Battery monomer, battery device and electric device

Abstract

The utility model provides a battery monomer, a battery device and a power utilization device. The battery monomer comprises a shell which comprises a bottom wall, a side wall and a cavity which is enclosed by the bottom wall and the side wall and is provided with an opening at one end in a first direction; the electrode assembly is arranged in the cavity; the end cover assembly covers the opening, and the end cover assembly is connected with the electrode assembly; the heat conduction assembly comprises a first heat conduction part and a second heat conduction part which are connected with each other, the first heat conduction part is arranged on the surface of the side, away from the electrode assembly, of the end cover assembly, the second heat conduction part is arranged on the side wall, and an external heat conduction channel of the single battery is established through the first heat conduction part arranged on the surface of the side, away from the electrode assembly, of the end cover assembly; the total area of the heat conduction assembly is increased through the second heat conduction part arranged on the side wall, and the heat exchange rate of the battery monomer and the external environment is increased, so that the problem that the performance and the service life of the battery monomer are adversely affected due to the fact that the temperature of the battery monomer is too high or too low is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of battery, in particular to a battery monomer, a battery device and a power consumption device. BACKGROUND

[0002] The battery device is widely used in electronic equipment, such as mobile phone, notebook computer, electric vehicle, electric vehicle, electric aircraft, electric ship, electric toy car, electric toy ship, electric toy aircraft and electric tool, etc.

[0003] However, the temperature of the battery monomer is too high or too low in the actual working process, which will adversely affect the service life and performance of the battery monomer. Utility model content

[0004] In view of the above problems, the present application provides a battery monomer, a battery device and a power consumption device, which can enhance the heat dissipation performance of the battery monomer, so as to enhance the performance and service life of the battery monomer.

[0005] In the first aspect, the present application provides a battery monomer, comprising: a shell comprising a bottom wall, a side wall and a cavity open at one end in a first direction enclosed by the bottom wall and the side wall; an electrode assembly arranged in the cavity; an end cover assembly covering the opening, the end cover assembly and the electrode assembly are connected; a heat conduction assembly comprising a first heat conduction part and a second heat conduction part connected to each other, the first heat conduction part is arranged on the side surface of the end cover assembly away from the electrode assembly, the second heat conduction part is arranged on the side wall, and the heat conductivity of the heat conduction assembly is greater than that of the end cover assembly and the shell.

[0006] In the scheme of the present application, the battery monomer comprises a shell, an end cover assembly and an electrode assembly, the shell comprises a bottom wall, a side wall and a cavity open at one end in a first direction enclosed by the bottom wall and the side wall, the electrode assembly is contained in the shell, the end cover assembly covers the opening of the shell and is connected with the electrode assembly, so that the electrode assembly can form a loop with external devices through the end cover assembly, the heat conduction assembly comprises a first heat conduction part and a second heat conduction part, the heat conductivity of the heat conduction assembly is greater than that of the end cover assembly and the shell, the first heat conduction part arranged on the side surface of the end cover assembly away from the electrode assembly is used to establish the external heat conduction channel of the battery monomer, so as to reduce the thermal resistance at the end cover assembly, and the second heat conduction part arranged on the side wall is used to increase the total area of the heat conduction assembly and improve the heat exchange rate between the battery monomer and the external environment, so as to solve the problem that the performance and service life of the battery monomer are adversely affected due to the temperature being too high or too low.

[0007] In some embodiments, the side wall includes two first side walls and two second side walls, the two first side walls are oppositely arranged in a second direction, the two second side walls 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 wall is greater than an area of the second side wall, the second heat conduction part is arranged on the first side wall, and / or the second heat conduction part is arranged on the second side wall.

[0008] In the scheme of the embodiments of the present application, the second heat conduction part is arranged on at least one of the first side wall and the second side wall, so that when the battery monomer is arranged in the box body, the second heat conduction part can be close to the heat exchange mechanism, so as to improve the heat exchange rate between the heat exchange mechanism and the battery monomer, better balance the temperature of the battery monomer, and improve the use performance of the battery device.

[0009] In some embodiments, the second heat conduction part covers the entire first side wall, or the second heat conduction part covers the entire second side wall.

[0010] In the scheme of the embodiments of the present application, the second heat conduction part covers the entire first side wall, or the second heat conduction part covers the entire second side wall, so as to increase the contact area between the second heat conduction part and the external environment, and improve the heat conduction performance of the heat conduction assembly.

[0011] In some embodiments, the side wall and the end cover assembly are connected through a round corner, and the round corner and the heat conduction assembly are arranged in a spaced manner.

[0012] In the scheme of the embodiments of the present application, the side wall and the end cover assembly are connected through a round corner, and the round corner and the heat conduction assembly are arranged in a spaced manner, so that there is a gap between the shell and the heat conduction assembly which can accommodate the expansion deformation of the shell, thereby reducing the risk that the heat conduction assembly is expanded and broken due to the expansion of the battery monomer.

[0013] In some embodiments, the heat conduction assembly further includes an adhesive layer, and the adhesive layer includes a first adhesive layer, and the second heat conduction part is adhered to the side wall through the first adhesive layer.

[0014] In the scheme of the embodiments of the present application, the second heat conduction part is adhered to the side wall through the first adhesive layer, which can not only reduce the connection difficulty of the second heat conduction part and the side wall, but also improve the stability of the second heat conduction part.

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

[0016] In these embodiments, when the thickness of the adhesive layer satisfies the above condition, the adhesive layer forms a sufficient gap between the second heat conduction part and the side wall to accommodate the expansion deformation of the shell, thereby reducing the risk that the heat conduction assembly is expanded and broken due to the expansion of the battery monomer.

[0017] In some embodiments, the first adhesive layer is arranged in a spaced manner between an end of the first heat conduction part in the first direction and an edge of the side wall.

[0018] In the scheme of the embodiment of the application, the first adhesive layer is arranged at a distance from the edge of the side wall and the end of the first heat-conducting part in the first direction, so as to facilitate the common deformation of the second heat-conducting part and the shell during the expansion of the battery monomer and reduce the risk of the heat-conducting assembly being broken by expansion during the expansion of the battery monomer.

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

[0020] In the scheme of the embodiment of the application, when the minimum distance between the edge of the side wall and the end of the first heat-conducting part in the first direction meets the above condition, the common deformation of the second heat-conducting part and the shell during the expansion of the battery monomer is facilitated, the risk of the heat-conducting assembly being broken by expansion during the expansion of the battery monomer is reduced, and the processing cost of the battery monomer is also reduced.

[0021] In some embodiments, the side wall includes two first side walls and two second side walls, the two first side walls are arranged opposite to each other in the second direction, the two second side walls 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 wall is greater than the area of the second side wall, and at least two second heat-conducting parts are arranged on the first side wall and the second side wall, wherein the second heat-conducting parts arranged on the first side wall and the second side wall are independent of each other.

[0022] In the scheme of the embodiment of the application, at least two second heat-conducting parts are arranged on the first side wall and the second side wall, and the second heat-conducting parts arranged on the first side wall and the second side wall are independent of each other, so that the two second heat-conducting parts arranged on the first side wall and the second side wall move independently of each other during the expansion of the battery monomer, thereby reducing the risk of the heat-conducting assembly being broken by expansion.

[0023] In some embodiments, the minimum distance L2 between the second heat-conducting part arranged on the first side wall and the adjacent second side wall in the third direction satisfies L2≥10 mm, and / or the minimum distance L3 between the second heat-conducting part arranged on the second side wall and the adjacent first side wall in the second direction satisfies L3≥10 mm.

[0024] In the scheme of the embodiment of the application, when the minimum distance between the second heat-conducting part arranged on the first side wall and the adjacent second side wall in the third direction, and / or the minimum distance between the second heat-conducting part arranged on the second side wall and the adjacent first side wall in the second direction meets the above condition, the common deformation of the second heat-conducting part and the shell during the expansion of the battery monomer is facilitated, thereby reducing the risk of the heat-conducting assembly being broken by expansion, and increasing the distance between the second heat-conducting parts arranged on the first side wall and the second side wall can reduce the risk of the two second heat-conducting parts being squeezed and damaged during the deformation of the second heat-conducting part caused by the expansion of the shell, thereby prolonging the service life of the heat-conducting assembly.

[0025] In some embodiments, the heat conduction assembly further comprises a third heat conduction part, the third heat conduction part is connected with the second heat conduction part, and the third heat conduction part is arranged on the bottom wall.

[0026] In the scheme of the embodiments of the application, the heat conduction assembly further comprises a third heat conduction part connected with the second heat conduction part, the third heat conduction part is arranged on the bottom wall, heat at the end cover assembly can be transmitted to the bottom wall through the first heat conduction part and the second heat conduction part and conducted to the external environment through the third heat conduction part, the contact area between the heat conduction assembly and the external environment can be increased through the third heat conduction part, the heat conduction performance of the heat conduction assembly is improved, the heat exchange efficiency between the end cover assembly and the external environment is enhanced, and the heat conduction performance of the bottom wall of the battery monomer is also enhanced, so that the temperature of the battery monomer can be better balanced and the use performance of the battery device is improved.

[0027] In some embodiments, the bottom wall comprises a first part and a second part, the third heat conduction part is arranged on the first part, and the second part is used for connecting with other components.

[0028] In the scheme of the embodiments of the application, the bottom wall comprises a first part and a second part, the third heat conduction part arranged on the first part is used for conducting heat, and the battery monomer is connected with the mounting position through the second part to fix the battery monomer.

[0029] In some embodiments, the side wall and the bottom wall are connected with a round corner, and the round corner is arranged apart from the heat conduction assembly.

[0030] In the scheme of the embodiments of the application, the side wall and the bottom wall are connected with a round corner, and the round corner is arranged apart from the heat conduction assembly, so that there is a gap between the shell and the heat conduction assembly that can accommodate the expansion deformation of the shell, and the risk of the heat conduction assembly being broken by the expansion of the battery monomer is reduced.

[0031] In some embodiments, the heat conduction assembly further comprises an adhesive layer, the adhesive layer comprises a second adhesive layer, and the third heat conduction part is adhered to the bottom wall through the second adhesive layer.

[0032] In the scheme of the embodiments of the application, the third heat conduction part is adhered to the bottom wall through the second adhesive layer, so as to improve the stability of the third heat conduction part.

[0033] In some embodiments, one end of the second adhesive layer towards the second heat conduction part is arranged apart from the edge of the bottom wall.

[0034] In the scheme of the embodiments of the application, one end of the second adhesive layer towards the second heat conduction part is arranged apart from the edge of the bottom wall, so as to facilitate the second heat conduction part to move together with the shell during the expansion of the battery monomer, and reduce the risk of the heat conduction assembly being broken during the expansion of the battery monomer.

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

[0036] In the scheme of the embodiment of the application, when the minimum distance between the one end of the second heat-conducting part facing the second heat-conducting part and the edge of the bottom wall meets the above condition, the synchronous deformation of the second heat-conducting part and the shell during the expansion of the battery monomer is facilitated, so as to reduce the risk of the heat-conducting assembly being broken by expansion, and the processing cost of the battery monomer is also reduced.

[0037] In some embodiments, the heat-conducting assembly further comprises an adhesive layer, and the adhesive layer comprises a third adhesive layer, and the first heat-conducting part is adhered to the end cover assembly through the third adhesive layer.

[0038] In the scheme of the embodiment of the application, the first heat-conducting part is adhered to the end cover assembly through the third adhesive layer, so as to improve the stability of the first heat-conducting part.

[0039] In some embodiments, the third adhesive layer is arranged at a distance from the one end of the second heat-conducting part facing the second heat-conducting part and the edge of the end cover assembly.

[0040] In the scheme of the embodiment of the application, the third adhesive layer is arranged at a distance from the one end of the second heat-conducting part facing the second heat-conducting part and the edge of the end cover assembly, so as to facilitate the movement of the second heat-conducting part together with the shell during the expansion of the battery monomer, and reduce the risk of the heat-conducting assembly being broken by expansion during the expansion of the battery monomer.

[0041] In some embodiments, the minimum distance between the one end of the third adhesive layer facing the second heat-conducting part and the edge of the end cover assembly is greater than or equal to 10 mm.

[0042] In the scheme of the embodiment of the application, when the minimum distance between the one end of the third adhesive layer facing the second heat-conducting part and the edge of the end cover assembly meets the above condition, the synchronous deformation of the second heat-conducting part and the shell during the expansion of the battery monomer is facilitated, so as to reduce the risk of the heat-conducting assembly being broken by expansion, and the processing cost of the battery monomer is also reduced.

[0043] In some embodiments, the end cover assembly comprises a cover plate and an electrode terminal arranged on the cover plate, the electrode terminal is connected with the electrode assembly, and the first heat-conducting part is connected with the electrode terminal.

