Battery cell, battery apparatus and electrical apparatus

Abstract

The present application provides a battery cell, a battery apparatus, and an electrical apparatus. The battery cell comprises: a casing; an electrode assembly located in the casing, the electrode assembly comprising an electrode body and tabs, the electrode body comprising a first end face and a second end face arranged opposite to each other in a first direction and side faces connected between the first end face and the second end face, and the tabs being connected to the electrode body and extending out of at least one of the first end face and the second end face; and a heat conduction assembly comprising a first heat conduction part, the first heat conduction part being thermally connected to the side faces, and the thermal conductivity of the heat conduction assembly being greater than the thermal conductivity of the casing.

Description

Battery cell, battery device and electric device TECHNICAL FIELD

[0001] The present application relates to the field of battery, in particular to a battery cell, a battery device and an electric device. BACKGROUND

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

[0003] However, the internal temperature of the battery cell is too high or too low during actual operation, which will adversely affect the service life and performance of the battery cell.

[0004] SUMMARY

[0005] In view of the above problems, the present application provides a battery cell, a battery device and an electric device, which can enhance the heat conduction between the electrode assembly inside the battery cell and the external environment, so as to balance the internal temperature of the battery cell and improve the performance and service life of the battery cell.

[0006] In a first aspect, the present application provides a battery cell, comprising: a shell; an electrode assembly located inside 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 oppositely arranged 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 out of at least one of the first end face and the second end face; a heat conduction assembly comprising a first heat conduction part, the first heat conduction part being in heat conduction with the side face, and the heat conductivity of the heat conduction assembly being greater than that of the shell.

[0007] In the scheme of the present application, the battery cell comprises a shell, an electrode assembly and a heat conduction assembly, the electrode assembly is located inside the shell, the shell provides accommodation and protection for the electrode assembly, the electrode assembly comprises an electrode body and a tab, the electrode body comprises a first end face and a second end face oppositely arranged in a first direction, and a side face connected between the first end face and the second end face, the electrode body forms a loop with the tab extending out of the first end face and / or the second end face and the external components, the heat conductivity of the heat conduction assembly is greater than that of the shell, the heat conduction assembly comprises a first heat conduction part, the first heat conduction part is in heat conduction with the side face of the electrode body, which can reduce the thermal resistance of the electrode body at its side face, improve the temperature uniformity of the electrode body at its side face, and improve the heat exchange rate between the electrode body at its side face and the external environment, so as to balance the internal temperature of the battery cell and improve the adverse effects of the performance and service life of the battery cell caused by the internal temperature of the battery cell being too high or too low.

[0008] In some embodiments, the side surface includes two first side surfaces and two second side surfaces, the two first side surfaces are oppositely arranged in a second direction, the two second side surfaces are oppositely arranged in a third direction, the first direction, the second direction and the third direction are intersected with each other, an area of the first side surface is greater than an area of the second side surface, and the first heat conduction part is arranged in at least one of the two first side surfaces.

[0009] In the technical scheme of the embodiments 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 greater than the area of the second side surface, the first heat conduction part is arranged in at least one of the two first side surfaces, which helps to increase the contact area of the first heat conduction part and the electrode body, so as to enhance the heat conduction rate of the electrode assembly, and better match the large-area water cooling scheme, shorten the heat conduction path of the first heat conduction part and the heat exchange mechanism, and improve the heat conduction rate of the electrode assembly, so as to better balance the internal temperature of the battery monomer.

[0010] In some embodiments, at least part of the first heat conduction part is arranged between the first side surface of the electrode assembly and the shell along the second direction.

[0011] In the technical scheme of the embodiments of the present application, at least part of the first heat conduction part is arranged between the first side surface of the electrode assembly and the shell along the second direction, so as to shorten the distance between the first heat conduction part and the shell, and the electrode assembly can realize heat exchange with the external environment through the first heat conduction part and the shell faster, thereby improving the heat conduction rate of the electrode assembly.

[0012] In some embodiments, the first heat conduction part is provided with a first through hole.

[0013] In the technical scheme of the embodiments of the present application, the first through hole arranged on the first heat conduction part is used to facilitate the flow of electrolyte to the electrode assembly, thereby improving the infiltration efficiency of the electrolyte on the electrode assembly.

[0014] In some embodiments, the first heat conduction part includes a side heat conduction part and two end heat conduction parts, the two end heat conduction parts are respectively arranged between the shell and the two adjacent first side surfaces, the side heat conduction part is arranged on at least one second side surface, and the side heat conduction part is connected to the two end heat conduction parts on both sides along the second direction.

[0015] In the technical scheme of the embodiments of the present application, the two end heat conduction parts are respectively arranged between the shell and the two adjacent first side surfaces, the side heat conduction part is arranged on the second side surface, and the side heat conduction part is connected to the two end heat conduction parts on both sides along the second direction, so that heat can be conducted between the two end heat conduction parts, so as to balance the heat of the two end heat conduction parts and improve the heat conduction efficiency of the first heat conduction part, and the scheme can better match the scheme of arranging the heat exchange mechanism on a single large surface of the battery monomer or arranging the heat exchange mechanism on two large surfaces, shorten the heat conduction path of the first heat conduction part and the heat exchange mechanism, and improve the heat conduction efficiency of the electrode assembly.

[0016] 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 part of the first heat conduction part is arranged between the adjacent two first sides of the adjacent two electrode assemblies.

[0017] In the technical scheme of the embodiments of the present application, the plurality of electrode assemblies are stacked along the second direction, and at least part of the first heat conduction part is arranged between the adjacent two first sides of the adjacent two electrode assemblies, so that the temperature of the electrode assemblies can be balanced in the first direction through the first heat conduction part, and the performance of the battery monomer is improved.

[0018] In some embodiments, the first heat conduction part includes a middle heat conduction part and a side heat conduction part, the middle heat conduction part is arranged between the adjacent two first sides of the adjacent two electrode assemblies, and the side heat conduction part is arranged at the at least one second side and connected to the middle heat conduction part.

[0019] In the technical scheme of the embodiments of the present application, the middle heat conduction part between the adjacent electrode assemblies helps to conduct the heat between the adjacent two first sides out, the side heat conduction part is arranged at the at least one second side and connected to the middle heat conduction part, the heat of the middle heat conduction part is transferred to the side heat conduction part, and heat exchange is performed between the side heat conduction part and the external environment, so as to balance the internal temperature of the battery monomer.

[0020] In some embodiments, the first heat conduction part further includes an end heat conduction part, the end heat conduction part is arranged between the shell and the adjacent one first side, and the side heat conduction part is connected to the middle heat conduction part and the end heat conduction part on two sides along the second direction.

[0021] In the technical scheme of the embodiments of the present application, the first heat conduction part further includes an end heat conduction part, the end heat conduction part is arranged between the shell and the adjacent one first side, and the side heat conduction part is connected to the middle heat conduction part and the end heat conduction part on two sides along the second direction, so that the heat between the adjacent electrode assemblies can be transferred to the end heat conduction part through the middle heat conduction part and the side heat conduction part, and heat exchange is performed between the end heat conduction part and the external environment, so as to balance the internal temperature of the battery monomer.

[0022] In some embodiments, the side heat conduction part is provided with two, the first heat conduction part further includes two end heat conduction parts, the two end heat conduction parts are arranged between the shell and the adjacent two first sides respectively, and the two side heat conduction parts are arranged at the second sides of different electrode assemblies, one side heat conduction part is connected to the middle heat conduction part and one end heat conduction part on two sides along the second direction, and the other side heat conduction part is connected to the middle heat conduction part and the other end heat conduction part on two sides along the second direction.

[0023] In the technical scheme of the embodiment of the present application, the first heat conduction part further comprises two end heat conduction members, heat between adjacent electrode assemblies can be transferred to the middle heat conduction member, the two end heat conduction members are respectively arranged between the shell and the two adjacent first sides, the two side heat conduction members are respectively arranged on the second sides of different electrode assemblies and are respectively connected to the middle heat conduction member and one end heat conduction member, so that the heat of the middle heat conduction member can be transferred to the end heat conduction member through the side heat conduction member, and heat exchange is performed between the end heat conduction member and the external environment, so as to balance the internal temperature of the battery monomer.

[0024] In some embodiments, the two side heat conduction members are respectively arranged on two sides of the plurality of electrode assemblies along the third direction.

[0025] In the technical scheme of the embodiment of the present application, the two side heat conduction members are respectively arranged on two sides of the plurality of electrode assemblies along the third direction, and the two side heat conduction members are connected to the two sides of the middle heat conduction member in the third direction, so as to improve the heat conduction efficiency between the middle heat conduction member and the side heat conduction member.

[0026] In some embodiments, the two side heat conduction members are arranged on the same side of the plurality of electrode assemblies along the third direction.

[0027] In the technical scheme of the embodiment of the present application, the two side heat conduction members are arranged on the same side of the plurality of electrode assemblies along the third direction, so as to reduce the overall size of the heat conduction assembly in the third direction, and improve the energy density of the battery monomer.

[0028] In some embodiments, the electrode assembly is a winding type or a stacked type.

[0029] In the technical scheme of the embodiment of the present application, the electrode assembly is a winding type or a stacked type, the first heat conduction part connected to the side surface of the electrode assembly can reduce the thermal resistance of the electrode body at the side surface thereof, improve the heat exchange rate between the electrode body at the side surface thereof and the external environment, balance the internal temperature of the battery monomer, and improve the problem of adverse effects on the performance and service life of the battery monomer due to the excessively high or low internal temperature of the battery monomer.

[0030] In some embodiments, the first heat conduction part is arranged around the circumferential side of the electrode body.

[0031] In the technical scheme of the embodiment of the present application, the first heat conduction part is arranged around the circumferential side of the electrode body, so as to improve the contact area between the heat conduction assembly and the side surface of the electrode body, further improve the heat exchange rate between the electrode body at the side surface thereof and the external environment, balance the internal temperature of the battery monomer, and improve the problem of adverse effects on the performance and service life of the battery monomer due to the excessively high or low internal temperature of the battery monomer.

[0032] In some embodiments, the first heat-conductive part is formed with a gap extending along the first direction and penetrating through the first heat-conductive part between the two ends of the peripheral side of the electrode body.

[0033] In the technical scheme of the embodiments of the present application, the first heat-conductive part is formed with a gap extending along the first direction and penetrating through the first heat-conductive part between the two ends of the peripheral side of the electrode body. By setting the gap, the first heat-conductive part can be deformed synchronously during the expansion of the electrode assembly, reducing the risk of the first heat-conductive part being expanded by the electrode body, improving the service life of the heat-conductive assembly, and improving the reliability of the battery monomer.

[0034] In some embodiments, the gap is provided at at least one of the two first sides.

[0035] In the technical scheme of the embodiments of the present application, the electrode assembly expands more at the first side during the expansion process, so the gap is provided at at least one of the two first sides to make the first heat-conductive part more easily absorb the expansion of the electrode assembly through the gap, further reducing the risk of the first heat-conductive part being expanded by the electrode body, improving the service life of the heat-conductive assembly, and improving the reliability of the battery monomer.

[0036] In some embodiments, the gap is provided at both of the two first sides.

[0037] In the technical scheme of the embodiments of the present application, the gap is provided at both of the two first sides to make the first heat-conductive part more easily deformed synchronously during the expansion of the electrode assembly, reducing the risk of the first heat-conductive part being expanded by the electrode body.

[0038] In some embodiments, a plurality of electrode assemblies are provided, the plurality of electrode assemblies are stacked along the second direction, and the first heat-conductive part is arranged around the outer periphery of the whole formed by the plurality of electrode assemblies.

[0039] In the technical scheme of the embodiments of the present application, a plurality of electrode assemblies are provided, the plurality of electrode assemblies are stacked along the second direction, and the first heat-conductive part is arranged around the outer periphery of the whole formed by the plurality of electrode assemblies, so as to shorten the heat-conductive path between the first heat-conductive part and the shell, and make the first heat-conductive part more easily perform heat transfer between the electrode assembly and the external environment.

[0040] In some embodiments, the tab protrudes from the first end face, and the heat-conductive assembly further comprises a second heat-conductive part arranged between the shell and at least part of the second end face along the first direction.

[0041] In the technical scheme of the embodiments of the present application, the heat-conductive assembly further comprises a second heat-conductive part arranged between the shell and at least part of the second end face along the first direction, so as to improve the heat exchange rate of the electrode body at the second end face thereof and the external environment through the second heat-conductive part.

[0042] In some embodiments, the first heat-conducting part and the second heat-conducting part are connected.

[0043] In the technical scheme of the embodiments of the present application, the first heat-conducting part and the second heat-conducting part are connected to increase the contact area of the heat-conducting assembly and the electrode assembly, and 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 adverse effects on the performance and service life of the battery cell caused by the excessively high or low internal temperature of the battery cell.

[0044] In some embodiments, the second heat-conducting part is provided with a second through hole.

[0045] In the technical scheme of the embodiments of the present application, the second through hole provided on the second heat-conducting part facilitates the flow of electrolyte to the electrode assembly and improves the wettability of the electrolyte to the electrode assembly.

[0046] In some embodiments, the side surface includes two first side surfaces and two second side surfaces, the two first side surfaces are oppositely arranged in the second direction, the two second side surfaces are oppositely arranged in the third direction, the first direction, the second direction and the third direction are intersected two by two, the area of the first side surface is larger than the area of the second side surface, the first heat-conducting part is arranged on at least one of the two first side surfaces, and the second heat-conducting part is connected with the first heat-conducting part arranged on the first side surface.

[0047] In the technical scheme of the embodiments of the present application, the second heat-conducting part is connected with the first heat-conducting part arranged on the first side surface, which can increase the contact area of the first heat-conducting part and the second heat-conducting part, improve the heat conduction efficiency between the first heat-conducting part and the second heat-conducting part, and improve the connection reliability between the first heat-conducting part and the second heat-conducting part.

[0048] In some embodiments, the electrode assembly is provided in plurality, the plurality of electrode assemblies are arranged in layers 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 electrode assemblies, and the second heat-conducting part is provided in plurality and independently.

[0049] In the technical scheme of the embodiments of the present application, the plurality of electrode assemblies are arranged in layers 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 electrode assemblies, and the second heat-conducting part is provided in plurality and independently.

[0050] In some embodiments, at least two of the plurality of second heat-conducting parts are arranged in layers along the first direction.

[0051] In the technical scheme of the embodiment of the present application, the at least two second heat-conducting parts arranged in the first direction in layers helps to improve the heat exchange capacity of the electrode assembly at the second end face.

[0052] In some embodiments, a plurality of electrode assemblies are arranged, and the plurality of electrode assemblies are arranged in the second direction in layers, the first heat-conducting part comprises a middle heat-conducting member arranged between the adjacent two first side faces of the adjacent two electrode assemblies and connected to the second heat-conducting part.

[0053] In the technical scheme of the embodiment of the present application, the middle heat-conducting member is arranged between the adjacent two first side faces of the adjacent two electrode assemblies and connected to the second heat-conducting part, so that the heat between the adjacent electrode assemblies can be transmitted to the second heat-conducting part through the middle heat-conducting member, and heat exchanged with the external environment through the second heat-conducting part, so as to balance the internal temperature of the battery monomer.

[0054] In some embodiments, two middle heat-conducting members independent of each other are arranged between the adjacent two first side faces of the adjacent two electrode assemblies, and the heat-conducting assembly comprises two second heat-conducting parts arranged at intervals, and the two second heat-conducting parts are respectively located on the two sides of the two middle heat-conducting members in the second direction, and each middle heat-conducting member is connected to the adjacent second heat-conducting part.

[0055] In the technical scheme of the embodiment of the present application, two middle heat-conducting members independent of each other are arranged between the adjacent two first side faces of the adjacent two electrode assemblies, and the two second heat-conducting parts are respectively located on the two sides of the two middle heat-conducting members in the second direction, and each middle heat-conducting member is connected to the adjacent second heat-conducting part, so that in the expansion process of the electrode assembly, the connected middle heat-conducting member and the second heat-conducting part 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 in the expansion process of the electrode body, and improve the reliability of the battery monomer.

[0056] In some embodiments, the two middle heat-conducting members between the adjacent electrode assemblies are arranged at intervals in the third direction, or the two middle heat-conducting members between the adjacent electrode assemblies abut each other in the third direction.

[0057] In the technical scheme of the embodiment of the present application, the two middle heat-conducting members between the adjacent electrode assemblies are arranged at intervals in the third direction or abut each other, which helps to reduce the size of the heat-conducting assembly, reduce the processing cost of the battery monomer while improving the heat-conducting efficiency of the electrode assembly, and also helps to reduce the overall size of the heat-conducting assembly in the second direction, and improve the energy density of the battery monomer.

[0058] In some embodiments, the first heat conduction part further comprises two end heat conduction members respectively arranged between the shell and the two adjacent first sides and connected to the second heat conduction part.

[0059] In the technical scheme of the embodiments of the present application, the first heat conduction part further comprises two end heat conduction members respectively arranged between the shell and the two adjacent first sides and connected to the second heat conduction part, heat can be transferred through the second heat conduction part or the electrode assembly can transfer heat to the external environment through the two end heat conduction members and the second heat conduction part, so as to improve the heat conduction efficiency of the heat conduction assembly.

[0060] In some embodiments, a plurality of electrode assemblies are provided, and the plurality of electrode assemblies are arranged in a stacking manner along the second direction, the first heat conduction part comprises a middle heat conduction member and an end heat conduction member, the middle heat conduction member is arranged between the two adjacent first sides of the two adjacent electrode assemblies, the end heat conduction member is arranged between the shell and the adjacent first side, and the middle heat conduction member and the end heat conduction member are connected to the second heat conduction part.

[0061] In the technical scheme of the embodiments of the present application, the first heat conduction part comprises a middle heat conduction member and an end heat conduction member, the middle heat conduction member is arranged between the two adjacent first sides of the two adjacent electrode assemblies, the end heat conduction member is arranged between the shell and the adjacent first side, and the middle heat conduction member and the end heat conduction member are connected to the second heat conduction part, so that the heat between the adjacent electrode assemblies can be transferred to the end heat conduction member through the middle heat conduction member and the second heat conduction part, and heat exchange is performed between the end heat conduction member and the external environment, so as to improve the heat conduction efficiency of the heat conduction assembly.

[0062] In some embodiments, a plurality of electrode assemblies are provided, and the plurality of electrode assemblies are arranged in a stacking manner along the second direction, the first heat conduction part comprises a middle heat conduction member and two end heat conduction members, the middle heat conduction member is arranged between the two adjacent first sides of the two adjacent electrode assemblies, the two end heat conduction members are respectively arranged between the shell and the two adjacent first sides, and the middle heat conduction member and the two end heat conduction members are connected to the second heat conduction part.

[0063] In the technical scheme of the embodiments of the present application, the first heat conduction part comprises a middle heat conduction member and two end heat conduction members, the middle heat conduction member is arranged between the two adjacent first sides of the two adjacent electrode assemblies, the two end heat conduction members are respectively arranged between the shell and the two adjacent first sides, and the middle heat conduction member and the two end heat conduction members are connected to the second heat conduction part, so that the heat between the adjacent electrode assemblies can be transferred to the end heat conduction member through the middle heat conduction member and the second heat conduction part, and heat exchange is performed between the end heat conduction member and the external environment, so as to improve the heat conduction efficiency of the heat conduction assembly.

[0064] In some embodiments, two middle heat conduction members are arranged between the two adjacent first sides of the two adjacent electrode assemblies, the heat conduction assembly comprises four second heat conduction parts, the four second heat conduction parts are arranged in the second direction and are spaced between the two end heat conduction members, the two outermost second heat conduction parts are connected to the two end heat conduction members respectively, and the two middle second heat conduction parts are connected to the two middle heat conduction members respectively.

[0065] In the technical scheme of the embodiments of the present application, two middle heat conduction members are arranged between the two adjacent first sides of the two adjacent electrode assemblies, the two outermost second heat conduction parts are connected to the two end heat conduction members respectively, and the two middle second heat conduction parts are connected to the two middle heat conduction members respectively, so that when the electrode assembly expands, the combination of the end heat conduction members and the second heat conduction parts and the combination of the middle heat conduction members and the second heat conduction parts can move in the second direction to buffer the extrusion force of the electrode assembly, the problem of extrusion and damage of the heat conduction assembly during the expansion of the electrode assembly is improved, and the reliability of the battery monomer is improved.

[0066] In some embodiments, the heat conduction assembly and the electrode assembly are adhesively connected.

[0067] In the technical scheme of the embodiments of the present application, the heat conduction assembly and the electrode assembly are adhesively connected, so as to improve the connection reliability of the electrode assembly of the heat conduction assembly.

[0068] In some embodiments, the heat conduction assembly has a second direction projection area S1, the electrode body has a second direction projection area S2, 0.1≤S1 / S2≤1 is satisfied, and the first direction and the second direction intersect.

[0069] In the technical scheme of the embodiments of the present application, when the above conditions are satisfied, the problem that the first heat conduction part cannot obviously improve the heat conduction efficiency of the electrode assembly due to the too small area of the first heat conduction part can be improved, and the problem that the first heat conduction part interferes with other structures in the battery monomer due to the too large area of the first heat conduction part, causing damage to the battery monomer can be improved.

[0070] In some embodiments, the shell comprises an opening in the first direction, the battery monomer further comprises a top cover assembly, the top cover assembly covers the opening, the top cover assembly has an electrode terminal, the electrode terminal is connected with the tab, the heat conduction assembly further comprises a third heat conduction part, the third heat conduction part is in heat conduction connection with the tab, and the third heat conduction part is in heat conduction connection with the first heat conduction part.

[0071] In the technical scheme of the embodiment of the present application, the top cover assembly covers the opening of the shell, the tab and the electrode terminal of the top cover assembly are connected to realize electrical connection, the heat conduction assembly further comprises a third heat conduction part in heat conduction connection with the tab, and the third heat conduction part is in heat conduction connection with the first heat conduction part, so that the heat conduction assembly can improve the heat conduction rate at the tab, balance the temperature at the tab and the electrode body, and improve the problem that the performance of the battery cell is affected due to the excessively high temperature at the tab.

[0072] In some embodiments, the battery cell further comprises a switching mechanism connected between the tab and the electrode terminal, and the switching mechanism is in heat conduction connection with the third heat conduction part.

[0073] In the technical scheme of the embodiment of the present application, the battery cell further comprises a switching mechanism connected between the tab and the electrode terminal, and the switching mechanism is in heat conduction connection with the third heat conduction part, so that the heat conduction assembly can improve the heat conduction rate at the switching mechanism, balance the temperature at the switching mechanism, and improve the problem that the performance of the battery cell is affected due to the excessively high temperature at the switching mechanism.

[0074] In some embodiments, the tab comprises a folding section and an extension section, one side of the extension section is connected to the folding section, and the other side of the extension section is connected to the switching mechanism, the third heat conduction part is connected to the side of the extension section facing the folding section, or the third heat conduction part is connected to the side of the extension section facing the switching mechanism.

[0075] In the technical scheme of the embodiment of the present application, the third heat conduction part is connected to the side of the extension section facing the folding section, or the third heat conduction part is connected to the side of the extension section facing the switching mechanism, so that the third heat conduction part improves the heat conduction rate at the tab, and improves the problem that the tab is heated due to the excessively high temperature at the tab, the electrode body is heated, and the performance of the battery cell is reduced.

[0076] In some embodiments, the extension section comprises a first sub-section, a second sub-section and a third sub-section connecting the first sub-section and the second sub-section, which are arranged at intervals along a first direction, the first sub-section is connected to the folding section, the second sub-section is connected to the switching mechanism, and the third heat conduction part is connected to the side of the first sub-section facing the folding section.

[0077] In the technical scheme of the embodiment of the present application, the extension section comprises a first sub-section, a second sub-section and a third sub-section connecting the first sub-section and the second sub-section, which are arranged at intervals along a first direction, the second sub-section is connected to the switching mechanism to improve the contact area of the switching mechanism and the tab, and the third heat conduction part is connected to the side of the first sub-section facing the folding section to reduce the connection difficulty of the third heat conduction part and the tab.

[0078] In some embodiments, the side surface includes two first side surfaces and two second side surfaces, the two first side surfaces are oppositely arranged in a second direction, the two second side surfaces are oppositely arranged in a third direction, the first direction, the second direction and the third direction are intersected with each other, the area of the first side surface is greater than the area of the second side surface, the tab is provided with two, the two tabs are arranged at intervals along the third direction and extend from the first end surface, the first heat conduction part and the third heat conduction part are respectively provided with two, the two first heat conduction parts are respectively arranged on the two second side surfaces, the two third heat conduction parts are respectively connected to one end of the two first heat conduction parts towards the tab, and the two third heat conduction parts are respectively connected to the extension sections of the two tabs.

[0079] In the technical scheme of the embodiments of the present application, the two tabs extend from the first end surface and are arranged at intervals along the third direction, the two first heat conduction parts are respectively arranged on the two second side surfaces, which does not cause the thickness of the battery monomer to increase due to the arrangement of the heat conduction assembly, and since the expansion of the electrode assembly mainly occurs at the first side surface, when the first heat conduction part is arranged at the second side surface, the interference of the first heat conduction part to the expansion of the electrode assembly can be reduced, the two third heat conduction parts are respectively connected to one end of the two first heat conduction parts towards the tab, and the two third heat conduction parts are respectively connected to the extension sections of the two tabs, each tab is connected to a third heat conduction part, so that the heat at the electrode main body and each tab can be transmitted to the first heat conduction part through the third heat conduction part, so as to improve the heat conduction rate at the tab, and improve the problem that the battery monomer performance is reduced due to the overheating of the tab and the heating of the electrode sheet.

[0080] In some embodiments, the side surface includes two first side surfaces and two second side surfaces, the two first side surfaces are oppositely arranged in a second direction, the two second side surfaces are oppositely arranged in a third direction, the first direction, the second direction and the third direction are intersected with each other, the area of the first side surface is greater than the area of the second side surface, the first heat conduction part and the third heat conduction part are respectively provided with two, the two first heat conduction parts are respectively arranged on the two first side surfaces, and each third heat conduction part is connected to one first heat conduction part, and the two third heat conduction parts are respectively connected to different positions of the extension section of the same tab.

[0081] In the technical scheme of the embodiments of the present application, each third heat conduction part is connected to one first heat conduction part, and the two third heat conduction parts are respectively connected to different positions of the extension section of the same tab, so as to better improve the heat conduction rate at the tab and improve the problem that the battery monomer performance is affected due to the overheating of the tab.

[0082] In some embodiments, the extension section includes a first sub-section, a second sub-section and a third sub-section connecting the first sub-section and the second sub-section, which are arranged at intervals along the first direction, the first sub-section is connected to the folding section, and the second sub-section is connected to the switching mechanism; one of the two third heat conduction parts is connected to the first sub-section, and the other is connected to the second sub-section.

[0083] In the technical scheme of the embodiment of the application, one of the two third heat-conducting parts is connected to the first sub-portion, and the other is connected to the second sub-portion, and the connection areas of the two third heat-conducting parts and the tab are reasonably distributed, so as to improve the connection reliability of the third heat-conducting part and the tab.

[0084] In some embodiments, the side surface includes two first side surfaces and two second side surfaces, the two first side surfaces are oppositely arranged in the second direction, the two second side surfaces are oppositely arranged in the third direction, the first direction, the second direction and the third direction are intersected two by two, the area of the first side surface is greater than the area of the second side surface, the adapter 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 part is connected to the second connecting segment.

[0085] In the technical scheme of the embodiment of the application, the adapter mechanism includes a first connecting segment and a second connecting segment, the tab is connected to the first connecting segment, and the third heat-conducting part is connected to the second connecting segment, so that the heat conduction rate at the adapter mechanism is improved, and the problem that the battery monomer performance is reduced due to the overheating of the adapter mechanism and the heating of the electrode plate is solved.

[0086] In some embodiments, two first heat-conducting parts are respectively arranged, the two first heat-conducting parts are respectively arranged on the two first side surfaces, each third heat-conducting part is connected to a first heat-conducting part, and the two third heat-conducting parts are respectively connected to different positions of the second connecting segment of the same adapter mechanism.

