

[0412] When the electrode assembly 5 expands, the combination formed by the middle heat conducting member 812 and the second heat conducting portion 82 can move in the second direction Y to buffer the squeezing force, thereby extending the service life of the heat conducting assembly 8 .

[0413] The two middle heat conducting members 812 are respectively connected to a first side surface 5231 , which can also improve the heat transfer efficiency between adjacent electrode assemblies 5 and between the heat conducting assemblies 8 .

[0414] See also Figure 24 , Figure 24 Schematic diagram of a thermally conductive component of a battery cell provided in one embodiment of the present application.

[0415] In some embodiments, as Figure 4 、 Figure 5 and Figure 24 As shown, the two middle heat conductive members 812 located between adjacent electrode assemblies 5 are spaced apart in the third direction Z, or the two middle heat conductive members 812 located between adjacent electrode assemblies 5 are in contact with each other in the third direction Z.

[0416] In these embodiments, the two middle heat-conducting parts 812 located between adjacent electrode assemblies 5 are spaced apart or abutted against each other in the third direction Z, which not only helps to reduce the size of the heat-conducting component 8, while improving the heat-conducting efficiency of the electrode assembly 5, but also reduces the processing cost of the battery cell 3, and also helps to reduce the overall size of the heat-conducting component 8 in the second direction Y, thereby improving the energy density of the battery cell 3.

[0417] The two middle heat conducting members 812 located between adjacent electrode assemblies 5 are arranged to be non-overlapping in the second direction Y, so as to reduce the overall size of the heat conducting assembly 8 in the second direction Y and improve the energy density of the battery cell 3 .

[0418] The size of the middle heat-conducting component 812 located between adjacent electrode assemblies 5 in the third direction Z is smaller than the size of the first side surface 5231 , so as to reduce the manufacturing cost of the heat-conducting component 8 .

[0419] If the sum of the dimensions of the two middle heat conductive members 812 between adjacent electrode assemblies 5 in the third direction Z is smaller than the dimension of the first side surface 5231 in the third direction Z, the two middle heat conductive members 812 between adjacent electrode assemblies 5 are spaced apart.

[0420] The sum of the dimensions of the two middle heat-conducting parts 812 located between adjacent electrode assemblies 5 in the third direction Z is equal to the dimension of the first side 5231 in the third direction Z. Then the two middle heat-conducting parts 812 located between adjacent electrode assemblies 5 abut against each other, and the shape of each middle heat-conducting part 812 can be designed by oneself.

[0421] Optionally, the size of the middle heat conductor 812 located between adjacent electrode assemblies 5 in the third direction Z is half of the size of the first side 5231 in the third direction Z, then the two middle heat conductors 812 can have the same shape and size to reduce the processing difficulty of the middle heat conductor 812.

[0422] See also Figure 25 , Figure 25 This is a partial structural diagram of a battery cell provided in one embodiment of the present application.

[0423] In some embodiments, as Figure 4 、 Figure 5 and Figure 25 As shown, the first heat conducting portion 81 further includes two end heat conducting members 813 . The two end heat conducting members 813 are respectively disposed between the housing 4 and two adjacent first side surfaces 5231 and are respectively connected to the second heat conducting portion 82 .

[0424] In these embodiments, the first heat-conducting part 81 also includes two end heat-conducting parts 813, which are respectively arranged between the shell 4 and the two adjacent first side surfaces 5231 and respectively connected to the second heat-conducting part 82. The two end heat-conducting parts 813 can transfer heat through the second heat-conducting part 82, or the electrode assembly 5 can transfer heat to the external environment through the two end heat-conducting parts 813 and the second heat-conducting part 82 to improve the thermal conductivity efficiency of the heat-conducting component 8.

[0425] The two end heat conductive members 813 are respectively arranged between the shell 4 and the two adjacent first side surfaces 5231 , which means that in the second direction Y, two end heat conductive members 813 are respectively arranged between the shell 4 and the two first side surfaces 5231 closest to the shell 4 .

[0426] When the ambient temperatures on both sides of the housing 4 in the second direction Y are similar, or when the heat exchange performance of the heat exchange mechanisms on both sides of the housing 4 in the second direction Y is similar, the heat from the first side surface 5231 is transferred to the end heat conducting member 813 and then to the heat exchange mechanism, while the heat from the second end surface 522 is transferred to the second heat conducting portion 82 and can be transferred to the heat exchange mechanism through the end heat conducting members 813 on both sides, thereby improving the heat exchange rate at the second end surface 522.

[0427] When the temperature difference between the external environment and the internal environment of the shell 4 on one side of the second direction Y is greater, or when the heat exchange performance of the heat exchange mechanism on both sides of the shell 4 in the second direction Y is different, for the convenience of description, the two end heat conductors 813 are respectively the third end heat conductor and the fourth end heat conductor, the third end heat conductor is close to a heat exchange mechanism with higher thermal conductivity efficiency, the fourth end heat conductor is close to a heat exchange mechanism with lower thermal conductivity efficiency, or no heat exchange mechanism is set, then after the heat on the first side 5231 is transferred to the fourth end heat conductor, part of the heat of the fourth end heat conductor is transferred to the heat exchange mechanism close to it, and the other part of the heat is transferred to the third end heat conductor through the second heat conductive part 82, and then transferred to the heat exchange mechanism, so as to improve the overall thermal conductivity rate of the heat conductive component 8.

[0428] Optionally, the end heat conductor 813 and the second heat conductor 82 are integrally formed to reduce the joint seam of the heat conductor assembly 8 and improve the structural strength of the heat conductor assembly 8; or the end heat conductor 813 and the second heat conductor 82 are prepared separately and connected to each other to more conveniently adjust the size of each part to adapt to electrode assemblies 5 of different sizes.

[0429] Optionally, at least one of the two end heat conductors 813 is connected to the pole tab 51 to enhance the thermal conductivity at the pole tab 51, or the two end heat conductors 813 are respectively connected to both sides of the same pole tab 51 in the second direction Y to enhance the thermal conductivity at the pole tab 51.

[0430] See also Figure 26 , Figure 26 This is a partial structural diagram of a battery cell provided in one embodiment of the present application.

[0431] In some embodiments, as Figure 4 、 Figure 5 and Figure 26 As shown, a plurality of electrode assemblies 5 are provided, and the plurality of electrode assemblies 5 are stacked along the second direction Y. The first heat-conducting part 81 includes a middle heat-conducting part 812 and an end heat-conducting part 813. The middle heat-conducting part 812 is provided between two adjacent first side surfaces 5231 of two adjacent electrode assemblies 5, and the end heat-conducting part 813 is provided between the shell 4 and an adjacent first side surface 5231. The middle heat-conducting part 812 and the end heat-conducting part 813 are respectively connected to the second heat-conducting part 82.

[0432] In these embodiments, the first heat-conducting part 81 includes a middle heat-conducting part 812 and an end heat-conducting part 813. The middle heat-conducting part 812 is arranged between two adjacent first side surfaces 5231 of two adjacent electrode assemblies 5, and the end heat-conducting part 813 is arranged between the shell 4 and an adjacent first side surface 5231. The middle heat-conducting part 812 and the end heat-conducting part 813 are respectively connected to the second heat-conducting part 82. In this way, the heat between the adjacent electrode assemblies 5 can be transferred to the end heat-conducting part 813 through the middle heat-conducting part 812 and the second heat-conducting part 82, and heat exchange is performed with the external environment through the end heat-conducting part 813 to improve the thermal conductivity efficiency of the heat-conducting component 8.

[0433] The heat between adjacent electrode assemblies 5 is not easily exchanged with the outside world through the shell 4. Therefore, in this embodiment, a middle heat conductor 812 is arranged between the first side surfaces 5231 of adjacent electrode assemblies 5. The heat of the two adjacent first side surfaces 5231 is transferred to the middle heat conductor 812, and is transferred to the end heat conductor 813 through the second heat conductor 82, and is transferred to the outside world through the shell 4 at the end heat conductor 813 and / or the second heat conductor 82.

[0434] Illustratively, the heat exchange mechanism is disposed on one side of the shell 4 close to the end heat conductor 813 in the second direction Y. The heat of the middle heat conductor 812 is transferred to the end heat conductor 813 and then to the heat exchange mechanism.

[0435] Exemplarily, two electrode assemblies 5 are provided, and the two electrode assemblies 5 are stacked along the second direction Y. Each electrode assembly 5 is provided with a middle heat conductive member 812 , an end heat conductive member 813 and a second heat conductive portion 82 .

[0436] Optionally, the end heat conductive part 813, the second heat conductive part 82 and the middle heat conductive part 812 are integrally formed to reduce the joint seams of the heat conductive component 8 and improve the structural strength of the heat conductive component 8; or the end heat conductive part 813, the second heat conductive part 82 and the middle heat conductive part 812 are prepared separately and connected to each other to more conveniently adjust the size of each part to adapt to electrode assemblies 5 of different sizes.

[0437] Optionally, at least one of the middle heat conductor 812 and the end heat conductor 813 is connected to the pole lug 51 through the third heat conductor 83 to enhance the thermal conductivity at the pole lug 51, or the middle heat conductor 812 and the end heat conductor 813 are respectively connected to the same pole lug 51 on both sides of the second direction Y through the third heat conductor 83 to enhance the thermal conductivity at the pole lug 51.

[0438] See also Figure 27 , Figure 27 This is a partial structural diagram of a battery cell provided in one embodiment of the present application.

[0439] In some embodiments, as Figure 4 、 Figure 5 and Figure 27 As shown, a plurality of electrode assemblies 5 are provided, and the plurality of electrode assemblies 5 are stacked along the second direction Y. The first heat-conducting part 81 includes a middle heat-conducting part 812 and two end heat-conducting parts 813. The middle heat-conducting part 812 is provided between two adjacent first side surfaces 5231 of two adjacent electrode assemblies 5. The two end heat-conducting parts 813 are respectively provided between the shell 4 and the two adjacent first side surfaces 5231. The middle heat-conducting part 812 and the two end heat-conducting parts 813 are respectively connected to the second heat-conducting part 82.

[0440] In these embodiments, the first heat-conducting part 81 includes a middle heat-conducting part 812 and two end heat-conducting parts 813. The middle heat-conducting part 812 is arranged between the two adjacent first side surfaces 5231 of the two adjacent electrode assemblies 5. The two end heat-conducting parts 813 are respectively arranged between the shell 4 and the two adjacent first side surfaces 5231. The middle heat-conducting part 812 and the two end heat-conducting parts 813 are respectively connected to the second heat-conducting part 82. In this way, the heat between the adjacent electrode assemblies 5 can be transferred to the end heat-conducting parts 813 through the middle heat-conducting part 812 and the second heat-conducting part 82, and heat exchange is performed with the external environment through the end heat-conducting parts 813 to improve the thermal conductivity efficiency of the heat-conducting component 8.

[0441] The end heat conductor 813 and the middle heat conductor 812 are both connected to the second heat conducting part 82. The heat of the first side surface 5231 of the adjacent electrode body 52 is transferred to the middle heat conductor 812, and then transferred from the middle heat conductor 812 to the second heat conducting part 82, and then transferred to the end heat conductor 813, and finally transferred to the external environment by the shell 4.

[0442] Alternatively, the temperature difference between the external environment and the internal environment of the shell 4 on the side of the second direction Y is greater, and the heat of the middle heat conductor 812 and one of the end heat conductors 813 is transferred to the other end heat conductor 813 through the second heat conductor 82, and heat exchange is carried out here with the outside world. Exemplarily, the heat exchange mechanism is arranged at one end of the shell 4 in the second direction Y.

[0443] Alternatively, the temperature difference between the external environment and the internal environment of the shell 4 in the first direction X is greater, and the heat of the middle heat conductive member 812 and the two end heat conductive members 813 is transferred to the second heat conductive part 82 and heat exchanged with the external environment here.

[0444] Optionally, the thickness of the middle heat conductor 812 is greater than or equal to the thickness of the end heat conductor 813 to enhance the thermal conductivity of the middle heat conductor 812, so that the middle heat conductor 812 can quickly transfer the heat accumulated between adjacent electrode bodies 52, or heat two adjacent electrode assemblies 5 to improve the reliability of the thermal conductor 8.

[0445] See also Figure 28 、 Figure 29 and Figure 30 , Figure 28 This is a partial structural diagram of a battery cell provided in one embodiment of the present application; Figure 29 The battery cell provided in one embodiment of the present application is Figure 28 Enlarged view of point A in the middle; Figure 30 Another embodiment of the present invention provides a battery cell. Figure 28 Enlarged view of point A in the middle.

[0446] In some embodiments, as Figure 4 、 Figure 5 、 Figures 28 to 30 As shown, two independent middle heat-conducting parts 812 are arranged between two adjacent first side surfaces 5231 of two adjacent electrode assemblies 5, and the heat-conducting assembly 8 includes four second heat-conducting parts 82, and the four second heat-conducting parts 82 are arranged between the two end heat-conducting parts 813 at intervals along the second direction Y. The two outermost second heat-conducting parts 82 are respectively connected to the two end heat-conducting parts 813, and the two middle second heat-conducting parts 82 are respectively connected to the two middle heat-conducting parts 812.

[0447] In these embodiments, two independent middle heat-conducting parts 812 are arranged between two adjacent first side surfaces 5231 of two adjacent electrode assemblies 5, the two outermost second heat-conducting parts 82 are respectively connected to the two end heat-conducting parts 813, and the two middle second heat-conducting parts 82 are respectively connected to the two middle heat-conducting parts 812, so that when the electrode assembly 5 expands, the combination of the end heat-conducting parts 813 and the second heat-conducting parts 82 and the middle heat-conducting parts 812 and the second heat-conducting parts 82 can move in the second direction Y to buffer the extrusion force of the electrode assembly 5, improve the problem of extrusion and damage of the heat-conducting component 8 during the expansion of the electrode assembly 5, and improve the reliability of the battery cell 3.

[0448] Specifically, the two first side surfaces 5231 of a single electrode assembly 5 are thermally connected to the end heat conductive member 813 and the middle heat conductive member 812, respectively. The second end surface 522 of the electrode assembly 5 is thermally connected to two spaced second heat conductive portions 82. One second heat conductive portion 82 is connected to the end heat conductive member 813 and extends toward the middle heat conductive member 812, and the other second heat conductive portion 82 is connected to the middle heat conductive member 812 and extends toward the end heat conductive member 813. When the electrode assembly 5 expands, the combination of the second heat conductive portion 82 and the end heat conductive member 813 and the combination of the second heat conductive portion 82 and the middle heat conductive member 812 can deform synchronously with the electrode assembly 5 to buffer the extrusion force exerted by the electrode assembly 5 on the heat conductive member 8. The same applies to the other electrode assembly 5 and the middle heat conductive member 812, the end heat conductive member 813, and the second heat conductive portion 82 connected to the electrode assembly 5.

[0449] The distance between adjacent second heat conducting portions 82 can be designed arbitrarily.