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

[0045] In some embodiments, the battery monomer further comprises a first insulating layer arranged on the outer surface of the shell and the end cover assembly, and the heat-conducting assembly is arranged on the side of the first insulating layer away from the shell and the end cover assembly.

[0046] In the scheme of the embodiment of the application, the battery monomer further comprises a first insulation layer arranged on the outer surface of the shell and the end cover assembly, and the heat conduction assembly is arranged on the side of the first insulation layer away from the shell and the end cover assembly, so as to insulate the battery monomer, the box and the heat conduction assembly from each other.

[0047] In some embodiments, the heat conduction assembly comprises an insulation member and a heat conduction member, the insulation member forms a containing cavity in at least a partial region, and the heat conduction member is arranged in the containing cavity, the heat conduction member comprises a first heat conduction sheet and a second heat conduction sheet connected to each other, the first heat conduction sheet is arranged on the end cover assembly, and the second heat conduction sheet is arranged on the side wall, the first heat conduction part is composed of the first heat conduction sheet and the insulation member, and the second heat conduction part is composed of the second heat conduction sheet and the insulation member.

[0048] In the scheme of the embodiment of the application, the heat conduction assembly comprises an insulation member and a heat conduction member, the insulation member forms a containing cavity in at least a partial region, and the heat conduction member is arranged in the containing cavity, the heat conduction member comprises a first heat conduction sheet and a second heat conduction sheet connected to each other, the first heat conduction sheet is arranged on the end cover assembly to conduct the heat of the end cover assembly, and the second heat conduction sheet is arranged on the side wall to conduct the heat of the first heat conduction sheet and the shell, the first heat conduction part is composed of the first heat conduction sheet and the insulation member, and the second heat conduction part is composed of the second heat conduction sheet and the insulation member, so that the heat conduction member and the electrode body can be insulated by the insulation member, and the heat conduction rate of the end cover assembly and the external environment can be improved by the heat conduction member.

[0049] In some embodiments, the insulation member is arranged on the outer surface of the end cover assembly and the shell.

[0050] In the scheme of the embodiment of the application, the insulation member is arranged on the outer surface of the end cover assembly and the shell, so that the battery monomer, the box and the adjacent battery monomer are insulated from each other, and no additional insulation blue film needs to be arranged, thereby reducing the preparation cost of the battery monomer.

[0051] In some embodiments, the battery monomer further comprises a second insulation layer, the second insulation layer is connected with the insulation member, and the insulation member and the second insulation layer are collectively arranged on the outer surface of the shell and the end cover assembly.

[0052] In these embodiments, the second insulation layer is connected with the insulation member, and the insulation member and the second insulation layer are collectively arranged on the outer surface of the shell and the end cover assembly, the insulation of the battery monomer is realized by the combination of the second insulation layer and the insulation member, the size of the second insulation layer is reduced to reduce the preparation cost of the battery monomer, and the self weight of the battery monomer is reduced to improve the energy density of the battery monomer.

[0053] In some embodiments, the end cover assembly comprises a cover plate and a pressure relief mechanism arranged on the cover plate, the insulation member is provided with a first opening, and the pressure relief mechanism is exposed to the first opening.

[0054] In the scheme of the embodiment of the application, the insulating piece is provided with a first opening, so that the pressure relief mechanism can be exposed from the first opening, thereby reducing the risk that the insulating piece hinders the starting of the pressure relief mechanism, and improving the reliability of the battery monomer.

[0055] In some embodiments, the battery device further comprises a heat exchange mechanism, the heat exchange mechanism is arranged in the box, the shell comprises a bottom wall and a side wall connected with each other, the bottom wall and the opening are oppositely arranged, the insulating piece is provided with a second opening, and the heat exchange mechanism is connected with the bottom wall through the second opening.

[0056] In the scheme of the embodiment of the application, the insulating piece is provided with a second opening, so that the heat exchange mechanism can be stably connected with the bottom wall of the battery monomer through the second opening.

[0057] In some embodiments, the side wall comprises two first side walls and two second side walls, the two first side walls are oppositely arranged in a second direction, the two second side walls 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 wall is greater than the area of the second side wall, and at least two second heat conduction pieces are arranged on the first side wall and the second side wall, wherein each second heat conduction piece arranged on the first side wall and the second side wall is independent of each other.

[0058] In the scheme of the embodiment of the application, at least two second heat conduction pieces are arranged on the first side wall and the second side wall, and each second heat conduction piece arranged on the first side wall and the second side wall is independent of each other, so that in the expansion process of the battery monomer, the two second heat conduction pieces arranged on the first side wall and the second side wall move independently of each other, thereby reducing the risk that the heat conduction piece is broken by expansion.

[0059] In some embodiments, the heat conduction piece further comprises a third heat conduction piece, the third heat conduction piece is connected with the second heat conduction piece, and the third heat conduction piece is arranged on the bottom wall.

[0060] In the scheme of the embodiment of the application, the heat conduction piece further comprises a third heat conduction piece connected with the second heat conduction piece, the third heat conduction piece is arranged on the bottom wall, the volume of the heat conduction piece is increased to improve the heat conduction performance of the heat conduction assembly, and the heat at the end cover assembly is better conducted through the heat conduction assembly.

[0061] In some embodiments, the thickness D1 of the heat conduction piece satisfies 40 μm≤D1≤180 μm.

[0062] In the scheme of the embodiment of the application, when the above condition is satisfied, the problem that the battery monomer has a large volume and a low energy density due to the over-thickness of the heat conduction piece can be improved, and the problem that the heat conduction piece is easily broken due to the over-thin of the heat conduction piece can be improved.

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

[0064] In the scheme of the embodiment of the application, the insulating member comprises polyethylene, polypropylene, polyimide or polyester resin, so as to improve the insulation reliability of the insulating member.

[0065] In some embodiments, the heat-conducting member comprises graphite, graphene or carbon nanotube.

[0066] In the scheme of the embodiment of the application, the heat-conducting member comprises graphite, graphene or carbon nanotube, so as to improve the heat-conducting performance of the heat-conducting assembly by using the graphite, graphene or carbon nanotube heat-conducting material.

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

[0068] In the scheme of the embodiment of the application, when the heat conductivity 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.

[0069] In a second aspect, the embodiment of the application provides a battery device, comprising a box body and the battery monomer of the first aspect.

[0070] In the scheme of the embodiment of the application, the battery monomer is arranged in the box body, the box body serves to accommodate the battery monomer, the battery monomer comprises a heat-conducting assembly, an external heat-conducting channel of the battery monomer is established by the first heat-conducting part arranged on the side surface of the end cover assembly away from the electrode assembly and the second heat-conducting part arranged on the side wall, so as to reduce the thermal resistance at the end cover assembly and the side wall, improve the heat exchange rate between the battery monomer and the external environment, and improve the performance of the battery device.

[0071] In some embodiments, the battery device further comprises a heat exchange mechanism arranged in the box body, and the heat-conducting assembly and the heat exchange mechanism are in heat-conducting connection.

[0072] In the scheme of the embodiment of the application, the battery device further comprises a heat exchange mechanism arranged in the box body, and the heat-conducting assembly and the heat exchange mechanism are in heat-conducting connection, so as to improve the heat exchange rate between the battery monomer and the heat exchange mechanism, better balance the temperature of the battery monomer, and improve the use performance of the battery device.

[0073] In some embodiments, the side wall includes two first side walls and two second side walls, the two first side walls are oppositely arranged in the second direction, the two second side walls are oppositely arranged in the third direction, the first direction, the second direction and the third direction are intersected with each other, the area of the first side wall is greater than the area of the second side wall, the heat exchange mechanism and the first side wall are spaced apart in the second direction, and the at least one second heat conduction part is arranged between the first side wall and the heat exchange mechanism, or the heat exchange mechanism and the second side wall are spaced apart in the third direction, and the at least one second heat conduction part is arranged between the second side wall and the heat exchange mechanism.

[0074] In the scheme of the embodiments of the present application, the heat exchange mechanism and the first side wall are spaced apart in the second direction, and the at least one second heat conduction part is arranged between the first side wall and the heat exchange mechanism, or the heat exchange mechanism and the second side wall are spaced apart in the third direction, and the at least one second heat conduction part is arranged between the second side wall and the heat exchange mechanism, so as to shorten the distance between the heat conduction assembly and the heat exchange mechanism, to better transfer heat between the heat exchange mechanism and the end cover assembly through the heat conduction assembly, to better balance the temperature of the battery monomer, and to improve the use performance of the battery device.

[0075] In some embodiments, the heat conduction assembly further includes a third heat conduction part, the third heat conduction part is connected with the second heat conduction part, and the third heat conduction part is arranged on the bottom wall, and the heat exchange mechanism is arranged on the side of the third heat conduction part away from the bottom wall.

[0076] In the scheme of the embodiments of the present application, in the case that the heat exchange mechanism is arranged on the bottom wall of the battery monomer, the third heat conduction part can transfer heat at the end cover assembly to the heat exchange mechanism, to better balance the heat at the end cover assembly, to balance the internal temperature of the battery device, and to improve the performance of the battery device.

[0077] In some embodiments, the at least two battery monomers are heat-conductively connected to the same heat conduction assembly.

[0078] In the scheme of the embodiments of the present application, the at least two battery monomers are heat-conductively connected to the same heat conduction assembly, so as to reduce the matching difficulty of the heat conduction assembly and the battery monomer.

[0079] In a third aspect, the embodiments of the present application provide a power utilization device, which includes the battery device of the second aspect. BRIEF DESCRIPTION OF DRAWINGS

[0080] 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 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:

[0081] Figure 1 is a structural schematic diagram of a vehicle provided by an embodiment of the present application;

[0082] Figure 2 Figure 1 is a structural schematic diagram of a battery device according to an embodiment of the present application;

[0083] Figure 3 Figure 2 is a structural schematic diagram of a battery module according to an embodiment of the present application;

[0084] Figure 4 Figure 3 is an exploded view of a battery cell according to an embodiment of the present application;

[0085] Figure 5 Figure 4 is a partial structural schematic diagram of a battery cell according to an embodiment of the present application;

[0086] Figure 6 Figure 5 is a structural schematic diagram of a battery cell according to an embodiment of the present application;

[0087] Figure 7 Figure 6 is a structural schematic diagram of a battery cell according to an embodiment of the present application;

[0088] Figure 8 Figure 7 is a structural schematic diagram of a battery cell according to an embodiment of the present application;

[0089] Figure 9 Figure 8 is a structural schematic diagram of a battery cell according to an embodiment of the present application;

[0090] Figure 10 Figure 9 is a partial structural schematic diagram of a battery cell according to an embodiment of the present application;

[0091] Figure 11 Figure 10 is a side view of a battery cell according to an embodiment of the present application;

[0092] Figure 12 Figure 11 is a side view of a battery cell according to an embodiment of the present application;

[0093] Figure 13 Figure 12 is a structural schematic diagram of a battery cell according to an embodiment of the present application;

[0094] Figure 14 Figure 13 is a structural schematic diagram of a battery cell according to an embodiment of the present application;

[0095] Figure 15 Figure 14 is a bottom view of a battery cell according to an embodiment of the present application;

[0096] Figure 16 Figure 15 is a top view of a battery cell according to an embodiment of the present application;

[0097] Figure 17 Figure 16 is a structural schematic diagram of a battery cell according to an embodiment of the present application;

[0098] Figure 18is a structural schematic diagram of a battery monomer provided by an embodiment of the present application;

[0099] Figure 19 is a cross-sectional view of a heat conduction component of a battery monomer provided by an embodiment of the present application;

[0100] Figure 20 is a structural schematic diagram of a battery monomer provided by an embodiment of the present application;

[0101] Figure 21 is a structural schematic diagram of a battery monomer provided by an embodiment of the present application;

[0102] Figure 22 is a structural schematic diagram of a battery device provided by an embodiment of the present application;

[0103] Figure 23 is a structural schematic diagram of a battery monomer provided by an embodiment of the present application;

[0104] Figure 24 is a structural schematic diagram of a battery device provided by an embodiment of the present application;

[0105] Figure 25 is Figure 24 is an enlarged structural schematic diagram of A in FIG. 1;

[0106] Figure 26 is a partial structural schematic diagram of a battery device provided by an embodiment of the present application;

[0107] Figure 27 is Figure 26 is an enlarged structural schematic diagram of B in FIG. 1;

[0108] Figure 28 is a partial structural schematic diagram of a battery device provided by an embodiment of the present application.