[0087] In the technical scheme of the embodiment of the application, two first heat-conducting parts are respectively arranged on the two first side surfaces, each third heat-conducting part is connected to a first heat-conducting part, and the two third heat-conducting parts are respectively connected to different positions of the second connecting segment of the same adapter mechanism, so that the heat conduction rate at the adapter mechanism is better improved, and the problem that the battery monomer performance is affected due to the overheating of the adapter mechanism is solved.

[0088] In some embodiments, two electrode assemblies are arranged, the two electrode assemblies are arranged in a stacking manner along the second direction, the adapter mechanism is provided with two first connecting segments, the two first connecting segments are arranged on two 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 first heat-conducting parts and two third heat-conducting parts are respectively arranged, the two first heat-conducting parts are arranged on the 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 towards the adapter mechanism, and the two third heat-conducting parts are respectively connected to the second connecting segment of the adapter mechanism and the tab.

[0089] In the technical scheme of the embodiment of the present application, the two first heat-conducting parts are arranged on two sides of the electrode body in the second direction, 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 of the adapter mechanism and the tab, so as to reduce the connection difficulty of the third heat-conducting part and the tab and the adapter mechanism, and the two third heat-conducting parts are respectively connected to the tab and the adapter mechanism, so as to better stabilize the temperature at the tab.

[0090] In some embodiments, the tab extends from the first end face, and the heat-conducting assembly further comprises a second heat-conducting part arranged between the shell and at least part of the second end face in the first direction, and the second heat-conducting part is connected to the first heat-conducting part.

[0091] In the technical scheme of the embodiment of the present application, the heat-conducting assembly further comprises a second heat-conducting part arranged between the shell and at least part of the second end face in the first direction, and the second heat-conducting part is connected to the first heat-conducting part, so as to increase the contact area of the heat-conducting assembly and the shell, improve the heat conduction rate of the heat-conducting assembly to the tab, and improve the problem of affecting the performance of the battery monomer due to the excessively high temperature at the tab.

[0092] In some embodiments, the tab extends from the first end face, and the battery monomer further comprises a first insulating film covering the side surface and the second end surface of the electrode body; wherein the first heat-conducting part is located between the first insulating film and the electrode assembly, or the first heat-conducting part is located between the first insulating film and the shell.

[0093] In the technical scheme of the embodiment of the present application, the first insulating film covers the side surface and the second end surface of the electrode body, so as 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 supporting and protecting role on the first heat-conducting part, reduces the problem of damage of 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, so as 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.

[0094] In some embodiments, the heat-conducting assembly comprises an insulating piece and a heat-conducting piece, at least part of the insulating piece forms a containing cavity, the heat-conducting piece is arranged in the containing cavity, the heat-conducting piece comprises a first heat-conducting sheet, the first heat-conducting sheet is arranged on the side surface, and the first heat-conducting part is composed of the first heat-conducting sheet and the insulating piece.

[0095] In the technical scheme of the embodiment of the present application, the heat conduction assembly comprises an insulating piece and a heat conduction piece, the insulating piece forms a containing cavity in at least a partial region, and the heat conduction piece is arranged in the containing cavity. The heat conduction piece comprises a first heat conduction sheet, and the first heat conduction sheet is arranged on the side surface. The first heat conduction part is composed of the first heat conduction sheet and the insulating piece. In this way, the heat conduction piece and the electrode body can be insulated by the insulating piece, and the heat conduction piece and the electrolyte can be isolated by the insulating piece, so as to improve the problem that the heat conduction piece and the electrolyte are incompatible and affect the performance of the battery monomer.

[0096] In some embodiments, the tab extends from the first end surface, and the battery monomer further comprises a second insulating film, the second insulating film is connected with the insulating piece, and the insulating piece and the second insulating film jointly cover the second end surface and the side surface of the electrode body.

[0097] In the technical scheme of the embodiment of the present application, the second insulating film is connected with the insulating piece, and the insulating piece and the second insulating film jointly cover the second end surface and the side surface of the electrode body. The combination of the second insulating film and the insulating piece realizes the insulation between the electrode body and the shell, helps to reduce the size of the Mylar film, reduces the manufacturing cost of the battery monomer, helps to reduce the thickness of the battery monomer, and improves the energy density of the battery monomer.

[0098] In some embodiments, the tab extends from the first end surface, and the insulating piece covers the second end surface and the side surface of the electrode body.

[0099] In the technical scheme of the embodiment of the present application, the insulating piece covers the second end surface and the side surface of the electrode body, so as to insulate the shell and the electrode assembly, and no Mylar film is needed, which helps to reduce the segmented manufacturing cost of the battery monomer, can reduce the thickness of the battery monomer, and improves the energy density of the battery monomer.

[0100] In some embodiments, the side surface comprises two first side surfaces and two second side surfaces, the two first side surfaces are oppositely arranged in a second direction, the two second side surfaces are oppositely arranged in a third direction, the first direction, the second direction and the third direction are intersected two by two, the area of the first side surface is greater than the area of the second side surface, the insulating piece comprises a first insulating part, the first insulating part comprises a body part and a bending part which are connected with each other, the body part and the bending part are connected, the body parts of the two first insulating parts are arranged on the two first side surfaces respectively, the two bending parts are arranged on the two second side surfaces respectively, and the first heat conduction sheet is arranged on at least one of the body part and the bending part.

[0101] In the technical scheme of the embodiment of the present application, the first insulating part comprises a body part and a bending part which are connected with each other, the body part and the bending part are connected, the body parts of the two first insulating parts are arranged on the two first side surfaces respectively, and the two bending parts are arranged on the two second side surfaces respectively, so as to realize the insulation of the electrode assembly on the circumferential surface and the shell. The first heat conduction sheet is arranged on at least one of the body part and the bending part, so as to improve the heat conduction rate at the first side surface and / or the second side surface of the electrode assembly.

[0102] In some embodiments, the first insulation part is provided with a first through hole penetrating therethrough, and the first through hole is spaced from the accommodating cavity.

[0103] In the technical scheme of the embodiments of the present application, the first insulation part is provided with a first through hole penetrating therethrough, so that the electrolyte can soak the electrode assembly through the first through hole, and the first through hole is spaced from the accommodating cavity, so as to avoid the electrolyte from contacting the first heat-conducting sheet.

[0104] In some embodiments, the first heat-conducting sheet is provided with a first avoiding hole penetrating therethrough, the first insulation part covers the inner wall of the first avoiding hole, the first insulation part is provided with a first through hole penetrating therethrough, and the first through hole is located in the first avoiding hole.

[0105] In the technical scheme of the embodiments of the present application, the first heat-conducting sheet is provided with a first avoiding hole penetrating therethrough, the first insulation part is provided with a first through hole penetrating therethrough, and the first through hole is located in the first avoiding hole, so that the electrolyte can soak the electrode assembly through the first through hole and the first avoiding hole, the first insulation part covers the inner wall of the first avoiding hole, so as to avoid the electrolyte from contacting the first heat-conducting sheet and keep the first heat-conducting sheet insulated from the electrode assembly.

[0106] In some embodiments, the tab extends from the first end face, the insulation piece further comprises a second insulation part, the second insulation part is arranged between the second end face of the electrode body and the shell, the second insulation part is insulated from the shell and the second end face of the electrode assembly, and the bodies of the two first insulation parts are respectively connected to the two sides of the second insulation part.

[0107] In the technical scheme of the embodiments of the present application, the insulation piece further comprises a second insulation part arranged between the second end face of the electrode body and the shell, and the bodies of the two first insulation parts are respectively connected to the two sides of the second insulation part, so as to reduce the alignment difficulty of the second insulation part and the first insulation part and reduce the cooperation difficulty of the insulation piece and the electrode assembly.

[0108] In some embodiments, the heat-conducting piece comprises a second heat-conducting sheet, and the second heat-conducting sheet is arranged on the second insulation part.

[0109] In the technical scheme of the embodiments of the present application, the heat-conducting piece comprises a second heat-conducting sheet arranged on the second insulation part, so as to improve the heat-conducting rate at the second end face.

[0110] In some embodiments, the second insulation part is provided with a second through hole penetrating therethrough, and the second through hole is spaced from the accommodating cavity.

[0111] In the technical scheme of the embodiments of the present application, the second insulation part is provided with a second through hole penetrating therethrough, so that the electrolyte can soak the electrode assembly through the second through hole, and the second through hole is spaced from the accommodating cavity, so as to avoid the electrolyte from contacting the second heat-conducting sheet.

[0112] In some embodiments, the second heat-conductive sheet is provided with a second avoiding hole penetrating therethrough, the second insulating part covers the inner wall of the second avoiding hole, and the second insulating part is provided with a second through hole penetrating therethrough, the second through hole being located in the second avoiding hole.

[0113] In the technical scheme of the embodiments of the present application, the second heat-conductive sheet is provided with a second avoiding hole penetrating therethrough, the second insulating part is provided with a second through hole penetrating therethrough, the second through hole being located in the second avoiding hole, so that the electrolyte can be soaked in the electrode assembly through the second through hole and the second avoiding hole, the second insulating part covers the inner wall of the second avoiding hole, so as to avoid the contact between the electrolyte and the second heat-conductive sheet and keep the second heat-conductive sheet and the electrode assembly insulated.

[0114] In some embodiments, the electrode assembly is provided in plurality, the plurality of electrode assemblies are arranged in a stacking manner along the second direction, the insulating part further comprises a middle insulating part, the middle insulating part is arranged between the electrode bodies of adjacent electrode assemblies, the middle insulating part and the second insulating part are connected to each other, the first heat-conductive sheet comprises a middle heat-conductive sheet, and the middle heat-conductive sheet is arranged in the middle insulating part.

[0115] In the technical scheme of the embodiments of the present application, the middle insulating part is arranged between the electrode bodies, so as to insulate the adjacent electrode bodies, the middle insulating part and the second insulating part are connected to each other, so as to improve the insulation reliability of the middle insulating part, and the middle heat-conductive sheet is arranged in the middle insulating part, so as to improve the heat conduction rate between the adjacent electrode bodies.

[0116] In some embodiments, the body part is connected with a bending part on each side in the third direction, and the two bending parts of the two first insulating parts and located on the same side of the electrode assembly extend towards each other in the second direction.

[0117] In the technical scheme of the embodiments of the present application, the body part is connected with a bending part on each side in the third direction, and the two bending parts of the two first insulating parts and located on the same side of the electrode assembly extend towards each other in the second direction, so that the splicing part of the two bending parts is located on the second side surface, and the first side surface with a larger area can be provided with a larger-area heat-conductive layer, so as to improve the heat conduction capacity of the heat conduction assembly.

[0118] In some embodiments, the two bending parts extend towards each other in the second direction, and the two bending parts at least partially overlap in the third direction.

[0119] In the technical scheme of the embodiments of the present application, the two bending parts extend towards each other in the second direction, and the two bending parts at least partially overlap in the third direction, so as to improve the insulation reliability of the first insulating part between the electrode assembly and the shell.

[0120] In some embodiments, the shell comprises an opening in the first direction, the battery monomer further comprises a top cover assembly, the top cover assembly covers the opening and is connected to the tab, and the at least one body part extends out of the first end surface in the first direction and is connected to the top cover assembly.

[0121] In the technical scheme of the embodiments of the present application, the at least one body part extends out of the first end surface in the first direction and is connected to the top cover assembly, the top cover assembly plays a role of positioning and fixing the heat conduction assembly, and the stability of the heat conduction assembly in the shell is improved.

[0122] In some embodiments, the size L3 of the body part extending out of the first end surface in the first direction is greater than or equal to 2 mm.

[0123] In the technical scheme of the embodiments of the present application, when the above conditions are met, the connection reliability of the heat conduction assembly and the top cover assembly is improved.

[0124] In some embodiments, the minimum distance from the orthogonal projection of the heat conduction member in the thickness direction of the heat conduction assembly to the edge of the orthogonal projection of the insulating member in the thickness direction of the heat conduction assembly is greater than or equal to 2 mm.

[0125] In the technical scheme of the embodiments of the present application, the minimum distance from the orthogonal projection of the heat conduction member in the thickness direction of the heat conduction assembly to the edge of the orthogonal projection of the insulating member in the thickness direction of the heat conduction assembly is greater than or equal to 2 mm, so that there is sufficient plastic sealing area between the heat conduction member and the edge of the insulating member, and the sealing reliability of the accommodation cavity is improved.

[0126] In some embodiments, the thickness D3 of the heat conduction member satisfies 40 μm≤D3≤180 μm.

[0127] In the technical scheme of the embodiments of the present application, when the above conditions are met, the problems of the battery monomer being too large in size and the energy density being reduced due to the heat conduction member being too thick can be improved, and the problem of the heat conduction member being easily damaged due to the heat conduction member being too thin can be improved.

[0128] In some embodiments, the insulating member comprises two sub-insulating layers, the two sub-insulating layers are stacked and connected to each other to form the accommodation cavity, and the thickness D1 of the sub-insulating layer satisfies 5 μm≤D1≤100 μm.

[0129] In the technical scheme of the embodiments of the present application, when the above conditions are met, the problems of the battery monomer being too large in size and the energy density being reduced due to the sub-insulating layer being too thick can be improved, and the problem of the sub-insulating layer being easily damaged due to the sub-insulating layer being too thin can be improved.

[0130] In some embodiments, the insulating member comprises polyethylene or polypropylene or polyimide or polyester resin.

[0131] In the technical scheme of the embodiment of the present application, the insulating member comprises polyethylene or polypropylene or polyimide or polyester resin, so as to improve the insulation reliability of the insulating member.

[0132] In some embodiments, the heat-conducting member comprises graphite or graphene or carbon nanotube.

[0133] In the technical scheme of the embodiment of the present application, the heat-conducting member comprises graphite or graphene or carbon nanotube, so as to improve the heat-conducting performance of the heat-conducting assembly by using the graphite or graphene or carbon nanotube heat-conducting material.

[0134] In some embodiments, the heat-conducting rate k of the heat-conducting member satisfies k>500 W / (m·K).

[0135] In the technical scheme of the embodiment of the present application, when the heat-conducting rate k of the heat-conducting member satisfies the above condition, the heat-conducting assembly has sufficient heat-conducting performance to conduct the heat of the electrode body.

[0136] In a second aspect, the embodiment of the present application provides a battery device, comprising the battery monomer of any one of the embodiments of the first aspect.

[0137] In a third aspect, the embodiment of the present application provides a power consumption device, comprising the battery device of the embodiment of the second aspect. BRIEF DESCRIPTION OF DRAWINGS

[0138] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The accompanying drawings are included to provide a description of the preferred embodiments and are not intended to limit the scope of the present application. Moreover, the same reference numerals are used throughout the drawings to represent similar components. In the drawings:

[0139] FIG. 1 is a structural schematic diagram of a vehicle according to an embodiment of the present application;

[0140] FIG. 2 is a structural schematic diagram of a battery device according to an embodiment of the present application;

[0141] FIG. 3 is a structural schematic diagram of a battery module according to an embodiment of the present application;

[0142] FIG. 4 is an exploded view of a battery monomer according to an embodiment of the present application;

[0143] FIG. 5 is a structural schematic diagram of an electrode assembly of a battery monomer according to an embodiment of the present application;

[0144] FIG. 6 is a partial structural schematic diagram of a battery monomer according to an embodiment of the present application;

[0145] FIG. 7 is a partial structural schematic diagram of a battery monomer according to another embodiment of the present application;

[0146] FIG. 8 is a schematic diagram of a partial structure of a battery cell according to an embodiment of the present application;

[0147] FIG. 9 is a schematic diagram of a partial structure of a battery cell according to an embodiment of the present application;

[0148] FIG. 10 is a schematic diagram of a partial structure of a battery cell according to an embodiment of the present application;

[0149] FIG. 11 is a schematic diagram of a partial structure of a battery cell according to an embodiment of the present application;

[0150] FIG. 12 is a schematic diagram of a partial structure of a battery cell according to an embodiment of the present application;

[0151] FIG. 13 is a schematic diagram of a partial structure of a battery cell according to an embodiment of the present application;

[0152] FIG. 14 is a schematic diagram of a partial structure of a battery cell according to an embodiment of the present application;

[0153] FIG. 15 is a schematic diagram of a partial structure of a battery cell according to an embodiment of the present application;

[0154] FIG. 16 is a schematic diagram of a partial structure of a battery cell according to an embodiment of the present application;

[0155] FIG. 17 is a schematic diagram of a partial structure of a battery cell according to an embodiment of the present application;

[0156] FIG. 18 is a schematic diagram of a partial structure of a battery cell according to an embodiment of the present application;

[0157] FIG. 19 is a schematic diagram of a heat conduction assembly of a battery cell according to an embodiment of the present application;

[0158] FIG. 20 is a schematic diagram of a partial structure of a battery cell according to an embodiment of the present application;

[0159] FIG. 21 is a schematic diagram of a partial structure of a battery cell according to an embodiment of the present application;

[0160] FIG. 22 is a schematic diagram of a partial structure of a battery cell according to an embodiment of the present application;

[0161] FIG. 23 is a schematic diagram of a partial structure of a battery cell according to an embodiment of the present application;

[0162] FIG. 24 is a schematic diagram of a heat conduction assembly of a battery cell according to an embodiment of the present application;

[0163] FIG. 25 is a schematic diagram of a partial structure of a battery cell according to an embodiment of the present application;

[0164] FIG. 26 is a schematic diagram of a partial structure of a battery cell according to an embodiment of the present application;

[0165] FIG. 27 is a partial structural schematic diagram of a battery cell according to an embodiment of the present application;

[0166] FIG. 28 is a partial structural schematic diagram of a battery cell according to an embodiment of the present application;

[0167] FIG. 29 is an enlarged view of A in FIG. 27 according to an embodiment of the present application;

[0168] FIG. 30 is an enlarged view of A in FIG. 27 according to another embodiment of the present application;

[0169] FIG. 31 is an exploded view of a battery cell according to another embodiment of the present application;

[0170] FIG. 32 is a partial structural schematic diagram of a battery cell according to an embodiment of the present application;

[0171] FIG. 33 is a partial structural schematic diagram of a battery cell according to an embodiment of the present application;

[0172] FIG. 34 is an exploded view of a battery cell according to another embodiment of the present application;

[0173] FIG. 35 is a partial structural schematic diagram of a battery cell according to an embodiment of the present application;

[0174] FIG. 36 is a partial structural schematic diagram of a battery cell according to an embodiment of the present application;

[0175] FIG. 37 is a partial structural schematic diagram of a battery cell according to an embodiment of the present application;

[0176] FIG. 38 is a partial structural schematic diagram of a battery cell according to an embodiment of the present application;

[0177] FIG. 39 is an enlarged structural schematic diagram of B in FIG. 38;

[0178] FIG. 40 is a partial structural schematic diagram of a battery cell according to an embodiment of the present application;

[0179] FIG. 41 is a partial structural schematic diagram of a battery cell according to an embodiment of the present application;

[0180] FIG. 42 is a partial structural schematic diagram of a battery cell according to an embodiment of the present application;

[0181] FIG. 43 is an exploded view of a battery cell according to another embodiment of the present application;

[0182] FIG. 44 is a structural schematic diagram of a heat conduction assembly of a battery cell according to an embodiment of the present application;

[0183] FIG. 45 is a sectional view of C-C in FIG. 44;

[0184] FIG. 46 is an exploded view of a battery cell according to another embodiment of the application;

[0185] FIG. 47 is an exploded view of a battery cell according to another embodiment of the application;

[0186] FIG. 48 is a partial structural schematic view of a battery cell according to an embodiment of the application;

[0187] FIG. 49 is a structural schematic view of a heat-conducting assembly of a battery cell according to an embodiment of the application;

[0188] FIG. 50 is an expanded view of a heat-conducting assembly of a battery cell according to an embodiment of the application;

[0189] FIG. 51 is a structural schematic view of a heat-conducting assembly of a battery cell according to an embodiment of the application;

[0190] FIG. 52 is a structural schematic view of a heat-conducting assembly of a battery cell according to an embodiment of the application;

[0191] FIG. 53 is a partial structural schematic view of a heat-conducting assembly of a battery cell according to an embodiment of the application;

[0192] FIG. 54 is a structural schematic view of a heat-conducting assembly of a battery cell according to an embodiment of the application;

[0193] FIG. 55 is a partial structural schematic view of a heat-conducting assembly of a battery cell according to another embodiment of the application;

[0194] FIG. 56 is a structural schematic view of a heat-conducting assembly of a battery cell according to an embodiment of the application;

[0195] FIG. 57 is a structural schematic view of a heat-conducting assembly of a battery cell according to an embodiment of the application;

[0196] FIG. 58 is a partial structural schematic view of a heat-conducting assembly of a battery cell according to an embodiment of the application;

[0197] FIG. 59 is a structural schematic view of a heat-conducting assembly of a battery cell according to an embodiment of the application;

[0198] FIG. 60 is a partial structural schematic view of a heat-conducting assembly of a battery cell according to another embodiment of the application;

[0199] FIG. 61 is a structural schematic view of a heat-conducting assembly of a battery cell according to an embodiment of the application;

[0200] FIG. 62 is an expanded view of a heat-conducting assembly of a battery cell according to an embodiment of the application.

[0201] Reference Signs:

[0202] 1. Vehicle; 101. Motor; 102. Controller; 2. Battery device; 201. Battery module; 202. Box; 2021. First box; 2022. Second box;

[0203] 3. Battery cell;

[0204] 4. Housing; 41. Opening;

[0205] 5. Electrode assembly; 51. Tab; 52. Electrode body; 521. First end face; 522. Second end face; 523. Side face; 5231. First side face; 5232. Second side face; 5241. Positive pole piece; 5242. Negative pole piece; 511. Contraction section; 512. Extension section; 5121. First sub-section; 5122. Second sub-section; 5123. Third sub-section;

[0206] 6. Top cover assembly; 61. Electrode terminal;

[0207] 7. Adapter mechanism; 71. First connecting section; 72. Second connecting section;

[0208] 8. Heat conduction assembly; 81. First heat conduction part; 82. Second heat conduction part; 83. Third heat conduction part; 811. Gap; 812. Middle heat conduction piece; 813. End heat conduction piece; 814. Side heat conduction piece; 815. First through hole; 821. Second through hole;

[0209] 84. Heat conduction piece; 85. Insulation piece; 851. Containing cavity; 852. First insulation part; 8521. Body part; 8522. Bending part; 853. Second insulation part; 854. Middle insulation part; 855. Sub-insulation layer; 841. First heat conduction sheet; 842. Second heat conduction sheet; 8414. First avoiding hole; 8421. Second avoiding hole; 856. Plastic sealing area; 8411. Middle heat conduction sheet; 8412. End heat conduction sheet; 8413. Side heat conduction sheet;

[0210] 91. First insulation film; 92. Second insulation film;

[0211] X. First direction; Y. Second direction; Z. Third direction. DETAILED DESCRIPTION

[0212] The embodiments of the technical scheme of the present application will be described in detail below with reference to the drawings. The following embodiments are only used to more clearly illustrate the technical scheme of the present application, and therefore only serve as examples, and cannot limit the protection scope of the present application.

[0213] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in the embodiments of the present application should be the usual meaning understood by the skilled in the art to which the embodiments of the present application belong.

[0214] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship shown in the drawings, which 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 devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the embodiments of the present application.

[0215] In addition, the technical terms "first", "second" and the like are only for descriptive purposes and cannot 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 "a plurality of" is two or more, unless otherwise explicitly specified and limited.

[0216] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical terms "mounting", "connecting", "connecting", "fixing" and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0217] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the first feature "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature "above", "above" and "above" the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0218] At present, from the development of market situation, the application of battery device is more and more widely. The battery device is not only applied to the energy storage power supply system of hydropower, thermal power, wind power and solar power station, but also widely applied to electric bicycles, electric motorcycles, electric vehicles and other electric vehicles, military equipment, aerospace and other fields. With the continuous expansion of the application field of battery device, the market demand is also increasing.

[0219] During use of the battery cell, a large temperature difference between the inside and outside of the battery cell leads to a decrease in performance and service life of the battery cell.

[0220] The above problem is caused by the fact that, during operation of the battery cell, the electrode assembly performs an electrochemical reaction and generates heat, and this part of heat needs to be exchanged with the outside environment through the shell. Due to the limited heat conduction rate of the shell, the internal temperature of the battery cell cannot be quickly conducted to the outside, and the internal temperature accumulates and rises, and the electrode assembly is prone to lithium precipitation due to the excessively high temperature. In a low-temperature environment, the external environment is also difficult to heat the electrode assembly, leading to a decrease in capacity and pulse performance of the battery cell due to low temperature, affecting the performance of the battery cell.

[0221] Based on the above problem, the embodiments of the present application provide a battery cell, which includes a shell, an electrode assembly and a heat conduction 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 tab. The electrode body includes a first end face and a second end face oppositely arranged in a first direction, and a side face connected between the first end face and the second end face. The electrode body forms a loop with the tab extending from the first end face and / or the second end face and an external component. The heat conductivity of the heat conduction assembly is greater than that of the shell. The heat conduction assembly includes a first heat conduction part. The first heat conduction part is connected to the side face of the electrode body through heat conduction. This can reduce the thermal resistance of the electrode body at the side face, improve the temperature uniformity of the electrode body at the side face, and improve the heat exchange rate between the electrode body at the side face and the external environment, so as to balance the internal temperature of the battery cell and improve the adverse effects of excessively high or low internal temperature of the battery cell on the performance and service life of the battery cell.

[0222] The technical solutions described in the embodiments of the present application are applicable to battery devices and electric devices using battery devices.

[0223] The electric device can be a vehicle, a mobile phone, a portable device, a notebook computer, a ship, a spacecraft, an electric toy and an electric tool, etc. The vehicle can be a fuel automobile, a gas automobile or a new energy automobile, and the new energy automobile can be a pure electric automobile, a hybrid electric automobile or a range extended automobile, etc. The spacecraft includes an airplane, a rocket, a space shuttle and a spacecraft, etc. The electric toy includes a fixed or mobile electric toy, such as a game console, an electric automobile toy, an electric ship toy and an electric airplane toy, etc. The electric tool includes a metal cutting electric tool, a grinding electric tool, an assembling electric tool and a railway electric tool, such as an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact electric drill, a concrete vibrator and an electric planer, etc. The embodiments of the present application do not specially limit the above electric devices.

[0224] In the embodiments of the present application, the battery cell can be a secondary battery, which refers to a battery cell that can be activated by charging after discharging to continue to be used.

[0225] The battery cell can be a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel-hydrogen battery, a nickel-cadmium battery, a lead-acid battery, etc. The embodiments of the present application are not limited thereto. The battery cell can be in the shape of a cylinder, a flat body, a cuboid or other shapes, etc. The embodiments of the present application are not limited thereto.

[0226] The battery device mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity. For example, the battery device mentioned in the present application can include a battery module or a battery pack, etc. The battery pack generally includes a box for packaging one or more battery cells. The box can avoid the influence of liquid or other foreign matters on the charging or discharging of the battery cell.

[0227] The battery cell includes an electrode assembly and an electrolyte. The electrode assembly includes a positive electrode sheet, a negative electrode sheet and a separator. The battery cell mainly relies on the movement of metal ions between the positive electrode sheet and the negative electrode sheet to work. The positive electrode sheet includes a positive current collector and a positive active material layer, and the positive active material layer is coated on the surface of the positive current collector; the positive current collector includes a positive current collecting portion and a positive tab connected to the positive current collecting portion, and the positive current collecting portion is coated with the positive active material layer, and the positive 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, which can be lithium cobaltate, lithium iron phosphate, ternary lithium or lithium manganate, etc. The negative electrode sheet includes a negative current collector and a negative active material layer, and the negative active material layer is coated on the surface of the negative current collector; the negative current collector includes a negative current collecting portion and a negative tab connected to the negative current collecting portion, and the negative current collecting portion is coated with the negative active material layer, and the negative tab is not coated with the negative active material layer. The material of the negative current collector can be copper, and the negative active material layer includes a negative active material, which can be carbon or silicon, etc. The material of the separator can be PP (polypropylene) or PE (polyethylene), etc.