[0450] Optionally, the end heat conducting member 813 and the second heat conducting portion 82 connected thereto are integrally prepared and formed by bending the same base material once to reduce the difficulty of processing. The middle heat conducting member 812 and the second heat conducting portion 82 connected thereto are integrally prepared and formed by bending the same base material once to reduce the difficulty of processing. Optionally, the end heat conducting member 813 and the middle heat conducting member 812 have the same shape and size, and the shape and size of each second heat conducting portion 82 are the same, so that the combination of the end heat conducting member 813 and the second heat conducting portion 82 and the combination of the middle heat conducting member 812 and the second heat conducting portion 82 can be universal, thereby saving the processing cost of the heat conducting component 8.

[0451] Optionally, the two second heat conducting portions 82 connected to the second end surface 522 of the same electrode assembly 5 are symmetrically arranged to make the temperature at the second end surface 522 uniform.

[0452] Optional, such as Figure 30As shown, a middle heat conductive member 812 is provided between two adjacent first side surfaces 5231 of two adjacent electrode assemblies 5, and the heat conductive assembly 8 includes two second heat conductive portions 82, which are arranged between two end heat conductive portions 813 at intervals along the second direction Y, and the two second heat conductive portions 82 are respectively connected to the two end heat conductive portions 813.

[0453] In some embodiments, as Figure 4 and Figure 5 As shown, the heat conducting component 8 and the electrode component 5 are bonded together.

[0454] In these embodiments, the heat conducting component 8 and the electrode component 5 are bonded together to improve the connection reliability between the heat conducting component 8 and the electrode component 5 .

[0455] Optionally, the heat-conducting assembly 8 and the electrode assembly 5 are provided with an adhesive layer. Exemplarily, the adhesive layer may be a double-sided tape.

[0456] Optionally, the heat-conducting component 8 and the electrode component 5 are connected via a heat-conducting colloid to improve the heat-conducting efficiency of the heat-conducting component 8 and the electrode component 5 .

[0457] Optionally, the heat-conducting component 8 and the electrode component 5 are connected via an insulating colloid, and the heat-conducting component 8 and the electrode component 5 are insulated by the insulating colloid.

[0458] In some embodiments, as Figure 4 and Figure 5 As shown, the orthographic projection area of ​​the heat conducting component 8 in the second direction Y is S1, the orthographic projection area of ​​the electrode body 52 in the second direction Y is S2, 0.1≤S1 / S2≤1 is satisfied, and the first direction X and the second direction intersect.

[0459] In these embodiments, when the above conditions are met, it is possible to improve the problem that the first heat-conducting part 81 does not significantly improve the thermal conductivity efficiency of the electrode assembly 5 due to the small area of ​​the first heat-conducting part 81, and it is also possible to improve the problem that the first heat-conducting part 81 is too large and interferes with other structures in the battery cell 3, causing damage to the battery cell 3.

[0460] Exemplarily, the ratio of S1 to S2 is 0.1, 0.2, 0.3, 0.5, 0.7, 0.8, 0.9 or 1, etc.

[0461] Optionally, the electrode assembly 5 includes an electrode body 52, and the first heat-conducting part 81 covers the two first side surfaces 5231 of the electrode body 52, or the electrode assembly 5 includes more than two electrode bodies 52, and the first heat-conducting part 81 covers the first side surfaces 5231 of each electrode body 52, so as to increase the contact area between the electrode assembly 5 and the first heat-conducting part 81 and increase its thermal conductivity rate.

[0462] Optionally, the electrode body 52 is cylindrical, the area of ​​the side surface 523 of the cylindrical electrode body 52 is S3, and the projected area of ​​the heat conducting component 8 on the side surface of the electrode body 52 is S4, satisfying 0.1≤S4 / S3≤1.

[0463] Optionally, the ratio of the orthographic projection area of ​​the second heat conducting portion 82 in the first direction X to the area of ​​the second end surface 522 is less than 1.

[0464] Optionally, the first side surface 5231 and the second side surface 5232 are connected with a rounded transition, and the heat conducting component 8 is arranged on the plane portion of the side surface 523 to reduce the difficulty of arrangement.

[0465] See also Figure 31 、 Figure 32 and Figure 33 , Figure 31 is an exploded view of a battery cell provided in another embodiment of the present application; Figure 32 This is a partial structural diagram of a battery cell provided in one embodiment of the present application; Figure 33 This is a partial structural diagram of a battery cell provided in one embodiment of the present application.

[0466] In some embodiments, as Figures 31 to 33 As shown, the shell 4 includes an opening 41 in the first direction X, the battery cell 3 also includes a top cover assembly 6, the top cover assembly 6 covers the opening 41, the top cover assembly 6 has an electrode terminal, the electrode terminal 61 is connected to the pole ear 51, and the heat-conducting assembly 8 also includes a third heat-conducting part 83, the third heat-conducting part 83 is thermally connected to the pole ear 51, and the third heat-conducting part 83 is thermally connected to the first heat-conducting part 81.

[0467] In these embodiments, the top cover assembly 6 covers the opening 41 of the shell 4, the tab 51 is connected to the electrode terminal 61 of the top cover assembly 6 to achieve electrical connection, and the heat-conducting assembly 8 also includes a third heat-conducting portion 83 heat-conductingly connected to the tab 51, and the third heat-conducting portion 83 is heat-conductingly connected to the first heat-conducting portion 81, so that the heat-conducting assembly 8 can increase the heat conduction rate at the tab 51 to balance the temperature at the tab 51, thereby improving the problem of affecting the performance of the battery cell 3 due to the excessively high temperature at the tab 51.

[0468] When the battery cell 3 is in working state, the current is output from the pole ear 51 to the outside through the electrode terminal 61. The current passing through the pole ear 51 causes the temperature to rise. The high temperature will be transmitted from the pole ear 51 to the electrode body 52, causing the temperature of the electrode body 52 to rise. The battery cell 3 reaches the current limiting temperature prematurely, resulting in a decrease in the performance of the battery cell 3.

[0469] Therefore, the tab 51 and the third heat conducting portion 83 are thermally connected, so that the heat at the tab 51 can be transferred to the outside through the first heat conducting portion 81 and the third heat conducting portion 83, thereby improving the problem of the tab 51 heating the electrode body 52. ​​Alternatively, in a low temperature environment, the first heat conducting portion 81 and the third heat conducting portion 83 can also be used to increase the temperature of the tab 51.

[0470] The third heat-conducting part 83 is thermally connected to the first heat-conducting part 81. Specifically, the heat-conducting assembly 8 includes an insulating part (not shown) and a heat-conducting part (not shown). The insulating part forms a receiving cavity in at least a part of its area, and the heat-conducting part is arranged in the receiving cavity. Then, the heat-conducting part in the first heat-conducting part 81 and the heat-conducting part in the third heat-conducting part 83 can be directly connected. Exemplarily, the heat-conducting part in the first heat-conducting part 81 and the heat-conducting part in the third heat-conducting part 83 are integrally formed or bonded to each other or abutted against each other; or the heat-conducting part in the first heat-conducting part 81 and the heat-conducting part in the third heat-conducting part 83 are indirectly connected through a heat-conducting medium, which can be a metal material or a heat-conducting glue, etc.

[0471] Optional, such as Figure 32 As shown, the third heat conducting portion 83 is connected between the first heat conducting portion 81 and the tab 51, and the first heat conducting portion 81 extends to the first side surface 5231 of the electrode body 52. ​​Then, the first heat conducting portion 81 can be used to conduct heat from the first side surface 523 of the electrode body 52 and the tab 51 at the same time; or, as shown Figure 31 As shown, the first heat-conducting portion 81 extends to the second side surface 5232, which helps to reduce the size of the heat-conducting component 8 in the second direction Y, and since the expansion of the electrode assembly 5 mainly occurs at the first side surface 5231, when the first heat-conducting portion 81 is arranged at the second side surface 5232, the interference of the first heat-conducting portion 81 on the expansion of the electrode assembly 5 can be reduced.

[0472] Optionally, the third heat conducting portion 83 may be connected to one first heat conducting portion 81 ; or the third heat conducting portion 83 may be connected to two or more first heat conducting portions 81 that are spaced apart.

[0473] Optionally, the electrode body 52 includes a positive electrode ear and a negative electrode ear, and the positive electrode ear and the negative electrode ear are connected to different third heat-conducting parts 83, thereby reducing the size of a single third heat-conducting part 83 and reducing the risk of interference between the third heat-conducting part 83 and other components of the battery cell 3; or the positive electrode ear and the negative electrode ear are connected to the same third heat-conducting part 83 to increase the connection area between the third heat-conducting part 83 and the first heat-conducting part 81, thereby improving the thermal conductivity efficiency of the heat-conducting component 8.

[0474] Optionally, the third heat conducting portion 83 and the tab 51 may be connected by abutment, welding, bonding, etc., or the third heat conducting portion 83 and the tab 51 may be connected by a heat transfer medium.

[0475] Optionally, the first heat conducting portion 81 and the third heat conducting portion 83 are integrally formed to enhance the heat conducting efficiency of the heat conducting assembly 8 .

[0476] Optionally, the positive and negative electrode ears extend from the first end face 521 and the second end face 522 respectively, and the two third heat conducting parts 83 are respectively connected to the positive electrode ear and the negative electrode ear. The two third heat conducting parts 83 can be connected to the same first heat conducting part 81 to reduce the material cost of the heat conducting component 8, or the two third heat conducting parts 83 are connected to the two first heat conducting parts 81 to improve the heat conduction rate of the heat conducting component 8.

[0477] See also Figure 34 , Figure 34 This is an exploded view of a battery cell provided in another embodiment of the present application.

[0478] In some embodiments, as Figure 34 As shown, the battery cell 3 further includes a switching mechanism 7 , which is connected between the tab 51 and the top cover assembly 6 , and the switching mechanism 7 is thermally connected to the third heat conducting portion 83 .

[0479] In these embodiments, the battery cell 3 also includes a transfer mechanism 7, which is connected between the tab 51 and the top cover assembly 6. The transfer mechanism 7 and the third heat conducting part 83 are thermally connected so that the heat conducting assembly 8 can increase the heat conduction rate at the transfer mechanism 7 to balance the temperature at the transfer mechanism 7 and improve the problem of affecting the performance of the battery cell 3 due to excessive temperature at the transfer mechanism 7.

[0480] The third heat conducting part 83 and the adapter mechanism 7 are thermally connected, and the third heat conducting part 83 and the adapter mechanism 7 are directly connected, or the third heat conducting part 83 and the adapter mechanism 7 are indirectly connected through a heat conducting medium, and the heat conducting medium can be air, metal, or heat conducting glue, etc.

[0481] At least one of the tab 51 and the adapter mechanism 7 is thermally connected to the third heat conducting portion 83 .

[0482] The tab 51 is connected to the electrode terminal 61 through the adapter mechanism 7. The high temperature at the electrode terminal 61 can also be transmitted to the electrode body 52 through the tab 51, causing the temperature of the electrode body 52 to rise, and the battery cell 3 to reach the current limiting temperature prematurely, resulting in a decrease in the performance of the battery cell 3.

[0483] Therefore, the adapter mechanism 7 and the third heat conducting portion 83 are connected so that the heat at the adapter mechanism 7 can be transferred to the outside through the first heat conducting portion 81 and the third heat conducting portion 83, thereby improving the problem of the adapter mechanism 7 heating the electrode body 52. ​​Alternatively, in a low-temperature environment, the temperature of the adapter mechanism 7 can also be increased through the first heat conducting portion 81 and the third heat conducting portion 83.

[0484] Optionally, the tab 51 and the adapter 7 are respectively connected to a third heat conducting portion 83 to improve the heat conduction rate of the heat conducting component 8; or the tab 51 and the adapter 7 are connected to the same third heat conducting portion 83 to save the material cost of the heat conducting component 8.

[0485] Optionally, the third heat conducting part 83 and the adapter mechanism 7 may be connected by abutment, welding, bonding, etc., or the third heat conducting part 83 and the adapter mechanism 7 may be connected by a heat transfer medium.

[0486] Optionally, the electrode terminal 61 and the tab 51 are respectively connected to the two side surfaces of the adapter mechanism 7 in the first direction X, and the connection area between the third heat conducting part 83 and the adapter mechanism 7 and the connection area between the adapter mechanism and the electrode terminal 61 and the tab 51 are spaced apart. The third heat conducting part 83 can be arranged on either side of the adapter mechanism 7 in the first direction X, or the third heat conducting part 83 can be arranged on the two side surfaces of the adapter mechanism 7 in the first direction X.

[0487] See also Figure 35 , Figure 35 This is a partial structural diagram of a battery cell provided in one embodiment of the present application.

[0488] In some embodiments, as Figure 31 、 Figure 32 and Figure 35 As shown, the electrode tab 51 includes a folded section 511 and an extended section 512, the folded section 511 is connected to the electrode body 52, one side of the extended section 512 is connected to the folded section 511, and the other side is connected to the adapter mechanism 7, the third heat conducting portion 83 is connected to the side of the extended section 512 facing the folded section 511, or the third heat conducting portion 83 is connected to the side of the extended section 512 facing the adapter mechanism 7.

[0489] In these embodiments, the third heat conducting portion 83 is connected to the side of the extension section 512 toward the retracted section 511, or the third heat conducting portion 83 is connected to the side of the extension section 512 toward the adapter mechanism 7. The third heat conducting portion 83 is used to improve the heat conduction rate at the pole tab 51, thereby improving the problem that the temperature at the pole tab 51 is too high, thereby heating the pole piece, causing the electrode body 52 to heat up, and the performance of the battery cell 3 to decrease.

[0490] Illustratively, the gathering section 511 extends along the first direction X, one end of the extension section 512 is connected to the gathering section 511, and the other end extends along the second direction Y, the adapter mechanism 7 is connected to the extension section 512, and the extension section 512 is used to increase the connection area between the tab 51 and the adapter mechanism 7, thereby improving the connection reliability between the tab 51 and the adapter mechanism 7.

[0491] like Figure 35As shown, the adapter mechanism 7 is connected to the side of the extension section 512 close to the top cover assembly 6 in the first direction X, and the third heat conducting part 83 is connected to the side of the extension section 512 away from the top cover assembly 6 in the first direction X, so that the pole tab 51 and the third heat conducting part 83 have sufficient contact area, thereby improving the connection reliability between the third heat conducting part 83 and the pole tab 51, and ensuring that the pole tab 51 and the adapter mechanism 7 have sufficient contact area.

[0492] Or, as Figure 32 As shown, the extension section 512 extends in the third direction Z, the adapter mechanism 7 and the third heat-conducting part 83 are both connected to the side surface of the extension section 512 facing the top cover assembly 6, and the adapter mechanism 7 and the third heat-conducting part 83 are spaced apart in the third direction Z to reasonably coordinate the positions of the third heat-conducting part 83, the tab 51 and the adapter mechanism 7, thereby reducing the difficulty of connecting the third heat-conducting part 83 and the tab 51.