[0109] Reference signs:

[0110] 1, vehicle; 101, motor; 102, controller; 2, battery device; 201, battery module; 202, box body; 2021, first box body; 2022, second box body;

[0111] 3, battery monomer;

[0112] 4, shell; 41, opening; 42, side wall; 43, bottom wall; 421, first side wall; 422, second side wall; 431, first part; 432, second part;

[0113] 5, electrode assembly; 51, tab; 52, electrode body;

[0114] 6, end cover assembly; 61, cover plate; 62, electrode terminal; 63, pressure relief mechanism;

[0115] 7, heat conducting component; 71, first heat conducting part; 72, second heat conducting part; 73, third heat conducting part; 74, adhesive layer; 741, first adhesive layer; 742, second adhesive layer; 743, third adhesive layer; 75, insulating part; 76, heat conducting part; 761, first heat conducting sheet; 762, second heat conducting sheet; 763, third heat conducting sheet; 751, first opening; 752, second opening; 77, accommodating cavity;

[0116] 8, heat exchanging mechanism;

[0117] 91, first insulating layer; 92, second insulating layer;

[0118] X, first direction; Y, second direction; Z, third direction. DETAILED DESCRIPTION

[0119] The embodiments of the technical scheme of the present application will be described in detail below with reference to the accompanying 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.

[0120] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in the embodiments of the present application should be understood as the usual meaning understood by the skilled person in the field to which the embodiments of the present application belong.

[0121] In the description of the embodiments of the present application, the orientations or positional relationships indicated by the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements indicated 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.

[0122] In addition, the technical terms "first", "second" and the like are only for description 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 specified.

[0123] In the description of the embodiments of the present application, unless explicitly defined and limited otherwise, the terms "mounting", "connection", "connecting", "fixing" and the like should be interpreted broadly, for example, can be fixed connection, can also be detachable connection, or integral; can be mechanical connection, can also be electrical connection; can be direct connection, can also be indirect connection through an intermediate medium, or the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0124] In the description of the embodiments of the present application, unless explicitly defined and limited otherwise, the first feature is "on" or "under" the second feature. The first and second features can be in direct contact, or the first and second features can be in indirect contact through an intermediate medium. Moreover, the first feature "above", "over" and "on" 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", "under" and "under" 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.

[0125] 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 water power, fire 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.

[0126] In the use process of the battery monomer, the temperature of the battery monomer is too high or too low, which leads to the problem that the performance of the battery monomer cannot meet the expected requirements.

[0127] The reason for the above problem is that during the working process of the battery device, a large amount of heat is generated at the end cover assembly of the battery monomer due to overcurrent. This part of heat cannot be dissipated to the external environment in time, so as to reversely heat the electrode assembly, so that the battery monomer reaches the current limiting temperature too early, so as to affect the performance of the battery monomer, and further affect the performance and service life of the battery device.

[0128] Based on the above problems, the battery cell provided in the embodiments of the present application includes a shell, an end cover assembly and an electrode assembly. The shell includes a bottom wall, a side wall and a cavity open at one end in a first direction enclosed by the bottom wall and the side wall. The electrode assembly is accommodated in the shell. The end cover assembly covers the opening of the shell and is connected with the electrode assembly, so that the electrode assembly can form a loop with external devices through the end cover assembly. The heat conduction assembly includes a first heat conduction part and a second heat conduction part. The heat conductivity of the heat conduction assembly is greater than that of the end cover assembly and the shell. The external heat conduction channel of the battery cell is established through the first heat conduction part arranged on the side surface of the end cover assembly away from the electrode assembly, so as to reduce the thermal resistance at the end cover assembly. The total area of the heat conduction assembly is increased through the second heat conduction part arranged on the side wall, so as to increase the heat exchange rate between the battery cell and the external environment, and to improve the problem that the performance and service life of the battery cell are adversely affected due to excessively high or low temperature.

[0129] The technical solutions described in the embodiments of the present application are suitable for battery devices and electric devices using the battery devices.

[0130] 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.

[0131] 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.

[0132] 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 do not limit this. 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 also do not limit this.

[0133] The battery device mentioned in the embodiments of the present application refers to a single physical module including one or more battery monomers 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 monomers. The box can avoid the influence of liquid or other foreign matters on the charging or discharging of the battery monomers.

[0134] The battery monomer includes an electrode assembly and an electrolyte, and the electrode assembly includes a positive electrode sheet, a negative electrode sheet and a separator. The battery monomer 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 electrode current collector and a positive electrode active material layer coated on the surface of the positive electrode current collector; the positive electrode current collector includes a positive electrode current collecting portion and a positive electrode tab connected to the positive electrode current collecting portion, the positive electrode current collecting portion is coated with the positive electrode active material layer, and the positive electrode tab is not coated with the positive electrode active material layer. Taking a lithium ion battery as an example, the material of the positive electrode current collector can be aluminum, and the positive electrode active material layer includes a positive electrode active material, which can be lithium cobaltate, lithium iron phosphate, ternary lithium or lithium manganate, etc. The negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer coated on the surface of the negative electrode current collector; the negative electrode current collector includes a negative electrode current collecting portion and a negative electrode tab connected to the negative electrode current collecting portion, the negative electrode current collecting portion is coated with the negative electrode active material layer, and the negative electrode tab is not coated with the negative electrode active material layer. The material of the negative electrode current collector can be copper, and the negative electrode active material layer includes a negative electrode active material, which can be carbon or silicon, etc. The material of the separator can be PP (polypropylene) or PE (polyethylene), etc.

[0135] It should be understood that the technical solutions described in the embodiments of the present application are not only limited to the above-described battery device and electric equipment, but also can be applied to all battery devices including a box and electric equipment using the battery device, but for the sake of brevity of description, the following embodiments are described taking an electric vehicle as an example.

[0136] Please refer to Figure 1 , Figure 1 A structural schematic diagram of a vehicle 1 provided by some embodiments of the present application is shown. The vehicle 1 can be a fuel automobile, a gas automobile or a new energy automobile, and the new energy automobile can be a pure electric vehicle, a hybrid electric 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 the operating power supply 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 working power demand of the vehicle 1 during starting, navigation and driving.

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

[0138] Figure 2 A structural schematic diagram of the battery device according to an embodiment of the present application is shown.

[0139] 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 through a busbar component.

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

[0141] As an 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. As an example, the battery module 201 can be formed by bundling a plurality of battery cells 3 with a cable tie.

[0142] 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.

[0143] As an 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.

[0144] As an 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.

[0145] 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 buckled so that an enclosed space is formed inside the box 202 to accommodate the battery cell assembly. Here, enclosed means covered or closed, which can be sealed or unsealed. The first box 2021 can be a top cover or a bottom plate.

[0146] 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.

[0147] 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.

[0148] Figure 3 A structural schematic diagram of a battery module 201 according to an embodiment of the present application is shown.

[0149] In some embodiments, as shown in FIG. 1, a plurality of battery monomers 3 are connected in series or in parallel or in a mixed manner to form a battery module 201. Figure 2 and Figure 3 As shown in FIG. 1, a plurality of battery monomers 3 are connected in series or in parallel or in a mixed manner to form a battery module 201. A plurality of battery modules 201 are connected in series or in parallel or in a mixed manner to form a whole and are accommodated in a box 202.

[0150] The plurality of battery monomers 3 in the battery module 201 can be electrically connected through a busbar component to realize parallel connection, series connection or mixed connection of the plurality of battery monomers 3 in the battery module 201.

[0151] Figure 4 An exploded view of a battery monomer according to an embodiment of the present application is shown. The battery monomer 3 refers to the smallest unit that constitutes a battery device. As shown in FIG. 2, the battery monomer 3 includes an end cap assembly 6, a housing 4 and an electrode assembly 5. Figure 4

[0152] The electrode assembly 5 is a component in which electrochemical reactions occur in the battery monomer 3. The housing 4 can contain one or more electrode assemblies 5. The electrode assembly 5 is mainly formed by winding or stacking electrode sheets. The electrode sheets are divided into positive electrode sheets and negative electrode sheets, and a separator is usually arranged between the positive electrode sheets and the negative electrode sheets. The positive electrode sheets and the negative electrode sheets have a part of active material constituting an electrode body 52, and each of the positive electrode sheets and the negative electrode sheets has a part without active material constituting a tab 51. The positive electrode tab and the negative electrode tab can be located at one end of the electrode body 52 or at two ends of the electrode body 52, respectively. In the charging and discharging process of the battery monomer 3, the positive active material and the negative active material react with the electrolyte, and the tab 51 connects the electrode terminal to form a current loop.

[0153] The electrode assembly 5 can be a winding structure, a laminated structure or a hybrid structure of winding and laminating.

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

[0155] In some embodiments, the electrode assembly 5 is a laminated structure. As an example, a plurality of positive electrode sheets and a plurality of negative electrode sheets are alternately and laminatedly arranged, and a plurality of separators are arranged between any adjacent positive electrode sheets or negative electrode sheets, or the separators are continuously arranged by being folded between any adjacent positive electrode sheets or negative electrode sheets.

[0156] In some embodiments, the shape of the electrode assembly 5 can be cylindrical, flat or polygonal, etc. ​

[0157] In some embodiments, the electrode assembly 5 is provided with tabs, which can lead current out of the electrode assembly. The tabs include positive tabs and negative tabs.

[0158] The battery cell 3 can include a shell 4. The shell 4 is an assembly for fitting the end cover assembly 6 to form an internal environment of the battery cell 3, wherein the formed internal environment can be used to accommodate the electrode assembly 5, electrolyte (not shown in the figure), and other components. The shell 4 can be a steel shell, an aluminum shell, a plastic shell (such as polypropylene), a composite metal shell (such as a copper-aluminum composite shell), or an aluminum-plastic film, etc. In some embodiments, the shell 4 can be a sealed structure, or a non-sealed structure. As an example, when the shell 4 is a non-sealed structure, the shell 4 serves to protect the electrode assembly 5, and a sealing bag is further included between the shell 4 and the electrode assembly 5, which 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 shell 4 is a sealed structure, it is used to package the electrode assembly 5, the electrolyte, and other components.

[0159] As an example, the battery cell 3 can be a cylindrical battery cell, a prismatic battery cell, a soft-pack battery cell, or a battery cell of other shapes, including a square battery cell, a blade battery cell, a multi-prismatic battery cell (such as a hexagonal battery cell), etc., without specific limitation in the present application.

[0160] The shell 4 and the end cover assembly 6 can be independent components, and one or more openings 41 can be provided on the shell 4, and the end cover assembly 6 covers the openings 41 to form the internal environment of the battery cell 3. Alternatively, the end cover assembly 6 and the shell 4 can be integrated. Alternatively, the end cover assembly 6 and the shell 4 can form a common connecting surface before other components enter the shell, and then the end cover assembly 6 covers the shell 4 when it is necessary to seal the internal environment of the shell 4.

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

[0162] Please refer to Figure 5 , Figure 6 and Figure 7 , Figure 5 is a partial structure schematic diagram of a battery cell provided by an embodiment of the present application; Figure 6 is a structure schematic diagram of a battery cell provided by an embodiment of the present application; Figure 7 is a structure schematic diagram of a battery cell provided by an embodiment of the present application; Figure 8 is a structure schematic diagram of a battery cell provided by an embodiment of the present application.

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

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

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

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

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

[0168] Optionally, the first heat-conducting part 71 and the end cover assembly 6 are connected by bonding or abutting.

[0169] The first heat-conducting part 71 and the end cover assembly 6 are in thermal connection, specifically, the first heat-conducting part 71 directly abuts or bonds to the end cover assembly 6; or the first heat-conducting part 71 is a plating layer provided on the end cover assembly 6; or the first heat-conducting part 71 and the end cover assembly 6 are spaced apart, and the first heat-conducting part 71 is indirectly connected to the end cover assembly 6 through a heat-conducting medium, which can be air or metal or heat-conducting glue, etc.

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

[0171] Optionally, a plurality of first heat-conducting parts 71 are spaced apart on the end cover assembly 6, which can not only conduct the heat of the end cover assembly 6 through the first heat-conducting part 71, but also reduce the size of the heat-conducting assembly 7 and the preparation cost of the battery monomer 3.

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

[0173] Optionally, the first heat-conducting part 71 is arranged around the circumferential edge of the end cover assembly 6, so as to increase the contact area of the heat-conducting assembly 7 and the end cover assembly 6 and improve the heat exchange efficiency between the heat-conducting assembly 7 and the end cover assembly 6.

[0174] Optionally, the second heat-conducting part is arranged on the side surface of the side wall 42 away from the electrode assembly 5, so as to help the second heat-conducting part 72 to transfer the heat of the shell 4 to the external environment.