[0228] It should be understood that the technical solutions described in the embodiments of the present application are not only limited to the above-described battery device and electric equipment, but can also be applied to all battery devices including a box and electric equipment using the battery device. However, for the sake of brevity of description, the following embodiments are described taking an electric vehicle as an example.

[0229] Please refer to FIG. 1, which is a structural schematic diagram of a vehicle 1 according to some embodiments of the present application. The vehicle 1 can be a fuel vehicle, a gas vehicle, or a new energy vehicle, which can be a pure electric vehicle, a hybrid vehicle, or a range extended vehicle, etc. The vehicle 1 is internally provided with a battery device 2, which can be arranged at the bottom, the head, or the tail of the vehicle 1. The battery device 2 can be used for power supply of the vehicle 1, for example, the battery device 2 can be used as an operating power source of the vehicle 1. The vehicle 1 can further include a controller 102 and a motor 101, and the controller 102 is used to control the battery to supply power to the motor 101, for example, to meet the power demand of the vehicle 1 during starting, navigation, and driving.

[0230] In some embodiments of the present application, the battery device 2 can not only be used as an operating power source of the vehicle 1, but also be used as a driving power source of the vehicle 1, to replace or partially replace fuel or natural gas to provide driving power for the vehicle 1.

[0231] FIG. 2 shows a structural schematic diagram of a battery device according to an embodiment of the present application.

[0232] The battery device 2 mentioned in the embodiments of the present application can include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly can include a plurality of battery cells 3 connected in series, in parallel, or in a mixed connection mode through a busbar component.

[0233] In some embodiments, the battery cell assembly is usually formed by arranging a plurality of battery cells 3.

[0234] For example, the battery cell assembly can be a battery module 201 formed by arranging and fixing a plurality of battery cells 3 into an independent module. For example, the battery module 201 can be formed by bundling a plurality of battery cells 3 with a cable tie.

[0235] In some embodiments, the battery device can be a battery pack including a box 202 and one or more battery cell assemblies accommodated in the box 202.

[0236] For example, the battery cell assembly can be a battery module 201, which can be accommodated in the box by fixing the battery module 201 in the box.

[0237] For example, the battery cell assembly can also be accommodated in the box 202 by directly fixing a plurality of battery cells 3 in the box 202.

[0238] As an example, the box 202 can include a first box 2021 and a second box 2022. The first box 2021 and the second box 2022 are fastened so that an enclosed space is formed inside the box 202 to accommodate the battery cell assembly. The enclosed here means covered or closed, which can be sealed or unsealed. The first box 2021 can be a top cover or a bottom plate.

[0239] As an example, the box 202 can include a top cover, a frame and a bottom plate. The top cover and the bottom plate are respectively connected with the frame so that an enclosed space is formed inside the box 202 to accommodate the battery cell assembly.

[0240] In some embodiments, the box 202 can be part of the chassis structure of the vehicle. For example, part of the box 202 can be at least part of the floor of the vehicle, or part of the box 202 can be at least part of the cross beam and the longitudinal beam of the vehicle.

[0241] FIG. 3 shows a structural schematic diagram of the battery module 201 according to an embodiment of the present application.

[0242] In some embodiments, as shown in FIGS. 2 and 3, the battery cell 3 is multiple, and the multiple battery cells 3 are connected in series or in parallel or in hybrid to form the battery module 201. The multiple battery modules 201 are connected in series or in parallel or in hybrid to form a whole and are accommodated in the box 202.

[0243] The multiple battery cells 3 in the battery module 201 can be electrically connected through a busbar component to realize parallel connection, series connection or hybrid connection of the multiple battery cells 3 in the battery module 201.

[0244] In the present application, the battery cell 3 can include a lithium ion battery cell, a sodium ion battery cell or a magnesium ion battery cell, etc., and the embodiments of the present application are not limited thereto.

[0245] FIG. 4 is an exploded view of the battery cell according to an embodiment of the present application. The battery cell 3 refers to the smallest unit that constitutes a battery. As shown in FIG. 4, the battery cell 3 includes a top cover assembly 6, a housing 4 and an electrode assembly 5.

[0246] The electrode assembly 5 is a component in which electrochemical reactions occur in the battery cell 3. One or more electrode assemblies 5 can be contained within the case 4. The electrode assembly 5 is mainly formed by winding or layering electrode sheets, which are divided into positive electrode sheets and negative electrode sheets, and a separator is generally provided between the positive electrode sheets and the negative electrode sheets. The positive electrode sheets and the negative electrode sheets each have a portion of an active material that constitutes an electrode body 52, and each have a portion that does not have an active material that constitutes a tab 51. The positive electrode tab and the negative electrode tab can be located together at one end of the electrode body 52 or can be located at opposite ends of the electrode body 52. During charging and discharging of the battery cell 3, the positive electrode active material and the negative electrode active material react with an electrolyte, and the tabs 51 connect to electrode terminals to form a current loop.

[0247] The electrode assembly 5 can be a wound structure, a stacked structure, or a hybrid structure of a wound structure and a stacked structure.

[0248] In some embodiments, the electrode assembly 5 is a wound structure. The positive electrode sheets and the negative electrode sheets are wound into a wound structure.

[0249] In some embodiments, the electrode assembly 5 is a stacked structure. As an example, a plurality of positive electrode sheets and a plurality of negative electrode sheets can be provided, and the plurality of positive electrode sheets and the plurality of negative electrode sheets can be alternately stacked. A plurality of separators can be provided and disposed between any adjacent positive electrode sheets or negative electrode sheets, or the separators can be continuously provided and disposed between any adjacent positive electrode sheets or negative electrode sheets by being folded.

[0250] In some embodiments, the electrode assembly 5 can have a cylindrical shape, a flat shape, or a polygonal shape.

[0251] In some embodiments, the electrode assembly 5 is provided with a tab that can lead current out of the electrode assembly. The tab includes a positive electrode tab and a negative electrode tab.

[0252] The battery cell can include a case. The case 4 is a component that cooperates with the top cover assembly 6 to form an internal environment of the battery cell 3, and the internal environment formed can be used to accommodate the electrode assembly 5, an electrolyte (not shown in the figure), and other components. The case 4 can be a steel case, an aluminum case, a plastic case (such as a polypropylene case), a composite metal case (such as a copper-aluminum composite case), or an aluminum-plastic film, etc. In some embodiments, the case 4 can be a sealed structure or a non-sealed structure. As an example, when the case 4 is a non-sealed structure, the case 4 serves to protect the electrode assembly 5, and a sealing bag is further included between the case 4 and the electrode assembly 5, and the sealing bag is used to package the electrode assembly and the electrolyte. Specifically, the sealing bag can be a bag-shaped insulating member or an aluminum-plastic film. When the case 4 is a sealed structure, it is used to package the electrode assembly 5, the electrolyte, and other components.

[0253] As an example, the battery cell 3 can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes, the prismatic battery cell including a square battery cell, a blade battery cell, a multi-prismatic battery cell, for example, a hexagonal battery cell, and the like, without specific limitation in the present application.

[0254] The shell 4 and the top cover assembly 6 can be independent components, one or more openings 41 can be provided on the shell 4, and the top cover assembly 6 covers the opening 41 to form an internal environment of the battery cell 3. Alternatively, the top cover assembly 6 and the shell 4 can be integrated. Alternatively, the top cover assembly 6 and the shell 4 can form a common connecting surface before other components enter the shell, and then the top cover assembly 6 covers the shell 4 when it is necessary to seal the internal environment of the shell 4.

[0255] In some embodiments, the electrode terminal 61 can be provided on the top cover assembly 6 or on the shell 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.

[0256] Please refer to FIG. 5, which is a structural schematic diagram of an electrode assembly of a battery cell according to an embodiment of the present application.

[0257] In the first aspect, as shown in FIG. 4 and FIG. 5, the present application provides a battery cell 3, which includes a shell 4, an electrode assembly 5, and a heat conduction assembly 8, the electrode assembly 5 is located in the shell 4, 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 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 tab 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 conduction assembly 8 includes a first heat conduction part 81, the first heat conduction part 81 is in heat conduction connection with the side face 523, and the heat conductivity of the heat conduction assembly 8 is greater than the heat conductivity of the shell 4.

[0258] In the scheme of the embodiment of the application, the battery monomer 3 comprises a shell 4, an electrode assembly 5 and a heat conduction assembly 8. The electrode assembly 5 is located inside the shell 4, and the shell 4 provides accommodation and protection for the electrode assembly 5. The electrode assembly 5 comprises an electrode main body 52 and a tab 51. The electrode main body 52 comprises 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 electrode main body 52 forms a loop with the tab 51 extending from the first end face 521 and / or the second end face 522 and external components. The heat conductivity of the heat conduction assembly 8 is greater than that of the shell 4. The heat conduction assembly 8 comprises a first heat conduction part 81. The first heat conduction part 81 is connected to the side face 523 of the electrode main body 52 through heat conduction. The first heat conduction part 81 can reduce the thermal resistance of the electrode main body 52 at the side face 523 thereof, improve the temperature uniformity of the electrode main body 52 at the side face 523 thereof, and improve the rate of heat exchange between the electrode main body 52 at the side face 523 thereof and the external environment, so as to balance the internal temperature of the battery monomer 3 and improve the performance and service life of the battery monomer 3 which are adversely affected by the excessively high or low internal temperature of the battery monomer 3.

[0259] The electrode main body 52 is formed in a winding or stacking manner by a separator, a positive electrode sheet 5241 and a negative electrode sheet 5242. The tab 51 comprises a positive tab and a negative tab. The positive tab and the negative tab both extend from the first end face 521 or the second end face 522, or one of the positive tab and the negative tab extends from the first end face 521 and the other extends from the second end face 522.

[0260] For example, the battery monomer 3 further comprises a top cover assembly 6 connected to the tab 51. The shell 4 comprises an opening 41 at one end 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 tab and the negative tab extend from the first end face 521 or the second end face 522 and are connected to the top cover assembly 6. Alternatively, the shell 4 comprises two openings 41 at two sides in the first direction X. Two top cover assemblies 6 cover the openings 41 respectively. The positive tab and the negative tab extend from the first end face 521 and the second end face 522 respectively and are connected to the top cover assemblies 6.

[0261] For example, the first direction X is the height direction of the electrode assembly 5.

[0262] The first heat conduction part 81 is in heat conduction connection with the side face 523 of the electrode main body 52. The first heat conduction part 81 is directly attached to or abuts against the side face 523 of the electrode main body 52. Alternatively, the first heat conduction part 81 is a plating layer arranged on the side face 523. Alternatively, the first heat conduction part 81 and the side face 523 of the electrode main body 52 are arranged in a spaced manner. The first heat conduction part 81 is connected to the side face 523 through a heat conduction medium. The heat conduction medium can be air, metal or heat conduction glue, etc.

[0263] During the working process of the battery cell 3, the heat generated by the electrode body 52 can be transmitted to the external environment through the heat conduction assembly 8, thereby improving the problem of the electrode body 52 being damaged due to excessively high temperature; or in a low-temperature environment, the heat conduction assembly 8 can conduct the heat from the external environment to the electrode body 52 to heat the electrode assembly 5.

[0264] Optionally, the battery device 2 comprises a heat exchange mechanism, the shell of the battery cell 3 is in heat conduction connection with the heat exchange mechanism, the heat conduction assembly 8 can conduct heat between the heat exchange mechanism and the electrode assembly 5, and the heat exchange mechanism can conduct heat into or out of the heat conduction assembly 8.

[0265] Illustratively, the heat exchange mechanism can be a water-cooled plate or a phase-change heat dissipation plate arranged on the outer surface of the battery cell 3, or a cavity containing a heat exchange medium.

[0266] The first heat conduction part 81 can be in a strip shape or a flat plate shape or a mesh plate shape, and the first heat conduction part 81 can be in a rectangular shape or a circular shape or a rhombic shape, and the specific shape and size of the first heat conduction part 81 can be flexibly designed.

[0267] Optionally, a plurality of first heat conduction parts 81 are arranged at intervals on the side surface 523 of the electrode body 52, which can not only conduct the heat of the electrode body 52 through the first heat conduction part 81, but also reduce the size of the heat conduction assembly 8 and reduce the preparation cost of the battery cell 3.

[0268] During the working process of the electrode assembly 5, the temperature of the end of the electrode body 52 close to the tab 51 is relatively high, and the temperature of the end far away from the tab 51 is relatively low, and the first heat conduction part 81 arranged on the side surface 523 of the electrode body 52 can conduct and balance the temperature of the electrode assembly 5 in the first direction X.

[0269] Optionally, in the first direction X, the first heat conduction part 81 extends to both ends of the electrode body 52.

[0270] Optionally, the first heat conduction part 81 covers the entire side surface 523 of the electrode body 52, so as to improve the heat conduction rate of the first heat conduction part 81.

[0271] The heat conductivity of the heat conduction assembly 8 is greater than that of the shell 4, and the heat conduction assembly 8 can comprise copper or copper alloy or silver or silver alloy or graphite or graphene or carbon nanotube, etc.

[0272] Please refer to FIG. 6, which is a partial structure schematic diagram of a battery cell according to an embodiment of the present application.

[0273] In some embodiments, as shown in FIGS. 4-6, the side surface 523 includes two first side surfaces 5231 and two second side surfaces 5232, the two first side surfaces 5231 are oppositely arranged in the second direction Y, and the two second side surfaces 5232 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 surface 5231 is greater than the area of the second side surface 5232, and the first heat conduction part 81 is arranged on at least one of the two first side surfaces 5231.

[0274] In these embodiments, the side surface 523 includes two first side surfaces 5231 and two second side surfaces 5232, the area of the first side surface 5231 is greater than the area of the second side surface 5232, and the first heat conduction part 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 conduction part 81 and the electrode body 52 to enhance the heat conduction rate of the electrode assembly 5, but also better matches the large-area heat exchange scheme, shortens the heat conduction path of the first heat conduction part 81 and the heat exchange mechanism, and improves the heat conduction rate of the electrode assembly 5 to better balance the internal temperature of the battery monomer 3.

[0275] Optionally, the second direction Y is the thickness direction of the electrode assembly 5, and the first side surface 5231 is the large area 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.

[0276] The electrode body 52 includes first side surfaces 5231 and second side surfaces 5232 with different areas, and the cross section of the electrode body 52 in the first direction X is rectangular or elliptical, for example.

[0277] The area of the first side surface 5231 is greater than the area of the second side surface 5232, so that a larger area of the first heat conduction part 81 can be arranged on the first side surface 5231 to improve the heat conduction rate of the first heat conduction part 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 yourself.

[0278] Optionally, the first heat conduction part 81 covers the entire first side surface 5231 to improve the heat conduction rate of the first heat conduction part 81.

[0279] In the large-area water cooling scheme, the heat exchange mechanism is heat-conductively connected to the side wall of the battery monomer 3 in the second direction Y, so that the first heat conduction part 81 arranged on the first side surface 5231 has a smaller distance and a larger projection overlap area with the heat exchange mechanism, which can better transfer heat between the heat exchange mechanism and the electrode assembly 5.

[0280] When heat is transferred inside an object in the form of heat conduction, the resistance encountered is called thermal resistance of heat conduction. In the battery cell 3, heat of the electrode assembly 5 is generally conducted along the current collector. Specifically, most of the heat is transferred along the length or width direction of the first side surface 5231 of the electrode body 52, which results in a relatively large thermal resistance of the electrode body 52 in the thickness direction, i.e., the second direction Y. Therefore, the first heat conduction part 81 is arranged on the first side surface 5231 to accelerate heat exchange of the electrode body 52 with the external environment in the second direction Y.

[0281] In some embodiments, as shown in FIGS. 4-6, at least part of the first heat conduction part 81 is arranged between the first side surface 5231 of the electrode assembly 5 and the shell 4 in the second direction Y.

[0282] In these embodiments, at least part of the first heat conduction part 81 is arranged between the first side surface 5231 of the electrode assembly 5 and the shell 4 in the second direction Y to shorten the distance between the first heat conduction part 81 and the shell 4, so that the electrode assembly 5 can exchange heat with the external environment through the first heat conduction part 81 and the shell 4 more quickly, thereby improving the heat conduction rate of the electrode assembly 5.

[0283] Specifically, when the electrode assembly 5 includes one electrode body 52 in the second direction Y, at least part of the first heat conduction part 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 conduction part 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.

[0284] The electrode assembly 5 exchanges heat with the external environment through the shell 4 and the first heat conduction part 81, the first heat conduction part 81 is arranged between the electrode assembly 5 and the shell 4 in the second direction Y to shorten the distance between the shell 4 and the first heat conduction part 81, thereby accelerating the heat exchange rate between the first heat conduction part 81 and the shell 4, and more quickly balancing the temperature of the electrode assembly 5.

[0285] Referring to FIG. 7, FIG. 7 is a schematic diagram of a partial structure of a battery cell according to another embodiment of the present application.

[0286] In some embodiments, as shown in FIGS. 5 and 7, the first heat conduction part 81 is provided with a first through hole 815.

[0287] In these embodiments, the first through hole 815 arranged on the first heat conduction part 81 facilitates the flow of electrolyte to the electrode assembly 5, thereby improving the infiltration efficiency of the electrolyte to the electrode assembly 5.

[0288] Inside the shell 4, the electrolyte can infiltrate the electrode assembly 5 through the first through hole 815.

[0289] The first heat-conducting part 81 can be provided with one or more first through holes 815. The shape and size of the first through holes 815 can be designed as needed. For example, the first through holes 815 can be circular holes, rectangular holes, triangular holes, or the like.

[0290] For example, the first heat-conducting part 81 is uniformly provided with a plurality of first through holes 815 to form a mesh. In this way, the first heat-conducting part 81 can provide uniform heat conduction for the side surface 523, and the electrolyte can be uniformly infiltrated into the electrode assembly 5.

[0291] FIG. 8 is a schematic diagram of a partial structure of a battery cell according to an embodiment of the present application.

[0292] In some embodiments, as shown in FIGS. 4, 5, and 8, 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 the 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.

[0293] In these embodiments, 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 the 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. The heat can be conducted between the two end heat-conducting members 813 through the side heat-conducting member 814, so as to balance the heat of the two end heat-conducting members 813 and improve the heat conduction efficiency of the first heat-conducting part 81. In addition, the first heat-conducting part 81 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 two large surfaces, shorten the heat conduction path of the first heat-conducting part 81 and the heat exchange mechanism, and improve the heat conduction efficiency on the electrode assembly 5.

[0294] When the ambient temperature on both sides of the shell 4 in the second direction Y is similar, or when the heat exchange performance of the heat exchange mechanism on both sides of the shell 4 in the second direction Y is similar, the heat of the first side surface 5231 is transferred to the end heat-conducting member 813 and then to the heat exchange mechanism. The heat of the second side surface 5232 is transferred to the side heat-conducting member 814 and then to the heat exchange mechanism through the two end heat-conducting members 813 on both sides, so as to improve the heat exchange rate at the second side surface 5232.

[0295] When the temperature difference between the external environment and the internal environment on the second direction Y side of the shell 4 is larger, or the heat exchange performance of the heat exchange mechanisms on both sides of the second direction Y of the shell 4 is different, for the convenience of description, the two end heat conduction members 813 are respectively a first end heat conduction member and a second end heat conduction member, the first end heat conduction member is close to a heat exchange mechanism with higher heat conduction efficiency, and the second end heat conduction member is close to a heat exchange mechanism with lower heat conduction efficiency, or no heat exchange mechanism is arranged, then the heat on the first side surface 5231 is transferred to the second end heat conduction member, part of the heat of the second end heat conduction member is transferred to the heat exchange mechanism close to it, and another part of the heat is transferred to the first end heat conduction member through the side heat conduction member 814, and is transferred to the heat exchange mechanism close to the first end heat conduction member, so as to improve the overall heat conduction rate of the heat conduction assembly 8.

[0296] Optionally, the end heat conduction member 813 and the side heat conduction member 814 are integrally formed to reduce the splicing seam of the heat conduction assembly 8 and improve the structural strength of the heat conduction assembly 8; or the end heat conduction member 813 and the side heat conduction member 814 are separately prepared and connected to each other, so as to more conveniently adjust the size of each part and adapt to electrode assemblies 5 of different sizes.

[0297] Please refer to FIG. 9, which is a partial structure diagram of a battery monomer provided by an embodiment of the present application.

[0298] In some embodiments, as shown in FIGS. 4, 5 and 9, a plurality of electrode assemblies 5 are provided, the plurality of electrode assemblies 5 are arranged in layers along the second direction Y, and at least part of the first heat conduction part 81 is arranged between adjacent two first side surfaces 5231 of adjacent two electrode assemblies 5.

[0299] In these embodiments, the plurality of electrode assemblies 5 are arranged in layers along the second direction Y, at least part of the first heat conduction part 81 is arranged between adjacent two first side surfaces 5231 of adjacent two electrode assemblies 5, and the temperature of the electrode assembly 5 can be balanced in the first direction X through the first heat conduction part 81, so as to improve the performance of the battery monomer 3.

[0300] The electrode assembly 5 is formed by stacking the positive electrode sheet 5241, the negative electrode sheet 5242 and the separator, and the positive electrode sheet 5241 and the negative electrode sheet 5242 are sequentially located between adjacent separators. The electrode sheet includes a current collector and a tab 51, and the current collectors of the positive electrode sheet 5241 and the negative electrode sheet 5242 and the separators are stacked to form an electrode body 52.

[0301] A plurality of electrode assemblies 5 are arranged in the shell 4, and the same number of positive electrode sheets 5241 and negative electrode sheets 5242 are included in a single electrode assembly. For example, 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.

[0302] At least part of the first heat-conducting part 81 is arranged between the two adjacent first side surfaces 5231 of the two adjacent electrode assemblies 5, so that the first heat-conducting part 81 does not affect the ion flow between the positive electrode tab 5241 and the negative electrode tab 5242 in the electrode assembly 5.

[0303] Optionally, the first heat-conducting part 81 is in the form of a flat plate and covers the entire first side surface 5231, so as to increase the contact area between the electrode assembly 5 and the heat-conducting assembly 8 and increase the heat-conducting rate of the heat-conducting assembly 8.

[0304] Optionally, the first heat-conducting part 81 is in the form of a mesh plate or a plurality of first heat-conducting parts 81 are arranged at intervals, so as to facilitate the ion flow between the adjacent electrode assemblies 5.

[0305] Optionally, the first heat-conducting part 81 extends to both ends of the current collector in the first direction X, so that the first heat-conducting part 81 can better balance the temperature of the electrode tab in the first direction X.

[0306] Optionally, the electrode assembly 5 and the first heat-conducting part 81 are insulated from each other, the first heat-conducting part 81 is made of an insulating material, or an insulating layer is arranged between the first heat-conducting part 81 and the electrode assembly 5, so as to improve the problem that the connection between the electrode assembly 5 and the heat-conducting assembly 8 causes the battery monomer 3 to malfunction.

[0307] The specific number of the electrode assemblies 5 can be designed by the user, for example, two or three or four or five or the like electrode assemblies 5 can be arranged in the shell 4.

[0308] Please refer to FIG. 10, FIG. 11 and FIG. 12, FIG. 10 is a partial structure schematic diagram of a battery monomer provided by an embodiment of the present application; FIG. 11 is a partial structure schematic diagram of a battery monomer provided by an embodiment of the present application; FIG. 12 is a partial structure schematic diagram of a battery monomer provided by an embodiment of the present application.

[0309] In some embodiments, as shown in FIG. 4, FIG. 5 and FIG. 10 to FIG. 12, the first heat-conducting part 81 includes a middle heat-conducting piece 812 and a side heat-conducting piece 814, the middle heat-conducting piece 812 is arranged between the two adjacent first side surfaces 5231 of the two adjacent electrode assemblies 5, and the side heat-conducting piece 814 is arranged on at least one second side surface 5232 and connected to the middle heat-conducting piece 812.

[0310] In these embodiments, the middle heat-conducting piece 812 between the adjacent electrode assemblies 5 helps to conduct the heat between the two adjacent first side surfaces 5231 out, the side heat-conducting piece 814 is arranged on at least one second side surface 5232 and connected to the middle heat-conducting piece 812, the heat of the middle heat-conducting piece 812 is transferred to the side heat-conducting piece 814, and the heat exchange between the side heat-conducting piece 814 and the external environment is performed, so as to balance the internal temperature of the battery monomer 3.

[0311] The heat between the adjacent electrode assemblies 5 is not easy to exchange with the outside through the shell 4, and therefore, in this embodiment, a middle heat conduction member 812 is arranged between the first side surfaces 5231 of the adjacent electrode assemblies 5, the heat of the adjacent two first side surfaces 5231 is transferred to the middle heat conduction member 812, and is transferred to the side heat conduction member 814 by the middle heat conduction member 812, and the heat exchanges with the outside environment at the side heat conduction member 814.

[0312] Alternatively, the side heat conduction member 814 and the end heat conduction member 813 are connected, and the heat is transferred to the end heat conduction member 813 by the side heat conduction member 814 and exchanges with the outside environment.

[0313] For example, one end of the side heat conduction member 814 is connected with the middle heat conduction member 812, and the other end extends along the second direction Y, that is, the first heat conduction part 81 is bent to form the side heat conduction member 814 and the middle heat conduction member 812, which reduces the processing difficulty of the heat conduction assembly 8; or the middle heat conduction member 812 is connected to the middle region of the side heat conduction member 814, and the two ends of the side heat conduction member 814 extend away from each other in the second direction Y, which extends the size of the side heat conduction member 814 to improve the heat conduction efficiency at the side heat conduction member 814.

[0314] Alternatively, two middle heat conduction members 812 are independently arranged and located between the adjacent first side surfaces 5231 of the adjacent two electrode assemblies 5, and two side heat conduction members 814 are respectively located on the two sides of the two middle heat conduction members 812 along the second direction Y, and each middle heat conduction member 812 is connected to the adjacent side heat conduction member 814, so that during the expansion of the electrode assembly 5, the connected middle heat conduction member 812 and side heat conduction member 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 conduction assembly 8 during the expansion of the electrode body 52, and improve the reliability of the battery monomer 3.

[0315] In some embodiments, as shown in FIGS. 4, 5 and 10, the first heat conduction part 81 further includes an end heat conduction member 813, the end heat conduction member 813 is arranged between the shell 4 and the adjacent first side surface 5231, and the two sides of the side heat conduction member 814 along the second direction Y are respectively connected to the middle heat conduction member 812 and the end heat conduction member 813.

[0316] In these embodiments, the first heat conduction part 81 further includes an end heat conduction member 813, the end heat conduction member 813 is arranged between the shell 4 and the adjacent first side surface 5231, and the two sides of the side heat conduction member 814 along the second direction Y are respectively connected to the middle heat conduction member 812 and the end heat conduction member 813, so that the heat between the adjacent electrode assemblies 5 can be transferred to the end heat conduction member 813 through the middle heat conduction member 812 and the side heat conduction member 814, and exchanges with the outside environment at the end heat conduction member 813 to balance the internal temperature of the battery monomer 3.

[0317] The middle heat conduction member 812 is arranged between the first side surfaces 5231 of the adjacent electrode assemblies 5. The heat of the adjacent two first side surfaces 5231 is transferred to the middle heat conduction member 812, and is transferred to the end heat conduction member 813 through the side heat conduction member 814, and is transferred to the outside through the shell 4 at the end heat conduction member 813 and / or the side heat conduction member 814.

[0318] For example, the heat exchange mechanism is arranged on the side of the shell 4 close to the end heat conduction member 813 in the second direction Y. After the heat of the middle heat conduction member 812 is transferred to the end heat conduction member 813, the heat is transferred to the heat exchange mechanism.

[0319] For example, two electrode assemblies 5 are arranged, and the two electrode assemblies 5 are arranged in a stacked manner in the second direction Y. The middle heat conduction member 812, the end heat conduction member 813, and the side heat conduction member 814 are arranged outside each electrode assembly 5.

[0320] Optionally, the end heat conduction member 813, the side heat conduction member 814, and the middle heat conduction member 812 are integrally formed to reduce the joint of the heat conduction assembly 8 and improve the structural strength of the heat conduction assembly 8. Alternatively, the end heat conduction member 813, the side heat conduction member 814, and the middle heat conduction member 812 are separately prepared and connected to each other, so as to more conveniently adjust the sizes of the parts and adapt to electrode assemblies 5 of different sizes.