[0493] In some embodiments, as Figure 31 and Figure 35 As shown, the extension section 512 includes a first sub-segment 5121, a second sub-segment 5122 and a third sub-segment 5123 connecting the first sub-segment 5121 and the second sub-segment 5122, which are arranged at intervals along the first direction X. The first sub-segment 5121 is connected to the gathering section 511, the second sub-segment 5122 is connected to the adapter mechanism 7, and the third heat conducting portion 83 is connected to the side of the first sub-segment 5121 facing the gathering section 511.

[0494] In these embodiments, the extension section 512 includes a first sub-segment 5121, a second sub-segment 5122, and a third sub-segment 5123 connecting the first sub-segment 5121 and the second sub-segment 5122, which are arranged at intervals along the first direction X. The second sub-segment 5122 is connected to the adapter mechanism 7 to increase the contact area between the adapter mechanism 7 and the tab 51. The third heat conducting portion 83 is connected to the side of the first sub-segment 5121 toward the convergence section 511 to reduce the difficulty of connecting the third heat conducting portion 83 and the tab 51.

[0495] One side of the extension section 512 is connected to the adapter mechanism 7, and the third heat conducting part 83 is connected to the side of the extension section 512 facing the retracted section 511. Specifically, the adapter mechanism 7 is connected to the second sub-segment 5122, and the third heat conducting part 83 is connected to the first sub-segment 5121.

[0496] Exemplarily, the tabs 51 of each pole piece are gathered in the folding section 511, and after folding, they are bent along the second direction Y to form a first sub-segment 5121, and then the tabs 51 are bent and extended along the first direction X to form a third sub-segment 5123, and then the tabs 51 are extended along the second direction Y to form a second sub-segment 5122.

[0497] Optionally, the area of ​​the second sub-segment 5122 is larger than that of the first sub-segment 5121, the third heat conducting part 83 is connected to the first sub-segment 5121, and the adapter mechanism 7 and another third heat conducting part 83 are connected to the second sub-segment 5122 to increase the contact area between the pole lug 51 and the adapter mechanism 7, and improve the connection reliability between the pole lug 51 and the adapter mechanism 7 and the pole lug and the third heat conducting part 83.

[0498] In some embodiments, as Figure 31 and Figure 33 As shown, the side surface 523 includes two first side surfaces 5231 and two second side surfaces 5232, the two first side surfaces 5231 are arranged opposite to each other in the second direction Y, and the two second side surfaces 5232 are arranged opposite to each other in the third direction Z, the first direction X, the second direction Y and the third direction Z intersect each other, the area of ​​the first side surface 5231 is larger than the area of ​​the second side surface 5232, two pole ears 51 are provided, the two pole ears 51 extend from the first end surface 521, and are arranged at intervals along the third direction Z, two first heat conducting parts 81 and two third heat conducting parts 83 are respectively provided, the two first heat conducting parts 81 are respectively arranged on the two second side surfaces 5232, the two third heat conducting parts 83 are respectively connected to one end of the two first heat conducting parts 81 facing the pole ear 51, and the two third heat conducting parts 83 are respectively connected to the extension sections 512 of the two pole ears 51.

[0499] In these embodiments, the two tabs 51 extend from the first end surface 521 and are spaced apart along the third direction Z. The two first heat-conducting portions 81 are respectively arranged on the two second side surfaces 5232. The thickness of the battery cell 3 will not be increased due to the provision of the heat-conducting component 8. Moreover, since the expansion of the electrode assembly 5 mainly occurs at the first side surface 5231, when the first heat-conducting portion 81 is arranged on the second side surface 5232, the interference of the first heat-conducting portion 81 on the expansion of the electrode assembly 5 can be reduced. The two third heat-conducting portions 83 are respectively connected to one end of the two first heat-conducting portions 81 facing the tabs 51, and the two third heat-conducting portions 83 are respectively connected to the extension sections 512 of the two tabs 51. Each tab 51 is connected to a third heat-conducting portion 83, so that heat from the electrode body 52 and each tab 51 can be transferred to the first heat-conducting portion 81 through the third heat-conducting portion 83, thereby improving the heat conduction rate at the tab 51 and improving the problem that the temperature at the tab 51 is too high, thereby heating the pole piece, causing the electrode body 52 to heat up, and reducing the performance of the battery cell 3.

[0500] Optionally, there are multiple first heat conducting parts 81, at least two first heat conducting parts 81 are arranged at intervals on the same second side 5232, and several first heat conducting parts 81 arranged on the same second side 5232 are connected to the same third heat conducting part 83. The interval-arranged first heat conducting parts 81 can not only save the material cost of the heat conducting component 8, but also improve the problem of excessive heat concentration in a part of the second side 5232 when the first heat conducting part 81 transfers the temperature of the tab 51, and can balance the temperature at the second side 5232.

[0501] Optionally, the first heat conducting part 81 and the third heat conducting part 83 are integrally formed, and the first heat conducting part 81 and the third heat conducting part 83 are formed by bending the base material once, which reduces the processing difficulty of the first heat conducting part 81 and the third heat conducting part 83.

[0502] See also Figure 36 , Figure 36 This is a partial structural diagram of a battery cell provided in one embodiment of the present application.

[0503] In some embodiments, as Figure 31 and Figure 36 As shown, the side surface 523 includes two first side surfaces 5231 and two second side surfaces 5232. The two first side surfaces 5231 are arranged opposite to each other in the second direction Y, and the two second side surfaces 5232 are arranged opposite to each other in the third direction Z. The first direction X, the second direction Y and the third direction Z intersect with each other. The area of ​​the first side surface 5231 is larger than the area of ​​the second side surface 523. Two first heat conducting parts 81 and two third heat conducting parts 83 are respectively provided. The two first heat conducting parts 81 are respectively provided on the two first side surfaces 5231. Each third heat conducting part 83 is respectively connected to one first heat conducting part 81. The two third heat conducting parts 83 are respectively connected to the extension section 512 of the same pole ear 51 at different positions in the first direction X.

[0504] In these embodiments, each third heat-conducting portion 83 is respectively connected to a first heat-conducting portion 81, and the two third heat-conducting portions 83 are respectively connected to the extension section 512 of the same pole tab 51 at different positions in the first direction X, so as to better improve the heat conduction rate at the pole tab 51 and improve the problem of affecting the performance of the battery cell 3 due to the excessively high temperature at the pole tab 51.

[0505] The two third heat conducting portions 83 are respectively connected to different positions of the extension section 512 of the same tab 51 . Thus, the two third heat conducting portions 83 conduct heat to the same tab 51 to better balance the temperature of the tab 51 .

[0506] The two third heat conducting portions 83 are connected to different positions of the extension section 512, and each third heat conducting portion can directly contact the extension section 512. The two third heat conducting portions 83 can be disposed on both sides of the extension section 512 in the first direction X, or the two third heat conducting portions 83 can be disposed on the same side of the extension section 512 in the first direction X.

[0507] Optionally, two third heat conducting parts 83 are respectively connected to the extension section 512 of the same tab 51 on both sides of the first direction X, which can ensure that each third heat conducting part 83 has sufficient contact area with the extension section 512, thereby reducing the difficulty of connecting the third heat conducting part 83 and the extension section 512.

[0508] Optionally, two third heat conducting portions 83 provided on both sides of the electrode body 52 in the second direction Y are spaced apart along the second direction Y on a surface of the extension section 512 in the first direction X. For example, the two third heat conducting portions 83 are spaced apart along the second direction Y on the second sub-segment 5122.

[0509] Alternatively, the two third heat conducting portions 83 provided on both sides of the electrode body 52 in the second direction Y are spaced apart along the first direction X on both sides of the extension section 512 in the first direction X. For example, the two third heat conducting portions 83 are spaced apart along the first direction X in the second sub-segment 5122.

[0510] Optionally, the battery cell 3 includes a plurality of electrode assemblies 5 , and a first heat conducting portion 81 is disposed between adjacent electrode assemblies 5 .

[0511] In some embodiments, as Figure 34 and Figure 36 As shown, the extension section 512 includes a first sub-segment 5121, a second sub-segment 5122 and a third sub-segment 5123 that are spaced apart along the first direction X. The first sub-segment 5121 is connected to the retracted section 511, and the second sub-segment 5122 is connected to the adapter mechanism 7; one of the two third heat-conducting parts 83 is connected to the first sub-segment 5121, and the other is connected to the second sub-segment 5122.

[0512] In these embodiments, one of the two third heat conducting parts 83 is connected to the first sub-segment 5121 , and the other is connected to the second sub-segment 5122 , and the connection areas between the two third heat conducting parts 83 and the tab 51 are reasonably allocated to improve the connection reliability between the third heat conducting parts 83 and the tab 51 .

[0513] Optionally, one third heat conducting portion 83 is connected to a side surface of the first sub-segment 5121 facing away from the second sub-segment 5122, and another third heat conducting portion 83 is connected to a side surface of the second sub-segment 5122 facing the first sub-segment 5121, so as to reduce the difficulty of connecting the tab 51 and the third heat conducting portion 53.

[0514] See also Figure 37 , Figure 37 This is a partial structural diagram of a battery cell provided in one embodiment of the present application.

[0515] In some embodiments, as Figure 34 and Figure 37 As shown, the side surface 523 includes two first side surfaces 5231 and two second side surfaces 5232. The two first side surfaces 5231 are arranged relative to each other in the second direction Y, and the two second side surfaces 5232 are arranged relative to each other in the third direction Z. The first direction X, the second direction and the third direction Z intersect. The area of ​​the first side surface 5231 is greater than the area of ​​the second side surface 5232. The adapter mechanism 7 includes a first connecting segment 71 and a second connecting segment 72 arranged along the third direction Z. The tab 51 is connected to the first connecting segment 71, and the third heat conducting portion 83 is connected to the second connecting segment 72.

[0516] In these embodiments, the adapter mechanism 7 includes a first connecting section 71 and a second connecting section 72, the pole ear 51 is connected to the first connecting section 71, and the third heat conducting portion 83 is connected to the second connecting section 72. The third heat conducting portion 83 is used to improve the heat conduction rate at the adapter mechanism 7, thereby improving the problem that the temperature at the adapter mechanism 7 is too high, thereby heating the pole piece and causing the performance of the battery cell 3 to be reduced.

[0517] The third heat conducting portion 83 is connected to the second connecting section 72, or the third heat conducting portion 83 and the electrode terminal 61 are both connected to the second connecting section 72. Specifically, the third heat conducting portion 83 is connected to the second connecting section 72, and the electrode terminal 61 and the tab 51 are connected to the first connecting section 71; or the third heat conducting portion 83 and the electrode terminal 62 are both connected to the second connecting section 72, and the third heat conducting portion 83 and the electrode terminal 62 are respectively provided on both sides of the second connecting section 72 in the first direction X; or the third heat conducting portion 83 and the electrode terminal 62 are provided on one side of the second connecting section 72 in the first direction X.

[0518] Optionally, the specific size and shape of the first connecting section 71 and the second connecting section 72 can be designed by oneself.

[0519] Optionally, the two second connecting sections 72 are provided on both sides of the first connecting section 71 , and the two third heat conducting parts 83 are respectively connected to the two second connecting sections 72 to increase the contact area between the third heat conducting parts 83 and the adapter mechanism 7 .

[0520] Optionally, a pressure relief valve is provided on the top cover assembly 6 so that when the pressure inside the shell 4 reaches a threshold value, the pressure is released to the outside through the pressure relief valve. The shape and size of the adapter mechanism 7 can be designed by oneself, and the adapter mechanism 7 and the pressure relief valve are spaced apart to avoid the adapter mechanism 7 blocking the pressure relief valve.

[0521] Optionally, a single second connecting segment 72 can connect more than two third heat conducting parts 83 ; or the adapter mechanism 7 includes multiple second connecting segments 72 to connect multiple third heat conducting parts 83 to enhance the heat conducting efficiency of the heat conducting assembly 8 .

[0522] In some embodiments, as Figure 34 and Figure 37 As shown, two first heat conducting parts 81 and two third heat conducting parts 83 are respectively provided, the two first heat conducting parts 81 are respectively provided on the two first side surfaces 5231, each third heat conducting part 83 is respectively connected to one first heat conducting part 81, and the two third heat conducting parts 83 are respectively connected to different positions of the second connecting section 72 of the same adapter mechanism 7.

[0523] In these embodiments, the two first heat-conducting parts 81 are respectively arranged on the two first side surfaces 5231, each third heat-conducting part 83 is respectively connected to one first heat-conducting part 81, and the two third heat-conducting parts 83 are respectively connected to different positions of the second connecting section 72 of the same adapter mechanism 7, so as to better improve the heat conduction rate at the adapter mechanism 7 and improve the problem of affecting the performance of the battery cell 3 due to excessive temperature at the adapter mechanism 7.

[0524] The two third heat conducting portions 83 are connected to different positions of the same second connecting section 72, and each third heat conducting portion 83 can directly contact the second connecting section 72. The two third heat conducting portions 83 can be provided on both sides of the second connecting section 72 in the first direction X, or on the same side of the second connecting section 72 in the first direction X; or at both ends of the second connecting section 72 in the second direction Y; or at one end of the second connecting section 72 in the second direction Y.

[0525] Optionally, the two third heat conducting parts 83 are respectively connected to the second connecting section 72 of the same adapter mechanism 7 on both sides of the second direction Y, thereby reducing the size of the third heat conducting part 83, reducing the material cost of the third heat conducting part 83, and reducing the difficulty of connecting the third heat conducting part 83 and the adapter mechanism 7.

[0526] Optionally, two second connecting segments 72 are arranged on both sides of the first connecting segment 71 in the second direction Y, and the two second connecting segments 72 have the same size. The two third heat conducting parts 83 are arranged on both sides of the electrode body 52 in the second direction Y and are respectively connected to the two second connecting segments 72.

[0527] Optionally, the positive electrode tab of the electrode body 52 and the third heat conducting portion 83 are connected to the same adapter mechanism 7 , or the negative electrode tab of the electrode body 52 and the third heat conducting portion 83 are connected to the same adapter mechanism.

[0528] Optionally, there are multiple electrode assemblies 5 , and one of the two third heat conducting portions 83 disposed on both sides of the electrode body 52 in the second direction Y is disposed between adjacent electrode assemblies 5 .

[0529] See also Figure 38 、 Figure 39 and Figure 40 , Figure 38 This is a partial structural diagram of a battery cell provided in one embodiment of the present application; Figure 39 yes Figure 38 Schematic diagram of the enlarged structure at B in the middle; Figure 40 This is a partial structural diagram of a battery cell provided in one embodiment of the present application.

[0530] In some embodiments, as Figure 31 、 Figures 38 to 40 As shown, there are two electrode assemblies 5, and the two electrode assemblies 5 are stacked along the second direction Y. The adapter mechanism 7 is provided with two first connecting sections 71, and the two first connecting sections 71 are respectively arranged on both sides of the second connecting section 72 in the second direction Y. The pole ears 51 of the two electrode assemblies 5 are respectively connected to the two first connecting sections 71, and two first heat conducting parts 81 and two third heat conducting parts 83 are respectively provided. The two first heat conducting parts 81 are respectively arranged on the two first side surfaces 5231 of the same electrode body 52, and the two third heat conducting parts 83 are respectively connected to one end of the two first heat conducting parts 81 facing the adapter mechanism 7, and the two third heat conducting parts 83 are respectively connected to the two second connecting sections 72 of the adapter mechanism 7.