[0175] The battery device can further include a heat exchange mechanism 8, which is usually arranged at the side wall 42 of the shell 4. The second heat-conducting part 72, which is connected to the first heat-conducting part 71 and arranged on the side wall 42, can shorten the distance between the heat-conducting assembly 7 and the heat exchange mechanism 8, so as to enhance the heat exchange rate of the end cover assembly 6 and the heat exchange mechanism 8.

[0176] The second heat-conducting part 72 is arranged on the side wall 42, and the second heat-conducting part 72 and the side wall 42 abut or bond to each other, or are spaced apart, and are in thermal connection through a heat-conducting medium, which can be air or heat-conducting glue, etc.

[0177] Optionally, the first heat-conducting part 71 and the second heat-conducting part 72 are separately prepared and are bonded to each other, so as to facilitate adjustment of the shape and size of the first heat-conducting part 71 and the second heat-conducting part 72; or the first heat-conducting part 71 and the second heat-conducting part 72 are integrally formed and are obtained by folding the same base material, so as to reduce the processing difficulty of the heat-conducting assembly 7.

[0178] During the working process of the battery monomer 3, the temperature of the end closer to the end cover assembly 6 is relatively high, and the temperature of the end farther from the end cover assembly 6 is relatively low. The second heat-conducting part 72 arranged on the side wall 42 can conduct and balance the temperature of the battery monomer 3 in the first direction X.

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

[0180] Optionally, a plurality of second heat-conducting parts 72 are arranged at intervals on the side wall 42, which can not only conduct the heat of the end cover assembly 6, but also reduce the size of the heat-conducting assembly 7 and the manufacturing cost of the battery monomer 3.

[0181] Optionally, the end cover assembly 6 is rectangular, and four mutually independent first heat-conducting parts 71 are arranged at four edges of the end cover assembly 6 in the second direction Y and the third direction Z, respectively. The four first heat-conducting parts 71 are connected by splicing and are arranged without overlapping each other, so as to increase the contact area of the first heat-conducting part 71 and the end cover assembly 6, and not to increase the size of the battery monomer 3 in the first direction X because of the arrangement of the heat-conducting assembly 7.

[0182] In some embodiments, as shown in FIG. 1, the side wall 42 includes two first side walls 421 and two second side walls 422, the two first side walls 421 are arranged opposite to each other in the second direction Y, and the two second side walls 422 are arranged opposite to each other in the third direction Z. The first direction X, the second direction Y and the third direction Z intersect with each other, the area of the first side wall 421 is greater than that of the second side wall 422, the second heat-conducting part 72 is arranged on the first side wall 421, and / or the second heat-conducting part 72 is arranged on the second side wall 422. Figure 5 to Figure 8 In these embodiments, the second heat-conducting part 72 is arranged on at least one of the first side wall 421 and the second side wall 422, so that when the battery monomer 3 is arranged in the box body 202, the second heat-conducting part 72 can be close to the heat exchange mechanism 8, so as to improve the heat exchange rate between the heat exchange mechanism 8 and the battery monomer 3, better balance the temperature of the battery monomer 3, and improve the use performance of the battery device 2.

[0183] Optionally, the second direction Y is the width direction of the battery monomer 3, the first direction X is the height direction of the battery monomer 3, and the third direction Z is the length direction of the battery monomer 3.

[0184]

[0185] ​The first side wall 421 has a larger area than the second side wall 422, and thus the second heat conduction part 72 can be arranged on the first side wall 421 with a larger area to improve the heat conduction rate of the second heat conduction part 72 to the shell. The specific areas of the first side wall 421 and the second side wall 422 can be designed as needed.

[0186] Optionally, the second heat conduction part 72 is arranged on one or two first side walls 421, or the second heat conduction part 72 is arranged on one or two second side walls 422.

[0187] In some embodiments, as shown in Figure 5 to Figure 8 , the second heat conduction part 72 covers the entire first side wall 421, or the second heat conduction part 72 covers the entire second side wall 422.

[0188] In these embodiments, the second heat conduction part 72 covers the entire first side wall 421, or the second heat conduction part 72 covers the entire second side wall 422, to increase the contact area between the second heat conduction part 72 and the external environment and improve the heat conduction performance of the heat conduction assembly 7.

[0189] Optionally, the second heat conduction part 72 and the first side wall 421 are bonded, and / or the second heat conduction part 72 and the second side wall 422 are bonded.

[0190] Optionally, the first heat conduction part 71 has the same size as the second heat conduction part 72 in the third direction Z, and / or the first heat conduction part 71 has the same size as the second heat conduction part 72 in the second direction Y, to increase the contact area between the first heat conduction part 71 and the second heat conduction part 72 and improve the heat conduction rate of the heat conduction assembly 7.

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

[0192] In some embodiments, as shown in Figure 5 and Figure 9 , the side wall 42 and the end cover assembly 6 are connected through a rounded corner, and the rounded corner is spaced apart from the heat conduction assembly 7.

[0193] In these embodiments, the side wall 42 and the end cover assembly 6 are connected through a rounded corner, and the rounded corner is spaced apart from the heat conduction assembly 7, so that there is a gap between the shell 4 and the heat conduction assembly 7 that can accommodate the expansion deformation of the shell 4, thereby reducing the risk that the heat conduction assembly 7 is broken by the expansion of the battery cell 3.

[0194] The side wall 42 and the end cover assembly 6 are connected through a transition rounded corner, which relieves the stress at the connection between the side wall 42 and the end cover assembly 6 and reduces the risk that a sharp angle between the side wall 42 and the end cover assembly 6 pierces other components.

[0195] Exemplarily, the fillet radius between the side wall 42 and the end cover assembly 6 is greater than or equal to 0.5 mm, and exemplarily, the fillet radius is 0.5 mm, 1 mm, 2 mm, 3 mm, or 5 mm, etc.

[0196] The fillet and the heat conduction assembly 7 are spaced apart, that is, there is a partial gap between the second heat conduction part 72 and the side wall 42, so that during the expansion of the battery monomer 3, the partial gap can accommodate at least part of the expansion deformation of the shell 4, so as to reduce the extrusion force of the shell 4 on the second heat conduction part 72, and reduce the risk of expansion of the heat conduction assembly 7.

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

[0198] Optionally, the first heat conduction part 71 and the second heat conduction part 72 are connected in a fillet transition to disperse the stress acting between the first heat conduction part 71 and the second heat conduction part 72, and reduce the risk of breakage at the connection between the first heat conduction part 71 and the second heat conduction part 72.

[0199] Please refer to Figure 10 , Figure 10 is a partial structure schematic diagram of a battery monomer provided by an embodiment of the present application.

[0200] In some embodiments, as shown in Figure 8 to Figure 10 , the heat conduction assembly 7 further includes a bonding layer 74, and the bonding layer 74 includes a first bonding layer 741, and the second heat conduction part 72 is bonded to the side wall 42 through the first bonding layer 741.

[0201] In these embodiments, the second heat conduction part 72 is bonded to the side wall 42 through the first bonding layer 741, which can not only reduce the connection difficulty of the second heat conduction part 72 and the side wall 42, but also improve the stability of the second heat conduction part 72.

[0202] Optionally, the first bonding layer 741 is an insulating adhesive layer, and the second heat conduction part 72 is connected to the side wall 42 through the insulating adhesive layer, so as to enhance the insulation performance of the battery monomer 3.

[0203] Optionally, the area of the first bonding layer 741 can be flexibly designed, and exemplarily, the first bonding layer 741 is applied to the entire side wall 42 to improve the connection reliability of the side wall 42 and the second heat conduction part 72.

[0204] Optionally, the shape of the first bonding layer 741 can be flexibly designed, and exemplarily, the first bonding layer 741 is in any two-dimensional image such as a circle, a rectangle, or a rhombus, etc.

[0205] In some embodiments, as shown in FIG. 7, the thickness L1 of the adhesive layer 74 satisfies L1≥0.5mm. Figure 8 to Figure 10

[0206] In these embodiments, when the thickness of the adhesive layer 74 satisfies the above condition, the adhesive layer 74 forms a sufficient gap between the second heat-conducting part 72 and the side wall 42 to accommodate the expansion deformation of the shell 4, so as to reduce the risk of the heat-conducting assembly 7 being burst due to the expansion of the battery cell 3.

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

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

[0209] For example, the end cover assembly 6 and the first side wall 421 are connected through a rounded corner, the second heat-conducting part 72 and the first side wall 421 are arranged in the second direction Y, the spacing between the second heat-conducting part 72 and the rounded corner at the end of the second heat-conducting part 72 close to the second heat-conducting part 72 in the second direction Y is greater than or equal to 0.5mm, and the spacing between the second heat-conducting part 72 and the rounded corner at the end of the second heat-conducting part 72 away from the second heat-conducting part 72 in the second direction Y is greater than or equal to 1.0mm.

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

[0211] In some embodiments, as shown in FIG. 7, the first adhesive layer 741 is arranged in the first direction X away from the edge of the side wall 42 at one end of the first heat-conducting part 71. Figure 8 to Figure 10 In these embodiments, the first adhesive layer 741 is arranged away from the edge of the side wall 42 at one end of the first heat-conducting part 71, so as to facilitate the co-deformation of the second heat-conducting part 72 and the shell 4 during the expansion of the battery cell 3, and reduce the risk of the heat-conducting assembly 7 being burst during the expansion of the battery cell 3.

[0212] In some embodiments, as shown in FIG. 7, the first adhesive layer 741 is arranged in the first direction X away from the edge of the side wall 42 at one end of the first heat-conducting part 71.

[0213] In these embodiments, the first adhesive layer 741 is arranged away from the edge of the side wall 42 at one end of the first heat-conducting part 71, so as to facilitate the co-deformation of the second heat-conducting part 72 and the shell 4 during the expansion of the battery cell 3, and reduce the risk of the heat-conducting assembly 7 being burst during the expansion of the battery cell 3.Part of the second heat-conducting part 72 is adhered to the side wall 42 by the first adhesive layer 741, while part of the second heat-conducting part 72 located in the region between the first adhesive layer 741 and the edge of the side wall 42 in the first direction X is not fixed, so that this part of the second heat-conducting part 72 is prone to deformation in the second direction Y during the expansion of the battery cell 3, and absorbs the expansion of the shell 4 through deformation, thereby reducing the risk of the heat-conducting assembly 7 being broken by expansion.

[0214] Optionally, the adhesive layer 74 and the rounded region are arranged at intervals, so that the part of the second heat-conducting part 72 corresponding to the rounded region is prone to deformation.

[0215] Optionally, a plurality of first adhesive layers 741 are arranged at the edge positions of the side wall 42 in the first direction X and the second direction Y, respectively, so that in the case where the first adhesive layer 741 can fix the second heat-conducting part 72 and the side wall 42, a gap for accommodating the expansion of the battery cell 3 can be formed between the middle region of the side wall 42 and the second heat-conducting part 72, and the material cost of the heat-conducting assembly 7 is reduced. For example, four first adhesive layers 741 in the shape of a rectangle are arranged end to end and at the edge positions of the first side wall 421 in the first direction X and the second direction Y, respectively.

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

[0217] In these embodiments, when the minimum distance between the end of the first adhesive layer 741 in the first direction X towards the first heat-conducting part 71 and the edge of the side wall 42 meets the above condition, the second heat-conducting part 72 can conveniently deform together with the shell 4 during the expansion of the battery cell 3, thereby reducing the risk of the heat-conducting assembly 7 being broken by expansion during the expansion of the battery cell 3, and the processing cost of the battery cell 3 is also reduced.

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

[0219] In some embodiments, as shown in Figure 5 and Figure 8As shown, the side wall 42 includes two first side walls 421 and two second side walls 422, the two first side walls 421 are oppositely arranged in the second direction Y, and the two second side walls 422 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 wall 421 is greater than the area of the second side wall 422, and at least two second heat conduction parts 72 are arranged on the first side wall 421 and the second side wall 422, wherein each second heat conduction part 72 arranged on the first side wall 421 and the second side wall 422 is independent of each other.

[0220] In some embodiments, at least two second heat conduction parts 72 are arranged on the first side wall 421 and the second side wall 422, and each second heat conduction part 72 arranged on the first side wall 421 and the second side wall 422 is independent of each other, so that during the expansion of the battery monomer 3, the two second heat conduction parts 72 arranged on the first side wall 421 and the second side wall 422 move independently of each other, thereby reducing the risk of expansion and breakage of the heat conduction assembly 7.

[0221] Specifically, one or two first side walls 421 are provided with second heat conduction parts 72, and one or two second side walls 422 are provided with second heat conduction parts 72, and each second heat conduction part 72 arranged on the first side wall 421 and the second side wall 422 is arranged independently of each other.