[0321] In some embodiments, as shown in FIGS. 4, 5, 11, and 12, the side heat conduction member 814 is provided with two, and the first heat conduction part 81 further includes two end heat conduction members 813. The two end heat conduction members 813 are arranged between the shell 4 and the adjacent two first side surfaces 5231, respectively. The two side heat conduction members 814 are arranged on the second side surfaces 5232 of different electrode assemblies 5, respectively. One side heat conduction member 814 is connected to the middle heat conduction member 812 and one end heat conduction member 813 on both sides in the second direction Y. The other side heat conduction member 814 is connected to the middle heat conduction member 812 and the other end heat conduction member 813 on both sides in the second direction Y.

[0322] In these embodiments, the first heat conduction part 81 further includes two end heat conduction members 813. The heat between the adjacent electrode assemblies 5 can be transferred to the middle heat conduction member 812. The two end heat conduction members 813 are arranged between the shell 4 and the adjacent two first side surfaces 5231, respectively. The two side heat conduction members 814 are arranged on the second side surfaces 5232 of different electrode assemblies 5, respectively, and are connected to the middle heat conduction member 812 and one end heat conduction member 813, respectively. In this way, the heat of the middle heat conduction member 812 can be transferred to the end heat conduction member 813 through the side heat conduction member 814, and heat exchange is performed between the end heat conduction member 813 and the outside environment, so as to balance the internal temperature of the battery monomer 3.

[0323] Through the combination of the middle heat conduction member 812, the end heat conduction member 813 and the side heat conduction member 814, the heat of the two first side surfaces 5231 of the adjacent electrode assembly 5 can be transferred to the middle heat conduction member 812, and then the heat of the middle heat conduction member 812 can be transferred to the two end heat conduction members 813 through the side heat conduction member 814 and to the outside through the shell 4;

[0324] Alternatively, the temperature difference between the outside environment and the inside environment of the shell 4 on the second direction Y side is larger, and the heat of the middle heat conduction member 812 and one of the end heat conduction members 813 is transferred to the other end heat conduction member 813 through the side heat conduction member 814, and heat exchange is performed at this position and the outside environment. For example, the heat exchange mechanism is arranged at one end of the shell 4 in the second direction Y.

[0325] Alternatively, the temperature difference between the outside environment and the inside environment of the shell 4 in the third direction Z is larger, and the heat of the middle heat conduction member 812 and the two end heat conduction members 813 is transferred to the side heat conduction member 814, and heat exchange is performed at this position and the outside environment. For example, the heat exchange mechanism is arranged at least one end of the shell 4 in the third direction Z.

[0326] In some embodiments, as shown in FIG. 4, FIG. 5 and FIG. 11, two side heat conduction members 814 are arranged on both sides of the plurality of electrode assemblies 5 along the third direction Z.

[0327] In these embodiments, two side heat conduction members 814 are arranged on both sides of the plurality of electrode assemblies 5 along the third direction Z, and then the two side heat conduction members 814 are connected to the middle heat conduction member 812 on both sides in the third direction Z, so as to improve the heat conduction efficiency between the middle heat conduction member 812 and the side heat conduction member 814.

[0328] The middle heat conduction member 812, the two side heat conduction members 814 and the two end heat conduction members 813 are integrally prepared, which can be formed by bending and winding a first heat conduction part 81 around the electrode assembly 5, and the processing difficulty is low.

[0329] Two side heat conduction members 814 are arranged on both sides of the plurality of electrode assemblies 5 along the third direction Z, so that the temperature of the adjacent two first side surfaces 5231 is transferred between the middle heat conduction member 812, and the heat is transferred from both ends of the middle heat conduction member 812 to the two side heat conduction 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 of the two first side surfaces 5231 in the third direction Z.

[0330] Optionally, the two side heat conduction members 814 have the same shape and size, so that the temperature transferred from the middle heat conduction member 812 to the two side heat conduction members 814 is similar.

[0331] In some embodiments, as shown in FIG. 4, FIG. 5 and FIG. 12, two side heat conductive members 814 are arranged on the same side of the plurality of electrode assemblies 5 along the third direction Z.

[0332] In these embodiments, two side heat conductive members 814 are arranged on the same side of the plurality of electrode assemblies 5 along the third direction Z to reduce the overall size of the heat conductive assembly 8 along the third direction Z and to improve the energy density of the battery monomer 3.

[0333] After the heat is transferred between the adjacent first side surfaces 5231 to the middle heat conductive member 812 and then to the side heat conductive member 814 at the same end along the third direction Z, the heat exchange mechanism arranged on one side of the shell 4 along the third direction Z can effectively exchange heat with the heat conductive assembly 8 and reduce the difficulty of arranging the heat exchange mechanism matched with the battery monomer 3.

[0334] Optionally, the two side heat conductive members 814 are in thermal conduction connection, 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 or to the other end heat conductive member 813.

[0335] Please refer to FIG. 13, which is a schematic diagram of the partial structure of the battery monomer provided in an embodiment of the present application.

[0336] In some embodiments, as shown in FIG. 9 and FIG. 13, the electrode assembly 5 is in a jelly-roll type or a stacked type.

[0337] In these embodiments, the electrode assembly 5 is in a jelly-roll type or a stacked type, and the first heat conductive part 81 in thermal conduction connection with the side surface 523 of the electrode assembly 5 can reduce the thermal resistance of the electrode body 52 at the side surface 523 thereof, improve the heat exchange rate between the electrode body 52 at the side surface thereof and the external environment, and balance the internal temperature of the battery monomer 3 to improve the performance and service life of the battery monomer 3 affected by the excessively high or low internal temperature of the battery monomer 3.

[0338] As shown in FIG. 13, the electrode assembly 5 in a jelly-roll type is formed by winding the positive electrode sheet 5241, the negative electrode sheet 5242 and the separator, and the first heat conductive part 81 is arranged between the separators of the adjacent two electrode assemblies 5; as shown in FIG. 9, the electrode assembly in a stacked type is formed by sequentially stacking the positive electrode sheet 5241, the negative electrode sheet 5242 and the separator, and the first heat conductive part 81 is arranged between the separators of the adjacent two electrode assemblies 5.

[0339] Please refer to FIG. 14 and FIG. 15, FIG. 14 is a schematic diagram of the partial structure of the battery monomer provided in an embodiment of the present application; and FIG. 15 is a schematic diagram of the partial structure of the battery monomer provided in an embodiment of the present application.

[0340] In some embodiments, as shown in FIG. 4, FIG. 14 and FIG. 15, the first heat-conducting part 81 is arranged around the circumferential side of the electrode body 52.

[0341] In these embodiments, the first heat-conducting part 81 is arranged around the circumferential side of the electrode body 52 to increase the contact area between the heat-conducting assembly 8 and the side surface 523 of the electrode body 52, further increase the heat exchange rate of the electrode body 52 at its side surface and the external environment, balance the temperature inside the battery monomer 3, and improve the problem of adverse effects on the performance and service life of the battery monomer due to the excessively high or low temperature inside the battery monomer 3.

[0342] The electrode body 52 is in a cylindrical shape, and the first heat-conducting part 81 is arranged around the circumferential surface of the electrode body 52; or the electrode body 52 is in a flat shape, and the first heat-conducting part 81 is arranged around the first side surface 5231 and the second side surface 5232.

[0343] The first heat-conducting part 81 arranged on the side surface 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.

[0344] Optionally, the first heat-conducting part 81 covers the entire side surface 523 of the electrode body 52 to increase the contact area between the first heat-conducting part 81 and the electrode body 52 and improve the heat conduction rate of the first heat-conducting part 81.

[0345] In some embodiments, as shown in FIG. 4, FIG. 14 and FIG. 15, the first heat-conducting part 81 is formed with a gap 811 extending along the first direction X and penetrating through the first heat-conducting part 81 between the two ends of the circumferential side of the electrode body 52.

[0346] In these embodiments, the first heat-conducting part 81 is formed with a gap 811 extending along the first direction X and penetrating through the first heat-conducting part 81 between the two ends of the circumferential side of the electrode body 52. By arranging the gap 811, the first heat-conducting part 81 can deform synchronously during the expansion of the electrode assembly 5, reducing the risk of the first heat-conducting part being expanded by the electrode body 52, improving the service life of the heat-conducting assembly 8, and improving the reliability of the battery monomer 3.

[0347] The first heat-conducting part 81 is formed with a gap 811 between the two ends of the circumferential side of the electrode body 52 to make the first heat-conducting part 81 elastically deformable. In this way, during the charging and discharging process of the battery monomer 3, when the electrode assembly 5 expands, the distance between the two ends of the first heat-conducting part 81 increases, reducing the risk of the first heat-conducting part 81 being crushed by the electrode assembly 5; when the electrode assembly 5 shrinks, the distance between the two ends of the first heat-conducting part 81 decreases, and the first heat-conducting part 81 is attached to the electrode assembly 5, maintaining good heat conduction effect. The specific size of the gap 811 can be designed by oneself.

[0348] Optionally, as shown in FIG. 15, the first side surface 5231 and the second side surface 5232 are connected by a rounded corner, and the gap 811 is arranged at the rounded corner of the first side surface 5231 and the second side surface 5232, so that the heat conduction assembly 8 can be arranged as large as possible on the flat part of the first side surface 5231 and / or the second side surface 5232.

[0349] Optionally, the gap 811 extends linearly along the first direction X, so as to reduce the size of the gap 811.

[0350] In some embodiments, as shown in FIG. 4 and FIG. 14, the gap 811 is arranged at at least one of the two first side surfaces 5231.

[0351] In these embodiments, the electrode assembly 5 expands more at the first side surface 5231 during the expansion of the electrode assembly 5, so that the gap 811 is arranged at at least one of the two first side surfaces 5231, so that the first heat conduction part 81 can more easily absorb the expansion of the electrode assembly 5 through the gap 811, further reducing the risk of the first heat conduction part 81 being expanded by the electrode body 52, improving the service life of the heat conduction assembly 8, and improving the reliability of the battery cell 3.

[0352] For example, the first heat conduction part 81 is arranged around the periphery of the electrode body 52, and the gap 811 is arranged at the corresponding part of the first heat conduction part 81 and at least one of the first side surfaces 5231; or the first heat conduction part 81 includes two end heat conduction members 813 and two side heat conduction members 814 connected to each other, and the gap 811 is arranged on at least one of the end heat conduction members 813; or the first heat conduction part 81 includes an end heat conduction member 813, a middle heat conduction member 812, and two side heat conduction members 814 connected to each other, and the gap 811 is arranged on the end heat conduction member 813 and / or the middle heat conduction member 812.

[0353] Optionally, the gap 811 is arranged at the central position of the first side surface 5231 in the third direction Z, and the central position of the first side surface 5231 in the third direction Z has a larger amplitude during the expansion of the electrode assembly 5, so that the gap 811 is arranged at this position, and the first heat conduction part 81 can better overcome the expansion of the electrode assembly 5 through the gap 811.

[0354] In some embodiments, as shown in FIG. 4 and FIG. 14, the gap 811 is arranged at the two first side surfaces 5231.

[0355] In these embodiments, the gap 811 is arranged at the two first side surfaces 5231, so that the first heat conduction part 81 can more easily deform synchronously during the expansion of the electrode assembly 5, so as to reduce the risk of the first heat conduction part 81 being expanded by the electrode body 52.

[0356] The gap 811 is arranged at the two first sides 5231, and the first heat conduction part 81 is divided into two parts arranged in the third direction Z, so as to reduce the risk that the first heat conduction part 81 is broken by the first sides 5231 of the electrode assembly 5 bulging during the expansion of the electrode assembly 5.

[0357] For example, the first heat conduction part 81 is arranged around the periphery of the electrode body 52, and the gap 811 is arranged at the two parts corresponding to the two first sides 5231 of the first heat conduction part 81; or the first heat conduction part 81 includes two end heat conduction members 813 and two side heat conduction members 814 connected with each other, and the gap 811 is arranged on the two end heat conduction members 813; or the first heat conduction part 81 includes the end heat conduction member 813, the middle heat conduction member 812 and the two side heat conduction members 814 connected with each other, and the gap 811 is arranged at the end heat conduction member 813 and the middle heat conduction member 812.

[0358] Optionally, the gap 811 is arranged at the central position of the first side 5231 in the third direction Z, so that the two parts of the first heat conduction part 81 on both sides of the gap 811 in the third direction Z have the same shape, and the two parts of the first heat conduction part 81 can be used universally, so as to save the processing cost of the first heat conduction part 81.

[0359] Please refer to FIG. 16, which is a schematic diagram of the partial structure of the battery monomer provided in an embodiment of the present application.

[0360] In some embodiments, as shown in FIG. 4 and FIG. 16, the electrode assembly 5 is provided in plurality, the plurality of electrode assemblies 5 are arranged in layers along the second direction Y, and the first heat conduction part 81 is arranged around the periphery of the whole formed by the plurality of electrode assemblies 5.

[0361] In these embodiments, the electrode assembly 5 is provided in plurality, the plurality of electrode assemblies 5 are arranged in layers along the second direction Y, and the first heat conduction part 81 is arranged around the periphery of the whole formed by the plurality of electrode assemblies 5, so as to shorten the heat conduction path between the first heat conduction part 81 and the shell 4, and make the first heat conduction part more easily conduct heat between the electrode assembly 5 and the external environment.

[0362] The first heat conduction part 81 is arranged around the periphery of the whole formed by the plurality of electrode assemblies 5, and the first heat conduction part 81 is arranged on the two first sides 5231 close to the shell 4 and the second side 5232 of each electrode assembly 5.

[0363] Optionally, the gap 811 is arranged at the connection between the circular corner close to the one first side 5231 of the shell 4 and the one second side 5232.

[0364] Please refer to FIG. 17 and FIG. 18, which are schematic diagrams of the partial structure of the battery monomer provided in an embodiment of the present application.

[0365] In some embodiments, as shown in FIG. 5, FIG. 17 and FIG. 18, the tab 51 extends out of the first end face 521, and the heat conduction assembly 8 further comprises a second heat conduction part 82, which is arranged between the shell 4 and at least part of the second end face 522 along the first direction X.

[0366] In these embodiments, the heat conduction assembly 8 further comprises a second heat conduction part 82 arranged between the shell 4 and at least part of the second end face 522 along the first direction X, through which the heat exchange rate of the electrode body 52 at the second end face 522 thereof and the external environment can be improved.

[0367] The positive and negative tabs of the electrode assembly 5 both extend out of the first end face 521, and the second heat conduction part 82 is arranged between the shell 4 and at least part of the second end face 522 along the first direction X, and the heat of the second end face 522 can be transferred to the second heat conduction part 82 and then to the outside by the second heat conduction part 82.

[0368] Optionally, the heat exchange mechanism is arranged at one end of the battery monomer 3 where no tab 51 is arranged, and the second heat conduction part 82 can transfer heat between the heat exchange mechanism and the second end face 522.

[0369] Optionally, the second heat conduction part 82 covers the entire second end face 522 of the electrode assembly 5, so as to improve the heat conduction rate of the second heat conduction part 82.

[0370] Optionally, the shape and size of the second heat conduction part 82 can be flexibly designed, for example, the second heat conduction part 82 is in the shape of a rectangle or a circle, etc.

[0371] In some embodiments, as shown in FIG. 5 and FIG. 18, the first heat conduction part 81 and the second heat conduction part 82 are connected.

[0372] In these embodiments, the first heat conduction part 81 and the second heat conduction part 82 are connected, so as to increase the contact area of the heat conduction assembly 8 and the electrode assembly 5, and further improve the heat exchange rate of the electrode assembly 5 and the external environment, so as to balance the internal temperature of the battery monomer 3 and improve the problem of adverse effects on the performance and service life of the battery monomer 3 due to excessively high or low internal temperature of the battery monomer 3.

[0373] When the first heat conduction part 81 is located between the shell 4 and the electrode assembly 5, the first heat conduction part and the second heat conduction part 82 are connected to each other, so as to increase the contact area of the heat conduction assembly 8 and the shell 4 and improve the heat conduction rate of the heat conduction assembly 8; or when the first heat conduction part 81 is located between adjacent electrode assemblies 5, the first heat conduction part 81 and the second heat conduction part 82 are connected, and then the heat of the adjacent electrode bodies 52 is transferred to the second heat conduction part 82 through the first heat conduction part 81 and then to the outside through the shell 4.

[0374] Optionally, the first heat-conducting part 81 and the second heat-conducting part 82 are integrally formed to reduce the connection gap between the first heat-conducting part 81 and the second heat-conducting part 82, improve the structural strength of the heat-conducting assembly 8, and improve the heat-conducting 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 respectively prepared and connected by bonding or clamping or welding to facilitate adjusting the size of the first heat-conducting part 81 and the second heat-conducting part 82 to adapt to the electrode assembly 5 of different sizes.

[0375] Please refer to FIG. 19, which is a schematic diagram of a heat-conducting assembly of a battery cell according to an embodiment of the present application.

[0376] In some embodiments, as shown in FIGS. 4, 5 and 19, the second heat-conducting part 82 is provided with a second through hole 821.

[0377] In these embodiments, the second through hole 821 provided on the second heat-conducting part 82 facilitates the flow of electrolyte to the electrode assembly 5 after the electrolyte is injected into the shell 4, thereby improving the infiltration efficiency of the electrolyte on the electrode assembly 5.

[0378] The electrolyte in the shell 4 can infiltrate the electrode assembly 5 through the second through hole 821.

[0379] The second heat-conducting part 82 can be provided with one or more second through holes 821, and the shape and size of the second through hole 821 can be designed as needed. For example, the second through hole 821 can be a circular hole, a rectangular hole, a triangular hole, or the like.

[0380] For example, the second heat-conducting part 82 is uniformly provided with a plurality of second through holes 821 to form a mesh, which can not only provide uniform heat-conducting effect for the second end face 522, but also facilitate the uniform infiltration of the electrolyte on the electrode assembly 5.

[0381] Please refer to FIG. 20, which is a schematic diagram of part of the structure of a battery cell according to an embodiment of the present application.

[0382] In some embodiments, as shown in FIGS. 5 and 20, 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, the two second side faces 5232 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 that of the second side face 5232, the first heat-conducting part 81 is arranged on at least one of the two first side faces 5231, and the second heat-conducting part 82 is connected with the first heat-conducting part 81 arranged on the first side face 5231.

[0383] In the embodiments, the second heat-conducting part 82 and the first heat-conducting part 81 arranged on the first side surface 5231 are connected, which can increase the contact area of the first heat-conducting part 81 and the second heat-conducting part 82, improve the heat conduction efficiency between the first heat-conducting part 81 and the second heat-conducting part 82, and improve the connection reliability between the first heat-conducting part 81 and the second heat-conducting part 82.

[0384] The area of the first side surface 5231 is greater than the area of the second side surface 5232, and thus, compared with the case where the second heat-conducting part 82 and the first heat-conducting part 81 located on the second side surface 5232 are connected, the contact range of the second heat-conducting part 82 and the first heat-conducting part 81 located on the first side surface 5231 is greater, which is more conducive to heat transfer between the first heat-conducting part 81 and the second heat-conducting part 82.

[0385] The first heat-conducting part 81 and the second heat-conducting part 82 can be connected in a fusion manner, and thus, when the second heat-conducting part 82 and the first heat-conducting part 81 located on the first side surface 5231 are connected, the contact range of the two is greater, and the connection strength is higher.

[0386] Please refer to FIG. 21, which is a schematic diagram of a partial structure of a battery cell according to an embodiment of the present application.

[0387] In some embodiments, as shown in FIG. 5 and FIG. 21, a plurality of electrode assemblies 5 are arranged, the plurality of electrode assemblies 5 are arranged in a stacking manner 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 the second heat-conducting part 82 is arranged in a plurality of independent manners, and the plurality of second heat-conducting parts 82 are arranged correspondingly to at least one electrode assembly 5.

[0388] In the embodiments, the plurality of electrode assemblies 5 are arranged in a stacking manner along the second direction Y, and 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, so that heat exchange can be performed between one first heat-conducting part 81 and the first side surface 5231 of one or two electrode assemblies 5, and the plurality of second heat-conducting parts 82 are arranged in an independent manner and correspondingly to at least one electrode assembly 5, so as to improve the heat conduction capacity of the electrode assembly 5 at the second end surface 522.

[0389] Optionally, the first heat-conducting part 81 and each second heat-conducting part 82 are arranged in a spaced manner, so as 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 exchanged with the external environment.

[0390] For example, the first heat conducting part 81 comprises an end heat conducting member 813, and the at least one second heat conducting part 82 is connected to the end heat conducting member 813; or the first heat conducting part 81 comprises a middle heat conducting member 812, and the at least one second heat conducting part 82 is connected to the middle heat conducting member 812; or the first heat conducting part 81 comprises the middle heat conducting member 812 and the end heat conducting member 813, and the at least one second heat conducting part 82 is connected between the middle heat conducting member 812 and the end heat conducting member 813.

[0391] The second heat conducting part 82 is arranged correspondingly to the electrode assembly 5, and the second heat conducting part 82 can be projected on the electrode assembly 5 in the first direction X.

[0392] Optionally, the second heat conducting parts 82 are spaced apart along the second direction Y, and the second heat conducting part 82 is arranged correspondingly to the second end surface 522 of the electrode assembly 5, or a plurality of second heat conducting parts 82 are arranged correspondingly to the second end surface 522 of the electrode assembly 5, and the heat conducting capacity of the electrode assembly 5 at the second end surface 522 is enhanced by the second heat conducting part 82.

[0393] In some embodiments, as shown in FIG. 5 and FIG. 21, at least two second heat conducting parts 82 of the plurality of second heat conducting parts 82 are arranged in a stack along the first direction X.

[0394] In these embodiments, the at least two second heat conducting parts 82 arranged in a stack along the first direction X help to improve the heat exchange capacity of the electrode assembly 5 at the second end surface 522.

[0395] In the second heat conducting parts 82 arranged in a stack, for the convenience of description, the second heat conducting part 82 farthest from the electrode assembly 5 in the first direction X can be referred to as an outer layer second heat conducting part, and the other second heat conducting parts 82 can be referred to as inner layer second heat conducting parts. For example, two or three or four second heat conducting parts 82 are arranged in a stack along the first direction X.

[0396] Optionally, the area of the outer layer second heat conducting part is greater than the area of the inner layer second heat conducting part, so as to improve the heat conducting capacity of the electrode assembly 5 at the second end surface 522.

[0397] Optionally, a plurality of independent inner layer second heat conducting parts are attached to the same outer layer second heat conducting part, so as to enhance the heat conduction between the independent inner layer second heat conducting parts and improve the temperature uniformity between the electrode assemblies 5.

[0398] Optionally, the inner layer second heat conducting part is connected to the middle heat conducting member 812 or the end heat conducting member 813, and the outer layer second heat conducting part is connected to the inner layer second heat conducting part, so that the contact area between the outer layer second heat conducting part and the middle heat conducting member 812 or the end heat conducting member 813 is increased by the inner layer second heat conducting part, thereby improving the heat exchange rate of the second heat conducting part 82 and the first heat conducting part 81.

[0399] Exemplarily, two electrode assemblies 5 are arranged in the second direction Y, two middle heat conduction members 812 are arranged between the adjacent two first side surfaces 5231 of the adjacent two electrode assemblies 5, and the first side surface 5231 of the electrode assembly 5 away from the other electrode assemblies 5 is provided with an end heat conduction member 813. The middle heat conduction member 812 and the end heat conduction member 813 are connected through an inner layer second heat conduction part. The two independent inner layer second heat conduction parts in the second direction Y are arranged on the outer layer second heat conduction part in the first direction X. The outer layer second heat conduction part is used to strengthen the heat conduction between the two inner layer second heat conduction parts, so as to improve the heat dissipation efficiency of the electrode assembly 5 at the second end surface 522.

[0400] Please refer to FIG. 22, which is a partial structure diagram of a battery monomer provided in an embodiment of the present application.

[0401] In some embodiments, as shown in FIG. 4, FIG. 5 and FIG. 22, the electrode assembly 5 is provided with a plurality of electrode assemblies 5 arranged in the second direction Y. The first heat conduction part 81 includes a middle heat conduction member 812 arranged between the adjacent two first side surfaces 5231 of the adjacent two electrode assemblies 5 and connected to the second heat conduction part 82.

[0402] In these embodiments, the middle heat conduction member 812 is arranged between the adjacent two first side surfaces 5231 of the adjacent two electrode assemblies 5 and connected to the second heat conduction part 82. Through the middle heat conduction member 812, the heat between the adjacent electrode assemblies 5 can be transferred to the second heat conduction part 82 through the middle heat conduction member 812, and then exchanged with the external environment through the second heat conduction part 82, so as to balance the internal temperature of the battery monomer 3.

[0403] The heat conduction assembly 8 includes the middle heat conduction member 812 arranged between the adjacent electrode assemblies 5 and the second heat conduction part 82 connected to the middle heat conduction member 812. The temperature between the adjacent two first side surfaces 5231 is transferred to the middle heat conduction member 812 and then transferred to the second heat conduction part 82 through the middle heat conduction member 812.

[0404] Exemplarily, the heat exchange mechanism is arranged on the side of the battery monomer 3 in the first direction X close to the second heat conduction part 82. The temperature between the adjacent first side surfaces 5231 is transferred to the heat exchange mechanism through the middle heat conduction member 812 and the second heat conduction part 82.

[0405] Optionally, a plurality of middle heat conduction members 812 can be arranged between the adjacent first side surfaces 5231 to improve the heat conduction rate of the heat conduction assembly 8. Exemplarily, 2 or 3 or 5 middle heat conduction members 812 can be arranged between the adjacent first side surfaces 5231.

[0406] Optionally, the plurality of electrode assemblies 5 are arranged in the shell 4, and a middle heat conduction member 812 is arranged between the first side surfaces 5231 of the adjacent electrode assemblies 5, so as to improve the heat conduction rate of the heat conduction assembly 8.

[0407] Optionally, the middle heat conduction member 812 covers the first side surface 5231, so as to improve the contact area of the middle heat conduction member 812 and the electrode assembly 5, and improve the heat conduction rate of the heat conduction assembly 8.

[0408] Please refer to FIG. 23, which is a partial structure diagram of a battery cell according to an embodiment of the present application.

[0409] In some embodiments, as shown in FIGS. 4, 5 and 23, two middle heat conduction members 812 are arranged between the adjacent first side surfaces 5231 of the adjacent electrode assemblies 5, and the heat conduction assembly 8 comprises two second heat conduction portions 82 arranged at intervals, and the two second heat conduction portions 82 are respectively located on the two sides of the two middle heat conduction members 812 along the second direction Y, and each middle heat conduction member 812 is connected to the adjacent second heat conduction portion 82.

[0410] In these embodiments, two middle heat conduction members 812 are arranged between the adjacent first side surfaces 5231 of the adjacent electrode assemblies 5, and the two second heat conduction portions 82 are respectively located on the two sides of the two middle heat conduction members 812 along the second direction Y, and each middle heat conduction member 812 is connected to the adjacent second heat conduction portion 82, so that during the expansion of the electrode assembly 5, the connected middle heat conduction member 812 and the second heat conduction portion 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 conduction assembly 8 during the expansion of the electrode body 52, and improve the reliability of the battery cell 3.

[0411] The middle heat conduction member 812 and the adjacent second heat conduction portion 82 are integrally formed, and they can be formed by bending the same base material, which has low processing difficulty.

[0412] The two middle heat conduction members 812 are arranged at intervals along the second direction Y between the adjacent first side surfaces 5231 of the adjacent electrode assemblies 5, each middle heat conduction member 812 is heat-conductively connected to the first side surface close to it, the two second heat conduction portions 82 are arranged at intervals along the second direction Y, the two middle heat conduction members 812 are located between the two second heat conduction portions 82 along the second direction Y, and one end of the second heat conduction portion 82 is connected to the middle heat conduction member 812 close to it along the second direction Y, and the other end thereof extends away from the other second heat conduction portion 82 along the second direction Y.