[0531] In these embodiments, the two first heat-conducting parts 81 are respectively arranged on both sides of an electrode body 52 in the second direction Y, the two third heat-conducting parts 83 are respectively connected to one end of the two first heat-conducting parts 81 facing the adapter mechanism 7, and the two third heat-conducting parts 83 are respectively connected to the two second connecting sections 72 of the adapter mechanism 7 to reduce the difficulty of connecting the third heat-conducting parts 83 and the pole ear 51 and the adapter mechanism 7; and the two third heat-conducting parts 83 are respectively connected to the pole ear 51 and the adapter mechanism 7 to better stabilize the temperature at the pole ear 51.

[0532] Figure 38 In order to facilitate observation of the connection relationship between the third heat conducting portion 83, the electrode tab 51 and the adapter mechanism 7, an electrode body 52 is hidden.

[0533] The adapter mechanism 7 is provided with two first connecting sections 71 , so that the adapter mechanism 7 can simultaneously connect the tabs of two electrode assemblies 5 , thereby reducing the overall size of the adapter mechanism 7 in the battery cell 3 and improving the energy density of the battery cell 3 .

[0534] The second connecting section 72 is located between the two first connecting sections 71 , and thus the second connecting section 72 is located between the two electrode assemblies 5 . One or more third heat conducting parts 83 are connected to the second connecting section 72 to conduct heat from the adapter 7 .

[0535] One or more third heat conducting portions 83 are located between the housing 4 and the tab 51 along the second direction Y. The third heat conducting portion 83 is connected to the tab 51 to conduct heat from the tab 51, thereby balancing the temperature of the tab 51 and improving the problem of the tab 51 heating the electrode body 52. ​​Exemplarily, the third heat conducting portion 83 is connected to the first sub-segment 5121 of the tab 51.

[0536] Optional, such as Figure 40 As shown, the heat-conducting component 8 includes three first heat-conducting parts 81 and three third heat-conducting parts 83 arranged at intervals. The two first heat-conducting parts 81 are respectively arranged between the two first side surfaces 5231 of the electrode assembly 5 and the shell 4. The two first heat-conducting parts 81 are connected to the electrode ear 51 through two third heat-conducting parts 83; one first heat-conducting part 81 is connected to the second connecting section 72 through one third heat-conducting part 83 to enhance the heat conduction rate of the heat-conducting component 8.

[0537] See also Figure 41 and Figure 42 , Figure 41 This is a partial structural diagram of a battery cell provided in one embodiment of the present application; Figure 42 This is a partial structural diagram of a battery cell provided in one embodiment of the present application.

[0538] In some embodiments, as Figure 31 、 Figure 41 and Figure 42 As shown, the heat conducting assembly 8 further includes a second heat conducting portion 82 , which is disposed between the housing 4 and at least a portion of the second end surface 522 along the first direction X, and is connected to the first heat conducting portion 81 .

[0539] In these embodiments, the heat-conducting component 8 also includes a second heat-conducting portion 82 arranged between the shell 4 and at least a portion of the second end surface 522 along the first direction X. The second heat-conducting portion 82 is connected to the first heat-conducting portion 81 to increase the contact area between the heat-conducting component 8 and the shell 4, so as to increase the heat conduction rate of the heat-conducting component 8 to the pole tab 51, thereby improving the problem of affecting the performance of the battery cell 3 due to the excessively high temperature at the pole tab 51.

[0540] The second heat-conducting part 82 is connected to the first heat-conducting part 81. Specifically, the heat-conducting assembly 8 includes an insulating part (not shown) and a heat-conducting part (not shown). The insulating part forms a receiving cavity in at least a part of its area, and the heat-conducting part is arranged in the receiving cavity. Then the heat-conducting part in the first heat-conducting part 81 and the heat-conducting part in the second heat-conducting part 82 are connected. Exemplarily, the heat-conducting part in the first heat-conducting part 81 and the heat-conducting part in the second heat-conducting part 82 are integrally formed or bonded to each other or abutted against each other; or the heat-conducting part in the first heat-conducting part 81 and the heat-conducting part in the second heat-conducting part 82 are spaced apart, and the insulating part of the first heat-conducting part 81 and the insulating part of the second heat-conducting part 82 are connected to each other.

[0541] The heat at the tab 51 can be transferred to the second heat conducting portion 82 through the third heat conducting portion 83 and the first heat conducting portion 81, and then transferred to the external environment at the second heat conducting portion 82. The interconnected first heat conducting portion and second heat conducting portion 82 increase the heat exchange area of ​​the heat conducting component 8 and improve the heat conduction rate of the heat conducting component 8.

[0542] Optionally, the heat exchange mechanism is provided along the first direction X at an end of the battery cell 3 where no tab 51 is provided, and the second heat conducting portion 82 can transfer heat between the heat exchange mechanism and the tab 51 .

[0543] Optionally, the second heat conducting portion 82 covers the entire second end surface 522 of the electrode assembly 5 to improve the heat conduction rate of the second heat conducting portion 82 .

[0544] Optionally, the shape and size of the second heat conducting portion 82 can be flexibly designed. For example, the second heat conducting portion 82 is rectangular or circular.

[0545] Optionally, the first heat conducting portion 81 , the second heat conducting portion 82 and the third heat conducting portion 83 are integrally formed to improve the heat conduction rate of the heat conducting component 8 .

[0546] Optionally, the two first heat conducting parts 81 are arranged at intervals, and the two first heat conducting parts 81 are connected to the third heat conducting part 83 at one end in the first direction X, and the two first heat conducting parts 81 are connected through the second heat conducting part 82 at the other end in the first direction X, so that the second heat conducting part 82 can balance the heat of the two first heat conducting parts 81.

[0547] See also Figure 43 , Figure 43 This is an exploded view of a battery cell provided in another embodiment of the present application.

[0548] In some embodiments, as Figure 43As shown, the tab 51 extends out of the first end face 521 , and the battery cell 3 further includes a first insulating film 91 , which covers the side face 523 and the second end face 522 of the electrode body 52 ; wherein the first heat conducting portion 81 is located between the first insulating film 91 and the electrode assembly 5 , or the first heat conducting portion 81 is located between the first insulating film 91 and the shell 4 .

[0549] In these embodiments, the first insulating film 91 is covered on the side surface 523 and the second end surface of the electrode body 52 to insulate the shell 4 and the electrode assembly 5. The first heat-conducting part 81 is located between the first insulating film 91 and the electrode assembly 5. The first insulating film 91 plays a role in supporting and protecting the first heat-conducting part 81, reducing the problem of damage to the first heat-conducting part 81 in the first insulating film 91 under external force impact, or the first heat-conducting part 81 is located between the first insulating film 91 and the shell 4 to improve the insulation reliability between the first heat-conducting part 81 and the electrode assembly 5, and improve the thermal conductivity efficiency between the first heat-conducting part 81 and the shell 4.

[0550] For example, the material of the first insulating film 91 may be PP or PI (polyimide) or PET (polyethylene terephthalate).

[0551] The first heat conducting portion 81 is located between the first insulating film 91 and the electrode assembly 5 , which helps to reduce the distance between the first heat conducting portion 81 and the electrode assembly 5 and improve the heat conduction rate between the electrode assembly 5 and the first heat conducting portion 81 .

[0552] Optionally, a groove is formed on the first insulating film 91 , and the first heat conducting portion 81 is accommodated in the groove, so as to reduce the overall thickness of the first insulating film 91 and the first heat conducting portion 81 .

[0553] The first heat conducting part 81 is located between the first insulating film 91 and the housing 4 . At least one of the first insulating film 91 and the housing 4 is bonded to the first heat conducting part 81 to keep the first heat conducting part 81 stable in the housing 4 .

[0554] See also Figure 44 、 Figure 45 and Figure 46 , Figure 44 This is a schematic structural diagram of a heat-conducting component of a battery cell provided in one embodiment of the present application; Figure 45 yes Figure 44 Cross-section at CC; Figure 46 This is an exploded view of a battery cell provided in another embodiment of the present application.

[0555] In some embodiments, as Figure 5 、 Figures 44 to 46The 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 heat conducting member 84 includes a first heat conducting sheet 841 disposed on the side surface 523. The first heat conducting portion 81 is composed of the first heat conducting sheet 841 and the insulating member 85.

[0556] In these embodiments, 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 arranged in the receiving cavity. The heat-conducting member 84 includes a first heat-conducting sheet 841. The first heat-conducting sheet 841 is arranged on the side 523. The first heat-conducting portion 81 is composed of the first heat-conducting sheet 841 and the insulating member 85. In this way, the insulating member 85 can be used to insulate the heat-conducting member 84 from the electrode body 52, and the insulating member 85 can be used to isolate the heat-conducting member 84 from the electrolyte, so as to improve the problem that the heat-conducting member 84 and the electrolyte are incompatible, thereby affecting the performance of the battery cell 3.

[0557] For example, the insulating member 85 may be made of PP, PI (polyimide), or PET (polyethylene terephthalate). The thermal conductive member 84 may be made of graphite, graphene, or carbon nanotubes. The thermal conductivity of the thermal conductive member 84 in the thermal conductive assembly 8 is greater than that of the housing 4.

[0558] Optionally, the heat conducting member 84 may be in a plate-like, strip-like, or mesh-like shape. For example, a plate-like heat conducting member, a mesh-like heat conducting member, or one or more strip-like heat conducting members arranged at intervals are provided in the accommodating cavity 851 .

[0559] It should be noted that the heat conductor 84 is located inside the insulating member 85 and is covered by the insulating member 85. In order to conveniently illustrate the position of the heat conductor 84 in the accompanying drawings, the shadow on the insulating member 85 is used to represent the heat conductor 84. Optionally, the insulating member 85 is provided with a receiving cavity 851 with an opening 41 at one end, and the heat conductor 84 is provided in the receiving cavity 851 and is bonded or welded to the opening of the insulating member 85 so that the heat conductor 84 is located in a sealed receiving cavity 851; or the two ends of the insulating member 85 are folded in half, the heat conductor 84 is located between the two ends of the insulating member 85, and the two ends of the insulating member 85 are bonded or welded together so that the heat conductor 84 is located in a sealed receiving cavity 851; or the insulating member 85 includes two sub-insulating layers 855 arranged opposite to each other, and the edges of the two sub-insulating layers 855 are bonded or welded so that the heat conductor 84 is located in a sealed receiving cavity 851.

[0560] Optionally, an adhesive layer is provided on the side of the insulating member 85 facing the electrode body 52 to bond the heat conducting component 8 to the electrode body 52. ​​For example, the adhesive layer can be an insulating colloid to enhance the insulation performance of the heat conducting component 8 and the electrode assembly 5.

[0561] At least a portion of the insulating member 85 extends from the side surface 523. The first heat conducting sheet 841 is disposed on the side surface 523 and 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 insulating member 85. Exemplarily, the first heat conducting sheet 841 covers the entire side surface 523 to improve the heat conduction rate of the first heat conducting portion 81.

[0562] Optionally, the orthographic projection area S1 of the heat conducting assembly 8 in the second direction Y in the above embodiment may refer to the orthographic projection area S1 of the heat conducting member 84 in the second direction Y. The projected area S4 of the heat conducting assembly 8 on the side of the electrode body 52 in the above embodiment may refer to the projected area S4 of the heat conducting member 84 on the side of the electrode body 52.

[0563] See also Figure 47 , Figure 47 This is an exploded view of a battery cell provided in another embodiment of the present application.

[0564] In some embodiments, as Figure 5 and Figure 47 As shown, the tab 51 extends from the first end surface 521 , and the battery cell 3 further includes a second insulating film 92 , which is connected to the insulating member 85 , and the insulating member 85 and the second insulating film 92 jointly cover the second end surface 522 and the side surface 523 of the electrode body 52 .

[0565] In these embodiments, the second insulating film 92 and the insulating member 85 are connected, and the insulating member 85 and the second insulating film 92 jointly cover the second end face 522 and the side face 523 of the electrode body 52. ​​The combination of the second insulating film 92 and the insulating member 85 can achieve insulation between the electrode body 52 and the shell 4, which helps to reduce the size of the second insulating film 92 and reduce the preparation cost of the battery cell 3, and helps to reduce the thickness of the battery cell 3 and improve the energy density of the battery cell 3.

[0566] The insulating part 85 of the thermal conductive component 8 covers part of the side surface 523 or part of the second end surface 522 of the electrode body 52, and the insulating part 85 of the thermal conductive component 8 is connected to the second insulating film 92. The combination of the insulating part 85 and the second insulating film 92 can cover the side surface 523 and the second end surface 522 of the electrode body 52.

[0567] The insulating member 85 and the second insulating film 92 are connected by bonding or welding. The specific dimensions of the insulating member 85 and the second insulating film 92 can be flexibly designed. For example, the insulating member 85 covers the first side surface 5231 and the second end surface 522, and the second insulating film 92 covers the second side surface 5232; or the insulating member covers the first side surface, and the second insulating film 92 covers the second end surface 522 and the second side surface 5232.

[0568] Exemplarily, the second insulating film 92 is a Mylar film.

[0569] See also Figure 48 , Figure 48 This is a partial structural diagram of a battery cell provided in one embodiment of the present application.

[0570] In some embodiments, as Figure 5 and Figure 48 As shown, the electrode tab 51 extends out of the first end surface 521 , and the insulating member 85 covers the second end surface 522 and the side surface 523 of the electrode body 52 .

[0571] In these embodiments, the insulating member 85 covers the second end face 522 and the side face 523 of the electrode body 52 to insulate the shell 4 and the electrode assembly 5, and there is no need to set the first insulating film 91, which helps to reduce the preparation cost of the battery cell 3, and can reduce the thickness of the battery cell 3 and improve the energy density of the battery cell 3.

[0572] In the embodiment of the present application, the shell 4 and the electrode assembly 5 are insulated by the insulating member 85, and the first insulating film 91 is not required, or the insulating member 85 replaces the first insulating film 91. The thermal conductivity of the insulating member 85 and the first insulating film 91 are similar, so in the embodiment of the present application, replacing the first insulating film 91 with the insulating member 85 does not significantly affect the heat dissipation of the electrode assembly; a heat conductive member 84 is provided inside the insulating member 85, and the thermal conductivity of the heat conductive member 84 is greater than the thermal conductivity of the first insulating film 91. Then, compared with the case where the insulating member 85 or the first insulating film 91 is provided between the electrode assembly 5 and the shell 4, another heat conductive member 84 is provided between the electrode assembly 5 and the shell 4. The heat conductive member 84 can improve the heat conduction rate between the electrode assembly 5 and the external environment, that is, the heat conductive member 8 can improve the heat conduction efficiency between the electrode assembly 5 and the external environment.