[0222] For example, during the expansion of the battery monomer 3, the second heat conduction part 72 arranged on the first side wall 421 deforms with the first side wall 421, and since the two first heat conduction parts 71 arranged on the first side wall 421 and the second side wall 422 are independent of each other, the second heat conduction part 72 arranged on the first side wall 421 will not be pulled by the second heat conduction part 72 arranged on the second side wall 422, thereby reducing the problem of excessive extrusion between the second heat conduction part 72 arranged on the first side wall 421 and the second side wall 422, and breakage of the second heat conduction part 72.

[0223] Optionally, the second heat conduction part 72 arranged on the first side wall 421 is arranged at intervals between the two ends of the third direction Z and the two side edges of the first side wall 421 in the third direction Z, and / or the second heat conduction part 72 arranged on the second side wall 422 is arranged at intervals between the two ends of the second direction Y and the two side edges of the second side wall 422 in the second direction Y.

[0224] Please refer to Figure 11 and Figure 12 , Figure 11 is a side view of a battery monomer provided by an embodiment of the present application; Figure 12 is a side view of a battery monomer provided by an embodiment of the present application.

[0225] In some embodiments, as Figure 5 , Figure 8 , Figure 11 andFigure 12 As shown, the minimum distance L2 between the second heat-conducting part 72 arranged on the first side wall 421 and the adjacent second side wall 422 in the third direction Z satisfies L2≥10 mm; and / or the minimum distance L3 between the second heat-conducting part 72 arranged on the second side wall 422 and the adjacent first side wall 421 in the second direction Y satisfies L3≥10 mm.

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

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

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

[0229] Optionally, the minimum distance between the second heat-conducting part 72 arranged on the first side wall 421 and the adjacent second side wall 422 in the third direction Z and the minimum distance between the second heat-conducting part 72 arranged on the second side wall 422 and the adjacent first side wall 421 in the second direction Y are the same, which reduces the difficulty of matching the second heat-conducting part and the shell.

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

[0231] In some embodiments, as shown in Figure 8 and Figure 13 , the heat-conducting assembly 7 further comprises a third heat-conducting part 73, the third heat-conducting part 73 is connected with the second heat-conducting part 72, and the third heat-conducting part 73 is arranged on the bottom wall 43.

[0232] In the embodiments, the heat conduction assembly 7 further comprises a third heat conduction part 73 connected with the second heat conduction part 72, and the third heat conduction part 73 is arranged on the bottom wall 43. The heat of the end cover assembly 6 can be transferred to the bottom wall 43 through the first heat conduction part 71 and the second heat conduction part 72, and then conducted to the external environment through the third heat conduction part 73. The third heat conduction part 73 can increase the contact area between the heat conduction assembly 7 and the external environment, improve the heat conduction performance of the heat conduction assembly 7, enhance the heat exchange efficiency between the end cover assembly 6 and the external environment, and enhance the heat conduction performance of the bottom wall 43 of the battery monomer 3. The heat conduction assembly 7 can better balance the temperature of the battery monomer 3 and improve the use performance of the battery device 2.

[0233] Specifically, the heat conduction assembly 7 comprises the first heat conduction part 71, the second heat conduction part 72 and the third heat conduction part 73, and the first heat conduction part 71 and the third heat conduction part 73 are respectively connected to the two ends of the second heat conduction part 72 in the first direction X.

[0234] The heat of the end cover assembly 6 is transferred to the third heat conduction part 73 through the first heat conduction part 71 and the second heat conduction part 72, and then transferred to the external environment.

[0235] Exemplarily, the heat exchange mechanism 8 is connected to the bottom wall 43 of the shell 4, and the heat of the end cover assembly 6 is transferred to the heat exchange mechanism 8 through the third heat conduction part 73.

[0236] Optionally, the third heat conduction part 73 and the second heat conduction part 72 are separately prepared and bonded to each other to facilitate adjustment of the shape and size of the third heat conduction part 73 and the second heat conduction part 72; or the third heat conduction part 73 and the second heat conduction part 72 are integrally formed and obtained by bending the same base material to reduce the processing difficulty of the heat conduction assembly 7. Exemplarily, the first heat conduction part 71, the second heat conduction part 72 and the third heat conduction part 73 are integrally formed and obtained by bending the same base material.

[0237] Optionally, a plurality of second heat conduction parts 72 are arranged at intervals and connected to the third heat conduction part 73 to increase the connection area of the second heat conduction part 72 and the third heat conduction part 73 and improve the heat conduction rate of the heat conduction assembly 7. Exemplarily, four second heat conduction parts 72 are arranged on the two first side walls 421 and the two second side walls 422 respectively, and the four second heat conduction parts 72 are connected to the third heat conduction part 73 to increase the connection area of the second heat conduction part 72 and the third heat conduction part 73.

[0238] Optionally, the size and shape of the third heat conduction part 73 can be designed as desired. Exemplarily, the third heat conduction part 73 is rectangular, circular or circular ring-shaped, etc.

[0239] In some embodiments, as Figure 13As shown, the bottom wall 43 comprises a first portion 431 and a second portion 432, and the third heat-conducting part 73 is arranged on the first portion 431, and the second portion 432 is used to connect with the mounting position.

[0240] In some embodiments, the bottom wall 43 comprises a first portion 431 and a second portion 432, the third heat-conducting part 73 arranged on the first portion 431 is used to conduct heat, and the second portion 432 is used to connect the battery monomer 3 with the mounting position to fix the battery monomer 3.

[0241] For example, the mounting position is arranged on the heat exchange mechanism 8 or the box body 202.

[0242] For example, the mounting position can be arranged on the heat exchange mechanism 8, the third heat-conducting part 73 is arranged on the first portion 431, and part of the heat exchange mechanism 8 is arranged on the side of the third heat-conducting part 73 away from the first portion 431, so that the heat of the end cover assembly 6 can be transmitted to the heat exchange mechanism 8 through the third heat-conducting part 73, and the other part of the heat exchange mechanism 8 is connected to the second portion 432 of the bottom wall 43, so that the battery monomer 3 and the heat exchange mechanism 8 are stably connected.

[0243] Optionally, the specific size and shape of the first portion 431 and the second portion 432 can be designed by oneself.

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

[0245] Please refer to Figure 14 , Figure 14 which is a structural schematic diagram of a battery monomer provided by an embodiment of the present application.

[0246] In some embodiments, as shown in Figure 14 , the side wall 42 and the bottom wall 43 are connected with a rounded corner, and the rounded corner is arranged away from the heat-conducting assembly 7.

[0247] In the scheme of the embodiment of the present application, the side wall 42 and the bottom wall 43 are connected with a rounded corner, and the rounded corner is arranged away from the heat-conducting assembly 7, so that there is a gap between the shell 4 and the heat-conducting assembly 7, which can accommodate the expansion deformation of the shell 4, thereby reducing the risk that the heat-conducting assembly 7 is broken by the expansion of the battery monomer 3.

[0248] The side wall 42 and the bottom wall 43 are connected through a rounded corner to relieve stress at the connection between the side wall 42 and the bottom wall 43 and reduce the risk of a sharp corner between the side wall 42 and the bottom wall 43 puncturing other components.

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

[0250] The rounded corner and the heat conduction assembly 7 are spaced apart, that is, there is a gap between the second heat conduction part 72 and the side wall 42, so that during the expansion of the battery monomer 3, at least part of the expansion of the shell 4 can be accommodated, so as to reduce the extrusion force of the shell 4 on the second heat conduction part 72 and reduce the risk of the heat conduction assembly 7 being expanded and broken.

[0251] Optionally, the third heat conduction part 73 and the second heat conduction part 72 are connected through a rounded corner to disperse stress between the third heat conduction part 73 and the second heat conduction part 72 and reduce the risk of the third heat conduction part 73 and the second heat conduction part 72 being broken at the connection.

[0252] Optionally, the side wall 42 and the bottom wall 43 are connected through a rounded corner, the side wall 42 and the end cover assembly 6 are connected through a rounded corner, and the rounded corner and the heat conduction assembly 7 are spaced apart to provide a gap between the shell 4 and the heat conduction assembly 7 that can accommodate the expansion and deformation of the shell 4 and reduce the risk of the heat conduction assembly 7 being expanded and broken due to the expansion of the battery monomer 3.

[0253] Please refer to Figure 15 , Figure 15 is a bottom view of a battery monomer provided in an embodiment of the present application.

[0254] In some embodiments, as shown in Figure 13 to Figure 15 , the heat conduction assembly 7 further includes an adhesive layer 74, and the adhesive layer 74 includes a second adhesive layer 742, and the third heat conduction part 73 is adhered to the bottom wall 43 through the second adhesive layer 742.

[0255] In these embodiments, the third heat conduction part 73 is adhered to the bottom wall 43 through the second adhesive layer 742 to improve the stability of the third heat conduction part 73.

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

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

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

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

[0260] In these embodiments, the second adhesive layer 742 is spaced apart from the edge of the bottom wall 43 at one end of the second heat-conducting part 72, so as to facilitate the movement of the second heat-conducting part 72 together with the shell 4 during the expansion of the battery monomer 3, and reduce the risk of the heat-conducting assembly 7 being damaged by expansion.

[0261] Part of the third heat-conducting part 73 is adhered to the bottom wall 43 by the second adhesive layer 742, and part of the third heat-conducting part 73 located between the second adhesive layer 742 and the edge of the bottom wall 43 is not fixed. The second heat-conducting part 72 and the third heat-conducting part 73 are connected, so that during the expansion of the battery monomer 3, the part of the third heat-conducting part 73 connected with the second heat-conducting part 72 is easy to deform to absorb the expansion of the shell 4, thereby reducing the risk of the heat-conducting assembly 7 being damaged by expansion.

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

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

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

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

[0266] In these embodiments, when the minimum distance between the end of the second heat-conducting part 72 and the edge of the bottom wall 43 towards which the second adhesive layer 742 is directed satisfies the above condition, it is convenient for the second heat-conducting part 72 and the shell 4 to deform synchronously during the expansion of the battery cell 3, so as to reduce the risk of the heat-conducting assembly 7 being broken by expansion, and the processing cost of the battery cell 3 is reduced.

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

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

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

[0270] In some embodiments, as shown in Figure 14 and Figure 16 , the heat-conducting assembly 7 further comprises an adhesive layer 74, and the adhesive layer 74 comprises a third adhesive layer 743, and the first heat-conducting part 71 is adhered to the end cover assembly 6 through the third adhesive layer 743.

[0271] In these embodiments, the first heat-conducting part 71 is adhered to the end cover assembly 6 through the third adhesive layer 743, so as to improve the stability of the first heat-conducting part 71.

[0272] Optionally, the third adhesive layer 743 is an insulating adhesive layer, and the first heat-conducting part 71 is connected to the end cover assembly 6 through the insulating adhesive layer, so as to enhance the insulation performance of the battery cell 3.

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

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

[0275] In some embodiments, as shown in Figure 14 and Figure 16 , the third adhesive layer 743 is arranged at a distance from the edge of the end cover assembly 6 towards the end of the second heat-conducting part 72.

[0276] In these embodiments, the third adhesive layer 743 is spaced apart from the edge of the end cover assembly 6 and the end of the second heat conduction part 72, so as to facilitate the second heat conduction part 72 to move together with the shell 4 during the expansion of the battery cell 3, and reduce the risk of the heat conduction assembly 7 being expanded and broken during the expansion of the battery cell 3.

[0277] Part of the first heat conduction part 71 is adhered to the end cover assembly 6 by the third adhesive layer 743, and part of the first heat conduction part 71 located between the third adhesive layer 743 and the edge of the end cover assembly 6 is not fixed. The second heat conduction part 72 is connected to the first heat conduction part 71, so that during the expansion of the battery cell 3, the part of the third heat conduction part 73 connected to the second heat conduction part 72 is easy to deform to absorb the expansion of the shell 4, thereby reducing the risk of the heat conduction assembly 7 being expanded and broken.

[0278] Optionally, the third adhesive layer 743 is spaced apart from the rounded corner region, so that the part of the first heat conduction part 71 corresponding to the rounded corner region is easy to deform.

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

[0280] In some embodiments, as shown in Figure 14 and Figure 16 the minimum distance between the third adhesive layer 743 and the edge of the end cover assembly 6 towards the end of the second heat conduction part 72 is greater than or equal to 10 mm.

[0281] In these embodiments, when the minimum distance between the third adhesive layer 743 and the edge of the end cover assembly 6 towards the end of the second heat conduction part 72 meets the above condition, it not only facilitates the second heat conduction part 72 to deform synchronously with the shell 4 during the expansion of the battery cell 3, thereby reducing the risk of the heat conduction assembly 7 being expanded and broken, but also reduces the processing cost of the battery cell 3.