[0413] During the expansion of the electrode assembly 5, the combination of the middle heat conduction member 812 and the second heat conduction portion 82 can move in the second direction Y to buffer the extrusion force, so as to prolong the service life of the heat conduction assembly 8.

[0414] Two middle heat conduction members 812 are connected to a first side surface 5231 respectively, which can also improve the heat transfer efficiency between adjacent electrode assemblies 5 and heat conduction assemblies 8.

[0415] Please refer to FIG. 24, which is a schematic diagram of a heat conduction assembly of a battery cell according to an embodiment of the present application.

[0416] In some embodiments, as shown in FIG. 4, FIG. 5 and FIG. 24, two middle heat conduction members 812 located between adjacent electrode assemblies 5 are spaced apart in the third direction Z, or two middle heat conduction members 812 located between adjacent electrode assemblies 5 abut each other in the third direction Z.

[0417] In these embodiments, two middle heat conduction members 812 located between adjacent electrode assemblies 5 are spaced apart or abut each other in the third direction Z, which not only helps to reduce the size of the heat conduction assembly 8, but also helps to reduce the overall size of the heat conduction assembly 8 in the second direction Y, thereby improving the energy density of the battery cell 3.

[0418] Two middle heat conduction members 812 located between adjacent electrode assemblies 5 are not overlapped in the second direction Y, so as to reduce the overall size of the heat conduction assembly 8 in the second direction Y, thereby improving the energy density of the battery cell 3.

[0419] The middle heat conduction member 812 located between adjacent electrode assemblies 5 has a size in the third direction Z smaller than that of the first side surface 5231, so as to reduce the manufacturing cost of the heat conduction assembly 8.

[0420] The sum of the sizes of two middle heat conduction members 812 located between adjacent electrode assemblies 5 in the third direction Z is smaller than the size of the first side surface 5231 in the third direction Z, so that the two middle heat conduction members 812 are spaced apart.

[0421] The sum of the sizes of two middle heat conduction members 812 located between adjacent electrode assemblies 5 in the third direction Z is equal to the size of the first side surface 5231 in the third direction Z, so that the two middle heat conduction members 812 abut each other, and the shape of each middle heat conduction member 812 can be designed as needed.

[0422] Optionally, the size of the middle heat conduction member 812 located between adjacent electrode assemblies 5 in the third direction Z is half of the size of the first side surface 5231 in the third direction Z, so that the two middle heat conduction members 812 have the same shape and size, thereby reducing the manufacturing difficulty of the middle heat conduction member 812.

[0423] Please refer to FIG. 25, which is a schematic diagram of a partial structure of a battery cell according to an embodiment of the present application.

[0424] In some embodiments, as shown in FIG. 4, FIG. 5 and FIG. 25, the first heat conduction part 81 further comprises two end heat conduction members 813, which are respectively arranged between the shell 4 and the two adjacent first side surfaces 5231 and connected to the second heat conduction part 82.

[0425] In these embodiments, the first heat conduction part 81 further comprises two end heat conduction members 813, which are respectively arranged between the shell 4 and the two adjacent first side surfaces 5231 and connected to the second heat conduction part 82. The two end heat conduction members 813 can transfer heat through the second heat conduction part 82, or the electrode assembly 5 can transfer heat to the external environment through the two end heat conduction members 813 and the second heat conduction part 82, so as to improve the heat conduction efficiency of the heat conduction assembly 8.

[0426] The two end heat conduction members 813 are respectively arranged between the shell 4 and the two adjacent first side surfaces 5231 in the second direction Y, which means that two end heat conduction members 813 are respectively arranged between the shell 4 and the two first side surfaces 5231 closest to the shell 4 in the second direction Y.

[0427] When the external environment temperature on both sides of the shell 4 in the second direction Y is similar, or the heat exchange performance of the heat exchange mechanism on both sides of the shell 4 in the second direction Y is similar, the heat of the first side surface 5231 is transferred to the end heat conduction member 813 and then to the heat exchange mechanism, and the heat of the second end surface 522 is transferred to the second heat conduction part 82 and then to the heat exchange mechanism through the two end heat conduction members 813, so as to improve the heat exchange rate at the second end surface 522.

[0428] When the temperature difference between the external environment and the internal environment on one side of the shell 4 in the second direction Y is larger, or 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 conduction members 813 are respectively a third end heat conduction member and a fourth end heat conduction member, the third end heat conduction member is close to a heat exchange mechanism with higher heat conduction efficiency, and the fourth end heat conduction member is close to a heat exchange mechanism with lower heat conduction efficiency or no heat exchange mechanism is arranged. After the heat of the first side surface 5231 is transferred to the fourth end heat conduction member, part of the heat of the fourth end heat conduction member is transferred to the heat exchange mechanism close to it, and the other part of the heat is transferred to the third end heat conduction member through the second heat conduction part 82 and then to the heat exchange mechanism, so as to improve the overall heat conduction rate of the heat conduction assembly 8.

[0429] Optionally, the end heat conducting member 813 and the second heat conducting part 82 are integrally formed to reduce the joint of the heat conducting assembly 8 and improve the structural strength of the heat conducting assembly 8; or the end heat conducting member 813 and the second heat conducting part 82 are separately prepared and connected to each other to facilitate the adjustment of the size of each part and adapt to the electrode assembly 5 of different sizes.

[0430] Optionally, at least one of the two end heat conducting members 813 is connected to the tab 51 to enhance the heat conduction rate at the tab 51, or the two end heat conducting members 813 are respectively connected to the same tab 51 on both sides in the second direction Y to enhance the heat conduction rate at the tab 51.

[0431] Please refer to FIG. 26, which is a schematic diagram of the partial structure of the battery cell according to an embodiment of the present application.

[0432] In some embodiments, as shown in FIG. 4, FIG. 5 and FIG. 26, the electrode assembly 5 is provided in plurality, the plurality of electrode assemblies 5 are arranged in stack in the second direction Y, the first heat conducting part 81 includes the middle heat conducting member 812 and the end heat conducting member 813, the middle heat conducting member 812 is arranged between the adjacent two first side surfaces 5231 of the adjacent two electrode assemblies 5, the end heat conducting member 813 is arranged between the shell 4 and the adjacent one first side surface 5231, and the middle heat conducting member 812 and the end heat conducting member 813 are respectively connected to the second heat conducting part 82.

[0433] In these embodiments, the first heat conducting part 81 includes the middle heat conducting member 812 and the end heat conducting member 813, the middle heat conducting member 812 is arranged between the adjacent two first side surfaces 5231 of the adjacent two electrode assemblies 5, the end heat conducting member 813 is arranged between the shell 4 and the adjacent one first side surface 5231, and the middle heat conducting member 812 and the end heat conducting member 813 are respectively connected to the second heat conducting part 82, so that the heat between the adjacent electrode assemblies 5 can be transferred to the end heat conducting member 813 through the middle heat conducting member 812 and the second heat conducting part 82, and exchanged with the external environment through the end heat conducting member 813 to improve the heat conduction efficiency of the heat conducting assembly 8.

[0434] The heat between the adjacent electrode assemblies 5 is not easy to exchange with the external environment through the shell 4, and therefore in the present embodiment, the middle heat conducting member 812 is arranged between the first side surfaces 5231 of the adjacent electrode assemblies 5, the heat of the adjacent two first side surfaces 5231 is transferred to the middle heat conducting member 812, and then transferred to the end heat conducting member 813 through the second heat conducting part 82, and then transferred to the external environment through the shell 4 at the end heat conducting member 813 and / or the second heat conducting part 82.

[0435] For example, the heat exchange mechanism is arranged on the side of the shell 4 close to the end heat conducting member 813 in the second direction Y, and the heat of the middle heat conducting member 812 is transferred to the end heat conducting member 813 and then to the heat exchange mechanism.

[0436] For example, the electrode assembly 5 is provided with two electrode assemblies 5, and the two electrode assemblies 5 are stacked along the second direction Y, and each electrode assembly 5 is provided with the middle heat conduction member 812, the end heat conduction member 813 and the second heat conduction part 82.

[0437] Optionally, the end heat conduction member 813, the second heat conduction part 82 and the middle heat conduction member 812 are integrally formed to reduce the joint of the heat conduction assembly 8 and improve the structural strength of the heat conduction assembly 8, or the end heat conduction member 813, the second heat conduction part 82 and the middle heat conduction member 812 are separately prepared and connected to each other to more conveniently adjust the size of each part and adapt to electrode assemblies 5 of different sizes.

[0438] Optionally, at least one of the middle heat conduction member 812 and the end heat conduction member 813 is connected to the tab 51 through the third heat conduction part 83 to enhance the heat conduction rate at the tab 51, or the middle heat conduction member 812 and the end heat conduction member 813 are respectively connected to the same tab 51 on both sides of the second direction Y through the third heat conduction part 83 to enhance the heat conduction rate at the tab 51.

[0439] Please refer to FIG. 27, which is a partial structure diagram of a battery monomer provided by an embodiment of the present application.

[0440] In some embodiments, as shown in FIGS. 4, 5 and 27, the electrode assembly 5 is provided with multiple electrode assemblies 5, and the multiple electrode assemblies 5 are stacked along the second direction Y, and the first heat conduction part 81 includes the middle heat conduction member 812 and two end heat conduction members 813, the middle heat conduction member 812 is arranged between the adjacent two first side surfaces 5231 of the adjacent two electrode assemblies 5, the two end heat conduction members 813 are respectively arranged between the shell 4 and the adjacent two first side surfaces 5231, and the middle heat conduction member 812 and the two end heat conduction members 813 are respectively connected to the second heat conduction part 82.

[0441] In these embodiments, the first heat conduction part 81 includes the middle heat conduction member 812 and two end heat conduction members 813, the middle heat conduction member 812 is arranged between the adjacent two first side surfaces 5231 of the adjacent two electrode assemblies 5, the two end heat conduction members 813 are respectively arranged between the shell 4 and the adjacent two first side surfaces 5231, and the middle heat conduction member 812 and the two end heat conduction members 813 are respectively connected to the second heat conduction part 82, so that the heat between the adjacent electrode assemblies 5 can be transferred to the end heat conduction member 813 through the middle heat conduction member 812 and the second heat conduction part 82, and heat exchanged with the external environment through the end heat conduction member 813, to improve the heat conduction efficiency of the heat conduction assembly 8.

[0442] The end heat conducting member 813 and the middle heat conducting member 812 are connected to the second heat conducting part 82, and the heat of the first side surface 5231 of the adjacent electrode body 52 is transferred to the middle heat conducting member 812, then transferred to the second heat conducting part 82 by the middle heat conducting member 812, and then transferred to the end heat conducting member 813, and finally transferred to the external environment by the shell 4.

[0443] Alternatively, the temperature difference between the external environment and the internal environment of the shell 4 on the second direction Y side is larger, and the heat of the middle heat conducting member 812 and one of the end heat conducting members 813 is transferred to the other end heat conducting member 813 through the second heat conducting part 82, and heat exchange is performed with the external environment at this position. For example, the heat exchange mechanism is arranged at one end of the shell 4 in the second direction Y.

[0444] Alternatively, the temperature difference between the external environment and the internal environment of the shell 4 on the first direction X side is larger, and the heat of the middle heat conducting member 812 and the two end heat conducting members 813 is transferred to the second heat conducting part 82, and heat exchange is performed with the external environment at this position.

[0445] Optionally, the thickness of the middle heat conducting member 812 is greater than or equal to the thickness of the end heat conducting member 813, so as to enhance the heat conducting performance of the middle heat conducting member 812, so that the middle heat conducting member 812 can quickly transfer the heat accumulated between the adjacent electrode bodies 52, or heat the adjacent two electrode assemblies 5, so as to improve the reliability of the heat conducting assembly 8.

[0446] Please refer to FIG. 28, FIG. 29 and FIG. 30, FIG. 28 is a partial structure schematic diagram of a battery monomer provided by an embodiment of the application; FIG. 29 is an enlarged view of position A in FIG. 28 according to an embodiment of the application; and FIG. 30 is an enlarged view of position A in FIG. 28 according to another embodiment of the application.

[0447] In some embodiments, as shown in FIG. 4, FIG. 5, FIG. 28 and FIG. 30, two middle heat conducting members 812 are arranged between the two first side surfaces 5231 of the adjacent two electrode assemblies 5, and the heat conducting assembly 8 comprises four second heat conducting parts 82, which are arranged between the two end heat conducting members 813 in the second direction Y, and the two outermost second heat conducting parts 82 are connected to the two end heat conducting members 813 respectively, and the two middle second heat conducting parts 82 are connected to the two middle heat conducting members 812 respectively.

[0448] In the embodiments, two middle heat-conducting members 812 are arranged between the two adjacent first side surfaces 5231 of the two adjacent electrode assemblies 5, and the two outermost second heat-conducting members 82 are connected to the two end heat-conducting members 813 respectively, and the two middle second heat-conducting members 82 are connected to the two middle heat-conducting members 812 respectively, so that when the electrode assembly 5 expands, the combination of the end heat-conducting member 813 and the second heat-conducting member 82 and the combination of the middle heat-conducting member 812 and the second heat-conducting member 82 can move in the second direction Y to buffer the extrusion force of the electrode assembly 5, improve the problem of extrusion damage of the heat-conducting assembly 8 during the expansion of the electrode assembly 5, and improve the reliability of the battery monomer 3.

[0449] Specifically, the two first side surfaces 5231 of a single electrode assembly 5 are respectively connected in heat conduction with the end heat-conducting member 813 and the middle heat-conducting member 812, and the second end surface 522 of the electrode assembly 5 is connected in heat conduction with two spaced second heat-conducting members 82, one of which is connected with the end heat-conducting member 813 and extends towards the middle heat-conducting member 812, and the other of which is connected with the middle heat-conducting member 812 and extends towards the end heat-conducting member 813. When the electrode assembly 5 expands, the combination of the second heat-conducting member 82 and the end heat-conducting member 813 and the combination of the second heat-conducting member 82 and the middle heat-conducting member 812 can deform synchronously with the electrode assembly 5 to buffer the extrusion force of the electrode assembly 5 on the heat-conducting assembly 8. The other electrode assembly 5 and the middle heat-conducting member 812, the end heat-conducting member 813 and the second heat-conducting member 82 connected to the electrode assembly 5 are the same.

[0450] The spacing between the two adjacent second heat-conducting members 82 can be designed as needed.

[0451] Optionally, the end heat-conducting member 813 and the second heat-conducting member 82 connected thereto are integrally prepared by one-time bending of the same base material to reduce the processing difficulty. The middle heat-conducting member 812 and the second heat-conducting member 82 connected thereto are integrally prepared by one-time bending of the same base material to reduce the processing difficulty. Optionally, the end heat-conducting member 813 and the middle heat-conducting member 812 have the same shape and size, and each second heat-conducting member 82 has the same shape and size, so that the combination of the end heat-conducting member 813 and the second heat-conducting member 82 and the combination of the middle heat-conducting member 812 and the second heat-conducting member 82 can be universal, thereby saving the processing cost of the heat-conducting assembly 8.

[0452] Optionally, the two second heat-conducting members 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.

[0453] Optionally, as shown in FIG. 30, a middle heat conduction member 812 is arranged between the two adjacent first side surfaces 5231 of the two adjacent electrode assemblies 5, and the heat conduction assembly 8 comprises two second heat conduction parts 82, which are arranged in the second direction Y and spaced between the two end heat conduction members 813, and the two second heat conduction parts 82 are connected to the two end heat conduction members 813 respectively.

[0454] In some embodiments, as shown in FIGS. 4 and 5, the heat conduction assembly 8 and the electrode assembly 5 are connected by bonding.

[0455] In these embodiments, the heat conduction assembly 8 and the electrode assembly 5 are connected by bonding, so as to improve the connection reliability of the electrode assembly 5 of the heat conduction assembly 8.

[0456] Optionally, the heat conduction assembly 8 and the electrode assembly 5 are provided with an adhesive layer. For example, the adhesive layer can be double-sided tape.

[0457] Optionally, the heat conduction assembly 8 and the electrode assembly 5 are connected by heat-conducting glue, so as to improve the heat conduction efficiency of the heat conduction assembly 8 and the electrode assembly 5.

[0458] Optionally, the heat conduction assembly 8 and the electrode assembly 5 are connected by insulating glue, so as to insulate the heat conduction assembly 8 and the electrode assembly 5.

[0459] In some embodiments, as shown in FIGS. 4 and 5, the heat conduction assembly 8 has a projection area S1 in the second direction Y, the electrode body 52 has a projection area S2 in the second direction Y, and 0.1≤S1 / S2≤1 is satisfied, and the first direction X and the second direction intersect.

[0460] In these embodiments, when the above condition is satisfied, the problem that the heat conduction efficiency of the first heat conduction part 81 to the electrode assembly 5 is not obvious due to the too small area of the first heat conduction part 81 can be improved, and the problem that the battery monomer 3 is damaged due to the interference between the first heat conduction part 81 and other structures in the battery monomer 3 due to the too large area of the first heat conduction part 81 can be improved.

[0461] For example, the ratio of S1 to S2 is 0.1, 0.2, 0.3, 0.5, 0.7, 0.8, 0.9 or 1, etc.

[0462] Optionally, the electrode assembly 5 comprises one electrode body 52, and the first heat conduction part 81 covers the two first side surfaces 5231 of the electrode body 52, or the electrode assembly 5 comprises two or more electrode bodies 52, and the first heat conduction part 81 covers the first side surface 5231 of each electrode body 52, so as to improve the contact area of the electrode assembly 5 and the first heat conduction part 81 and improve the heat conduction rate.

[0463] Optionally, the electrode body 52 is in a cylindrical shape, the side surface 523 of the cylindrical electrode body 52 has an area S3, and the projection area of the heat conduction assembly 8 on the side surface of the electrode body 52 is S4, and 0.1≤S4 / S3≤1 is satisfied.

[0464] Optionally, the area ratio of the second heat conduction part 82 in the first direction X and the second end surface 522 is less than 1.

[0465] Optionally, the first side surface 5231 and the second side surface 5232 are connected through a rounded corner, and the heat conduction assembly 8 is arranged on the planar part of the side surface 523 to reduce the arrangement difficulty.

[0466] Please refer to FIG. 31, FIG. 32 and FIG. 33, FIG. 31 is an exploded view of a battery cell provided by another embodiment of the application; FIG. 32 is a partial structural schematic view of a battery cell provided by an embodiment of the application; and FIG. 33 is a partial structural schematic view of a battery cell provided by an embodiment of the application.

[0467] In some embodiments, as shown in FIG. 31 to FIG. 33, the shell 4 includes an opening 41 in the first direction X, and the battery cell 3 further 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 with the tab 51, the heat conduction assembly 8 further includes a third heat conduction part 83, the third heat conduction part 83 is in heat conduction connection with the tab 51, and the third heat conduction part 83 is in heat conduction connection with the first heat conduction part 81.

[0468] In these embodiments, the top cover assembly 6 covers the opening 41 of the shell 4, the tab 51 is connected with the electrode terminal 61 of the top cover assembly 6 to realize electrical connection, the heat conduction assembly 8 further includes the third heat conduction part 83 in heat conduction connection with the tab 51, and the third heat conduction part 83 is in heat conduction connection with the first heat conduction part 81, so that the heat conduction assembly 8 can improve the heat conduction rate at the tab 51 to balance the temperature at the tab 51 and improve the problem that the performance of the battery cell 3 is affected due to the excessively high temperature at the tab 51.

[0469] When the battery cell 3 is in a working state, the current is output to the outside through the electrode terminal 61 from the tab 51, the temperature at the tab 51 rises due to the current, the high temperature is transmitted to the electrode body 52 from the tab 51, the temperature of the electrode body 52 rises, and the battery cell 3 reaches the current limiting temperature too early, resulting in the performance of the battery cell 3 being reduced.

[0470] Therefore, the tab 51 is in heat conduction connection with the third heat conduction part 83, so that the heat at the tab 51 can be transmitted to the outside through the first heat conduction part 81 and the third heat conduction part 83 to improve the problem that the electrode body 52 is heated by the tab 51. Alternatively, in a low-temperature environment, the temperature of the tab 51 can also be improved through the first heat conduction part 81 and the third heat conduction part 83.

[0471] The third heat conduction part 83 and the first heat conduction part 81 are in thermal conduction connection. Specifically, the heat conduction assembly 8 comprises an insulating part (not shown in the figure) and a heat conduction part (not shown in the figure). The insulating part forms a containing cavity in at least a partial region, and the heat conduction part is arranged in the containing cavity. Then, the heat conduction part in the first heat conduction part 81 and the heat conduction part in the third heat conduction part 83 can be directly connected. For example, the heat conduction part in the first heat conduction part 81 and the heat conduction part in the third heat conduction part 83 are integrally formed or are mutually bonded or abutted; or the heat conduction part in the first heat conduction part 81 and the heat conduction part in the third heat conduction part 83 are indirectly connected through a heat conduction medium. The heat conduction medium can be a metal material part or a heat conduction adhesive or the like.

[0472] Optionally, as shown in FIG. 32, the third heat conduction part 83 is connected between the first heat conduction part 81 and the tab 51, and the first heat conduction part 81 extends on the first side surface 5231 of the electrode body 52. Then, the first heat conduction part 81 can be used to conduct heat at the first side surface 5231 of the electrode body 52 and the tab 51 at the same time; or as shown in FIG. 31, the first heat conduction part 81 extends on the second side surface 5232, which helps to reduce the size of the heat conduction assembly 8 in the second direction Y. Since the expansion of the electrode assembly 5 mainly occurs at the first side surface 5231, when the first heat conduction part 81 is arranged at the second side surface 5232, the interference of the first heat conduction part 81 with the expansion of the electrode assembly 5 can be reduced.

[0473] Optionally, the third heat conduction part 83 can be connected to one first heat conduction part 81; or the third heat conduction part 83 can be connected to two or more first heat conduction parts 81 arranged at intervals.

[0474] Optionally, the electrode body 52 comprises a positive tab and a negative tab. The positive tab and the negative tab are connected to different third heat conduction parts 83, which reduces the size of a single third heat conduction part 83 and reduces the risk of interference between the third heat conduction part 83 and other components of the battery monomer 3; or the positive tab and the negative tab are connected to the same third heat conduction part 83, which increases the connection area between the third heat conduction part 83 and the first heat conduction part 81 and improves the heat conduction efficiency of the heat conduction assembly 8.

[0475] Optionally, the connection mode between the third heat conduction part 83 and the tab 51 can be abutment or fusion or bonding or the like, or the third heat conduction part 83 and the tab 51 are connected through a heat transfer medium.

[0476] Optionally, the first heat conduction part 81 and the third heat conduction part 83 are integrally formed to enhance the heat conduction efficiency of the heat conduction assembly 8.

[0477] Optionally, the positive and negative tabs extend from the first and second end faces 521 and 522 respectively, and the two third heat-conducting parts 83 are connected to the positive and negative tabs respectively, and 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 assembly 8, or the two third heat-conducting parts 83 are connected to two first heat-conducting parts 81 to improve the heat-conducting rate of the heat-conducting assembly 8.

[0478] Please refer to FIG. 34, which is an exploded view of the battery cell according to another embodiment of the application.

[0479] In some embodiments, as shown in FIG. 34, the battery cell 3 further comprises a transition mechanism 7 connected between the tab 51 and the top cover assembly 6, and the transition mechanism 7 is in heat-conducting connection with the third heat-conducting part 83.

[0480] In these embodiments, the battery cell 3 further comprises a transition mechanism 7 connected between the tab 51 and the top cover assembly 6, and the transition mechanism 7 is in heat-conducting connection with the third heat-conducting part 83, so that the heat-conducting assembly 8 can improve the heat-conducting rate at the transition mechanism 7 to balance the temperature at the transition mechanism 7 and improve the performance of the battery cell 3 affected by the excessively high temperature at the transition mechanism 7.

[0481] The third heat-conducting part 83 is in heat-conducting connection with the transition mechanism 7 directly or indirectly through a heat-conducting medium, which can be air, metal or heat-conducting glue, etc.

[0482] At least one of the tab 51 and the transition mechanism 7 is in heat-conducting connection with the third heat-conducting part 83.

[0483] The tab 51 is connected to the electrode terminal 61 through the transition mechanism 7, and the high temperature at the electrode terminal 61 can also be transmitted to the electrode body 52 through the tab 51 to cause the temperature of the electrode body 52 to rise, and the battery cell 3 reaches the current-limiting temperature prematurely, resulting in the performance of the battery cell 3 being reduced.

[0484] Therefore, the transition mechanism 7 is connected to the third heat-conducting part 83, so that the heat at the transition mechanism 7 can be transmitted to the outside through the first and third heat-conducting parts 81 and 83 to improve the problem of the transition mechanism 7 heating the electrode body 52. Or in a low-temperature environment, the temperature of the transition mechanism 7 can also be improved through the first and third heat-conducting parts 81 and 83.

[0485] Optionally, the tab 51 and the transition mechanism 7 are connected to one third heat-conducting part 83 to improve the heat-conducting rate of the heat-conducting assembly 8, or the tab 51 and the transition mechanism 7 are connected to the same third heat-conducting part 83 to save the material cost of the heat-conducting assembly 8.

[0486] Optionally, the third heat conduction part 83 and the adapter 7 can be connected by abutting, welding, bonding or other connection methods, or the third heat conduction part 83 and the adapter 7 can be connected by a heat transfer medium.

[0487] Optionally, the electrode terminal 61 and the tab 51 are respectively connected to the two side surfaces of the adapter 7 in the first direction X, the connection area of the third heat conduction part 83 and the adapter 7 is spaced apart from the connection area of the adapter and the electrode terminal 61 and the tab 51, and the third heat conduction part 83 can be arranged on either side of the adapter 7 in the first direction X, or the third heat conduction part 83 can be arranged on both side surfaces of the adapter 7 in the first direction X.

[0488] Please refer to FIG. 35, which is a partial structure diagram of a battery cell according to an embodiment of the present application.

[0489] In some embodiments, as shown in FIGS. 31, 32 and 35, the tab 51 includes a folding section 511 and an extension section 512, the folding section 511 is connected to the electrode body 52, one side of the extension section 512 is connected to the folding section 511, and the other side is connected to the adapter 7, the third heat conduction part 83 is connected to the side of the extension section 512 facing the folding section 511, or the third heat conduction part 83 is connected to the side of the extension section 512 facing the adapter 7.

[0490] In these embodiments, the third heat conduction part 83 is connected to the side of the extension section 512 facing the folding section 511, or the third heat conduction part 83 is connected to the side of the extension section 512 facing the adapter 7, so that the third heat conduction part 83 can improve the heat conduction rate at the tab 51, and solve the problem that the temperature at the tab 51 is too high to heat the electrode sheet, causing the electrode body 52 to heat up and the performance of the battery cell 3 to decrease.

[0491] For example, the folding section 511 extends in the first direction X, one end of the extension section 512 is connected to the folding section 511, and the other end extends in the second direction Y, the adapter 7 is connected to the extension section 512, and the extension section 512 can increase the connection area between the tab 51 and the adapter 7, and improve the connection reliability of the tab 51 and the adapter 7.

[0492] As shown in FIG. 35, the adapter 7 is connected to the side of the extension section 512 in the first direction X close to the top cover assembly 6, and the third heat conduction part 83 is connected to the side of the extension section 512 in the first direction X away from the top cover assembly 6, so that the tab 51 and the third heat conduction part 83 have sufficient contact area, the connection reliability of the third heat conduction part 83 and the tab 51 is improved, and the tab 51 and the adapter 7 have sufficient contact area.

[0493] Alternatively, as shown in FIG. 32, the extension section 512 extends in the third direction Z, the adapter mechanism 7 and the third heat conduction part 83 are 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 conduction part 83 are arranged in the third direction Z in a manner of matching the positions of the third heat conduction part 83, the tab 51 and the adapter mechanism 7, so as to reduce the connection difficulty of the third heat conduction part 83 and the tab 51.

[0494] In some embodiments, as shown in FIGS. 31 and 35, the extension section 512 comprises a first sub-section 5121, a second sub-section 5122 and a third sub-section 5123 connecting the first sub-section 5121 and the second sub-section 5122, which are arranged in the first direction X in a manner of being spaced apart, the first sub-section 5121 is connected to the gathering section 511, the second sub-section 5122 is connected to the adapter mechanism 7, and the third heat conduction part 83 is connected to the side of the first sub-section 5121 facing the gathering section 511.