[0573] The thermal conductivity of the heat conducting assembly 8 can be measured by heat flow method, hot plate method, hot wire method, etc. When performing thermal conductivity test on the heat conducting assembly 8, the test sample of the heat conducting assembly 8 should include a heat conducting member 84 and an insulating member 85 covering the outer surface of the heat conducting member 84.

[0574] By combining the insulating member 85 and the heat conducting member 84 , the insulating member 85 can achieve insulation between the electrode body 52 and the shell 4 , while also achieving insulation between the heat conducting member 84 and the electrode body 52 , and isolating the heat conducting member 84 from the electrolyte.

[0575] The insulating member 85 covers the second end surface 522 and the side surface 523 of the electrode body 52, and the size of the heat conducting member 84 located in the accommodating cavity 851 can be designed. For example, the heat conducting member 84 covers at least one of the first side surface 5231 and the second side surface 5232 and the second end surface 522.

[0576] Optionally, the heat conducting member 84 is arranged in the accommodating cavity 851, and the area of ​​the heat conducting member 84 matches the area of ​​the accommodating cavity 851. The area of ​​the accommodating cavity 851 can be smaller than the area of ​​the insulating member 85. The heat conducting member 84 contacts the cavity wall of the accommodating cavity 851, and the accommodating cavity 851 serves to limit the heat conducting member 84.

[0577] See also Figure 49 、 Figure 50 and Figure 51 , Figure 49 This is a schematic structural diagram of a heat-conducting component of a battery cell provided in one embodiment of the present application; Figure 50 This is an expanded view of a thermally conductive component of a battery cell provided in one embodiment of the present application; Figure 51 Schematic diagram of the structure of a heat-conducting component of a battery cell provided in one embodiment of the present application.

[0578] In some embodiments, as Figure 5 、 Figures 49 to 51 As shown, the side surface 523 includes two first side surfaces 5231 and two second side surfaces 5232, the two first side surfaces 5231 are arranged opposite to each other in the second direction Y, and the two second side surfaces 5232 are arranged opposite to each other in the third direction Z, the first direction X, the second direction and the third direction intersect each other, the area of ​​the first side surface 5231 is greater than the area of ​​the second side surface 5232, the insulating member 85 includes a first insulating portion 852, the first insulating portion 852 includes a main body portion 8521 and a bending portion 8522 connected to each other, the main body portion 8521 and the bending portion 8522 are connected, the main body portions 8521 of the two first insulating portions 852 are respectively arranged on the two first side surfaces 5231, and the two bending portions 8522 are respectively arranged on the two second side surfaces 5232, and the first heat conducting plate 841 is arranged on at least one of the main body portion 8521 and the bending portion 8522.

[0579] In these embodiments, the first insulating part 852 includes a main body part 8521 and a bending part 8522 that are connected to each other, the main body part 8521 and the bending part 8522 are connected, the main bodies of the two first insulating parts 852 are respectively arranged on the two first side surfaces 5231, and the two bending parts 8522 are respectively arranged on the two second side surfaces 5232 to achieve insulation of the electrode assembly 5 on its peripheral side surface and the shell 4, and the first thermal conductive sheet 841 is arranged on at least one of the main body part 8521 and the bending part 8522 to improve the thermal conductivity rate at the first side surface 5231 and / or the second side surface 5232 of the electrode assembly 5.

[0580] The first heat conducting sheet 841 is disposed on the main body 8521 , or the first heat conducting sheet 841 is disposed on the bent portion 8522 , or the first heat conducting sheet 841 is disposed on the main body 8521 and the bent portion 8522 to form the first heat conducting portion 81 .

[0581] In the same shell 4 , the insulating member 85 includes two first insulating portions 852 , and the two first insulating portions 852 , which are arranged opposite to each other, cover at least a portion of the outer circumferential surface of the electrode assembly 5 .

[0582] like Figure 50 As shown, the first insulating part 852 includes a main body part 8521 and a bending part 8522 that are interconnected. The main body part 8521 and the bending part 8522 are integrally formed to improve the structural strength of the first insulating part 852. There is a fold line between the main body part 8521 and the bending part 8522. The main body part 8521 covers the first side surface 5231, and the bending part 8522 is bent along the fold line and covers the second side surface 5232, or the main body part 8521 and the bending part 8522 are prepared separately, and the main body part 8521 and the bending part 8522 are bonded or welded together.

[0583] The first insulating portion 852 includes a main body 8521 and a bent portion 8522 connected to one end of the main body 8521 in the third direction Z. The main body 8521 covers a first side surface 5231 of the electrode assembly 5. One end of the bent portion 8522 is connected to the main body 8521, and the other end extends along the second direction Y toward the main body 8521 of another first insulating portion 852. The bent portion 8522 is connected to two main bodies 8521, or the bent portion 8522 and the main body 8521 are spaced apart and connected by a Mylar film.

[0584] Alternatively, the first insulating part 852 includes a main body part 8521 and a bending part 8522 connected to the two ends of the main body part 8521 in the third direction Z, the main body part 8521 covers the first side surface 5231 of the electrode assembly 5, and the bending parts 8522 of the two oppositely arranged first insulating parts 852 extend relative to each other in the second direction Y and are connected to each other, or the bending parts 8522 of the two oppositely arranged first insulating parts 852 extend relative to each other in the second direction Y, and the two bending parts 8522 are connected by a Mylar film.

[0585] Optionally, in the same shell 4 , the insulating member 85 includes two first insulating portions 852 , which are integrally formed and surround the outer peripheral surface of the electrode assembly 5 .

[0586] Optionally, the main body 8521 covers the first side surface 5231 of the electrode assembly 5 , and the bent portion 8522 covers the second side surface 5232 of the electrode assembly 5 , so that the first insulating portion 852 can reliably insulate the electrode assembly 5 and the shell 4 .

[0587] Optionally, the heat conducting member 84 is provided on the entire main body portion 8521 or the bending portion 8522 ; or a plurality of heat conducting members 84 are provided at intervals on the main body portion 8521 or the bending portion 8522 .

[0588] Optionally, a plurality of electrode assemblies 5 are provided, the main body 8521 is provided between the shell 4 and the first side surface 5231 closest to the shell 4 , and the bending portion 8522 is provided on one or more second side surfaces 5232 .

[0589] See also Figure 52 and Figure 53 , Figure 52 This is a schematic structural diagram of a heat-conducting component of a battery cell provided in one embodiment of the present application; Figure 53 This is a partial structural diagram of a heat-conducting component of a battery cell provided in one embodiment of the present application.

[0590] In some embodiments, as Figure 52 and Figure 53 As shown, a first through hole 815 is provided through the first insulating portion 852 , and the first through hole 815 and the accommodating cavity 851 are spaced apart.

[0591] In these embodiments, a first through hole 815 is provided through the first insulating portion 852 so that the electrolyte can penetrate the electrode assembly 5 through the first through hole 815 . The first through hole 815 and the accommodating cavity 851 are spaced apart to avoid contact between the electrolyte and the first thermal conductive plate 841 .

[0592] The accommodating cavity (not shown) is provided in a portion of the first insulating portion 852, the first thermally conductive sheet 841 is provided in the accommodating cavity 851, and the first through-hole 815 extends through another portion of the first insulating portion 852. The first through-hole 815 and the accommodating cavity 851 are not connected. Thus, when the electrolyte penetrates the electrode assembly 5 through the first through-hole 815, the electrolyte does not enter the accommodating cavity 851 and contact the first thermally conductive sheet 841, and the insulating member 85 can still maintain the insulation between the first thermally conductive sheet 841 and the electrode assembly 5. The specific shape and size of the first through-hole 815 can be designed voluntarily. For example, the first through-hole 815 is a circular hole or a rectangular hole.

[0593] Exemplarily, the insulating member 85 is molded to form the accommodating cavity 851 , and the first through hole 815 can be disposed in the molding area 856 , or the first through hole 815 can be disposed on a side of the molding area 856 away from the accommodating cavity.

[0594] See also Figure 54 and Figure 55 , Figure 54 This is a partial structural diagram of a heat-conducting component of a battery cell provided in another embodiment of the present application; Figure 55 It is a partial structural diagram of a heat-conducting component of a battery cell provided in another embodiment of the present application.

[0595] In some embodiments, as Figure 54 and Figure 55 As shown, a first avoidance hole 8414 is provided through the first heat conducting plate 841 , the first insulating portion 852 covers the inner wall of the first avoidance hole 8414 , a first through hole 815 is provided through the first insulating portion 852 , and the first through hole 815 is located in the first avoidance hole 8414 .

[0596] In these embodiments, a first avoidance hole 8414 is provided through the first thermal conductive sheet 841, and a first through hole 815 is provided through the first insulating portion 852. The first through hole 815 is located in the first avoidance hole 8414 so that the electrolyte can penetrate into the electrode assembly 5 through the first through hole 815 and the first avoidance hole 8414. The first insulating portion 852 covers the inner wall of the first avoidance hole 8414 to prevent the electrolyte from contacting the first thermal conductive sheet 841 and to keep the first thermal conductive sheet 841 and the electrode assembly 5 insulated.

[0597] A first escape hole 8414 is provided on the first heat conducting sheet 841, and a first through-hole 815 is provided on the first insulating portion 852. The first through-hole 815 is located within the first escape hole 8414, or in other words, the orthographic projection of the first escape hole 8414 in the thickness direction of the insulating member 85 is located within the first through-hole 815. This allows the electrolyte to penetrate the electrode assembly 5 through the first through-hole 815 and the first escape hole 8414. The first insulating portion 852 covers the inner wall of the first escape hole 8414 and is used to isolate the electrolyte passing through the first through-hole 815 from contact with the inner wall of the first escape hole 8414. Furthermore, the first insulating portion 852 insulates the electrode assembly 5 from the inner wall of the first escape hole 8414. The shape and size of the first escape hole 8414 can be designed arbitrarily. For example, the first escape hole 8414 is a circular hole or a rectangular hole.

[0598] Optionally, the first avoidance hole 8414 and the first through hole 815 have the same shape to better match the two. Exemplarily, the first avoidance hole 8414 and the first through hole 815 are both circular holes.

[0599] Exemplarily, the first insulating part 852 is plastic-sealed to form a accommodating cavity 851, the first heat-conducting plate 841 is accommodated in the accommodating cavity, part of the first insulating part 852 is plastic-sealed and connected to the first avoidance hole 8414, the first through hole 815 passes through the plastic-sealed area 856, and the first through hole 815 and the inner wall of the first avoidance hole 8414 are spaced apart by the plastic-sealed area 856.

[0600] See also Figure 56 , Figure 56 Schematic diagram of the structure of a heat-conducting component of a battery cell provided in one embodiment of the present application.

[0601] In some embodiments, as Figure 5 、 Figure 48 and Figure 56 As shown, the electrode ear 51 extends out of the first end face 521, and the insulating member 85 also includes a second insulating portion 853, which is arranged between the second end face 522 of the electrode body 52 and the shell 4. The second insulating portion 853 is insulated from the shell 4 and the second end face 522 of the electrode assembly 5, and the main body portions 8521 of the two first insulating portions 852 are respectively connected to the two sides of the second insulating portion 853.

[0602] In these embodiments, the insulating part 85 also includes a second insulating part 853 arranged between the second end face 522 of the electrode body 52 and the shell 4, and the main body 8521 of the two first insulating parts 852 are respectively connected to the two sides of the second insulating part 853, thereby reducing the difficulty of aligning the second insulating part 853 and the first insulating part 852, and reducing the difficulty of matching the insulating part 85 and the electrode assembly 5.

[0603] Optionally, the second insulating part 853 and the first insulating part 852 are bonded or welded to facilitate adjustment of the sizes of the second insulating part 853 and the first insulating part 852; or the second insulating part 853 and the first insulating part 852 are integrally formed to reduce the seams of the insulating part 85 and improve the structural stability of the insulating part 85.

[0604] Optionally, the second insulating portion 853 and the first insulating portion 852 are integrally formed, the second insulating portion 853 covers the second end face 522, and then the main body portion 8521 is bent and covers the first side face 5231 of the electrode assembly 5, and then the bent portion 8522 is bent and covers the second side face 5232 of the electrode assembly 5.

[0605] Optionally, a plurality of electrode assemblies 5 are provided, and the second insulating portion 853 is provided along the first direction X between one or more electrode assemblies 5 and the shell 4 .

[0606] In some embodiments, as Figure 48 and Figure 56 As shown, the heat conducting member 84 includes a second heat conducting plate 842 , and the second heat conducting plate 842 is disposed on the second insulating portion 853 .

[0607] In these embodiments, the heat conducting member 84 includes a second heat conducting sheet 842 disposed on the second insulating portion 853 to improve the heat conduction rate at the second end surface 522 .

[0608] The second heat conducting portion 82 is composed of a second heat conducting sheet 842 and a second insulating portion 853 .

[0609] Optionally, the orthographic projection of the second heat conducting sheet 842 in the first direction X covers the second end surface 522 of the electrode assembly 5; or there are multiple electrode assemblies 5, and the orthographic projection of the second heat conducting sheet 842 in the first direction X covers the second end surfaces 522 of multiple electrode assemblies 5.

[0610] For example, the size and shape of the second heat conducting plate 842 can be designed independently, and the second heat conducting plate 842 is rectangular or elliptical.

[0611] See also Figure 57 and Figure 58 , Figure 57 This is a schematic structural diagram of a heat-conducting component of a battery cell provided in one embodiment of the present application; Figure 58 This is a partial structural diagram of a heat-conducting component of a battery cell provided in one embodiment of the present application.

[0612] In some embodiments, as Figures 56 to 58 As shown, a second through hole 821 is provided through the second insulating portion 853 , and the second through hole 821 and the accommodating cavity 851 are spaced apart.

[0613] In these embodiments, a second through hole 821 is provided through the second insulating portion 853 so that the electrolyte can penetrate the electrode assembly 5 through the second through hole 821 . The second through hole 821 and the accommodating cavity 851 are spaced apart to avoid contact between the electrolyte and the second heat conducting plate 842 .

[0614] The accommodating cavity 851 is disposed within a portion of the second insulating portion 853 , the second thermally conductive sheet 842 is disposed within the accommodating cavity 851 , and the second through-hole 821 extends through another portion of the second insulating portion 853 . The second through-hole 821 and the accommodating cavity 851 are not connected. Thus, when the electrolyte penetrates the electrode assembly 5 through the first through-hole 815 , the electrolyte does not enter the accommodating cavity 851 and contact the second thermally conductive sheet 842 , and the insulating member 85 can still insulate the second thermally conductive sheet 842 from the electrode assembly 5 . The specific shape and size of the second through-hole 821 can be designed arbitrarily. For example, the second through-hole 821 is a circular hole or a rectangular hole.

[0615] Exemplarily, the insulating member 85 is molded to form the accommodating cavity 851 , and the second through hole 821 can be disposed in the molding area 856 , or the second through hole 821 can be disposed on a side of the molding area 856 away from the accommodating cavity.