[0282] For example, when the second heat conduction part 72 is arranged on the first side wall 421, the minimum distance between the second adhesive layer 742 and the edge of the end cover assembly 6 towards the end of the second heat conduction part 72 in the second direction Y is greater than or equal to 10 mm; and / or when the second heat conduction part 72 is arranged on the second side wall 422, the minimum distance between the second adhesive layer 742 and the edge of the end cover assembly 6 towards the end of the second heat conduction part 72 in the third direction Z is greater than or equal to 10 mm.

[0283] For example, the minimum distance between the third adhesive layer and the edge of the end cover assembly towards the end of the second heat conduction part can be 10 mm, 11 mm, 12 mm, or 15 mm, etc.

[0284] Optionally, the heat conduction assembly 7 comprises a first heat conduction part 71, a second heat conduction part 72 and a third heat conduction part 73, the minimum distance between the first adhesive layer 741 and the edge of the side wall 42 in the first direction X is greater than or equal to 10 mm, the minimum distance between the second adhesive layer 742 and the edge of the bottom wall 43 towards one end of the second heat conduction part 72 is greater than or equal to 10 mm, and the minimum distance between the third adhesive layer 743 and the edge of the end cover assembly 6 towards one end of the second heat conduction part 72 is greater than or equal to 10 mm.

[0285] Please refer to Figure 17 , Figure 17 is a structural schematic diagram of a battery cell provided by an embodiment of the present application.

[0286] In some embodiments, as shown in Figure 17 , the end cover assembly 6 comprises a cover plate 61 and an electrode terminal 62 arranged on the cover plate 61, the electrode terminal 62 is connected with the electrode assembly 5, and the first heat conduction part 71 is connected with the electrode terminal 62.

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

[0288] The cover plate 61 covers the shell 4 to form a cavity accommodating the electrode assembly 5, the electrode terminal 62 is connected to the cover plate 61, one end of the electrode terminal 62 is electrically connected with the electrode assembly 5, and the other end of the electrode terminal 62 extends out of the cover plate 61 and is used to form a loop with external components.

[0289] The electrode terminal 62 is the main overcurrent component of the end cover assembly 6, and the heat at the electrode terminal 62 is higher than that of the cover plate 61 during the charging and discharging process of the battery cell 3, so that the first heat conduction part 71 is connected with the electrode terminal 62, which helps to improve the heat conduction efficiency of the first heat conduction part 71.

[0290] Optionally, the first heat conduction part 71 is sleeved on the electrode terminal 62 to increase the contact area of the first heat conduction part 71 and the electrode terminal 62 and improve the heat conduction efficiency of the first heat conduction part 71. For example, the electrode terminal 62 is in a cylindrical shape, and a circular hole is arranged on the first heat conduction part 71 to enable the first heat conduction part 71 to be sleeved on the electrode terminal 62.

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

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

[0293] Referring to Figure 18 , Figure 18 is a structural schematic diagram of a battery cell provided by an embodiment of the present application.

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

[0295] In these embodiments, the battery cell 3 further includes a first insulating layer 91 arranged on the outer surface of the shell 4 and the end cover assembly 6, and the heat-conducting assembly 7 is arranged on the side of the first insulating layer 91 away from the shell 4 and the end cover assembly 6, so that the battery cell 3 and the cabinet 202 and the heat-conducting assembly 7 are insulated from each other.

[0296] For example, the material of the first insulating layer 91 can be PP or PI (Polyimide) or PET (Polyethylene terephthalate) or the like.

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

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

[0299] Referring to Figure 19 and Figure 20 , Figure 19 is a cross-sectional view of a heat-conducting assembly of a battery cell provided by an embodiment of the present application. Figure 20 is a structural schematic diagram of a battery cell provided by an embodiment of the present application.

[0300] In some embodiments, as shown in Figure 19 and Figure 20As shown, the heat-conducting assembly 7 comprises an insulating member 75 and a heat-conducting member 76. The insulating member 75 forms a receiving cavity 77 at least in part, and the heat-conducting member 76 is arranged in the receiving cavity 77. The heat-conducting member 76 comprises a first heat-conducting sheet 761 and a second heat-conducting sheet 762. The first heat-conducting sheet 761 is arranged on the end cover assembly 6, and the second heat-conducting sheet 762 is arranged on the side wall 42. The first heat-conducting part 71 is composed of the first heat-conducting sheet 761 and the insulating member 75, and the second heat-conducting part 72 is composed of the second heat-conducting sheet 762 and the insulating member 75.

[0301] In these embodiments, the heat-conducting assembly 7 comprises an insulating member 75 and a heat-conducting member 76. The insulating member 75 forms a receiving cavity 77 at least in part, and the heat-conducting member 76 is arranged in the receiving cavity 77. The heat-conducting member 76 comprises a first heat-conducting sheet 761 and a second heat-conducting sheet 762. The first heat-conducting sheet 761 is arranged on the end cover assembly 6 to conduct the heat of the end cover assembly 6, and the second heat-conducting sheet 762 is arranged on the side wall 42 to conduct the heat of the first heat-conducting sheet 761 and the shell 4. The first heat-conducting part 71 is composed of the first heat-conducting sheet 761 and the insulating member 75, and the second heat-conducting part 72 is composed of the second heat-conducting sheet 762 and the insulating member 75. In this way, the heat-conducting member 76 can be insulated from the electrode body by the insulating member 75, and the heat-conducting rate of the end cover assembly 6 and the external environment can be improved by the heat-conducting member 76.

[0302] For example, the insulating member 75 can be made of PP, PI (Polyimide) or PET (Polyethylene terephthalate), etc. The heat-conducting member 76 can be made of graphite, graphene or carbon nanotubes. The heat-conducting rate of the heat-conducting member 76 in the heat-conducting assembly 7 is greater than that of the shell 4.

[0303] Optionally, the heat-conducting member 76 can be in the form of a plate, a strip or a net, etc. For example, the receiving cavity 77 can be 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.

[0304] It should be noted that the heat-conducting member 76 is arranged in the insulating member 75, and the heat-conducting member 76 is covered by the insulating member 75. In the drawings, the heat-conducting member 76 is shown by the shadow on the insulating member 75 for convenience. Optionally, the insulating member 75 is provided with a receiving cavity 77 with an open end 41, and the heat-conducting member 76 is arranged in the receiving cavity 77 and bonded or fused to the open end 41 of the insulating member 75, so that the heat-conducting member 76 is arranged in a sealed receiving cavity 77. Alternatively, the insulating member 75 can be folded at both ends, and the heat-conducting member 76 is arranged between the two ends of the insulating member 75. The two ends of the insulating member 75 are bonded or fused together, so that the heat-conducting member 76 is arranged in a sealed receiving cavity 77. Alternatively, the insulating member 75 comprises two oppositely arranged sub-insulating layers, and the edges of the two sub-insulating layers are bonded or fused together, so that the heat-conducting member 76 is arranged in a sealed receiving cavity 77.

[0305] Optionally, the insulation member 75 is provided with an adhesive layer 74 on the side surface facing the battery monomer 3, so as to adhesively connect the heat-conducting assembly 7 and the battery monomer 3.

[0306] The insulation member 75 extends at least partially on the end cover assembly 6, and the first heat-conducting sheet 761 is arranged on the end cover assembly 6 and is in heat-conducting connection with the end cover assembly 6. The first heat-conducting part 71 is composed of the first heat-conducting sheet 761 and the insulation member 75. For example, the first heat-conducting sheet 761 covers the entire end cover assembly 6, so as to improve the heat-conducting rate of the first heat-conducting part 71.

[0307] Optionally, the first heat-conducting sheet 761 and the second heat-conducting sheet 762 are separately prepared and adhesively connected with each other, so as to facilitate adjustment of the shape and size of the first heat-conducting sheet 761 and the second heat-conducting sheet 762; or the first heat-conducting sheet 761 and the second heat-conducting sheet 762 are integrally formed and are obtained by folding the same base material, so as to reduce the processing difficulty of the heat-conducting assembly 7.

[0308] Optionally, the second heat-conducting sheet 762 covers the entire side wall 42, so as to improve the heat-conducting effect of the second heat-conducting part 72.

[0309] For example, the size and shape of the second heat-conducting sheet 762 can be designed at will, and the second heat-conducting sheet 762 is in the shape of a rectangle or an ellipse, etc.

[0310] In some embodiments, as shown in Figs. 1 and 2, the battery monomer 3 further comprises a second insulation layer 92, the second insulation layer 92 is connected with the insulation member 75, and the insulation member 75 and the second insulation layer 92 jointly cover the outer surface of the shell 4 and the end cover assembly 6. Figure 5 and Figure 20 In some embodiments, as shown in Figs. 1 and 2, the battery monomer 3 further comprises a second insulation layer 92, the second insulation layer 92 is connected with the insulation member 75, and the insulation member 75 and the second insulation layer 92 jointly cover the outer surface of the shell 4 and the end cover assembly 6.

[0311] In these embodiments, the second insulation layer 92 is connected with the insulation member 75, and the insulation member 75 and the second insulation layer 92 jointly cover the outer surface of the shell 4 and the end cover assembly 6. The combination of the second insulation layer 92 and the insulation member 75 achieves the insulation of the battery monomer 3, and also helps to reduce the size of the second insulation layer 92, reduce the manufacturing cost of the battery monomer 3, and reduce the self-weight of the battery monomer 3, thereby improving the energy density of the battery monomer 3.

[0312] The insulation member 75 of the heat-conducting assembly 7 covers part of the outer surface of the shell 4 of the battery monomer 3 or part of the outer surface of the end cover assembly 6. Then, the insulation member 75 of the heat-conducting assembly 7 is connected with the second insulation layer 92, and the combination of the insulation member 75 and the second insulation layer 92 can cover the outer surface of the shell 4 and the end cover assembly 6.

[0313] The connection mode of the insulation member 75 and the second insulation layer 92 is adhesion or fusion, etc. The specific size of the insulation member 75 and the second insulation layer 92 can be designed flexibly.

[0314] For example, four second heat-conducting parts 72 are arranged at intervals and are arranged on the first side wall 421 and the second side wall 422 respectively, and the second insulating layer 92 is connected between two adjacent second heat-conducting parts 72.

[0315] Referring to Figure 21 and Figure 22 , Figure 21 is a structural schematic diagram of a battery cell provided by an embodiment of the present application; Figure 22 is a structural schematic diagram of a battery device provided by an embodiment of the present application.

[0316] In some embodiments, as shown in Figure 5 , Figure 20 to Figure 22 , the insulating part 75 is arranged on the outer surface of the end cover assembly 6 and the shell 4.

[0317] In these embodiments, the insulating part 75 is arranged on the outer surface of the end cover assembly 6 and the shell 4, so that the battery cell 3 and the box body 202 and the adjacent battery cell 3 are insulated from each other, and no additional insulating film needs to be arranged, thereby reducing the manufacturing cost of the battery cell 3.

[0318] In the embodiments of the present application, the battery cell 3 and the box body 202 are insulated by the insulating part 75, and no first insulating layer 91 needs to be arranged, or in other words, the first insulating layer 91 is replaced by the insulating part 75. The thermal conductivity of the insulating part 75 and the first insulating layer 91 is similar, so in the embodiments of the present application, replacing the first insulating layer 91 with the insulating part 75 will not greatly affect the heat dissipation of the electrode assembly 5; the heat-conducting part 76 is arranged in the insulating part 75, and the thermal conductivity of the heat-conducting part 76 is greater than that of the first insulating layer 91, so compared with the case where the insulating part 75 or the first insulating layer 91 is arranged, arranging the heat-conducting part 76 in the insulating part 75 can improve the heat conduction rate between the battery cell 3 and the external environment, that is, the heat-conducting assembly 7 can improve the heat conduction efficiency between the battery cell 3 and the external environment.

[0319] The thermal conductivity of the heat-conducting assembly 7 can be measured by a heat flow method or a hot plate method or a hot wire method, etc. When the thermal conductivity of the heat-conducting assembly 7 is tested, the test sample of the heat-conducting assembly 7 should include the heat-conducting part 76 and the insulating part 75 wrapped on the outer surface of the heat-conducting part 76.

[0320] Through the combination of the insulating part 75 and the heat-conducting part 76, the insulating part 75 not only achieves the insulation between the battery cell 3 and the box body 202, but also achieves the insulation effect of the heat-conducting part 76 and the battery cell 3.

[0321] Optionally, the heat-conducting member 76 is arranged in the accommodating cavity 77, the area of the heat-conducting member 76 matches the area of the accommodating cavity 77, the area of the accommodating cavity 77 can be smaller than the area of the insulating member 75, the heat-conducting member 76 is in contact with the cavity wall of the accommodating cavity 77, and the accommodating cavity 77 serves as a limiting part for the heat-conducting member 76.