[0495] In these embodiments, the extension section 512 comprises a first sub-section 5121, a second sub-section 5122 and a third sub-section 5123 connecting the first sub-section 5121 and the second sub-section 5122, which are arranged in the first direction X in a manner of being spaced apart, the second sub-section 5122 is connected to the adapter mechanism 7, so as to increase the contact area of the adapter mechanism 7 and the tab 51, and the third heat conduction part 83 is connected to the side of the first sub-section 5121 facing the gathering section 511, so as to reduce the connection difficulty of the third heat conduction part 83 and the tab 51.

[0496] The side of the extension section 512 is connected to the adapter mechanism 7, and the third heat conduction part 83 is connected to the side of the extension section 512 facing the gathering section 511. Specifically, the adapter mechanism 7 is connected to the second sub-section 5122, and the third heat conduction part 83 is connected to the first sub-section 5121.

[0497] For example, the tabs 51 of the pole pieces are gathered on the gathering section 511, and then are bent in the second direction Y to form the first sub-section 5121, then are bent in the first direction X to form the third sub-section 5123, and then are extended in the second direction Y to form the second sub-section 5122.

[0498] Optionally, the area of the second sub-section 5122 is greater than that of the first sub-section 5121, the third heat conduction part 83 is connected to the first sub-section 5121, and the adapter mechanism 7 is connected to another third heat conduction part 83 and the second sub-section 5122, so as to increase the contact area of the tab 51 and the adapter mechanism 7, and improve the connection reliability of the tab 51 and the adapter mechanism 7 as well as the tab and the third heat conduction part 83.

[0499] In some embodiments, as shown in FIGS. 31 and 33, the side surface 523 includes two first side surfaces 5231 and two second side surfaces 5232, the two first side surfaces 5231 are oppositely arranged in the second direction Y, the two second side surfaces 5232 are oppositely arranged 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 tab 51 is provided with two, the two tabs 51 extend from the first end surface 521 and are spaced apart along the third direction Z, the first heat conduction part 81 and the third heat conduction part 83 are respectively provided with two, the two first heat conduction parts 81 are respectively arranged on the two second side surfaces 5232, the two third heat conduction parts 83 are respectively connected to one end of the two first heat conduction parts 81 towards the tab 51, and the two third heat conduction parts 83 are respectively connected to the extension section 512 of the two tabs 51.

[0500] 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 conduction parts 81 are respectively arranged on the two second side surfaces 5232, which will not cause the thickness of the battery monomer 3 to increase due to the arrangement of the heat conduction assembly 8, and since the expansion of the electrode assembly 5 mainly occurs at the first side surface 5231, when the first heat conduction part 81 is arranged at the second side surface 5232, the interference of the first heat conduction part 81 to the expansion of the electrode assembly 5 can be reduced, the two third heat conduction parts 83 are respectively connected to one end of the two first heat conduction parts 81 towards the tab 51, and the two third heat conduction parts 83 are respectively connected to the extension section 512 of the two tabs 51, each tab 51 is connected to one third heat conduction part 83, so that the heat at the electrode main body 52 and each tab 51 can be transmitted to the first heat conduction part 81 through the third heat conduction part 83, so as to improve the heat conduction rate at the tab 51, and improve the problem that the temperature at the tab 51 is too high to heat the tab, causing the electrode main body 52 to heat up and the performance of the battery monomer 3 to decrease.

[0501] Optionally, the number of the first heat conduction part 81 is a plurality, at least two first heat conduction parts 81 are spaced apart on the same second side surface 5232, and a plurality of first heat conduction parts 81 arranged on the same second side surface 5232 are connected to the same third heat conduction part 83. The first heat conduction part 81 arranged at intervals can not only save the material cost of the heat conduction assembly 8, but also improve the problem that the first heat conduction part 81 causes the heat to be too concentrated in some areas of the second side surface 5232 when transmitting the temperature of the tab 51, and can balance the temperature at the second side surface 5232.

[0502] Optionally, the first heat conduction part 81 and the third heat conduction part 83 are integrally formed, the first heat conduction part 81 and the third heat conduction part 83 are formed by once bending the base material, which reduces the processing difficulty of the first heat conduction part 81 and the third heat conduction part 83.

[0503] Please refer to FIG. 36, which is a schematic diagram of a partial structure of a battery cell according to an embodiment of the present application.

[0504] In some embodiments, as shown in FIG. 31 and FIG. 36, the side surface 523 includes two first side surfaces 5231 and two second side surfaces 5232, the two first side surfaces 5231 are oppositely arranged in the second direction Y, and the two second side surfaces 5232 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 surface 5231 is greater than the area of the second side surface 523, and the first heat conduction part 81 and the third heat conduction part 83 are respectively provided with two, the two first heat conduction parts 81 are respectively arranged on the two first side surfaces 5231, each third heat conduction part 83 is respectively connected to one first heat conduction part 81, and the two third heat conduction parts 83 are respectively connected to different positions of the extension section 512 of the same tab 51 in the first direction X.

[0505] In these embodiments, each third heat conduction part 83 is respectively connected to one first heat conduction part 81, and the two third heat conduction parts 83 are respectively connected to different positions of the extension section 512 of the same tab 51 in the first direction X, so as to better improve the heat conduction rate at the tab 51 and improve the problem of affecting the performance of the battery cell 3 due to the excessively high temperature at the tab 51.

[0506] The two third heat conduction parts 83 are respectively connected to different positions of the extension section 512 of the same tab 51, so that the two third heat conduction parts 83 conduct heat for the same tab 51, so as to better balance the temperature at the tab 51.

[0507] The two third heat conduction parts 83 are connected to different positions of the extension section 512, and each third heat conduction part can directly contact the extension section 512. The two third heat conduction parts 83 can be arranged on both sides of the extension section 512 in the first direction X, or the two third heat conduction parts 83 can be arranged on the same side of the extension section 512 in the first direction X.

[0508] Optionally, the two third heat conduction parts 83 are respectively connected to both sides of the extension section 512 of the same tab 51 in the first direction X, which can make each third heat conduction part 83 have sufficient contact area with the extension section 512, and reduce the connection difficulty of the third heat conduction part 83 and the extension section 512.

[0509] Optionally, the two third heat conduction parts 83 arranged on both sides of the electrode main body 52 in the second direction Y are arranged on one side surface of the extension section 512 in the first direction X in the second direction Y, for example, the two third heat conduction parts 83 are arranged in the second direction Y.

[0510] Alternatively, the two third heat-conducting parts 83 arranged on both sides of the electrode body 52 in the second direction Y are arranged on both sides of the extension section 512 in the first direction X, and the two third heat-conducting parts 83 are arranged on both sides of the second sub-section 5122 in the first direction X.

[0511] Optionally, the battery monomer 3 includes a plurality of electrode assemblies 5, and one first heat-conducting part 81 is arranged between adjacent electrode assemblies 5.

[0512] In some embodiments, as shown in FIGS. 34 and 36, the extension section 512 includes a first sub-section 5121, a second sub-section 5122 and a third sub-section 5123 connecting the first sub-section 5121 and the second sub-section 5122, the first sub-section 5121 is connected to the folding section 511, and the second sub-section 5122 is connected to the adapter mechanism 7; one of the two third heat-conducting parts 83 is connected to the first sub-section 5121, and the other is connected to the second sub-section 5122.

[0513] In these embodiments, one of the two third heat-conducting parts 83 is connected to the first sub-section 5121, and the other is connected to the second sub-section 5122, and the connection areas of the two third heat-conducting parts 83 and the tab 51 are reasonably distributed to improve the connection reliability of the third heat-conducting part 83 and the tab 51.

[0514] Optionally, one third heat-conducting part 83 is connected to a side surface of the first sub-section 5121 away from the second sub-section 5122, and the other third heat-conducting part 83 is connected to a side surface of the second sub-section 5122 facing the first sub-section 5121, so as to reduce the connection difficulty of the tab 51 and the third heat-conducting part 53.

[0515] Please refer to FIG. 37, which is a partial structure diagram of a battery monomer according to an embodiment of the present application.

[0516] In some embodiments, as shown in FIGS. 34 and 37, 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, the area of the first side surface 5231 is greater than that of the second side surface 5232, the adapter mechanism 7 includes a first connecting section 71 and a second connecting section 72 arranged in the third direction Z, the tab 51 is connected to the first connecting section 71, and the third heat-conducting part 83 is connected to the second connecting section 72.

[0517] In the embodiments, the adapter 7 comprises a first connecting section 71 and a second connecting section 72, the tab 51 is connected to the first connecting section 71, and the third heat-conducting part 83 is connected to the second connecting section 72. The third heat-conducting part 83 is configured to improve the heat-conducting rate at the adapter 7 and to prevent the temperature at the adapter 7 from being too high to heat the tab 51 and to reduce the performance of the battery cell 3.

[0518] The third heat-conducting part 83 is connected to the second connecting section 72, or the third heat-conducting part 83 and the electrode terminal 61 are both connected to the second connecting section 72. Specifically, the third heat-conducting part 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. Alternatively, the third heat-conducting part 83 and the electrode terminal 62 are both connected to the second connecting section 72, and the third heat-conducting part 83 and the electrode terminal 62 are arranged on the two side surfaces of the second connecting section 72 in the first direction X or on one side surface of the second connecting section 72 in the first direction X.

[0519] Optionally, the specific size and shape of the first connecting section 71 and the second connecting section 72 can be designed by the user.

[0520] Optionally, two second connecting sections 72 are arranged on the two sides of the first connecting section 71, and two third heat-conducting parts 83 are connected to the two second connecting sections 72, respectively, to increase the contact area between the third heat-conducting part 83 and the adapter 7.

[0521] Optionally, the top cover assembly 6 is provided with a pressure relief valve, so that when the pressure inside the shell 4 reaches a threshold value, the pressure is discharged to the outside through the pressure relief valve. The shape and size of the adapter 7 can be designed by the user, and the adapter 7 is arranged apart from the pressure relief valve to avoid blocking the pressure relief valve.

[0522] Optionally, a single second connecting section 72 can be connected to more than two third heat-conducting parts 83, or the adapter 7 comprises a plurality of second connecting sections 72 to connect a plurality of third heat-conducting parts 83 to enhance the heat-conducting efficiency of the heat-conducting assembly 8.

[0523] In some embodiments, as shown in FIGS. 34 and 37, two first heat-conducting parts 81 and two third heat-conducting parts 83 are arranged, respectively. The two first heat-conducting parts 81 are arranged on the two first side surfaces 5231, respectively. Each third heat-conducting part 83 is connected to one first heat-conducting part 81, and the two third heat-conducting parts 83 are connected to different positions of the second connecting section 72 of the same adapter 7.

[0524] In the embodiments, two first heat-conducting parts 81 are arranged on the two first sides 5231 respectively, each third heat-conducting part 83 is connected to one first heat-conducting part 81, and two third heat-conducting parts 83 are 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 solve the problem of affecting the performance of the battery monomer 3 due to the excessively high temperature at the adapter mechanism 7.

[0525] The two third heat-conducting parts 83 are connected to different positions of the same second connecting section 72, and each third heat-conducting part 83 can directly contact the second connecting section 72. The two third heat-conducting parts 83 can be arranged on the two sides of the second connecting section 72 in the first direction X, or the two third heat-conducting parts 83 can be arranged on the same side of the second connecting section 72 in the first direction X; or the two third heat-conducting parts 83 can be arranged on the two ends of the second connecting section 72 in the second direction Y; or the two third heat-conducting parts 83 can be arranged on one end of the second connecting section 72 in the second direction Y.

[0526] Optionally, the two third heat-conducting parts 83 are connected to the two sides of the second connecting section 72 of the same adapter mechanism 7 in the second direction Y, which can reduce the size of the third heat-conducting part 83, reduce the material cost of the third heat-conducting part 83, and reduce the connection difficulty of the third heat-conducting part 83 and the adapter mechanism 7.

[0527] Optionally, the two second connecting sections 72 are arranged on the two sides of the first connecting section 71 in the second direction Y, and the two second connecting sections 72 have the same size. The two third heat-conducting parts 83 arranged on the two sides of the electrode body 52 in the second direction Y are connected to the two second connecting sections 72 respectively.

[0528] Optionally, the positive electrode tab of the electrode body 52 and the third heat-conducting part 83 are connected to the same adapter mechanism 7, or the negative electrode tab of the electrode body 52 and the third heat-conducting part 83 are connected to the same adapter mechanism.

[0529] Optionally, the number of the electrode assemblies 5 is multiple, and one of the two third heat-conducting parts 83 arranged on the two sides of the electrode body 52 in the second direction Y is arranged between adjacent electrode assemblies 5.

[0530] Please refer to FIG. 38, FIG. 39 and FIG. 40. FIG. 38 is a schematic structural diagram of a battery monomer according to an embodiment of the present application; FIG. 39 is an enlarged structural schematic diagram of B in FIG. 38; and FIG. 40 is a schematic structural diagram of a battery monomer according to an embodiment of the present application.

[0531] In some embodiments, as shown in FIG. 31, FIG. 38-40, the electrode assembly 5 is provided with two, the two electrode assemblies 5 are arranged in a second direction Y, the adapter mechanism 7 is provided with two first connecting segments 71, the two first connecting segments 71 are arranged on both sides of the second connecting segment 72 in the second direction Y, the tabs 51 of the two electrode assemblies 5 are respectively connected to the two first connecting segments 71, the first heat conduction part 81 and the third heat conduction part 83 are respectively provided with two, the two first heat conduction parts 81 are arranged on both sides of the same electrode body 52 in the first direction X, the two third heat conduction parts 83 are respectively connected to one end of the two first heat conduction parts 81 towards the adapter mechanism 7, and the two third heat conduction parts 83 are respectively connected to the two second connecting segments 72 of the adapter mechanism 7.

[0532] In these embodiments, the two first heat conduction parts 81 are arranged on both sides of the electrode body 52 in the second direction Y, the two third heat conduction parts 83 are respectively connected to one end of the two first heat conduction parts 81 towards the adapter mechanism 7, and the two third heat conduction parts 83 are respectively connected to the two second connecting segments 72 of the adapter mechanism 7, so as to reduce the connection difficulty of the third heat conduction part 83 and the tab 51 and the adapter mechanism 7; and the two third heat conduction parts 83 are respectively connected to the tab 51 and the adapter mechanism 7, so as to better stabilize the temperature at the tab 51.

[0533] In FIG. 38, in order to facilitate the observation of the connection relationship between the third heat conduction part 83, the tab 51 and the adapter mechanism 7, one electrode body 52 is hidden.

[0534] The adapter mechanism 7 is provided with two first connecting segments 71, so that the adapter mechanism 7 can simultaneously connect the tabs of the two electrode assemblies 5, reduce the overall size of the adapter mechanism 7 in the battery monomer 3, and improve the energy density of the battery monomer 3.

[0535] The second connecting segment 72 is located between the two first connecting segments 71, so that the second connecting segment 72 is located between the two electrode assemblies 5, and one or more third heat conduction parts 83 are connected to the second connecting segment 72 to conduct heat at the adapter mechanism 7.

[0536] The one or more third heat conduction parts 83 are located between the shell 4 and the tab 51 in the second direction Y, and the third heat conduction part 83 is connected to the tab 51 to conduct heat at the tab 51, so as to balance the temperature at the tab 51 and improve the problem of reverse heating of the electrode body 52 by the tab 51. For example, the third heat conduction part 83 is connected to the first sub-portion 5121 of the tab 51.

[0537] Optionally, as shown in FIG. 40, the heat conduction assembly 8 includes three first heat conduction parts 81 and three third heat conduction parts 83, two first heat conduction parts 81 are arranged between the two first side surfaces 5231 of the electrode assembly 5 and the shell 4, and the two first heat conduction parts 81 are connected to the tab 51 through the two third heat conduction parts 83; one first heat conduction part 81 is connected to the second connecting section 72 through one third heat conduction part 83, so as to enhance the heat conduction rate of the heat conduction assembly 8.

[0538] Please refer to FIG. 41 and FIG. 42, FIG. 41 is a partial structure diagram of a battery cell according to an embodiment of the present application; and FIG. 42 is a partial structure diagram of a battery cell according to an embodiment of the present application.

[0539] In some embodiments, as shown in FIG. 31, FIG. 41 and FIG. 42, the heat conduction assembly 8 further includes a second heat conduction part 82, the second heat conduction part 82 is arranged between the shell 4 and the at least partial second end surface 522 along the first direction X, and the second heat conduction part 82 is connected to the first heat conduction part 81.

[0540] In these embodiments, the heat conduction assembly 8 further includes a second heat conduction part 82 arranged between the shell 4 and the at least partial second end surface 522 along the first direction X, and the second heat conduction part 82 is connected to the first heat conduction part 81, so as to increase the contact area between the heat conduction assembly 8 and the shell 4, to improve the heat conduction rate of the heat conduction assembly 8 to the heat at the tab 51, and to improve the problem that the performance of the battery cell 3 is affected due to the excessively high temperature at the tab 51.

[0541] The second heat conduction part 82 is connected to the first heat conduction part 81, specifically, the heat conduction assembly 8 includes an insulating part (not shown in the figure) and a heat conduction part (not shown in the figure), the insulating part at least partially forms a receiving cavity, and the heat conduction part is arranged in the receiving cavity, so that the heat conduction part in the first heat conduction part 81 is connected to the heat conduction part in the second heat conduction part 82, for example, the heat conduction part in the first heat conduction part 81 and the heat conduction part in the second heat conduction part 82 are integrally formed or are mutually adhered or are mutually abutted, etc.; or the heat conduction part in the first heat conduction part 81 and the heat conduction part in the second heat conduction part 82 are arranged in a spaced manner, and the insulating part of the first heat conduction part 81 and the insulating part of the second heat conduction part 82 are mutually connected.

[0542] The heat at the tab 51 can be transmitted to the second heat conduction part 82 through the third heat conduction part 83 and the first heat conduction part 81, and is transmitted to the external environment at the second heat conduction part 82. The first heat conduction part and the second heat conduction part 82 that are mutually connected increase the heat exchange area of the heat conduction assembly 8, and increase the heat conduction rate of the heat conduction assembly 8.

[0543] Optionally, the heat exchange mechanism is arranged at one end of the battery cell 3 where no tab 51 is arranged along the first direction X, and the second heat conduction part 82 can transmit heat between the heat exchange mechanism and the tab 51.

[0544] Optionally, the second heat-conducting part 82 covers the entire second end surface 522 of the electrode assembly 5, so as to improve the heat-conducting rate of the second heat-conducting part 82.

[0545] Optionally, the second heat-conducting part 82 can be designed in various shapes and sizes, for example, the second heat-conducting part 82 can be rectangular or circular.

[0546] Optionally, the first heat-conducting part 81, the second heat-conducting part 82 and the third heat-conducting part 83 are integrally formed, so as to improve the heat-conducting rate of the heat-conducting assembly 8.

[0547] Optionally, the two first heat-conducting parts 81 are spaced apart, one end of the two first heat-conducting parts 81 in the first direction X is connected to the third heat-conducting part 83, and the other end of the two first heat-conducting parts 81 in the first direction X is connected through the second heat-conducting part 82, so that the second heat-conducting part 82 can balance the heat of the two first heat-conducting parts 81.

[0548] Please refer to FIG. 43, which is an exploded view of a battery cell according to another embodiment of the present application.

[0549] In some embodiments, as shown in FIG. 43, the tab 51 extends out of the first end surface 521, and the battery cell 3 further comprises a first insulating film 91, which covers the side surface 523 and the second end surface 522 of the electrode body 52; wherein the first heat-conducting part 81 is located between the first insulating film 91 and the electrode assembly 5, or the first heat-conducting part 81 is located between the first insulating film 91 and the shell 4.

[0550] In these embodiments, the first insulating film 91 covers the side surface 523 and the second end surface of the electrode body 52, so as 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 of supporting and protecting the first heat-conducting part 81, so as to reduce the problem of breakage of 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, so as to improve the insulation reliability between the first heat-conducting part 81 and the electrode assembly 5, and improve the heat-conducting efficiency between the first heat-conducting part 81 and the shell 4.

[0551] For example, the material of the first insulating film 91 can be PP or PI (Polyimide) or PET (Polyethylene terephthalate).

[0552] The first heat-conducting part 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 part 81 and the electrode assembly 5, and improve the heat-conducting rate between the electrode assembly 5 and the first heat-conducting part 81.

[0553] Optionally, the first insulating film 91 is provided with a groove, and the first heat-conducting part 81 is accommodated in the groove to reduce the overall thickness of the first insulating film 91 and the first heat-conducting part 81.

[0554] The first heat-conducting part 81 is located between the first insulating film 91 and the shell 4, and at least one of the first insulating film 91 and the shell 4 is bonded to the first heat-conducting part 81 to stabilize the first heat-conducting part 81 in the shell 4.

[0555] Referring to FIGS. 44, 45 and 46, FIG. 44 is a structural schematic diagram of a heat-conducting assembly of a battery monomer according to an embodiment of the present application; FIG. 45 is a sectional view of C-C in FIG. 44; and FIG. 46 is an exploded view of a battery monomer according to another embodiment of the present application.

[0556] In some embodiments, as shown in FIGS. 5, 44-46, the heat-conducting assembly 8 comprises an insulating member 85 and a heat-conducting member 84. The insulating member 85 is provided with a receiving cavity 851 at least in a partial region, and the heat-conducting member 84 is arranged in the receiving cavity 851. The heat-conducting member 84 comprises a first heat-conducting sheet 841 arranged on the side surface 523, and the first heat-conducting part 81 is composed of the first heat-conducting sheet 841 and the insulating member 85.

[0557] In these embodiments, the heat-conducting assembly 8 comprises an insulating member 85 and a heat-conducting member 84. The insulating member 85 is provided with a receiving cavity 851 at least in a partial region, and the heat-conducting member 84 is arranged in the receiving cavity 851. The heat-conducting member 84 comprises a first heat-conducting sheet 841 arranged on the side surface 523, and the first heat-conducting part 81 is composed of the first heat-conducting sheet 841 and the insulating member 85. In this way, the insulating member 85 can insulate the heat-conducting member 84 and the electrode body 52, and can also isolate the heat-conducting member 84 and the electrolyte, so as to improve the problem that the heat-conducting member 84 and the electrolyte are incompatible and affect the performance of the battery monomer 3.

[0558] For example, the insulating member 85 can be PP or PI (Polyimide) or PET (Polyethylene terephthalate) or the like. The heat-conducting member 84 can be made of graphite or graphene or carbon nanotubes. The heat-conducting rate of the heat-conducting member 84 in the heat-conducting assembly 8 is greater than the heat-conducting rate of the shell 4.

[0559] Optionally, the heat-conducting member 84 can be in the form of a plate, a strip or a net or the like. For example, the receiving cavity 851 is provided with a plate-shaped heat-conducting member, a net-shaped heat-conducting member or one or more strip-shaped heat-conducting members arranged at intervals.

[0560] It should be noted that the heat conducting member 84 is located in the insulating member 85, and the heat conducting member 84 is covered by the insulating member 85. In order to show the position of the heat conducting member 84, the heat conducting member 84 is represented by the shadow on the insulating member 85 in the drawings. Alternatively, the insulating member 85 is provided with a receiving cavity 851 with one end opening 41, the heat conducting member 84 is arranged in the receiving cavity 851, and is bonded or fused to the opening of the insulating member 85, so that the heat conducting member 84 is located in a sealed receiving cavity 851; or the insulating member 85 is folded at both ends, the heat conducting member 84 is located between the two ends of the insulating member 85, and the two ends of the insulating member 85 are bonded or fused together, so that the heat conducting member 84 is located in a sealed receiving cavity 851; or the insulating member 85 includes two oppositely arranged sub-insulating layers 855, the edges of the two sub-insulating layers 855 are bonded or fused, so that the heat conducting member 84 is located in a sealed receiving cavity 851.

[0561] Alternatively, the side surface of the insulating member 85 facing the electrode body 52 is provided with a bonding layer, so that the heat conducting assembly 8 and the electrode assembly 5 are bonded and connected. For example, the bonding layer can be an insulating glue, so as to enhance the insulation performance of the heat conducting assembly 8 and the electrode assembly 5.

[0562] At least part of the insulating member 85 extends to the side surface 523, the first heat conducting sheet 841 is arranged on the side surface 523 and is in heat conducting connection with the electrode assembly 5, and the first heat conducting part 81 is composed of the first heat conducting sheet 841 and the insulating member 85. For example, the first heat conducting sheet 841 covers the entire side surface 523, so as to improve the heat conducting rate of the first heat conducting part 81.

[0563] Alternatively, the heat conducting assembly 8 in the above embodiment has a projection area S1 in the second direction Y, which can be the projection area S1 of the heat conducting member 84 in the second direction Y. The heat conducting assembly 8 in the above embodiment has a projection area S4 on the side surface of the electrode body 52, which can be the projection area S4 of the heat conducting member 84 on the side surface of the electrode body 52.

[0564] Please refer to FIG. 47, which is an exploded view of the battery cell according to another embodiment of the present application.

[0565] In some embodiments, as shown in FIG. 5 and FIG. 47, the tab 51 extends out of the first end surface 521, and the battery cell 3 further includes a second insulating film 92, the second insulating film 92 is connected with 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.

[0566] 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 collectively cover the second end surface 522 and the side surface 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 case 4, and can also help to reduce the size of the second insulating film 92, reduce the manufacturing cost of the battery cell 3, and reduce the thickness of the battery cell 3 and improve the energy density of the battery cell 3.

[0567] The insulating member 85 of the heat conduction assembly 8 covers part of the side surface 523 or part of the second end surface 522 of the electrode body 52. The insulating member 85 of the heat conduction assembly 8 is connected with the second insulating film 92, and the combination of the insulating member 85 and the second insulating film 92 can cover the side surface 523 and the second end surface 522 of the electrode body 52.

[0568] The connection between the insulating member 85 and the second insulating film 92 can be adhesion or fusion, etc. The specific size 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.

[0569] For example, the second insulating film 92 is a Mylar film.

[0570] Please refer to FIG. 48, which is a partial structure diagram of a battery cell according to an embodiment of the present application.

[0571] In some embodiments, as shown in FIG. 5 and FIG. 48, the 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.

[0572] In these embodiments, the insulating member 85 covers the second end surface 522 and the side surface 523 of the electrode body 52 to insulate the case 4 and the electrode assembly 5, and there is no need to set the first insulating film 91, which helps to reduce the manufacturing cost of the battery cell 3, reduce the thickness of the battery cell 3, and improve the energy density of the battery cell 3.

[0573] In the embodiment of the present application, the insulation member 85 insulates the shell 4 and the electrode assembly 5, and the first insulation film 91 is not needed, or the first insulation film 91 is replaced by the insulation member 85. The thermal conductivity of the insulation member 85 is similar to that of the first insulation film 91, and thus in the embodiment of the present application, the replacement of the first insulation film 91 by the insulation member 85 does not greatly affect the heat dissipation of the electrode assembly. The heat-conducting member 84 is arranged in the insulation member 85, and the thermal conductivity of the heat-conducting member 84 is greater than that of the first insulation film 91. Compared with the case where the insulation member 85 or the first insulation film 91 is arranged between the electrode assembly 5 and the shell 4, the arrangement of the heat-conducting member 84 between the electrode assembly 5 and the shell 4 can improve the heat conduction rate between the electrode assembly 5 and the external environment, i.e., the heat-conducting assembly 8 can improve the heat conduction efficiency between the electrode assembly 5 and the external environment.

[0574] The thermal conductivity of the heat-conducting assembly 8 can be measured by a hot flow method, a hot plate method, a hot wire method or the like. When the thermal conductivity of the heat-conducting assembly 8 is measured, the test sample of the heat-conducting assembly 8 should include the heat-conducting member 84 and the insulation member 85 arranged on the outer surface of the heat-conducting member 84.

[0575] The combination of the insulation member 85 and the heat-conducting member 84 can make the insulation member 85 achieve the insulation between the electrode body 52 and the shell 4, the insulation between the heat-conducting member 84 and the electrode body 52, and the insulation between the heat-conducting member 84 and the electrolyte.