[0616] See also Figure 59 and Figure 60 , Figure 59 This is a schematic structural diagram of a heat-conducting component of a battery cell provided in one embodiment of the present application; Figure 60 It is a partial structural diagram of a heat-conducting component of a battery cell provided in another embodiment of the present application.

[0617] In some embodiments, as Figure 59 and Figure 60 As shown, a second avoidance hole 8421 is provided through the second heat conducting plate 842 , the second insulating portion 853 covers the inner wall of the second avoidance hole 8421 , a second through hole 821 is provided through the second insulating portion 853 , and the second through hole 821 is located inside the second avoidance hole 8421 .

[0618] In these embodiments, a second avoidance hole 8421 is provided through the second thermal conductive sheet 842, and a second through hole 821 is provided through the second insulating portion 853. The second through hole is located in the second avoidance hole 8421, so that the electrolyte can pass through the second through hole 821 and the second avoidance hole 8421 and infiltrate the electrode assembly 5. The second insulating portion 853 covers the inner wall of the second avoidance hole 8421 to prevent the electrolyte from contacting the second thermal conductive sheet 842 and keep the second thermal conductive sheet 842 and the electrode assembly 5 insulated.

[0619] A second avoidance hole 8421 is provided on the second heat conducting sheet 842, and a second through-hole 821 is provided on the insulating member 85. The second through-hole 821 is located within the second avoidance hole 8421, or in other words, the orthographic projection of the second avoidance hole 8421 in the thickness direction of the second insulating portion 853 is located within the second through-hole 821. This allows the electrolyte to penetrate the electrode assembly 5 through the second through-hole 821 and the second avoidance hole 8421. The second insulating portion 853 covers the inner wall of the second avoidance hole 8421 and is used to prevent the electrolyte passing through the second through-hole 821 from contacting the inner wall of the second avoidance hole 8421 of the second heat conducting member 84. Furthermore, the second insulating portion 853 insulates the electrode assembly 5 from the second avoidance hole 8421. The shape and size of the second avoidance hole 8421 can be designed arbitrarily. For example, the second avoidance hole 8421 is a circular hole or a rectangular hole.

[0620] Optionally, the second avoidance hole 8421 and the second through hole 821 have the same shape to facilitate better coordination between the two.

[0621] Exemplarily, the second insulating part 853 is plastic-sealed to form a accommodating cavity 851, the second heat-conducting plate 842 is accommodated in the accommodating cavity, part of the second insulating part 853 is plastic-sealed and connected to the second avoidance hole 8421, the second through hole 821 passes through the plastic-sealed area 856, and the inner walls of the second through hole 821 and the second avoidance hole 8421 are spaced apart by the plastic-sealed area 856.

[0622] See also Figure 61 and Figure 62 , Figure 61 This is a schematic structural diagram of a heat-conducting component of a battery cell provided in one embodiment of the present application; Figure 62 This is an expanded view of a thermally conductive component of a battery cell provided in one embodiment of the present application.

[0623] In some embodiments, as Figure 48 、 Figure 61 and Figure 62 As shown, a plurality of electrode assemblies 5 are provided, and the plurality of electrode assemblies 5 are stacked along the second direction Y. The insulating member 85 also includes a middle insulating portion 854, which is provided between the electrode bodies 52 of adjacent electrode assemblies 5. The middle insulating portion 854 and the second insulating portion 853 are connected to each other, and the first thermal conductive plate 841 includes an intermediate thermal conductive plate 8411, which is provided in the middle insulating portion 854.

[0624] In these embodiments, the middle insulating portion 854 is arranged between adjacent electrode bodies 52 to insulate the adjacent electrode bodies 52, the middle insulating portion 854 and the second insulating portion 853 are interconnected to improve the insulation reliability of the middle insulating portion 854, and the intermediate thermal conductive plate is arranged in the middle insulating portion 854 to improve the thermal conductivity between adjacent electrode bodies 52.

[0625] The first heat conducting plate 841 also includes an end heat conducting plate 8412 and a side heat conducting plate 8413. The middle heat conducting plate 8411 is arranged on the middle insulating portion 854 to form a middle heat conducting member 812; the end heat conducting plate 8412 is arranged on the main body portion 8521 to form an end heat conducting member 813; and the side heat conducting plate 8413 is arranged on the bending portion 8522 to form a side heat conducting member 814.

[0626] Optionally, the middle insulating part 854 and the second insulating part 853 are connected by bonding or welding, or the middle insulating part 854 and the second insulating part 853 are integrally formed to improve the connection stability between the middle insulating part 854 and the second insulating part 853.

[0627] Optionally, the middle insulating portion 854 , the second insulating portion 853 , and the bent portion 8522 are connected, so that the insulating member 85 can be wrapped around the circumferential side surface and the second end surface 522 of the electrode body 52 .

[0628] Exemplarily, if there are multiple electrode assemblies 5, the electrode body 52 is located between the second insulating part 853, the middle insulating part 854, the main body 8521 and the bending part 8522; or the electrode body 52 is located between the second insulating part 853, the two middle insulating parts 854 and the two bending parts 8522; or if there is only one electrode assembly 5, the electrode body 52 is located between the second insulating part 853, the two bending parts 8522 and the two main bodies 8521.

[0629] Optionally, part of the first heat conducting sheet 841 is disposed in the middle insulating portion 854 to conduct heat between adjacent electrode assemblies 5 .

[0630] In some embodiments, as Figure 46 、 Figure 48 and Figure 49 As shown, the main body 8521 is connected to a bending portion 8522 on both sides of the third direction Z, and the two bending portions 8522 of the two first insulating portions 852 and located on the same side of the electrode assembly 5 extend toward each other in the second direction Y.

[0631] In these embodiments, the main body 8521 is connected to a bending portion 8522 on both sides of the third direction Z, and the two bending portions 8522 of the two first insulating portions 852 and located on the same side of the electrode assembly 5 extend toward each other in the second direction Y. The joint of the two bending portions 8522 is located on the second side surface 5232, and the first side surface 5231 with a larger area can be provided with a larger area of ​​the heat conducting member 84 to improve the thermal conductivity of the heat conducting assembly 8.

[0632] Optionally, the two bent portions 8522 of the two first insulating portions 852 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 main body 8521 can cover the entire first side surface 5231, and the heat conducting member 84 can cover the entire first side surface to improve the heat conduction efficiency of the heat conducting component 8; or the two bent portions 8522 of the two first insulating portions 852 extend toward each other in the second direction Y and overlap with each other, then the overlapping part of the bent portions 8522 in the third direction Z will not increase the size of the battery cell 3 in the second direction.

[0633] For example, the bent portions 8522 of the two first insulating portions 852 are bent and connected to each other. The insulating member 85 is connected by two sub-insulating layers 855, which are connected at the body portion 8521 to form a receiving cavity 851 (not shown). Each bent portion 8522 includes two sub-insulating layers 855. For ease of understanding in the figure, some sub-insulating layers 855 are folded and some are unfolded.

[0634] Optionally, the two bending portions 8522 connected on both sides of the main body 8521 have the same size and shape to reduce the difficulty of processing the first insulating portion 852. The specific size and shape of the bending portion 8522 can be designed by yourself. For example, the bending portion 8522 is rectangular.

[0635] In some embodiments, as Figure 46 、 Figure 48 and Figure 49 As shown, the two bending portions 8522 extend toward each other in the second direction Y, and the two bending portions 8522 at least partially overlap in the third direction Z.

[0636] In these embodiments, the two bending portions 8522 extend toward each other in the second direction Y, and the two bending portions 8522 at least partially overlap in the third direction Z to improve the insulation reliability of the first insulating portion 852 between the electrode assembly 5 and the shell 4.

[0637] Optionally, the overlapping region of the two bent portions 8522 extends to both ends of the electrode body 52 in the first direction X to improve the insulation reliability of the first insulating portion 852 between the electrode assembly 5 and the housing 4. The shape of the overlapping region of the two bent portions 8522 can be designed arbitrarily. For example, the overlapping region is rectangular.

[0638] Optionally, the two bending portions 8522 are bonded or plastic-sealed in the overlapping area to improve the connection reliability of the bending portions 8522 .

[0639] Optionally, the sum of the extension dimensions of the two bending portions 8522 in the second direction Y is L 11 , the size of the electrode assembly 5 in the second direction Y is L2, which satisfies the following conditions: L2<L 11 , so that the two bent portions at least partially overlap in the third direction Z. For example, L 11 The difference from L2 is between 5mm and 10mm, which can save material costs and improve connection reliability;

[0640] The extension dimension of the bent portion 8522 in the second direction Y is L1, and the dimension of the electrode assembly 5 in the second direction Y is L2, satisfying L1=L2, thereby increasing the overlapping area of ​​the two bent portions 8522 and improving the insulation reliability of the bent portion 8522 on the third side surface 523 of the electrode body 52;

[0641] The extension dimension of the bent portion 8522 in the second direction Y is L1, and the dimension of the electrode assembly 5 in the second direction Y is L2, satisfying the condition L2 / 2<L1<L2. Even if there is a partial dimensional error in the bent portion 8522, it does not affect the partial overlap of the two bent portions 8522 in the third direction Z.

[0642] The extension dimension of the bending portion 8522 in the second direction Y is L1, and the dimension of the electrode assembly 5 in the second direction Y is L2 satisfying L2 / 2=L1, so that the two bending portions 8522 of the two oppositely arranged first insulating portions 852 abut against each other, so that the bending portion 8522 can be covered on the third side surface 523 of the electrode body 52 without increasing the dimension of the heat-conducting component 8 in the third direction Z, which helps to improve the energy density of the battery cell 3; each bending portion 8522 has the same size to reduce the processing difficulty of the first insulating portion 852.

[0643] In some embodiments, as Figure 45 、 Figure 48 and Figure 51 As shown, the shell 4 includes an opening 41 in the first direction X, and the battery cell 3 also includes a top cover assembly 6, which covers the opening 41 and is connected to the pole ear 51, and at least one main body portion 8521 extends from the first end surface 521 in the first direction X and is connected to the top cover assembly 6.

[0644] In these embodiments, at least one main body portion 8521 extends from the first end surface 521 in the first direction X and is connected to the top cover assembly 6. The top cover assembly 6 serves to position and fix the thermal conductive assembly 8, thereby improving the stability of the thermal conductive assembly 8 in the shell 4.

[0645] The main body 8521 extends out of the first end surface 521 and is welded to the lower plastic of the top cover assembly 6. The first heat conducting plate 841 is thermally connected to the side surface 523. The first heat conducting plate 841 does not extend beyond the first end surface 521. This can reduce the risk of damage to the first heat conducting plate 841 and reduce the material cost of the heat conducting assembly 8.

[0646] Optionally, both main body portions 8521 are connected to the top cover assembly 6 to enhance the connection stability between the insulating member 85 and the top cover assembly 6 .

[0647] Optionally, the main body 8521 includes a contact section and a welding section, the contact section contacts the side 523 of the electrode body 52, one end of the welding section is connected to the contact section, and the other end extends out of the first end face 521 and is connected to the top cover assembly 6, and the size of the welding section in the third direction Z is greater than or equal to the size of the contact section to improve the connection reliability between the insulating member 85 and the top cover assembly 6.

[0648] In some embodiments, as Figure 48 and Figure 51 As shown, the main body 8521 extends out of the first end surface 521 in the first direction X by a dimension L3 ≥ 2 mm.

[0649] In these embodiments, when the above conditions are met, the connection reliability between the heat conducting component 8 and the top cover component 6 is improved.

[0650] Optionally, a dimension L3 of the main body portion 8521 extending out of the first end surface 521 in the first direction X satisfies 2 mm ≤ L3 ≤ 7 mm, so as to reduce the risk of interference between the excessively long main body portion 8521 and other components.

[0651] Exemplarily, a dimension L3 of the main body portion 8521 extending out of the first end surface 521 in the first direction X is 2 mm, 3 mm, 5 mm, 7 mm, etc.

[0652] In some embodiments, as Figures 44 to 46 As shown, the minimum distance D2 from the orthographic projection of the heat-conducting member 84 in the thickness direction of the heat-conducting component 8 to the edge of the orthographic projection of the insulating member 85 in the thickness direction of the heat-conducting component 8 is greater than or equal to 2 mm.

[0653] In these embodiments, the minimum distance D2 from the edge of the orthographic projection of the thermal conductive member 84 in the thickness direction of the thermal conductive component 8 to the orthographic projection of the insulating member 85 in the thickness direction of the thermal conductive component 8 is greater than or equal to 2 mm, so that there is a sufficient plastic sealing area between the edge of the thermal conductive member 84 and the insulating member 85 to improve the sealing reliability of the accommodating cavity 851.

[0654] Exemplarily, the minimum distance D2 from the heat conducting member 84 to the edge of the insulating member 85 is 2 mm, 3 mm, 5 mm, etc.

[0655] Optionally, the insulating member 85 includes two sub-insulating layers 855 , which are stacked and connected by plastic sealing or bonding in the length and width directions to form an accommodating cavity 851 for accommodating the thermal conductor 84 , and the minimum distance from the thermal conductor 84 to the edge of the sub-insulating layer 855 is greater than or equal to 2 mm;

[0656] Alternatively, the insulating part 85 includes two sub-insulating layers 855 that are integrally formed and connected to each other. The two sub-insulating layers 855 are folded towards each other, and then the edges of their length or width are sealed to form a accommodating cavity 851. The minimum distance from the edge of the thermal conductor 84 to the sub-insulating layer 855 that needs to be sealed or bonded is greater than or equal to 2 mm.

[0657] Optionally, the areas of the two sub-insulating layers 855 are different, and the sub-insulating layer 855 with a smaller area is hot-melt connected to the sub-insulating layer 855 with a larger area to form a accommodating cavity 851. This can not only reduce the volume of the insulating part 85 and reduce the cost of the insulating part 85, but also reduce the volume of the thermal conductive component 8 and improve the energy density of the battery cell 3.

[0658] In some embodiments, as Figures 44 to 46 As shown, the thickness D3 of the heat conducting member 84 satisfies 40 μm≤D3≤180 μm.

[0659] In these embodiments, when the above conditions are met, the problem of excessively thick heat conductor 84 leading to excessive volume of battery cell 3 and reduced energy density can be improved, and the problem of easy damage of heat conductor 84 due to excessive thinness can also be improved.

[0660] Exemplarily, the thickness D3 of the heat-conducting component 8 is 40 μm, 50 μm, 110 μm, 180 μm, etc.

[0661] In some embodiments, as Figures 44 to 46 As shown, the insulating member 85 includes two sub-insulating layers 855 , which are stacked and connected to each other to form a receiving cavity 851 . The thickness D1 of the sub-insulating layer 855 satisfies 5 μm≤D1≤100 μm.

[0662] In these embodiments, when the above conditions are met, the problem of excessive thickness of the sub-insulating layer 855 leading to excessive volume of the battery cell 3 and reduced energy density can be solved, and the problem of easy damage of the sub-insulating layer 855 due to its thinness can also be solved.