[0322] In some embodiments, as shown in Figure 5 and Figure 21 The end cover assembly 6 includes a cover plate 61 and a pressure relief mechanism 63 arranged on the cover plate 61, the insulating member 75 is provided with a first opening 751, and the pressure relief mechanism 63 is exposed to the first opening 751.

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

[0324] The cover plate 61 is provided with the pressure relief mechanism 63, when the battery monomer 3 is in thermal runaway, the pressure in the shell 4 rises, and the gas in the shell 4 is released to the outside through the pressure relief mechanism 63 to balance the internal pressure of the shell 4, thereby relieving the damage of the battery monomer 3 in thermal runaway to the adjacent battery monomers 3. Therefore, when the insulating member 75 covers the end cover assembly 6, the insulating member 75 is provided with the first opening 751 to expose the pressure relief mechanism 63, so that the insulating member 75 does not affect the activation of the pressure relief mechanism 63, and the pressure relief mechanism 63 can timely release the internal pressure of the shell 4 when the battery monomer 3 is in thermal runaway.

[0325] Optionally, the shape and size of the first opening 751 match the shape and size of the pressure relief mechanism 63, for example, the pressure relief mechanism 63 and the first opening 751 are both circular or have a waist shape, etc.

[0326] Optionally, the first opening 751 and the accommodating cavity 77 are arranged in a spaced manner, so that the first heat-conducting sheet 761 is insulated from the end cover assembly 6; the first heat-conducting sheet 761 is provided with a first avoiding hole, the first opening 751 is located in the first avoiding hole, and the insulating member 75 covers the inner wall of the first avoiding hole, so that the first heat-conducting sheet 761 is insulated from the end cover assembly 6.

[0327] In some embodiments, as shown in Figure 5 and Figure 20As shown, the side wall 42 includes two first side walls 421 and two second side walls 422, the two first side walls 421 are oppositely arranged in the second direction Y, and the two second side walls 422 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 wall 421 is greater than that of the second side wall 422, and at least two second heat-conducting sheets 762 are arranged on the first side wall 421 and the second side wall 422, wherein each second heat-conducting sheet 762 arranged on the first side wall 421 and the second side wall 422 is independent of each other.

[0328] In some embodiments, at least two second heat-conducting sheets 762 are arranged on the first side wall 421 and the second side wall 422, and each second heat-conducting sheet 762 arranged on the first side wall 421 and the second side wall 422 is independent of each other, so that during the expansion of the battery monomer 3, the two second heat-conducting sheets 762 arranged on the first side wall 421 and the second side wall 422 move independently of each other, thereby reducing the risk of the heat-conducting member 76 being damaged by expansion.

[0329] The insulating member 75 is arranged on the outer surface of the battery monomer 3 to insulate the battery monomer 3 and the box body 202, and the elasticity of the insulating member 75 is stronger than that of the second heat-conducting sheet 762, so that the risk of the insulating member 75 being damaged by expansion and deformation during the charging and discharging of the battery monomer 3 is smaller than that of the second heat-conducting sheet 762. In some embodiments, the second heat-conducting sheets 762 arranged on the first side wall 421 and the second side wall 422 are independent of each other, so that when the shell 4 expands in the second direction Y, the second heat-conducting sheet 762 arranged on the first side wall 421 deforms together with the first side wall 421, thereby reducing the extrusion force between the second heat-conducting sheet 762 and the first side wall 421 and reducing the risk of damage to the second heat-conducting sheet 762.

[0330] Optionally, the second heat-conducting sheet 762 arranged on the first side wall 421 and the second heat-conducting sheet 762 arranged on the second side wall 422 have a sum of minimum distances in the second direction Y and the third direction Z greater than or equal to 10 mm, so as to reduce the risk of extrusion and damage of the two second heat-conducting sheets 762 during the deformation of the shell 4, thereby prolonging the service life of the heat-conducting member 76.

[0331] Please refer to Figure 23 , Figure 23 which is a structural schematic diagram of a battery monomer provided in some embodiments of the present application.

[0332] In some embodiments, as shown in Figure 5 , Figure 20 and Figure 23 , the heat-conducting member 76 further includes a third heat-conducting sheet 763, the third heat-conducting sheet 763 is connected with the second heat-conducting sheet 762, and the third heat-conducting sheet 763 is arranged on the bottom wall 43.

[0333] In these embodiments, the heat-conducting member 76 further comprises a third heat-conducting sheet 763 connected with the second heat-conducting sheet 762, and the third heat-conducting sheet 763 is arranged on the bottom wall 43, so as to increase the volume of the heat-conducting member 76 and improve the heat-conducting performance of the heat-conducting assembly 7, and better conduct the heat at the end cover assembly 6 through the heat-conducting assembly 7.

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

[0335] The heat-conducting member 76 comprises the first heat-conducting sheet 761, the second heat-conducting sheet 762, and the third heat-conducting sheet 763, and the heat of the end cover assembly 6 is transmitted to the third heat-conducting sheet 763 through the first heat-conducting sheet 761 and the second heat-conducting sheet 762.

[0336] Optionally, the first heat-conducting sheet 761, the second heat-conducting sheet 762, and the third heat-conducting sheet 763 are separately prepared and are connected with each other by adhesion, so as to facilitate adjustment of the shape and size of the first heat-conducting sheet 761, the second heat-conducting sheet 762, and the third heat-conducting sheet 763; or the first heat-conducting sheet 761, the second heat-conducting sheet 762, and the third heat-conducting sheet 763 are integrally formed and are obtained by folding the same base material, so as to reduce the processing difficulty of the heat-conducting assembly 7.

[0337] Illustratively, the size and shape of the third heat-conducting sheet 763 can be designed as required, and the third heat-conducting sheet 763 is in a rectangular or elliptical shape, etc.

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

[0339] In some embodiments, as shown in Figure 19 the thickness D1 of the heat-conducting member 76 satisfies 40 μm≤D1≤180 μm.

[0340] In these embodiments, when the above condition is met, the problem that the battery monomer 3 has a large volume and a low energy density due to the over-thickness of the heat-conducting member 76 can be improved, and the problem that the heat-conducting member 76 is easily damaged due to the over-thin thickness of the heat-conducting member 76 can also be improved.

[0341] Illustratively, the thickness D1 of the heat-conducting assembly 7 is 40 μm, or 50 μm, or 110 μm, or 180 μm, etc.

[0342] In some embodiments, as shown in Figure 19 the insulating member 75 comprises polyethylene, or polypropylene, or polyimide, or polyester resin.

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

[0344] Optionally, the insulating member 75 should have the characteristics of insulation and high temperature resistance, so that the insulating member 75 can be used to insulate the heat-conducting member 76 and the electrode assembly 5, and reduce the risk of melting and damage of the insulating member 75 under high temperature conditions.

[0345] In some embodiments, as shown in Figure 19 The heat-conducting member 76 includes graphite or graphene or carbon nanotubes.

[0346] 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 curling one or more graphite layers. The material of the heat-conducting member 76 includes graphite or graphene or carbon nanotubes, which improves the heat-conducting performance of the heat-conducting member 76 through graphite or graphene or carbon nanotube heat-conducting materials.

[0347] Optionally, the material of the heat-conducting member 76 is supercrystalline graphite, which has a larger grain size than ordinary graphite and a significantly improved thermal conductivity compared to ordinary graphite, so that the heat-conducting member 76 has better heat-conducting capacity.

[0348] Optionally, the heat-conducting member 76 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.

[0349] In some embodiments, as shown in Figure 19 The thermal conductivity k of the heat-conducting member 76 satisfies k≥500 W / (m·K).

[0350] In these embodiments, the thermal conductivity k of the heat-conducting member 76 satisfies the above condition, so that the heat-conducting assembly 7 has sufficient heat-conducting performance to conduct the heat of the electrode body.

[0351] Optionally, the thermal conductivity k of the heat-conducting member 76 satisfies 500 W / (m·K)≤k≤1600 W / (m·K), and the thermal conductivity of the heat-conducting member 76 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.

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

[0353] Optionally, the density of the heat-conducting member 76 is 2.1±0.05 g / cm 3The insulation resistance is greater than 1GΩ, the voltage resistance strength is 5400V, and the bending resistance is greater than 10000 times.

[0354] Please refer to Figure 24 and Figure 25 , Figure 24 is a structural schematic diagram of a battery device provided in an embodiment of the present application; Figure 25 is Figure 24 an enlarged structural schematic diagram of A in FIG. 2.

[0355] In a second aspect, as shown in Figure 8 , Figure 24 and Figure 25 , the present application provides a battery device 2, which comprises a box body 202 and the battery monomer 3 of the first aspect of the embodiment.

[0356] In the scheme of the embodiment of the present application, the battery monomer 3 is arranged in the box body 202, the box body 202 plays a role of containing the battery monomer 3, the battery monomer 3 comprises a heat conduction assembly 7, an external heat conduction channel of the battery monomer 3 is established through the first heat conduction part 71 arranged on the side surface of the end cover assembly 6 away from the electrode assembly 5 and the second heat conduction part 72 arranged on the side wall 42, so as to reduce the thermal resistance at the end cover assembly 6 and the side wall 42, improve the heat exchange rate between the battery monomer 3 and the external environment, and improve the problem that the performance and service life of the battery monomer 3 are adversely affected due to the excessively high or low temperature of the battery monomer 3, so as to improve the performance of the battery device 2.

[0357] The several battery monomers 3 are arranged in the box body 202, for example, one or two or three battery monomers 3 are arranged in the box body 202.

[0358] Optionally, the plurality of battery monomers 3 are arranged in the box body 202 in rows and columns.

[0359] In some embodiments, as shown in Figure 8 , Figure 24 and Figure 25 , the battery device 2 further comprises a heat exchange mechanism 8 arranged in the box body 202, and the heat conduction assembly 7 and the heat exchange mechanism 8 are in heat conduction connection.

[0360] In these embodiments, the battery device 2 further comprises the heat exchange mechanism 8 arranged in the box body 202, and the heat conduction assembly 7 and the heat exchange mechanism 8 are in heat conduction connection, so as to improve the heat exchange rate between the battery monomer 3 and the heat exchange mechanism 8, and better balance the temperature of the battery monomer 3, thereby improving the use performance of the battery device 2.

[0361] In the related art, the heat exchange mechanism 8 is arranged in the box body 202, the heat exchange mechanism 8 is in heat conduction connection with the shell 4 of the battery monomer 3, and the heat exchange mechanism 8 is used to transmit the heat of the battery monomer 3 to the outside. In the embodiment of the present application, in order to improve the heat conduction performance of the battery monomer 3, the heat conduction assembly 7 is arranged in heat conduction connection with the heat exchange mechanism 8, the heat conduction assembly 7 is an external cold bridge of the battery monomer 3 to improve the heat conduction efficiency between the heat exchange mechanism 8, and the temperature of the battery monomer 3 is better balanced.

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

[0363] For example, the shell 4 includes a bottom wall 43 and a side wall 42 connected with each other, the heat exchange mechanism 8 is arranged side by side with the side wall 42, or the heat exchange mechanism 8 is arranged side by side with the bottom wall 43.

[0364] The heat conduction assembly 7 is in heat conduction connection with the heat exchange mechanism 8, specifically, the heat conduction assembly 7 is directly attached to or abuts against the heat exchange mechanism 8; or the heat conduction assembly 7 and the heat exchange mechanism 8 are arranged at intervals, the heat conduction assembly 7 is indirectly connected with the heat exchange mechanism 8 through a heat conduction medium, and the heat conduction medium can be air, metal or heat conduction glue and the like.

[0365] For example, the heat conduction assembly 7 is bonded between the heat exchange mechanism 8 and at least one of the shell 4 and the end cover assembly 6 on both sides, so as to improve the heat exchange efficiency between the end cover assembly 6 and the heat exchange mechanism 8; or the heat conduction assembly 7 is bonded to at least one of the shell 4 and the end cover assembly 6, and the heat conduction assembly 7 abuts against the heat exchange mechanism, so as to reduce the installation difficulty of the heat conduction assembly 7.

[0366] In some embodiments, as shown in Figure 8 , Figure 24 and Figure 25 , the side wall 42 includes two first side walls 421 and two second side walls 422, the two first side walls 421 are arranged opposite to each other in the second direction Y, the two second side walls 422 are arranged opposite to each other 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 wall 421 is greater than the area of the second side wall 422, the heat exchange mechanism 8 is arranged at intervals with the first side wall 421 along the second direction Y, at least one second heat conduction part 72 is arranged between the first side wall 421 and the heat exchange mechanism 8, or the heat exchange mechanism 8 is arranged at intervals with the second side wall 422 along the third direction Z, and at least one second heat conduction part 72 is arranged between the second side wall 422 and the heat exchange mechanism 8.