[0576] The insulation 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 arranged in the accommodating cavity 851 can be designed as needed. For example, the heat-conducting member 84 covers at least one of the first side surface 5231, the second side surface 5232 and the second end surface 522.

[0577] Optionally, the heat-conducting member 84 is arranged in the accommodating cavity 851, 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 insulation member 85, the heat-conducting member 84 is in contact with the cavity wall of the accommodating cavity 851, and the accommodating cavity 851 plays a limiting role on the heat-conducting member 84.

[0578] Please refer to FIG. 49, FIG. 50 and FIG. 51. FIG. 49 is a structural schematic view of a heat-conducting assembly of a battery monomer according to an embodiment of the present application; FIG. 50 is an expanded view of the heat-conducting assembly of the battery monomer according to an embodiment of the present application; and FIG. 51 is a structural schematic view of the heat-conducting assembly of the battery monomer according to an embodiment of the present application.

[0579] In some embodiments, as shown in FIGS. 5, 49-51, the side surface 523 includes two first side surfaces 5231 and two second side surfaces 5232, the two first side surfaces 5231 are oppositely arranged in the second direction Y, the two second side surfaces 5232 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 surface 5231 is greater than the area of the second side surface 5232, the insulating member 85 includes a first insulating part 852, the first insulating part 852 includes a body part 8521 and a bending part 8522 connected to each other, the body part 8521 and the bending part 8522 are connected, the body parts 8521 of the two first insulating parts 852 are arranged on the two first side surfaces 5231 respectively, the two bending parts 8522 are arranged on the two second side surfaces 5232 respectively, and the first heat-conducting sheet 841 is arranged on at least one of the body part 8521 and the bending part 8522.

[0580] In these embodiments, the first insulating part 852 includes the body part 8521 and the bending part 8522 connected to each other, the body parts 8521 of the two first insulating parts 852 are arranged on the two first side surfaces 5231 respectively, the two bending parts 8522 are arranged on the two second side surfaces 5232 respectively, so as to realize the insulation of the electrode assembly 5 on the peripheral surface thereof and the shell 4, and the first heat-conducting sheet 841 is arranged on at least one of the body part 8521 and the bending part 8522, so as to improve the heat-conducting rate at the first side surface 5231 and / or the second side surface 5232 of the electrode assembly 5.

[0581] The first heat-conducting sheet 841 is arranged on the body part 8521, or the first heat-conducting sheet 841 is arranged on the bending part 8522, or the first heat-conducting sheet 841 is arranged on the body part 8521 and the bending part 8522 to form the first heat-conducting part 81.

[0582] In the same shell 4, the insulating member 85 includes two first insulating parts 852, and the oppositely arranged two first insulating parts 852 wrap at least part of the peripheral surface of the electrode assembly 5.

[0583] As shown in FIG. 50, the first insulating part 852 includes the body part 8521 and the bending part 8522 connected to each other, the body part 8521 and the bending part 8522 are integrally formed, so as to improve the structural strength of the first insulating part 852, there is a folding line between the body part 8521 and the bending part 8522, the body part 8521 covers the first side surface 5231, and the bending part 8522 is bent along the folding line and covers the second side surface 5232, or the body part 8521 and the bending part 8522 are prepared respectively, and the body part 8521 and the bending part 8522 are connected by bonding or fusion.

[0584] The first insulation part 852 includes a body part 8521 and a bending part 8522 connected to the body part 8521 at one end in the third direction Z, the body part 8521 covers one first side surface 5231 of the electrode assembly 5, one end of the bending part 8522 is connected to the body part 8521, and the other end of the bending part 8522 extends towards the body part 8521 of the other first insulation part 852 in the second direction Y, the bending part 8522 is connected to the two body parts 8521, or the bending part 8522 and the body part 8521 are arranged separately, and are connected by a Mylar film.

[0585] Alternatively, the first insulation part 852 includes a body part 8521 and a bending part 8522 connected to the body part 8521 at both ends in the third direction Z, the body part 8521 covers the first side surface 5231 of the electrode assembly 5, the bending parts 8522 of the two oppositely arranged first insulation parts 852 extend oppositely in the second direction Y and are connected to each other, or the bending parts 8522 of the two oppositely arranged first insulation parts 852 extend oppositely in the second direction Y, and the two bending parts 8522 are connected by a Mylar film.

[0586] Optionally, in the same shell 4, the insulation part 85 includes two first insulation parts 852, the two first insulation parts 852 are integrally formed and surround the outer circumferential surface of the electrode assembly 5.

[0587] Optionally, the body part 8521 covers the first side surface 5231 of the electrode assembly 5, and the bending part 8522 covers the second side surface 5232 of the electrode assembly 5, so that the first insulation part 852 can reliably insulate the electrode assembly 5 and the shell 4.

[0588] Optionally, the heat conduction part 84 is arranged on the entire body part 8521 or the bending part 8522; or a plurality of heat conduction parts 84 are arranged separately on the body part 8521 or the bending part 8522.

[0589] Optionally, a plurality of electrode assemblies 5 are provided, the body part 8521 is arranged between the shell 4 and the first side surface 5231 closest to the shell 4, and the bending part 8522 is arranged on one or more second side surfaces 5232.

[0590] Please refer to FIG. 52 and FIG. 53, FIG. 52 is a structural schematic diagram of a heat conduction assembly of a battery monomer provided by an embodiment of the application; and FIG. 53 is a partial structural schematic diagram of a heat conduction assembly of a battery monomer provided by an embodiment of the application.

[0591] In some embodiments, as shown in FIG. 52 and FIG. 53, a first through hole 815 is arranged through the first insulation part 852, and the first through hole 815 and the accommodating cavity 851 are arranged separately.

[0592] In these embodiments, the first insulating portion 852 has a first through hole 815 formed therethrough, and the first through hole 815 is spaced from the accommodating cavity 851 to avoid contact between the electrolyte and the first heat-conducting sheet 841.

[0593] The accommodating cavity (not shown) is formed in a portion of the first insulating portion 852, and the first heat-conducting sheet 841 is arranged in the accommodating cavity 851. The first through hole 815 is formed in another portion of the first insulating portion 852, and the first through hole 815 is not in communication with the accommodating cavity 851. In this way, when the electrolyte infiltrates the electrode assembly 5 through the first through hole 815, the electrolyte cannot enter the accommodating cavity 851 and contact the first heat-conducting sheet 841, and the insulating member 85 can still insulate the first heat-conducting sheet 841 from the electrode assembly 5. The specific shape and size of the first through hole 815 can be designed as desired. For example, the first through hole 815 can be a circular hole or a rectangular hole.

[0594] For example, the insulating member 85 is plastic encapsulated to form the accommodating cavity 851, and the first through hole 815 can be arranged in the plastic encapsulation region 856 or arranged on the side of the plastic encapsulation region 856 away from the accommodating cavity.

[0595] Referring to FIGS. 54 and 55, FIG. 54 is a schematic structural diagram of a heat-conducting assembly of a battery cell according to another embodiment of the present application, and FIG. 55 is a schematic structural diagram of a heat-conducting assembly of a battery cell according to another embodiment of the present application.

[0596] In some embodiments, as shown in FIGS. 54 and 55, the first heat-conducting sheet 841 has a first avoiding hole 8414 formed therethrough, the first insulating portion 852 covers the inner wall of the first avoiding hole 8414, and the first insulating portion 852 has a first through hole 815 formed therethrough, and the first through hole 815 is located in the first avoiding hole 8414.

[0597] In these embodiments, the first heat-conducting sheet 841 has a first avoiding hole 8414 formed therethrough, and the first insulating portion 852 has a first through hole 815 formed therethrough, and the first through hole 815 is located in the first avoiding hole 8414. In this way, the electrolyte can infiltrate the electrode assembly 5 through the first through hole 815 and the first avoiding hole 8414. The first insulating portion 852 covers the inner wall of the first avoiding hole 8414 to avoid contact between the electrolyte and the first heat-conducting sheet 841 and to insulate the first heat-conducting sheet 841 from the electrode assembly 5.

[0598] The first heat-conducting sheet 841 is provided with a first avoiding hole 8414, and the first insulation part 852 is provided with a first through hole 815. The first through hole 815 is located in the first avoiding hole 8414, or the orthographic projection of the first avoiding hole 8414 in the thickness direction of the insulation part 85 is located in the first through hole 815. In this way, the electrolyte can infiltrate the electrode assembly 5 through the first through hole 815 and the first avoiding hole 8414. The first insulation part 852 covers the inner wall of the first avoiding hole 8414, and is used to isolate the electrolyte passing through the first through hole 815 from contacting the inner wall of the first avoiding hole 8414, and to insulate the electrode assembly 5 and the inner wall of the first avoiding hole 8414. The shape and size of the first avoiding hole 8414 can be designed as needed. For example, the first avoiding hole 8414 is a circular hole or a rectangular hole.

[0599] Optionally, the first avoiding hole 8414 and the first through hole 815 have the same shape, so as to better match each other. For example, the first avoiding hole 8414 and the first through hole 815 are both circular holes.

[0600] For example, the first insulation part 852 is plastic-sealed to form a containing cavity 851, and the first heat-conducting sheet 841 is contained in the containing cavity. Part of the first insulation part 852 is plastic-sealed to be connected to the inside of the first avoiding hole 8414, and the first through hole 815 penetrates the plastic-sealed area 856. The first through hole 815 and the inner wall of the first avoiding hole 8414 are spaced apart by the plastic-sealed area 856.

[0601] Please refer to FIG. 56, which is a structural schematic diagram of a heat-conducting assembly of a battery monomer according to an embodiment of the present application.

[0602] In some embodiments, as shown in FIG. 5, FIG. 48 and FIG. 56, the tab 51 extends out of the first end face 521. The insulation part 85 further includes a second insulation part 853, which is arranged between the second end face 522 of the electrode body 52 and the shell 4. The second insulation part 853 is insulated from the shell 4 and the second end face 522 of the electrode assembly 5, and the body part 8521 of each of the two first insulation parts 852 is connected to one side of the second insulation part 853.

[0603] In these embodiments, the insulation part 85 further includes the second insulation part 853 arranged between the second end face 522 of the electrode body 52 and the shell 4. The body part 8521 of each of the two first insulation parts 852 is connected to one side of the second insulation part 853, which reduces the difficulty of aligning the second insulation part 853 and the first insulation part 852, and reduces the difficulty of matching the insulation part 85 and the electrode assembly 5.

[0604] Optionally, the second insulation part 853 and the first insulation part 852 are bonded or welded to connect, so as to facilitate the size adjustment of the second insulation part 853 and the first insulation part 852; or the second insulation part 853 and the first insulation part 852 are integrally formed to reduce the joint of the insulation part 85 and improve the structural stability of the insulation part 85.

[0605] Optionally, the second insulation part 853 and the first insulation part 852 are integrally formed, the second insulation part 853 covers the second end surface 522, then the body part 8521 is bent and covers the first side surface 5231 of the electrode assembly 5, and then the bent part 8522 is bent and covers the second side surface 5232 of the electrode assembly 5.

[0606] Optionally, a plurality of electrode assemblies 5 are provided, and the second insulation part 853 is arranged between one or more electrode assemblies 5 and the shell 4 along the first direction X.

[0607] In some embodiments, as shown in FIGS. 48 and 56, the heat conduction part 84 includes a second heat conduction sheet 842 arranged on the second insulation part 853.

[0608] In these embodiments, the heat conduction part 84 includes the second heat conduction sheet 842 arranged on the second insulation part 853, so as to improve the heat conduction rate at the second end surface 522.

[0609] The second heat conduction part 82 is composed of the second heat conduction sheet 842 and the second insulation part 853.

[0610] Optionally, the second heat conduction sheet 842 covers the second end surface 522 of the electrode assembly 5 in the first direction X; or the number of the electrode assemblies 5 is plural, and the second heat conduction sheet 842 covers the second end surfaces 522 of the plurality of electrode assemblies 5 in the first direction X.

[0611] For example, the size and shape of the second heat conduction sheet 842 can be designed by itself, and the second heat conduction sheet 842 is in a rectangular or elliptical shape, etc.

[0612] Please refer to FIGS. 57 and 58, FIG. 57 is a structural schematic diagram of a heat conduction assembly of a battery monomer according to an embodiment of the application; and FIG. 58 is a partial structural schematic diagram of a heat conduction assembly of a battery monomer according to an embodiment of the application.

[0613] In some embodiments, as shown in FIGS. 56 to 58, the second insulation part 853 is provided with a second through hole 821 penetrating therethrough, and the second through hole 821 and the accommodating cavity 851 are arranged at intervals.

[0614] In these embodiments, the second insulation part 853 has a second through hole 821 formed therethrough, and the second through hole 821 is spaced from the accommodating cavity 851 to avoid contact between the electrolyte and the second heat conduction sheet 842.

[0615] The accommodating cavity 851 is formed in a portion of the second insulation part 853, the second heat conduction sheet 842 is arranged in the accommodating cavity 851, and the second through hole 821 is formed in another portion of the second insulation part 853. The second through hole 821 is not in communication with the accommodating cavity 851. Thus, when the electrolyte infiltrates the electrode assembly 5 through the first through hole 815, the electrolyte cannot enter the accommodating cavity 851 and contact the second heat conduction sheet 842, and the insulation part 85 can still insulate the second heat conduction sheet 842 from the electrode assembly 5. The specific shape and size of the second through hole 821 can be designed as needed. For example, the second through hole 821 can be a circular hole or a rectangular hole.

[0616] For example, the insulation part 85 is plastic encapsulated to form the accommodating cavity 851. In this case, the second through hole 821 can be arranged in a plastic encapsulation area 856, or the second through hole 821 can be arranged on a side of the plastic encapsulation area 856 away from the accommodating cavity.

[0617] Please refer to FIG. 59 and FIG. 60. FIG. 59 is a structural schematic diagram of a heat conduction assembly of a battery cell according to an embodiment of the present application. FIG. 60 is a partial structural schematic diagram of a heat conduction assembly of a battery cell according to another embodiment of the present application.

[0618] In some embodiments, as shown in FIG. 59 and FIG. 60, the second heat conduction sheet 842 has a second avoiding hole 8421 formed therethrough, the second insulation part 853 covers an inner wall of the second avoiding hole 8421, and the second insulation part 853 has a second through hole 821 formed therethrough, and the second through hole 821 is located in the second avoiding hole 8421.

[0619] In these embodiments, the second heat conduction sheet 842 has a second avoiding hole 8421 formed therethrough, and the second insulation part 853 has a second through hole 821 formed therethrough, and the second through hole 821 is located in the second avoiding hole 8421. Thus, the electrolyte can infiltrate the electrode assembly 5 through the second through hole 821 and the second avoiding hole 8421. The second insulation part 853 covers an inner wall of the second avoiding hole 8421 to avoid contact between the electrolyte and the second heat conduction sheet 842 and to insulate the second heat conduction sheet 842 from the electrode assembly 5.

[0620] The second heat-conducting sheet 842 is provided with a second avoiding hole 8421, and the insulating member 85 is provided with a second through hole 821, the second through hole 821 is located in the second avoiding hole 8421, or the second avoiding hole 8421 is orthographically projected on the second through hole 821 in the thickness direction of the second insulating part 853, so that the electrolyte can be infiltrated into the electrode assembly 5 through the second through hole 821 and the second avoiding hole 8421. The second insulating part 853 covers the inner wall of the second avoiding hole 8421, the second insulating part 853 is used to isolate the electrolyte passing through the second through hole 821 from contacting the inner wall of the second avoiding hole 8421 of the second heat-conducting member 84, and the second insulating part 853 insulates the electrode assembly 5 and the second avoiding hole 8421. The shape and size of the second avoiding hole 8421 can be designed by itself, for example, the second avoiding hole 8421 is a circular hole or a rectangular hole.

[0621] Optionally, the shapes of the second avoiding hole 8421 and the second through hole 821 are the same, so that they can better match. For example, the second avoiding hole 8421 and the second through hole 821 are both circular holes.

[0622] For example, the second insulating part 853 is plastic encapsulated to form a containing cavity 851, the second heat-conducting sheet 842 is contained in the containing cavity, part of the second insulating part 853 is plastic encapsulated in the second avoiding hole 8421, the second through hole 821 penetrates the plastic encapsulation area 856, and the inner wall of the second avoiding hole 8421 and the second through hole 821 are spaced apart by the plastic encapsulation area 856.

[0623] Please refer to FIG. 61 and FIG. 62, FIG. 61 is a structural schematic diagram of a heat-conducting assembly of a battery monomer provided by an embodiment of the application, and FIG. 62 is an expanded view of the heat-conducting assembly of the battery monomer provided by an embodiment of the application.

[0624] In some embodiments, as shown in FIG. 48, FIG. 61 and FIG. 62, the electrode assembly 5 is provided in plurality, the plurality of electrode assemblies 5 are stacked along the second direction Y, the insulating member 85 further comprises a middle insulating part 854, the middle insulating part 854 is arranged between the electrode main bodies 52 of adjacent electrode assemblies 5, the middle insulating part 854 and the second insulating part 853 are connected to each other, the first heat-conducting sheet 841 comprises a middle heat-conducting sheet 8411, and the middle heat-conducting sheet 8411 is arranged in the middle insulating part 854.

[0625] In these embodiments, the middle insulating part 854 is arranged between the adjacent electrode main bodies 52 to insulate the adjacent electrode main bodies 52, the middle insulating part 854 and the second insulating part 853 are connected to each other to improve the insulation reliability of the middle insulating part 854, and the middle heat-conducting sheet is arranged in the middle insulating part 854 to improve the heat-conducting rate between the adjacent electrode main bodies 52.

[0626] The first heat-conducting sheet 841 further comprises an end heat-conducting sheet 8412 and a side heat-conducting sheet 8413, the middle heat-conducting sheet 8411 is arranged on the middle insulating part 854 to form the middle heat-conducting part 812, the end heat-conducting sheet 8412 is arranged on the body part 8521 to form the end heat-conducting part 813, and the side heat-conducting sheet 8413 is arranged on the bending part 8522 to form the side heat-conducting part 814.

[0627] Optionally, the middle insulating part 854 and the second insulating part 853 are bonded or welded, or the middle insulating part 854 and the second insulating part 853 are integrally formed, so as to improve the connection stability of the middle insulating part 854 and the second insulating part 853.

[0628] Optionally, the middle insulating part 854 and the second insulating part 853 and the bending part 8522 are connected, so that the insulating part 85 can be wrapped on the circumferential surface and the second end surface 522 of the electrode body 52.

[0629] Optionally, the middle insulating part 854 and the second insulating part 853 and the bending part 8522 are connected, so that the insulating part 85 can be wrapped on the circumferential surface and the second end surface 522 of the electrode body 52.

[0630] Optionally, part of the first heat-conducting sheet 841 is arranged in the middle insulating part 854 to conduct heat between adjacent electrode assemblies 5.

[0631] In some embodiments, as shown in FIGS. 46, 48 and 49, the body part 8521 is connected with one bending part 8522 on each side in the third direction Z, and the two bending parts 8522 of the two first insulating parts 852 and located on the same side of the electrode assembly 5 extend towards each other in the second direction Y.

[0632] In these embodiments, the body part 8521 is connected with one bending part 8522 on each side in the third direction Z, and the two bending parts 8522 of the two first insulating parts 852 and located on the same side of the electrode assembly 5 extend towards each other in the second direction Y, so that the splicing part of the two bending parts 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 heat-conducting part 84 to improve the heat-conducting capacity of the heat-conducting assembly 8.

[0633] Optionally, the two bending portions 8522 of the two first insulation portions 852 extend towards each other in the second direction Y and are spaced apart or abut each other in the second direction Y, so that the body portion 8521 can cover the entire first side surface 5231, and the heat conduction member 84 can cover the entire first side surface, thereby improving the heat conduction efficiency of the heat conduction assembly 8; or the two bending portions 8522 of the two first insulation portions 852 extend towards each other in the second direction Y and overlap each other, and the overlapping part of the bending portions 8522 in the third direction Z does not increase the size of the battery monomer 3 in the second direction.

[0634] For example, the bending portions 8522 of the two first insulation portions 852 are bent and connected to each other. The insulation member 85 is connected by two sub-insulation layers 855, and the two sub-insulation layers 855 are connected to form a containing cavity 851 (not shown in the figure) in the body portion 8521. Each bending portion 8522 includes two sub-insulation layers 855. For the convenience of understanding, part of the sub-insulation layer 855 is folded, and part of the sub-insulation layer 855 is unfolded.

[0635] Optionally, the two bending portions 8522 connected to the two sides of the body portion 8521 are of the same size and shape, so as to reduce the processing difficulty of the first insulation portion 852. The size and shape of the bending portion 8522 can be designed by the user. For example, the bending portion 8522 is rectangular.

[0636] In some embodiments, as shown in FIGS. 46, 48 and 49, the two bending portions 8522 extend towards each other in the second direction Y, and the two bending portions 8522 at least partially overlap in the third direction Z.

[0637] In these embodiments, the two bending portions 8522 extend towards each other in the second direction Y, and the two bending portions 8522 at least partially overlap in the third direction Z, so as to improve the insulation reliability of the first insulation portion 852 between the electrode assembly 5 and the shell 4.

[0638] Optionally, the overlapping area of the two bending portions 8522 extends to both ends of the electrode body 52 in the first direction X, so as to improve the insulation reliability of the first insulation portion 852 between the electrode assembly 5 and the shell 4. The shape of the overlapping area of the two bending portions 8522 can be designed by the user. For example, the overlapping area is rectangular.

[0639] Optionally, the two bending portions 8522 are bonded or plastic-welded in the overlapping area, so as to improve the connection reliability of the bending portion 8522.

[0640] Optionally, the sum of the extension sizes of the two bending portions 8522 in the second direction Y is L 11 , and the size of the electrode assembly 5 in the second direction Y is L2, which satisfies L2 11, so that the two bending portions at least partially overlap in the third direction Z, and the exemplary L 11 The difference between L1 and L2 is between 5mm and 10mm, which can save material cost and improve connection reliability.

[0641] The extension size of the bending portion 8522 in the second direction Y is L1, and the size of the electrode assembly 5 in the second direction Y is L2, which satisfies L1=L2, so as to improve the overlapping area of the two bending portions 8522 and the insulation reliability of the bending portion 8522 on the third side surface 523 of the electrode body 52.

[0642] The extension size of the bending portion 8522 in the second direction Y is L1, and the size of the electrode assembly 5 in the second direction Y is L2, which satisfies L2 / 2

[0643] The extension size of the bending portion 8522 in the second direction Y is L1, and the size of the electrode assembly 5 in the second direction Y is L2, which satisfies L2 / 2=L1, so that the two bending portions 8522 of the two first insulation portions 852 arranged oppositely abut each other, which can not only make the bending portion 8522 cover the third side surface 523 of the electrode body 52, but also not increase the size of the heat conduction assembly 8 in the third direction Z, which helps to improve the energy density of the battery monomer 3; the sizes of the bending portions 8522 are the same, so as to reduce the processing difficulty of the first insulation portion 852.

[0644] In some embodiments, as shown in FIGS. 45, 48 and 51, the shell 4 comprises an opening 41 in the first direction X, and the battery monomer 3 further comprises a top cover assembly 6, which covers the opening 41 and is connected to the tab 51. At least one body portion 8521 extends from the first end surface 521 in the first direction X and is connected to the top cover assembly 6.

[0645] In these embodiments, at least one body portion 8521 extends from the first end surface 521 in the first direction X and is connected to the top cover assembly 6, which plays a role in positioning and fixing the heat conduction assembly 8, thereby improving the stability of the heat conduction assembly 8 in the shell 4.

[0646] The body portion 8521 extends from the first end surface 521 and is fused to the lower plastic of the top cover assembly 6. The first heat conduction sheet 841 is in thermal conduction connection with the side surface 523, and the first heat conduction sheet 841 does not exceed the first end surface 521, which can not only reduce the risk of damage to the first heat conduction sheet 841, but also reduce the material cost of the heat conduction assembly 8.

[0647] Optionally, both body portions 8521 are connected to the top cover assembly 6, so as to improve the connection stability of the insulation member 85 and the top cover assembly 6.

[0648] Optionally, the body part 8521 comprises a contact section and a fusion section, the contact section contacts with the side surface 523 of the electrode body 52, the fusion section connects with the contact section at one end and extends out of the first end surface 521 and connects with the top cover assembly 6 at the other end, the fusion section has a dimension in the third direction Z greater than or equal to the dimension of the contact section, so as to improve the connection reliability of the insulating part 85 and the top cover assembly 6.

[0649] In some embodiments, as shown in FIGS. 48 and 51, the body part 8521 extends out of the first end surface 521 in the first direction X by a dimension L3≥2mm.

[0650] In these embodiments, the above condition is met to improve the connection reliability of the heat conduction assembly 8 and the top cover assembly 6.

[0651] Optionally, the dimension L3 of the body part 8521 extending out of the first end surface 521 in the first direction X satisfies 2mm≤L3≤7mm, so as to reduce the risk of interference between the excessively long body part 8521 and other components.

[0652] For example, the dimension L3 of the body part 8521 extending out of the first end surface 521 in the first direction X is 2mm or 3mm or 5mm or 7mm, etc.

[0653] In some embodiments, as shown in FIGS. 44-46, the minimum distance D2 between the orthographic projection of the heat conduction part 84 in the thickness direction of the heat conduction assembly 8 and the edge of the orthographic projection of the insulating part 85 in the thickness direction of the heat conduction assembly 8 is greater than or equal to 2mm.

[0654] In these embodiments, the minimum distance D2 between the orthographic projection of the heat conduction part 84 in the thickness direction of the heat conduction assembly 8 and the edge of the orthographic projection of the insulating part 85 in the thickness direction of the heat conduction assembly 8 is greater than or equal to 2mm, so as to provide sufficient plastic sealing area between the heat conduction part 84 and the edge of the insulating part 85, thereby improving the sealing reliability of the accommodating cavity 851.

[0655] For example, the minimum distance D2 between the heat conduction part 84 and the edge of the insulating part 85 is 2mm or 3mm or 5mm, etc.

[0656] Optionally, the insulating part 85 comprises two sub-insulating layers 855, the two sub-insulating layers 855 are arranged in a stacked manner and are plastic-sealed or bonded in the length and width directions to form the accommodating cavity 851 accommodating the heat conduction part 84, and the minimum distance between the heat conduction part 84 and the edge of the sub-insulating layer 855 is greater than or equal to 2mm.

[0657] Alternatively, the insulation member 85 comprises two sub-insulation layers 855 integrally connected to each other, the two sub-insulation layers 855 are folded against each other, and then the edges of the length or width of the two sub-insulation layers 855 are sealed to form the accommodating cavity 851, and the minimum distance from the heat conduction member 84 to the sealed edges of the two sub-insulation layers 855 is greater than or equal to 2 mm.

[0658] Optionally, the two sub-insulation layers 855 have different areas, and the sub-insulation layer 855 with a smaller area is heat-fused to the sub-insulation layer 855 with a larger area to form the accommodating cavity 851, so as to reduce the volume of the insulation member 85 and the cost of the insulation member 85, and also reduce the volume of the heat conduction assembly 8 and improve the energy density of the battery monomer 3.

[0659] In some embodiments, as shown in FIGS. 44-46, the thickness D3 of the heat conduction member 84 satisfies 40 μm≤D3≤180 μm.

[0660] In these embodiments, when the above condition is met, the problem of the battery monomer 3 having a large volume and a low energy density due to the heat conduction member 84 being too thick can be improved, and the problem of the heat conduction member 84 being easily damaged due to the heat conduction member 84 being too thin can also be improved.

[0661] For example, the thickness D3 of the heat conduction assembly 8 is 40 μm, 50 μm, 110 μm, 180 μm, or the like.

[0662] In some embodiments, as shown in FIGS. 44-46, the insulation member 85 comprises two sub-insulation layers 855, the two sub-insulation layers 855 are stacked and connected to each other to form the accommodating cavity 851, and the thickness D1 of the sub-insulation layer 855 satisfies 5 μm≤D1≤100 μm.