[0663] Illustratively, the thickness D1 of the sub-insulating layer 855 is 5 μm, 10 μm, 50 μm, 100 μm, etc.

[0664] Optionally, the two sub-insulating layers 855 have the same thickness to reduce the difficulty of processing the insulating member 85 .

[0665] In some embodiments, as Figures 44 to 46 As shown, the insulating member 85 includes polyethylene or polypropylene or polyimide or polyester resin.

[0666] In these embodiments, the insulating member 85 includes polyethylene, polypropylene, polyimide, or polyester resin to improve the insulation reliability of the insulating member 85 .

[0667] Optionally, the insulating member 85 should have insulating and high temperature resistant properties, so that the insulating member 85 can be used to insulate the thermal conductor 84 and the electrode assembly 5, and reduce the risk of the insulating member 85 melting and being damaged under high temperature conditions.

[0668] In some embodiments, as Figure 44 and Figure 45 As shown, the heat conductor 84 includes graphite, graphene, or carbon nanotubes.

[0669] 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 side atom thick, and has a fibrous shape. Carbon nanotubes are typically tubular structures formed by curling one or more layers of graphite. The material of the heat conductor 84 includes graphite, graphene, or carbon nanotubes, and the thermal conductivity of the heat conductor 84 is improved by using the graphite, graphene, or carbon nanotube thermal conductive material.

[0670] Optionally, the heat conducting member 84 is made of supercrystalline graphite, whose formed grain size is larger than that of ordinary graphite and whose thermal conductivity is significantly improved compared with ordinary graphite, so that the heat conducting member 84 has better thermal conductivity.

[0671] Optionally, heat conductor 84 utilizes graphite heat conduction technology, a heat conduction technology based on graphite materials and microporous structures. The principle is that the efficient thermal conductivity of graphite materials allows heat to be quickly transferred to the heat conducting plate, and then the heat is quickly dissipated to the external environment through the microporous structure, thereby achieving a heat exchange effect.

[0672] In some embodiments, as Figure 44and Figure 45 As shown, the thermal conductivity k of the heat conducting member 84 satisfies k≥500 W / (m·K).

[0673] In these embodiments, when the thermal conductivity k of the heat conducting member 84 satisfies the above conditions, the heat conducting member 84 has sufficient thermal conductivity to conduct heat from the electrode body 52. ​​Optionally, the thermal conductivity k of the heat conducting member 84 satisfies 500 W / (m·K) ≤ k ≤ 1600 W / (m·K). For example, the thermal conductivity k of the heat conducting member 84 is 500 W / (m·K), 550 W / (m·K), 1050 W / (m·K), 1550 W / (m·K), 1600 W / (m·K), etc.

[0674] Optionally, the thermal conductivity k of the heat conducting member 84 satisfies k≥1000 W / (m·K).

[0675] Optionally, the density of the heat conducting member 84 is 2.1±0.05 g / cm 3 , insulation resistance greater than 1GΩ, voltage resistance 5400V, bending resistance > 10000 times.

[0676] In a second aspect, an embodiment of the present application provides a battery device comprising a battery cell according to any one of the embodiments of the first aspect.

[0677] In a third aspect, an embodiment of the present application provides an electrical device, comprising the battery device of the embodiment of the second aspect described above.

[0678] In some embodiments, as Figures 1 to 62As shown, the battery cell 3 includes a shell 4, an electrode assembly 5 and a heat-conducting assembly 8. The electrode assembly 5 is located in the shell 4. The electrode assembly 5 is of a wound type or a laminated type. The electrode assembly 5 includes an electrode body 52 and a pole ear 51. The electrode body 52 includes a first end face 521 and a second end face 522 oppositely arranged in a first direction X, and a side face 523 connected between the first end face 521 and the second end face 522. The side face 523 includes two first side faces 5231 and two second side faces 5232. The two first side faces 5231 are oppositely arranged in the second direction Y, and the two second side faces 523 are oppositely arranged in the third direction Z. The first direction X, the second direction Y and the third direction Z are perpendicular to each other. The area of ​​the first side face 5231 is larger than the area of ​​the second side face 523. The first heat-conducting portion 81 is provided on at least one of the two first side faces 5231. The pole ear 51 is connected to The heat conducting component 8 is connected to the electrode body 52 and extends out of the first end surface 521. The heat conducting component 8 includes a first heat conducting portion 81 and a second heat conducting portion 82. The first heat conducting portion 81 is thermally connected to the first side surface 5231. The thermal conductivity of the heat conducting component 8 is greater than that of the shell 4. At least a portion of the first heat conducting portion 81 is arranged between the first side surface 5231 of the electrode assembly 5 and the shell 4 along the second direction Y. The first heat conducting portion 81 is provided with a first through hole 815. The second heat conducting portion 82 is arranged between the shell 4 and at least a portion of the second end surface 522 along the first direction X. The first heat conducting portion 81 and the second heat conducting portion 82 are connected. The second heat conducting portion 82 is provided with a second through hole 821. The heat conducting component 8 and the electrode assembly 5 are bonded together. The orthographic projection area of ​​the heat conducting component 8 in the second direction Y is S1, and the orthographic projection area of ​​the electrode body 52 in the second direction Y is S2, satisfying 0.1≤S1 / S2≤1.

[0679] The shell 4 includes an opening 41 in the first direction X, and the battery cell 3 also includes a top cover assembly 6 and a switching mechanism 7. The top cover assembly 6 covers the opening 41. The top cover assembly 6 has an electrode terminal 61. The switching mechanism 7 is connected between the pole ear 51 and the top cover assembly 6. At least one of the pole ear 51 and the switching mechanism 7 is connected to the third heat conducting portion 83. The third heat conducting portion 83 is connected to the first heat conducting portion 81. There are two electrode assemblies 5. The two electrode assemblies 5 are stacked along the second direction Y. The switching mechanism 7 is provided with two first connecting segments 71. The two first connecting segments 71 are respectively arranged on both sides of the second connecting segment 72 in the second direction Y. The pole ears 51 of the two electrode assemblies 5 are respectively connected to the two first connecting segments 71. The first heat conducting portion 81 and the third heat conducting portion 81 are connected. Two heat conducting portions 83 are provided. The two first heat conducting portions 81 are provided on both sides of an electrode body 52 in the second direction Y. The two third heat conducting portions 83 are respectively connected to one end of the two first heat conducting portions 81 facing the adapter mechanism 7, and the two third heat conducting portions 83 are respectively connected to the two second connecting sections 72 of the adapter mechanism 7. The extension section 512 includes a first sub-segment 5121 and a second sub-segment 5122 spaced apart along the first direction X, and a third sub-segment 5123 connecting the first sub-segment 5121 and the second sub-segment 5122. The first sub-segment 5121 is connected to the retracted section 511, and the second sub-segment 5122 is connected to the adapter mechanism 7. The third heat conducting portion 83 is connected to the side of the first sub-segment 5121 facing the retracted section 511.

[0680] The heat conducting assembly 8 includes an insulating member 85 and a heat conducting member 84. At least part of the insulating member 85 forms a receiving cavity 851. The heat conducting member 84 is arranged in the receiving cavity 851. The heat conducting member 84 includes a first heat conducting plate 841 and a second heat conducting plate 842. The first heat conducting plate 841 is arranged on the side 523. The first heat conducting portion 81 is composed of the first heat conducting plate and the insulating member 85. The pole ear 51 extends from the first end face 521. The insulating member 85 covers the second end face 522 and the side face 523 of the electrode body 52. ​​The insulating member 85 includes a first insulating portion 852, a second insulating portion 853 and a middle insulating portion 854. The first insulating portion 852 includes a main body portion 8521 and a bent portion 8522 connected to each other. The main body portion 8521 and the bent portion 8522 are connected. The main body 8521 of the first insulating part 852 is respectively arranged on the two first side surfaces 5231, the two bending parts 8522 are respectively arranged on the two second side surfaces 5232, the first heat conducting sheet 841 is arranged on at least one of the main body 8521 and the bending part 8522, the second insulating part 853 is arranged between the second end surface 522 of the electrode body 52 and the shell 4, the second insulating part 853 is insulated from the shell 4 and the second end surface 522 of the electrode assembly 5, the main bodies 8521 of the two first insulating parts 852 are respectively connected to the two sides of the second insulating part 853, the second heat conducting sheet 842 is arranged on the second insulating part 853, the electrode assembly 5 is provided with a plurality of, and the plurality of electrode assemblies 5 are stacked along the second direction Y, and the middle insulating part 854 is arranged between adjacent electrodes. The main body 52, the middle insulating portion 854 and the second insulating portion 853 are connected to each other, the intermediate heat conducting plate is provided in the middle insulating portion 854, the heat conducting member 84 includes a second heat conducting plate 842 provided in the second insulating portion 853, the first heat conducting plate 841 in the middle insulating portion 854 and the second heat conducting plate 842 in the second insulating portion 853 are connected to each other, the main body 8521 is connected to a bending portion 8522 on both sides of the third direction Z, and the two bending portions 8522 of the two first insulating portions 852 and located on the same side of the electrode assembly 5 extend toward each other in the second direction Y and at least partially overlap, at least one main body 8521 extends out from the first end surface 521 in the first direction X and is connected to the top cover assembly 6, and the main body 8521 in the first direction The dimension L3 of X extending from the first end face 521 is ≥ 2 mm. The minimum distance between the orthographic projection of the heat conducting member 84 in the thickness direction of the heat conducting component 8 and the edge of the orthographic projection of the insulating member 85 in the thickness direction of the heat conducting component 8 is greater than or equal to 2 mm. The thickness D3 of the heat conducting member 84 satisfies 40 μm ≤ D3 ≤ 180 μm. The insulating member 85 includes two sub-insulating layers 855. The two sub-insulating layers 855 are stacked and interconnected to form a receiving cavity 851. The thickness D1 of the sub-insulating layer 855 satisfies 5 μm ≤ D1 ≤ 100 μm. The insulating member 85 includes polyethylene, polypropylene, polyimide, or polyester resin. A first through hole 815 is provided through the first insulating portion 852, and a second through hole 821 is provided through the second insulating portion 853.The second through hole 821 and the first through hole 815 are spaced apart from the accommodating cavity 851 . The heat conducting member 84 includes graphite, graphene, or carbon nanotubes. The thermal conductivity k of the heat conducting member 84 satisfies k>500 W / (m·K).

[0681] In these embodiments, the battery cell 3 includes a housing 4, an electrode assembly 5, and a heat-conducting assembly 8. The electrode assembly 5 is located inside the housing 4. The housing 4 provides accommodation and protection for the electrode assembly 5. The electrode assembly 5 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 that are oppositely arranged in a first direction X, and a side face 523 connected between the first end face 521 and the second end face 522. The electrode body 52 extends through the tab 51 extending from the first end face 521 and / or the second end face 522. 1 forms a loop with external components, the thermal conductivity of the heat conducting component 8 is greater than that of the shell 4, and the heat conducting component 8 includes a first heat conducting portion 81. The first heat conducting portion 81 is thermally connected to the side surface 523 of the electrode body 52 through heat conduction, thereby reducing the thermal resistance of the electrode body 52 at its side surface 523 and improving the rate of heat exchange between the electrode body 52 and the external environment at its side surface 523, so as to balance the internal temperature of the battery cell 3 and improve the problem of adverse effects on the performance and service life of the battery cell 3 due to excessively high or low internal temperature of the battery cell 3.

[0682] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery cell, characterized in that: include: case; an electrode assembly located within the housing, the electrode assembly comprising an electrode body and a tab, the electrode body comprising a first end face and a second end face disposed opposite each other in a first direction, and a side face connected between the first end face and the second end face, the tab being connected to the electrode body and extending beyond at least one of the first end face and the second end face; The heat-conducting component comprises a first heat-conducting portion, wherein the first heat-conducting portion is heat-conductingly connected to the side surface, and the heat conductivity of the heat-conducting component is greater than the heat conductivity of the shell.

2. The battery cell according to claim 1, wherein: The side surfaces include two first side surfaces and two second side surfaces, the two first side surfaces are arranged opposite to each other in the second direction, the two second side surfaces are arranged opposite to each other in the third direction, the first direction, the second direction and the third direction intersect each other, the area of ​​the first side surface is greater than the area of ​​the second side surface, and the first heat conducting portion is arranged on at least one of the two first side surfaces.

3. The battery cell according to claim 2, characterized in that: At least a portion of the first heat conducting portion is disposed between the first side surface of the electrode assembly and the housing along the second direction.

4. The battery cell according to claim 2, characterized in that: The first heat conducting portion is provided with a first through hole.

5. The battery cell according to claim 3, characterized in that: The first heat-conducting part includes a side heat-conducting part and two end heat-conducting parts, the two end heat-conducting parts are respectively arranged between the shell and two adjacent first side surfaces, the side heat-conducting part is arranged on at least one second side surface, and the side heat-conducting part is respectively connected to the two end heat-conducting parts on both sides along the second direction.

6. The battery cell according to claim 2, characterized in that There are multiple electrode assemblies, and the multiple electrode assemblies are stacked along the second direction. At least a portion of the first heat conducting portion is disposed between two adjacent first side surfaces of two adjacent electrode assemblies.

7. The battery cell according to claim 6, characterized in that The first heat conducting part includes a middle heat conducting part and a side heat conducting part. The middle heat conducting part is arranged between two adjacent first side surfaces of two adjacent electrode assemblies. The side heat conducting part is arranged on at least one of the second side surfaces and connected to the middle heat conducting part.

8. The battery cell according to claim 7, characterized in that The first heat conducting part further includes an end heat conducting member, which is arranged between the shell and an adjacent first side surface, and the side heat conducting member is respectively connected to the middle heat conducting member and the end heat conducting member on both sides along the second direction.

9. The battery cell according to claim 7, characterized in that: There are two side heat conductive members, and the first heat conductive part also includes two end heat conductive members. The two end heat conductive members are respectively arranged between the shell and the two adjacent first side faces, and the two side heat conductive members are respectively arranged on the second side faces of different electrode assemblies. One of the side heat conductive members is respectively connected to the middle heat conductive member and the end heat conductive member on both sides along the second direction, and the other side heat conductive member is respectively connected to the middle heat conductive member and the other end heat conductive member on both sides along the second direction.

10. The battery cell according to claim 9, characterized in that The two side heat conducting members are respectively arranged on both sides of the plurality of electrode assemblies along the third direction.

11. The battery cell according to claim 9, characterized in that The two side heat conducting members are arranged on the same side of the plurality of electrode assemblies along the third direction.

12. The battery cell according to any one of claims 6 to 11, characterized in that: The electrode assembly is of a wound type or a laminated type.

13. The battery cell according to claim 2, characterized in that The first heat conducting portion is disposed around a circumference of the electrode body.

14. The battery cell according to claim 13, characterized in that A gap extending along the first direction and penetrating the first heat conducting portion is formed between two ends of the first heat conducting portion along the circumference of the electrode body.