[0663] In these embodiments, when the above condition is met, the problem of the battery monomer 3 having a large volume and a low energy density due to the sub-insulation layer 855 being too thick can be improved, and the problem of the sub-insulation layer 855 being easily damaged due to the sub-insulation layer 855 being too thin can also be improved.

[0664] For example, the thickness D1 of the sub-insulation layer 855 is 5 μm, 10 μm, 50 μm, 100 μm, or the like.

[0665] Optionally, the two sub-insulation layers 855 have the same thickness, so as to reduce the processing difficulty of the insulation member 85.

[0666] In some embodiments, as shown in FIGS. 44-46, the insulation member 85 comprises polyethylene, polypropylene, polyimide, or polyester resin.

[0667] In these embodiments, the insulation member 85 comprises polyethylene, polypropylene, polyimide, or polyester resin, so as to improve the insulation reliability of the insulation member 85.

[0668] Optionally, the insulating member 85 should have the characteristics of insulation and high temperature resistance, so that the insulating member 85 can be used to insulate the heat-conducting member 84 and the electrode assembly 5, and reduce the risk of melting and damage of the insulating member 85 under high temperature conditions.

[0669] In some embodiments, as shown in FIGS. 44 and 45, the heat-conducting member 84 includes graphite or graphene or carbon nanotubes.

[0670] In these embodiments, graphite is generally composed of parallel arranged layered carbon atoms, showing a planar sheet shape. Graphene is generally a two-dimensional crystal composed of carbon atoms with only one side atomic thickness, belonging to the shape of fibers. Carbon nanotubes are generally tubular structures formed by rolling one or more graphite layers. The material of the heat-conducting member 84 includes graphite or graphene or carbon nanotubes, which improves the heat-conducting performance of the heat-conducting member 84 through graphite or graphene or carbon nanotube heat-conducting materials.

[0671] Optionally, the material of the heat-conducting member 84 is supercrystalline graphite, which has a larger grain size than ordinary graphite, and the thermal conductivity is significantly improved compared with ordinary graphite, so that the heat-conducting member 84 has better heat-conducting capacity.

[0672] Optionally, the heat-conducting member 84 adopts graphite heat-conducting technology, which is a heat-conducting technology based on graphite materials and micro-porous structures. The principle is to quickly transfer heat to the heat-conducting sheet through the high-efficiency heat-conducting performance of graphite materials, and then quickly dissipate heat to the external environment through the micro-porous structure, so as to achieve the effect of heat exchange.

[0673] In some embodiments, as shown in FIGS. 44 and 45, the thermal conductivity k of the heat-conducting member 84 satisfies k≥500 W / (m·K).

[0674] In these embodiments, the thermal conductivity k of the heat-conducting member 84 satisfies the above condition, so that the heat-conducting member 84 has sufficient heat-conducting performance to conduct the heat of 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), and the thermal conductivity of the heat-conducting member 84 is 500 W / (m·K) or 550 W / (m·K) or 1050 W / (m·K) or 1550 W / (m·K) or 1600 W / (m·K), etc.

[0675] Optionally, the thermal conductivity k of the heat-conducting member 84 satisfies k≥1000 W / (m·K).

[0676] Optionally, the density of the heat-conducting member 84 is 2.1±0.05 g / cm 3 , the insulation resistance is greater than 1 GΩ, the withstand voltage strength is 5400 V, and the bending resistance is >10000 times.

[0677] In a second aspect, the embodiments of the present application provide a battery device, comprising the battery cell of any of the embodiments of the first aspect.

[0678] In a third aspect, the embodiments of the present application provide a power consumption device, comprising the battery device of the embodiments of the second aspect.

[0679] In some embodiments, as shown in FIGS. 1-62, the battery cell 3 comprises a shell 4, an electrode assembly 5 and a heat conduction assembly 8, the electrode assembly 5 is located in the shell 4, the electrode assembly 5 is of a jelly-roll type or a stacked type, the electrode assembly 5 comprises an electrode body 52 and a tab 51, the electrode body 52 comprises 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 comprises two first side faces 5231 oppositely arranged in a second direction Y and two second side faces 5232 oppositely arranged in a third direction Z, the first direction X, the second direction Y and the third direction Z are perpendicular to each other in pairs, an area of the first side face 5231 is greater than an area of the second side face 523, a first heat conduction part 81 is arranged on at least one of the two first side faces 5231, the tab 51 is connected to the electrode body 52 and extends out of the first end face 521; the heat conduction assembly 8 comprises the first heat conduction part 81 and a second heat conduction part 82, the first heat conduction part 81 is in thermal conduction connection with the first side face 5231, a thermal conductivity of the heat conduction assembly 8 is greater than a thermal conductivity of the shell 4, at least part of the first heat conduction part 81 is arranged between the first side face 5231 of the electrode assembly 5 and the shell 4 in the second direction Y, the first heat conduction part 81 is provided with a first through hole 815, the second heat conduction part 82 is arranged between the shell 4 and at least part of the second end face 522 in the first direction X, the first heat conduction part 81 and the second heat conduction part 82 are connected, the second heat conduction part 82 is provided with a second through hole 821, the heat conduction assembly 8 and the electrode assembly 5 are in adhesive connection, a projection area of the heat conduction assembly 8 in the second direction Y is S1, a projection area of the electrode body 52 in the second direction Y is S2, and 0.1≤S1 / S2≤1 is satisfied.

[0680] The shell 4 comprises an opening 41 in the first direction X, the battery cell 3 further comprises a top cover assembly 6 and an adapter mechanism 7, the top cover assembly 6 covers the opening 41, the top cover assembly 6 has an electrode terminal 61, the adapter mechanism 7 is connected between the tab 51 and the top cover assembly 6, at least one of the tab 51 and the adapter mechanism 7 is connected with the third heat conduction part 83, the third heat conduction part 83 is connected with the first heat conduction part 81, the electrode assembly 5 is provided with two, the two electrode assemblies 5 are stacked in the second direction Y, the adapter 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 tabs 51 of the two electrode assemblies 5 are respectively connected with the two first connecting segments 71, the first heat conduction part 81 and the third heat conduction part 83 are respectively provided with two, the two first heat conduction parts 81 are respectively arranged on both sides of the electrode body 52 in the second direction Y, the two third heat conduction parts 83 are respectively connected with one end of the two first heat conduction parts 81 towards the adapter mechanism 7, and the two third heat conduction parts 83 are respectively connected with the two second connecting segments 72 of the adapter mechanism 7, the extension segment 512 comprises a first sub-segment 5121, a second sub-segment 5122 and a third sub-segment 5123 connected between the first sub-segment 5121 and the second sub-segment 5122, the first sub-segment 5121 is connected with the folding segment 511, the second sub-segment 5122 is connected with the adapter mechanism 7, and the third heat conduction part 83 is connected with one side of the first sub-segment 5121 towards the folding segment 511;

[0681] The heat conduction assembly 8 comprises an insulating piece 85 and a heat conduction piece 84. The insulating piece 85 at least partially forms a containing cavity 851, and the heat conduction piece 84 is arranged in the containing cavity 851. The heat conduction piece 84 comprises a first heat conduction sheet 841 and a second heat conduction sheet 842. The first heat conduction sheet 841 is arranged on the side surface 523. The first heat conduction part 81 is composed of the first heat conduction sheet and the insulating piece 85. The tab 51 protrudes from the first end surface 521. The insulating piece 85 covers the second end surface 522 and the side surface 523 of the electrode main body 52. The insulating piece 85 comprises a first insulating part 852, a second insulating part 853 and a middle insulating part 854. The first insulating part 852 comprises a body part 8521 and a bent part 8522 which are connected to each other. The body part 8521 and the bent part 8522 are connected. The body part 8521 of each of the two first insulating parts 852 is arranged on the first side surface 5231. The bent part 8522 of each of the two first insulating parts 852 is arranged on the second side surface 5232. The first heat conduction sheet 841 is arranged on at least one of the body part 8521 and the bent part 8522. The second insulating part 853 is arranged between the second end surface 522 of the electrode main 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 body part 8521 of each of the two first insulating parts 852 is connected to the two sides of the second insulating part 853. The second heat conduction sheet 842 is arranged on the second insulating part 853. The electrode assembly 5 is provided in plurality. The plurality of electrode assemblies 5 are arranged in a stacking manner along the second direction Y. The middle insulating part 854 is arranged between the adjacent electrode main bodies 52. The middle insulating part 854 and the second insulating part 853 are connected to each other. The middle heat conduction sheet is arranged on the middle insulating part 854. The heat conduction piece 84 comprises the second heat conduction sheet 842 arranged on the second insulating part 853. The first heat conduction sheet 841 in the middle insulating part 854 and the second heat conduction sheet 842 in the second insulating part 853 are connected to each other. The body part 8521 is connected to one bent part 8522 on each side in the third direction Z. The two bent parts 8522 of each of the two first insulating parts 852 and on the same side of the electrode assembly 5 extend towards each other in the second direction Y and at least partially overlap. At least one body part 8521 protrudes from the first end surface 521 in the first direction X and is connected to the top cover assembly 6. The size L3 of the body part 8521 protruding from the first end surface 521 in the first direction X is greater than or equal to 2 mm. The minimum distance between the orthographic projection of the heat conduction piece 84 in the thickness direction of the heat conduction assembly 8 and the edge of the orthographic projection of the insulating piece 85 in the thickness direction of the heat conduction assembly 8 is greater than or equal to 2 mm. The thickness D3 of the heat conduction piece 84 satisfies 40 μm ≤ D3 ≤ 180 μm. The insulating piece 85 comprises two sub-insulating layers 855. The two sub-insulating layers 855 are arranged in a stacking manner and are connected to each other to form the containing cavity 851. The thickness D1 of the sub-insulating layer 855 satisfies 5 μm ≤ D1 ≤ 100 μm. The insulating piece 85 comprises polyethylene, polypropylene, polyimide or polyester resin. The first through hole 815 is arranged through the first insulating part 852. The second through hole 821 is arranged through the second insulating part 853.The second through hole 821 and the first through hole 815 are both spaced apart from the accommodating cavity 851, and the heat conduction piece 84 comprises graphite or graphene or carbon nanotubes, and the thermal conductivity k of the heat conduction piece 84 satisfies k>500W / (m·K).

[0682] In these embodiments, the battery cell 3 comprises a shell 4, an electrode assembly 5 and a heat conduction 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 comprises an electrode body 52 and a tab 51, the electrode body 52 comprises a first end face 521 and a second end face 522 oppositely arranged in the 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 the tab 51 and the external components which extend from the first end face 521 and / or the second end face 522, the heat conduction assembly 8 has a thermal conductivity greater than that of the shell 4, and the heat conduction assembly 8 comprises a first heat conduction part 81, and through the first heat conduction part 81 which is in thermal connection with the side face 523 of the electrode body 52, the thermal resistance of the electrode body 52 at the side face 523 thereof can be reduced, and the rate of heat exchange between the electrode body 52 at the side face 523 thereof and the external environment can be improved, so as to balance the temperature inside the battery cell 3 and improve the performance and service life of the battery cell 3 which are adversely affected by the excessively high or low temperature inside the battery cell 3.

[0683] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be covered in the scope of the claims and the specification of the present application. In particular, as long as there is no structural conflict, each technical feature mentioned in each embodiment can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, comprising: a housing; an electrode assembly located in 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 oppositely arranged 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 protruding from at least one of the first end face and the second end face; a heat conduction assembly comprising a first heat conduction part, the first heat conduction part being in thermal conduction with the side face, the heat conduction assembly having a thermal conductivity greater than that of the housing.

2. The battery cell of claim 1, wherein, The side face comprises two first side faces oppositely arranged in a second direction and two second side faces oppositely arranged in a third direction, the first direction, the second direction and the third direction intersecting with each other, the first side face having a larger area than the second side face, and the first heat conduction part being arranged at least one of the two first side faces.

3. The battery cell of claim 2, wherein, At least part of the first heat conduction part is arranged between the first side face of the electrode assembly and the housing along the second direction.

4. The battery cell of claim 2, wherein, The first heat conduction part is provided with a first through hole.

5. The battery cell of claim 3, wherein, The first heat conduction part comprises a side heat conduction part and two end heat conduction parts, the two end heat conduction parts being arranged between the housing and two adjacent first side faces respectively, and the side heat conduction part being arranged at least one of the second side faces and connected to the two end heat conduction parts along two sides of the second direction respectively.

6. The battery cell of claim 2, wherein, A plurality of electrode assemblies are arranged, and the plurality of electrode assemblies are arranged in a stacking manner along the second direction, and at least part of the first heat conduction part is arranged between two adjacent first side faces of two adjacent electrode assemblies.

7. The battery cell of claim 6, wherein, The first heat conduction part comprises a middle heat conduction part and a side heat conduction part, the middle heat conduction part being arranged between two adjacent first side faces of two adjacent electrode assemblies, and the side heat conduction part being arranged at least one of the second side faces and connected to the middle heat conduction part.

8. The battery cell of claim 7, wherein, The first heat conduction part further comprises an end heat conduction part arranged between the housing and one adjacent first side face, and the side heat conduction part is connected to the middle heat conduction part and the end heat conduction part along two sides of the second direction respectively.

9. The battery cell of claim 7, wherein, The side heat conduction part is provided with two side heat conduction parts, and the first heat conduction part further comprises two end heat conduction parts, the two end heat conduction parts being arranged between the housing and two adjacent first side faces respectively, and the two side heat conduction parts being arranged at the second side faces of different electrode assemblies respectively, wherein one side heat conduction part is connected to the middle heat conduction part and one end heat conduction part along two sides of the second direction respectively, and the other side heat conduction part is connected to the middle heat conduction part and the other end heat conduction part along two sides of the second direction respectively.

10. The battery cell of claim 9, wherein, The two side heat conduction parts are arranged at two sides of the plurality of electrode assemblies along the third direction respectively.

11. The battery cell of claim 9, wherein, The two side heat conduction parts are arranged at the same side of the plurality of electrode assemblies along the third direction.

12. The battery cell of any one of claims 6 to 11, wherein, The electrode assembly is a jelly-roll type or a stacked type.

13. The battery cell of claim 2, wherein, The first heat-conducting part is arranged around the periphery of the electrode body.

14. The battery cell of claim 13, wherein, The first heat-conducting part is formed with a gap extending along the first direction and penetrating through the first heat-conducting part between two ends of the periphery of the electrode body.

15. The battery cell of claim 14, wherein, The gap is arranged at at least one of the two first sides.

16. The battery cell of claim 15, wherein, The gap is arranged at both of the two first sides.

17. The battery cell of claim 13, wherein, A plurality of the electrode assemblies are arranged in layers along the second direction, and the first heat-conducting part is arranged around the periphery of the whole of the plurality of electrode assemblies.

18. The battery cell of any one of claims 1 to 17, wherein, The tab extends from the first end surface, and the heat-conducting assembly further comprises a second heat-conducting part arranged between the housing and at least part of the second end surface along the first direction.

19. The battery cell of claim 18, wherein, The first heat-conducting part and the second heat-conducting part are connected.

20. The battery cell of claim 18, wherein, The second heat-conducting part is provided with a second through hole.

21. The battery cell of claim 19, wherein, The side surface comprises two first sides and two second sides, the two first sides are arranged opposite to each other in the second direction, and the two second sides 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 is greater than the area of the second side, the first heat-conducting part is arranged at at least one of the two first sides, and the second heat-conducting part is connected with the first heat-conducting part arranged at the first side.

22. The battery cell of claim 21, wherein, A plurality of the electrode assemblies are arranged in layers along the second direction, the first heat-conducting part is arranged at at least one of the two first sides of at least two of the electrode assemblies, and the second heat-conducting part is arranged independently in a plurality of parts, each of which is arranged corresponding to at least one of the electrode assemblies.

23. The battery cell of claim 22, wherein, At least two of the plurality of second heat-conducting parts are arranged in layers along the first direction.

24. The battery cell of claim 21, wherein, A plurality of the electrode assemblies are arranged in layers along the second direction, and the first heat-conducting part comprises a middle heat-conducting part arranged between adjacent two first sides of adjacent two of the electrode assemblies and connected to the second heat-conducting part.

25. The battery cell of claim 24, wherein, Adjacent two of the first sides of adjacent two of the electrode assemblies are arranged with two middle heat-conducting parts independently, and the heat-conducting assembly comprises 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, and each of the middle heat-conducting parts is connected to the adjacent second heat-conducting part.

26. The battery cell of claim 25, wherein, The two middle heat-conducting parts located between adjacent electrode assemblies are arranged at intervals in the third direction, or the two middle heat-conducting parts located between adjacent electrode assemblies abut each other in the third direction.

27. The battery cell of claim 21, wherein, The first heat-conducting part further comprises two end heat-conducting parts, the two end heat-conducting parts are respectively arranged between the housing and adjacent two of the first sides and connected to the second heat-conducting part.

28. The battery cell of claim 21, wherein, The electrode assembly is provided with a plurality of electrode assemblies, and the plurality of electrode assemblies are arranged in a stack along the second direction. The first heat conduction part includes a middle heat conduction member and an end heat conduction member. The middle heat conduction member is arranged between two adjacent first sides of two adjacent electrode assemblies. The end heat conduction member is arranged between the shell and one adjacent first side. The middle heat conduction member and the end heat conduction member are respectively connected to the second heat conduction part.

29. The battery cell of claim 21, wherein, The electrode assembly is provided with a plurality of electrode assemblies, and the plurality of electrode assemblies are arranged in a stack along the second direction. The first heat conduction part includes a middle heat conduction member and an end heat conduction member. The middle heat conduction member is arranged between two adjacent first sides of two adjacent electrode assemblies. The end heat conduction member is arranged between the shell and one adjacent first side. The middle heat conduction member and the end heat conduction member are respectively connected to the second heat conduction part.

30. The battery cell of claim 29, wherein, Two middle heat conduction members are arranged between two adjacent first sides of two adjacent electrode assemblies. The heat conduction assembly includes four second heat conduction parts. The four second heat conduction parts are arranged in a space between the two end heat conduction members along the second direction. Two outermost second heat conduction parts are respectively connected to the two end heat conduction members. Two middle second heat conduction parts are respectively connected to the two middle heat conduction members.

31. The battery cell of any one of claims 1 to 30, wherein, The heat conduction assembly and the electrode assembly are adhesively connected.

32. The battery cell of any one of claims 1-31, wherein, The heat conduction assembly has a second direction projection area S1, and the electrode body has a second direction projection area S2. The ratio of S1 to S2 satisfies 0.1≤S1 / S2≤1. The first direction and the second direction intersect.

33. The battery cell of any one of claims 1 to 32, wherein, The shell includes an opening in the first direction. The battery monomer 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 conduction assembly also includes a third heat conduction part. The third heat conduction part is in thermal contact with the tab. The third heat conduction part is in thermal contact with the first heat conduction part.

34. The battery cell of claim 33, wherein, The battery monomer also includes a switching mechanism. The switching mechanism is connected between the tab and the electrode terminal. The switching mechanism is in thermal contact with the third heat conduction part.

35. The battery cell of claim 34, wherein, The tab includes a folding section and an extension section. The folding section is connected to the electrode body. One side of the extension section is connected to the folding section, and the other side is connected to the switching mechanism. The third heat conduction part is connected to the side of the extension section facing the folding section, or the third heat conduction part is connected to the side of the extension section facing the switching mechanism.

36. The battery cell of claim 35, wherein, The extension section includes a first sub-section, a second sub-section, and a third sub-section connecting the first sub-section and the second sub-section arranged in a space along the first direction. The first sub-section is connected to the folding section. The second sub-section is connected to the switching mechanism. The third heat conduction part is connected to the side of the first sub-section facing the folding section.

37. The battery cell of claim 35, wherein, The side surface comprises two first side surfaces and two second side surfaces, the two first side surfaces are oppositely arranged in a second direction, the two second side surfaces are oppositely arranged in a third direction, the first direction, the second direction and the third direction intersect with each other, the area of the first side surface is larger than that of the second side surface, The first heat-conducting part and the third heat-conducting part are respectively provided with two, two first heat-conducting parts are respectively arranged on two second side surfaces, two third heat-conducting parts are respectively connected to one end of two first heat-conducting parts towards the lug, and two third heat-conducting parts are respectively connected to the extension section of two lugs.

38. The battery cell of claim 35, wherein, The side surface comprises two first side surfaces and two second side surfaces, the two first side surfaces are oppositely arranged in a second direction, the two second side surfaces are oppositely arranged in a third direction, the first direction, the second direction and the third direction intersect with each other, the area of the first side surface is larger than that of the second side surface, The first heat-conducting part and the third heat-conducting part are respectively provided with two, two first heat-conducting parts are respectively arranged on two second side surfaces, two third heat-conducting parts are respectively connected to one end of two first heat-conducting parts towards the lug, and two third heat-conducting parts are respectively connected to the extension section of two lugs.

39. The battery cell of claim 38, wherein, The extension section comprises a first sub-section, a second sub-section and a third sub-section connecting the first sub-section and the second sub-section, which are arranged in the first direction, the first sub-section is connected to the folding section, and the second sub-section is connected to the switching mechanism; One of the two third heat-conducting parts is connected to the first sub-section, and the other is connected to the second sub-section.

40. The battery cell of claim 34, wherein, The side surface comprises two first side surfaces and two second side surfaces, the two first side surfaces are oppositely arranged in a second direction, the two second side surfaces are oppositely arranged in a third direction, the first direction, the second direction and the third direction intersect with each other, the area of the first side surface is larger than that of the second side surface, The switching mechanism comprises a first connecting section and a second connecting section arranged in the third direction, the lug is connected to the first connecting section, and the third heat-conducting part is connected to the second connecting section.

41. The battery cell of claim 40, wherein, The first heat-conducting part and the third heat-conducting part are respectively provided with two, two first heat-conducting parts are respectively arranged on two second side surfaces, two third heat-conducting parts are respectively connected to one end of two first heat-conducting parts towards the lug, and two third heat-conducting parts are respectively connected to the extension section of two lugs.

42. The battery cell of claim 40, wherein, The electrode assembly is provided with two, two electrode assemblies are arranged in the second direction, the switching mechanism is provided with two first connecting sections, two first connecting sections are arranged on both sides of the second connecting section in the second direction, and the lug of two electrode assemblies is respectively connected to two first connecting sections, The first heat-conducting part and the third heat-conducting part are provided with two respectively, the two first heat-conducting parts are arranged on the two first sides of the same electrode body, the two third heat-conducting parts are connected to the one end of the two first heat-conducting parts towards the adapter mechanism respectively, and the two third heat-conducting parts are connected to the second connecting section and the tab of the adapter mechanism respectively.

43. The battery cell of any one of claims 33-42, wherein, The tab extends from the first end face, and the heat-conducting assembly further comprises a second heat-conducting part, the second heat-conducting part is arranged between the shell and at least part of the second end face along the first direction, and the second heat-conducting part is connected with the first heat-conducting part.

44. The battery cell of any one of claims 1-43, wherein, The tab extends from the first end face, and the battery monomer further comprises a first insulating film, the first insulating film covers the side face and the second end face of the electrode body; wherein the first heat-conducting part is located between the first insulating film and the electrode assembly, or the first heat-conducting part is located between the first insulating film and the shell.

45. The battery cell of any one of claims 1-44, wherein, The heat-conducting assembly comprises an insulating piece and a heat-conducting piece, the insulating piece forms a containing cavity in at least part of the region, and the heat-conducting piece is arranged in the containing cavity, The heat-conducting piece comprises a first heat-conducting sheet, the first heat-conducting sheet is arranged on the side face, and the first heat-conducting part is composed of the first heat-conducting sheet and the insulating piece.

46. The battery cell of claim 45, wherein, The tab extends from the first end face, and the battery monomer further comprises a second insulating film, the second insulating film is connected with the insulating piece, and the insulating piece and the second insulating film jointly cover the second end face and the side face of the electrode body.

47. The battery cell of claim 45, wherein, The tab extends from the first end face, and the insulating piece covers the second end face and the side face of the electrode body.

48. The battery cell of claim 47, wherein, The side face comprises two first side faces and two second side faces, the two first side faces are oppositely arranged in a second direction, the two second side faces are oppositely arranged in a third direction, the first direction, the second direction and the third direction intersect with each other, the area of the first side face is greater than the area of the second side face, The insulating piece comprises two first insulating parts, the first insulating part comprises a body part and a bending part which are connected with each other, the body part and the bending part are connected, the body part of the two first insulating parts is arranged on the two first side faces respectively, the bending part of the two first insulating parts is arranged on the two second side faces respectively, and the first heat-conducting sheet is arranged on at least one of the body part and the bending part.

49. The battery cell of claim 48, wherein, A first through hole is arranged through the first insulating part, and the first through hole and the containing cavity are arranged at intervals.

50. The battery cell of claim 48, wherein, A first avoiding hole is arranged through the first heat-conducting sheet, the first insulating part covers the inner wall of the first avoiding hole, a first through hole is arranged through the first insulating part, and the first through hole is located in the first avoiding hole.

51. The battery cell of claim 48, wherein, The insulating piece further comprises a second insulating part, the second insulating part is arranged between the second end face of the electrode body and the shell, and the body part of the two first insulating parts is connected to the two sides of the second insulating part respectively.

52. The battery cell of claim 51, wherein, The heat-conducting piece comprises a second heat-conducting sheet, and the second heat-conducting sheet is arranged on the second insulating part.

53. The battery cell of claim 52, wherein, The second insulation part is provided with a second through hole penetrating therethrough, and the second through hole is spaced apart from the accommodating cavity.

54. The battery cell of claim 53, wherein, The second heat conduction sheet is provided with a second avoiding hole penetrating therethrough, the second insulation part covers the inner wall of the second avoiding hole, the second insulation part is provided with a second through hole penetrating therethrough, and the second through hole is located in the second avoiding hole.

55. The battery cell of any one of claims 51 to 54, wherein, The electrode assembly is provided in plurality, and the plurality of electrode assemblies are stacked along the second direction, The insulation part further comprises a middle insulation part, the middle insulation part is arranged between the electrode bodies of adjacent electrode assemblies, the middle insulation part and the second insulation part are connected to each other, the first heat conduction sheet comprises a middle heat conduction sheet, and the middle heat conduction sheet is arranged in the middle insulation part.

56. The battery cell of any one of claims 48-55, wherein, The body part is connected with one of the bending parts on each side in the third direction, and the two bending parts on the same side of the electrode assembly of the two first insulation parts extend towards each other in the second direction.

57. The battery cell of claim 56, wherein, The two bending parts extend towards each other in the second direction, and the two bending parts at least partially overlap in the third direction.

58. The battery cell of any one of claims 48-57, wherein, The shell comprises an opening in the first direction, the battery monomer further comprises a top cover assembly, the top cover assembly covers the opening and is connected to the tab, and at least one of the body parts extends out of the first end surface in the first direction and is connected to the top cover assembly.

59. The battery cell of claim 58, wherein, The size L3 of the body part extending out of the first end surface in the first direction is greater than or equal to 2 mm.

60. The battery cell of any one of claims 45-59, wherein, The minimum distance from the orthographic projection of the heat conduction part in the thickness direction of the heat conduction assembly to the edge of the orthographic projection of the insulation part in the thickness direction of the heat conduction assembly is greater than or equal to 2 mm.

61. The battery cell of any one of claims 45-60, wherein, The thickness D3 of the heat conduction part satisfies 40 μm≤D3≤180 μm.

62. The battery cell of any one of claims 45-61, wherein, The insulation part comprises two sub-insulation layers, the two sub-insulation layers are stacked and connected to each other to form the accommodating cavity, and the thickness D1 of the sub-insulation layer satisfies 5 μm≤D1≤100 μm.

63. The battery cell of any one of claims 45-62, wherein, The insulation part comprises polyethylene, polypropylene, polyimide or polyester resin.

64. The battery cell of any one of claims 45-63, wherein, The heat conduction part comprises graphite, graphene or carbon nanotube.

65. The battery cell of any one of Claims 45 to 64, wherein, The heat conductivity k of the heat conduction part satisfies k≥500 W / (m·K).

66. A battery device comprising the battery monomer of any one of claims 1-65.

67. An electric device comprising the battery device of claim 66.

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