15. The battery cell according to claim 14, characterized in that The gap is provided at at least one of the two first side surfaces.

16. The battery cell according to claim 15, characterized in that The gap is provided at the two first side surfaces.

17. The battery cell according to claim 13, characterized in that There are a plurality of electrode assemblies, and the plurality of electrode assemblies are stacked along the second direction. The first heat conducting portion is arranged around the outer periphery of the entire structure formed by the plurality of electrode assemblies.

18. The battery cell according to any one of claims 1 to 17, characterized in that: The tab extends out of the first end surface. The heat-conducting assembly further includes a second heat-conducting portion, which is disposed along the first direction between the housing and at least a portion of the second end surface.

19. The battery cell according to claim 18, characterized in that The first heat conducting portion and the second heat conducting portion are connected.

20. The battery cell according to claim 18, characterized in that The second heat conducting portion is provided with a second through hole.

21. The battery cell according to claim 19, characterized in that The side surfaces include two first side surfaces and two second side surfaces, the two first side surfaces are arranged opposite to each other in the second direction, and the two second side surfaces are arranged opposite to each other in the third direction, the first direction, the second direction and the third direction intersect each other, the area of ​​the first side surface is greater than the area of ​​the second side surface, the first heat conducting portion is arranged on at least one of the two first side surfaces, and the second heat conducting portion is connected to the first heat conducting portion arranged on the first side surface.

22. The battery cell according to claim 21, characterized in that There are multiple electrode assemblies, and the multiple electrode assemblies are stacked along the second direction. The first heat-conducting part is arranged on at least one of the two first side surfaces of at least two of the electrode assemblies. There are multiple independent second heat-conducting parts, and the multiple second heat-conducting parts are arranged corresponding to at least one electrode assembly.

23. The battery cell according to claim 22, characterized in that At least two of the plurality of second heat conducting portions are stacked along the first direction.

24. The battery cell according to claim 21, characterized in that There are multiple electrode assemblies, and the multiple electrode assemblies are stacked along the second direction. The first heat-conducting part includes a middle heat-conducting part, which is arranged between two adjacent first side surfaces of two adjacent electrode assemblies and connected to the second heat-conducting part.

25. The battery cell according to claim 24, characterized in that Two independent middle heat-conducting parts are arranged between two adjacent first side surfaces of two adjacent electrode assemblies. The heat-conducting assembly includes two second heat-conducting parts arranged at intervals. The two second heat-conducting parts are respectively located on both sides of the two middle heat-conducting parts along the second direction. Each middle heat-conducting part is connected to the adjacent second heat-conducting part.

26. The battery cell according to claim 25, characterized in that The two middle heat-conducting members located between adjacent electrode assemblies are spaced apart in the third direction, or the two middle heat-conducting members located between adjacent electrode assemblies abut against each other in the third direction.

27. The battery cell according to claim 21, characterized in that The first heat-conducting portion further includes two end heat-conducting pieces, which are respectively disposed between the housing and two adjacent first side surfaces and are respectively connected to the second heat-conducting portion.

28. The battery cell according to claim 21, characterized in that There are multiple electrode assemblies, and the multiple electrode assemblies are stacked along the second direction. The first heat-conducting part includes a middle heat-conducting part and an end heat-conducting part. The middle heat-conducting part is arranged between two adjacent first side surfaces of two adjacent electrode assemblies, and the end heat-conducting part is arranged between the shell and an adjacent first side surface. The middle heat-conducting part and the end heat-conducting part are respectively connected to the second heat-conducting part.

29. The battery cell according to claim 21, characterized in that There are multiple electrode assemblies, and the multiple electrode assemblies are stacked along the second direction. The first heat-conducting part includes a middle heat-conducting part and two end heat-conducting parts. The middle heat-conducting part is arranged between two adjacent first side surfaces of two adjacent electrode assemblies. The two end heat-conducting parts are respectively arranged between the shell and two adjacent first side surfaces. The middle heat-conducting part and the two end heat-conducting parts are respectively connected to the second heat-conducting part.

30. The battery cell according to claim 29, characterized in that Two independent middle heat-conducting parts are arranged between two adjacent first side surfaces of two adjacent electrode assemblies. The heat-conducting assembly includes four second heat-conducting parts, and the four second heat-conducting parts are arranged between the two end heat-conducting parts along the second direction. The two outermost second heat-conducting parts are respectively connected to the two end heat-conducting parts, and the two middle second heat-conducting parts are respectively connected to the two middle heat-conducting parts.

31. The battery cell according to any one of claims 1 to 30, characterized in that: The heat-conducting component and the electrode component are bonded and connected.

32. The battery cell according to any one of claims 1 to 31, characterized in that: The orthographic projection area of ​​the heat conducting component in the second direction is S1, the orthographic projection area of ​​the electrode body in the second direction is S2, 0.1≤S1 / S2≤1 is satisfied, and the first direction and the second direction intersect.

33. The battery cell according to any one of claims 1 to 32, characterized in that: The shell includes an opening in the first direction, and the battery cell also includes a top cover assembly, which covers the opening, and has an electrode terminal, which is connected to the tab. The heat-conducting assembly also includes a third heat-conducting part, which is thermally connected to the tab, and the third heat-conducting part is thermally connected to the first heat-conducting part.

34. The battery cell according to claim 33, characterized in that The battery cell further includes a switching mechanism connected between the tab and the electrode terminal, and the switching mechanism is thermally connected to the third heat conducting portion.

35. The battery cell according to claim 34, characterized in that The electrode tab includes a retracted section and an extended section, the retracted section is connected to the electrode body, one side of the extended section is connected to the retracted section, and the other side is connected to the adapter mechanism, the third heat conducting portion is connected to the side of the extended section facing the retracted section, or the third heat conducting portion is connected to the side of the extended section facing the adapter mechanism.

36. The battery cell according to claim 35, characterized in that The extension section includes a first sub-segment and a second sub-segment spaced apart along the first direction, and a third sub-segment connecting the first sub-segment and the second sub-segment, the first sub-segment is connected to the gathering section, the second sub-segment is connected to the transfer mechanism, and the third heat-conducting portion is connected to a side of the first sub-segment facing the gathering section.

37. The battery cell according to claim 35, characterized in that The side surfaces include two first side surfaces and two second side surfaces, the two first side surfaces are arranged opposite to each other in the second direction, the two second side surfaces are arranged opposite to each other in the third direction, the first direction, the second direction and the third direction intersect each other, the area of ​​the first side surface is larger than the area of ​​the second side surface, and the two tabs are provided, the two tabs extend from the first end surface, and are spaced apart along the third direction. Two of the first heat conducting parts and two of the third heat conducting parts are respectively provided, the two first heat conducting parts are respectively provided on the two second side surfaces, the two third heat conducting parts are respectively connected to one end of the two first heat conducting parts facing the tabs, and the two third heat conducting parts are respectively connected to the extension sections of the two tabs.

38. The battery cell according to claim 35, characterized in that The side surfaces include two first side surfaces and two second side surfaces, the two first side surfaces are arranged opposite to each other in the second direction, the two second side surfaces are arranged opposite to each other in the third direction, the first direction, the second direction and the third direction intersect each other, and the area of ​​the first side surface is greater than the area of ​​the second side surface. Two of the first heat conducting parts and two of the third heat conducting parts are respectively provided, the two first heat conducting parts are respectively provided on the two first side surfaces, each of the third heat conducting parts is respectively connected to one of the first heat conducting parts, and the two third heat conducting parts are respectively connected to different positions of the extension section of the same tab.

39. The battery cell according to claim 38, characterized in that The extension section includes a first sub-segment and a second sub-segment spaced apart along the first direction, and a third sub-segment connecting the first sub-segment and the second sub-segment, the first sub-segment is connected to the gathering section, and the second sub-segment is connected to the transition mechanism; One of the two third heat conducting parts is connected to the first sub-segment, and the other is connected to the second sub-segment.

40. The battery cell according to claim 34, characterized in that The side surfaces include two first side surfaces and two second side surfaces, the two first side surfaces are arranged opposite to each other in the second direction, the two second side surfaces are arranged opposite to each other in the third direction, the first direction, the second direction and the third direction intersect each other, and the area of ​​the first side surface is greater than the area of ​​the second side surface. The transfer mechanism includes a first connecting section and a second connecting section arranged along the third direction, the tab is connected to the first connecting section, and the third heat conducting portion is connected to the second connecting section.

41. The battery cell according to claim 40, characterized in that Two of the first heat conducting parts and two of the third heat conducting parts are respectively provided, and the two first heat conducting parts are respectively provided on the two first side surfaces, each of the third heat conducting parts is respectively connected to one of the first heat conducting parts, and the two third heat conducting parts are respectively connected to different positions of the second connecting section of the same adapter mechanism.

42. The battery cell according to claim 40, characterized in that There are two electrode assemblies, and the two electrode assemblies are stacked along the second direction. The switching mechanism is provided with two first connecting segments, and the two first connecting segments are respectively provided on both sides of the second connecting segment in the second direction. The tabs of the two electrode assemblies are respectively connected to the two first connecting segments. Two of the first heat conducting parts and two of the third heat conducting parts are respectively provided, and the two first heat conducting parts are arranged on the two first side surfaces of the same electrode body, and the two third heat conducting parts are respectively connected to one end of the two first heat conducting parts facing the adapter mechanism, and the two third heat conducting parts are respectively connected to the second connecting section and the electrode ear of the adapter mechanism.

43. The battery cell according to any one of claims 33 to 42, characterized in that The tab extends out of the first end surface. The heat-conducting assembly further includes a second heat-conducting portion, which is arranged between the housing and at least a portion of the second end surface along the first direction, and is connected to the first heat-conducting portion.

44. The battery cell according to any one of claims 1 to 43, characterized in that: The tab extends out from the first end face, and the battery cell further includes a first insulating film, which covers the side face and the second end face of the electrode body; wherein the first heat-conducting portion is located between the first insulating film and the electrode assembly, or the first heat-conducting portion is located between the first insulating film and the shell.

45. The battery cell according to any one of claims 1 to 44, characterized in that: The heat-conducting assembly includes an insulating member and a heat-conducting member, wherein at least a portion of the insulating member forms a receiving cavity, and the heat-conducting member is disposed in the receiving cavity. The heat conducting member includes a first heat conducting sheet, which is arranged on the side surface, and the first heat conducting portion is composed of the first heat conducting sheet and the insulating member.

46. ​​The battery cell according to claim 45, characterized in that The tab extends from the first end surface. The battery cell further includes a second insulating film connected to the insulating member. The insulating member and the second insulating film jointly cover the second end surface and the side surface of the electrode body.

47. The battery cell according to claim 45, characterized in that The electrode tab extends from the first end surface, and the insulating member covers the second end surface and the side surface of the electrode body.

48. The battery cell according to claim 47, characterized in that The side surfaces include two first side surfaces and two second side surfaces, the two first side surfaces are arranged opposite to each other in the second direction, the two second side surfaces are arranged opposite to each other in the third direction, the first direction, the second direction and the third direction intersect each other, and the area of ​​the first side surface is greater than the area of ​​the second side surface. The insulating member includes two first insulating parts, each of which includes a main body and a bent part that are connected to each other. The main body and the bent part are connected, and the main bodies of the two first insulating parts are respectively arranged on the two first side surfaces, and the two bent parts are respectively arranged on the two second side surfaces. The first heat conductive sheet is arranged on at least one of the main body and the bent part.

49. The battery cell according to claim 48, characterized in that A first through hole is formed through the first insulating portion, and the first through hole and the accommodating cavity are spaced apart.

50. The battery cell according to claim 48, characterized in that A first avoidance hole is provided through the first heat conducting plate, the first insulating portion covers the inner wall of the first avoidance hole, a first through hole is provided through the first insulating portion, and the first through hole is located in the first avoidance hole.

51. The battery cell according to claim 48, characterized in that The insulating member further includes a second insulating portion, which is disposed between the second end surface of the electrode body and the shell, and the main bodies of the two first insulating portions are respectively connected to two sides of the second insulating portion.

52. The battery cell according to claim 51, characterized in that The heat conducting member includes a second heat conducting sheet, and the second heat conducting sheet is arranged on the second insulating portion.

53. The battery cell according to claim 52, characterized in that A second through hole is formed through the second insulating portion, and the second through hole and the accommodating cavity are spaced apart.

54. The battery cell according to claim 53, characterized in that A second avoidance hole is provided through the second heat conducting plate, the second insulating portion covers the inner wall of the second avoidance hole, a second through hole is provided through the second insulating portion, and the second through hole is located in the second avoidance hole.

55. The battery cell according to any one of claims 51 to 54, characterized in that: There are multiple electrode assemblies, and the multiple electrode assemblies are stacked along the second direction. The insulating member also includes a middle insulating portion, which is arranged between the electrode bodies of adjacent electrode assemblies. The middle insulating portion and the second insulating portion are connected to each other. The first thermal conductive plate includes an intermediate thermal conductive plate, which is arranged in the middle insulating portion.

56. The battery cell according to any one of claims 48 to 55, characterized in that: The main body is connected to a bending portion on both sides of the third direction respectively, and the two bending portions of the two first insulating portions and located on the same side of the electrode assembly extend toward each other in the second direction.

57. The battery cell according to claim 56, characterized in that The two bending portions extend toward each other in the second direction, and the two bending portions at least partially overlap in the third direction.

58. The battery cell according to any one of claims 48 to 57, characterized in that: The shell includes an opening in the first direction, and the battery cell also includes a top cover assembly, which covers the opening and is connected to the tab. At least one of the main bodies extends from the first end surface in the first direction and is connected to the top cover assembly.

59. The battery cell according to claim 58, characterized in that A dimension L3 of the main body extending out of the first end surface in the first direction is ≥2 mm.

60. The battery cell according to any one of claims 45 to 59, characterized in that: The minimum distance between the orthographic projection of the heat-conducting member in the thickness direction of the heat-conducting component and the edge of the orthographic projection of the insulating member in the thickness direction of the heat-conducting component is greater than or equal to 2 mm.

61. The battery cell according to any one of claims 45 to 60, characterized in that: The thickness D3 of the heat conducting member satisfies 40 μm≤D3≤180 μm.

62. The battery cell according to any one of claims 45 to 61, characterized in that: The insulating member includes two sub-insulating layers, which are stacked and connected to each other to form the accommodation cavity. The thickness D1 of the sub-insulating layer satisfies 5 μm≤D1≤100 μm.

63. The battery cell according to any one of claims 45 to 62, characterized in that: The insulating member comprises polyethylene, polypropylene, polyimide or polyester resin.

64. The battery cell according to any one of claims 45 to 63, characterized in that: The heat conducting member includes graphite, graphene or carbon nanotubes.

65. The battery cell according to any one of claims 45 to 64, characterized in that The thermal conductivity k of the heat conducting member satisfies k≥500 W / (m·K).

66. A battery device, characterized in that A battery cell comprising any one of claims 1 to 65.

67. An electrical device, characterized in that: A battery device comprising the battery device described in claim 66 above.

Images