[0367] In these embodiments, the heat exchange mechanism 8 and the first side wall 421 are spaced apart along the second direction Y, and the at least one second heat conduction part 72 is arranged between the first side wall 421 and the heat exchange mechanism 8, or the heat exchange mechanism 8 and the second side wall 422 are spaced apart along the third direction Z, and the at least one second heat conduction part 72 is arranged between the second side wall 422 and the heat exchange mechanism 8, so as to shorten the distance between the heat conduction assembly 7 and the heat exchange mechanism 8, to better transfer heat between the heat exchange mechanism 8 and the end cover assembly 6 through the heat conduction assembly 7, to better balance the temperature of the battery monomer 3, and to improve the use performance of the battery device 2.

[0368] For example, in the large-area water cooling scheme, the heat exchange mechanism 8 and the first side wall 421 are arranged side by side along the second direction Y, and the second heat conduction part 72 is arranged between the first side wall 421 and the heat exchange mechanism 8. The second heat conduction part 72 arranged between the first side wall 421 and the heat exchange mechanism 8 has a smaller distance and a larger overlapping projection area, so that the second heat conduction part 72 can better transfer heat between the end cover assembly 6 and the heat exchange mechanism 8, and the second heat conduction part 72 also improves the heat exchange rate of the first side wall 421 and the heat exchange mechanism 8 of the battery monomer 3.

[0369] For example, the heat exchange mechanism 8 and the second side wall 422 are arranged side by side along the third direction Z, and the second heat conduction part 72 is arranged between the second side wall 422 and the heat exchange mechanism 8. The second heat conduction part 72 arranged between the second side wall 422 and the heat exchange mechanism 8 has a smaller distance and a larger overlapping projection area, so that the second heat conduction part 72 can better transfer heat between the end cover assembly 6 and the heat exchange mechanism 8, and the second heat conduction part 72 also improves the heat exchange rate of the first side wall 421 and the heat exchange mechanism 8 of the battery monomer 3.

[0370] Please refer to Figure 26 and Figure 27 , Figure 26 is a partial structure schematic diagram of a battery device provided by an embodiment of the present application; Figure 27 is Figure 26 an enlarged structure schematic diagram at B in FIG. 8.

[0371] In some embodiments, as shown in Figure 13 , Figure 26 and Figure 27 , the heat conduction assembly 7 further comprises a third heat conduction part 73, the third heat conduction part 73 is connected with the second heat conduction part 72, and the third heat conduction part 73 is arranged on the bottom wall 43. The heat exchange mechanism 8 is arranged on the side of the third heat conduction part 73 away from the bottom wall 43.

[0372] In these embodiments, in the case that the heat exchange mechanism 8 is arranged on the bottom wall 43 of the battery monomer 3, the third heat conduction part 73 can transfer heat at the end cover assembly 6 to the heat exchange mechanism 8, to better balance the heat at the end cover assembly 6, to balance the temperature inside the battery device 2, and to improve the performance of the battery device 2.

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

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

[0375] Exemplarily, the heat exchanging mechanism 8 is connected to the bottom wall 43 of the shell 4, and the heat of the end cover assembly 6 is transferred to the heat exchanging mechanism 8 through the third heat conducting part 73.

[0376] Optionally, the third heat conducting part 73 and the second heat conducting part 72 are separately prepared and are connected to each other by bonding, so as to facilitate adjustment of the shape and size of the third heat conducting part 73 and the second heat conducting part 72; or the third heat conducting part 73 and the second heat conducting part 72 are integrally formed and are obtained by folding the same base material, so as to reduce the processing difficulty of the heat conducting assembly 7. Exemplarily, the first heat conducting part 71, the second heat conducting part 72 and the third heat conducting part 73 are integrally formed and are obtained by folding the same base material.

[0377] Optionally, a plurality of second heat conducting parts 72 are arranged at intervals and are all connected to the third heat conducting part 73, so as to increase the connection area of the second heat conducting part 72 and the third heat conducting part 73 and improve the heat conducting rate of the heat conducting assembly 7. Exemplarily, four second heat conducting parts 72 are arranged on the two first side walls 421 and the two second side walls 422 respectively, and the four second heat conducting parts 72 are all connected to the third heat conducting part 73, so as to increase the connection area of the second heat conducting part 72 and the third heat conducting part 73.

[0378] Optionally, the size and shape of the third heat conducting part 73 can be designed at will, and exemplarily, the third heat conducting part 73 is rectangular or circular or annular, etc.

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

[0380] In some embodiments, as shown in Figure 5 , Figure 8 , Figure 13 and Figure 28 , at least two battery monomers 3 are heat conducting connected to the same heat conducting assembly 7.

[0381] In these embodiments, at least two battery monomers 3 are heat conducting connected to the same heat conducting assembly 7, so as to reduce the matching difficulty of the heat conducting assembly 7 and the battery monomer 3.

[0382] The plurality of battery cells 3 in the box 202 are arranged in rows and columns along the second direction Y and / or the third direction Z. In order to reduce the matching difficulty of the heat conduction assembly 7 and the battery cell 3, the plurality of battery cells 3 are heat-conductively connected to the same heat conduction assembly 7. For example, the heat conduction assembly 7 includes a first heat conduction part 71 and a second heat conduction part 72, the first heat conduction part 71 is connected to the end cover assembly 6 of at least two battery cells 3, and the second heat conduction part 72 is connected to the first side wall 421 or the second side wall 422 of the at least two battery cells 3. Alternatively, the heat conduction assembly 7 includes a first heat conduction part 71, a second heat conduction part 72, and a third heat conduction part 73, the first heat conduction part 71 is connected to the end cover assembly 6 of at least two battery cells 3, the second heat conduction part 72 is connected to the first side wall 421 or the second side wall 422 of the at least two battery cells 3, and the third heat conduction part 73 is connected to the bottom wall 43 of the at least two battery cells 3.

[0383] For example, the plurality of battery cells 3 in the box 202 are arranged in rows and columns along the second direction Y and the third direction Z, the plurality of heat exchange mechanisms 8 are arranged at intervals along the second direction Y and are arranged side by side with the first side wall 421 of the battery cell 3, and the plurality of heat conduction assemblies 7 are arranged at intervals along the second direction Y. The heat conduction assembly 7 includes a first heat conduction part 71 and a second heat conduction part 72, the first heat conduction part 71 is connected to the end cover assembly 6 of the plurality of battery cells 3, the second heat conduction part 72 is connected to the first side wall 421 of the plurality of battery cells 3, and is located between the heat exchange mechanism 8 and the first side wall 421 of the battery cell 3.

[0384] In a third aspect, the embodiments of the present application provide a power utilization device including the battery device of the second aspect.

[0385] In some embodiments, as Figure 1 to Figure 28As shown, the battery device 2 provided by the present application comprises a box 202, a battery cell 3, a heat conduction component 7 and a heat exchange mechanism 8. The battery cell 3 is arranged in the box 202. The battery cell 3 comprises a shell 4, an end cover component 6 and an electrode assembly 5. The shell 4 is provided with an opening 41 in a first direction X. The electrode assembly 5 is arranged in the shell 4. The end cover component 6 covers the opening 41. The end cover component 6 comprises a cover plate 61 and an electrode terminal 62 arranged on the cover plate 61. The electrode terminal 62 is connected with the electrode assembly 5. The shell 4 comprises a bottom wall 43 and a side wall 42 connected with each other. The bottom wall 43 is oppositely arranged with the opening 41. The side wall 42 is fillet-connected with the end cover component 6. The bottom wall 43 is fillet-connected with the side wall 42. The fillet is arranged in a space between the fillet and the heat conduction component 7. The side wall 42 comprises two first side walls 421 and two second side walls 422. The two first side walls 421 are oppositely arranged in a second direction Y. The two second side walls 422 are oppositely arranged in a third direction Z. The first direction X, the second direction Y and the third direction Z are intersected with each other. The area of the first side wall 421 is greater than that of the second side wall 422. The electrode assembly 5 is connected with the end cover component 6. The heat exchange mechanism 8 is arranged in the box 202. The heat exchange mechanism 8 is arranged in a space between the heat exchange mechanism 8 and the battery cell 3. The heat conduction component 7 comprises a first heat conduction part 71, a second heat conduction part 72 and a third heat conduction part 73. The first heat conduction part 71 is arranged on a side surface of the end cover component 6 away from the electrode assembly 5. The first heat conduction part 71 is connected with the electrode terminal 62. The heat conductivity of the heat conduction component 7 is greater than that of the end cover component 6 and the shell 4. The heat exchange mechanism 8 and the first side wall 421 are arranged in the second direction Y. At least one second heat conduction part 72 is arranged between the first side wall 421 and the heat exchange mechanism 8. Alternatively, the heat exchange mechanism 8 and the second side wall 422 are arranged in the third direction Z. At least one second heat conduction part 72 is arranged between the second side wall 422 and the heat exchange mechanism 8. The bottom wall 43 comprises a first part 431 and a second part 432. The third heat conduction part 73 is arranged on the first part 431. The heat exchange mechanism 8 is connected to the second part 432. The heat conduction component 7 further comprises an adhesive layer 74. The thickness L1 of the adhesive layer satisfies L1≥0.5mm, the adhesive layer 74 comprises a first adhesive layer 741, a second adhesive layer 742 and a third adhesive layer 743, the second heat conduction part 72 is adhered to the side wall 42 through the first adhesive layer 741, the third heat conduction part 73 is adhered to the bottom wall 43 through the second adhesive layer 742, and the first heat conduction part 71 is adhered to the end cover assembly 6 through the third adhesive layer 743, the at least two second heat conduction parts 72 are arranged on the first side wall 421 and the second side wall 422, the first adhesive layer 741 is located at one end of the first heat conduction part 71 in the first direction X, and the minimum distance between the first adhesive layer 741 and the edge of the side wall 42 is greater than or equal to 10mm, the minimum distance between the second adhesive layer 742 and the edge of the bottom wall 43 is greater than or equal to 10mm, the minimum distance between the third adhesive layer 743 and the edge of the end cover assembly 6 is greater than or equal to 10mm, the minimum distance L2 between the second heat conduction part 72 arranged on the first side wall 421 and the adjacent second side wall 422 in the third direction Z satisfies L2≥10mm, and / or the minimum distance L3 between the second heat conduction part 72 arranged on the second side wall 422 and the adjacent first side wall 421 in the second direction Y satisfies L3≥10mm, the heat conduction assembly 7 comprises an insulating part 75 and a heat conduction part 76, the insulating part 75 at least partially forms a containing cavity 77, and the heat conduction part 76 is arranged in the containing cavity 77, the heat conduction part 76 comprises a first heat conduction sheet 761 and a second heat conduction sheet 762 connected to each other, the first heat conduction sheet 761 is arranged on the end cover assembly 6, and the second heat conduction sheet 762 is arranged on the side wall 42, the first heat conduction part 71 is composed of the first heat conduction sheet 761 and the insulating part 75, the second heat conduction part 72 is composed of the second heat conduction sheet 762 and the insulating part 75, and the insulating part 75 is arranged on the outer surface of the end cover assembly 6 and the shell 4, the end cover assembly 6 comprises a cover plate 61 and a pressure relief mechanism 63 arranged on the cover plate 61, the insulating part 75 is provided with a first opening 751, and the pressure relief mechanism 63 is exposed to the first opening 751.

[0386] In the embodiments, the battery cell 3 comprises a shell 4, an end cover assembly 6 and an electrode assembly 5, the shell 4 comprises a bottom wall 43, a side wall 42 and a cavity 41 open at one end in a first direction X enclosed by the bottom wall 43 and the side wall 42, the electrode assembly 5 is accommodated in the shell 4, the end cover assembly 6 covers the opening 41 of the shell 4 and is connected with the electrode assembly 5, so that the electrode assembly 5 can form a loop with external devices through the end cover assembly 6, the heat conduction assembly 7 comprises a first heat conduction part 71 and a second heat conduction part 72, the heat conductivity of the heat conduction assembly 7 is greater than that of the end cover assembly 6 and the shell 4, the external heat conduction channel of the battery cell 3 is established through the first heat conduction part 71 arranged on the side surface of the end cover assembly 6 away from the electrode assembly 5, so as to reduce the thermal resistance at the end cover assembly 6, the total area of the heat conduction assembly 7 is increased through the second heat conduction part 72 arranged on the side wall 42, and the heat exchange rate between the battery cell 3 and the external environment is increased, so as to improve the problem that the performance and service life of the battery cell 3 are adversely affected due to excessively high or low temperature.

[0387] 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: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to 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 be covered in the scope of the claims and the description of the present application. Especially, 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 in the text, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized by, The application relates to a shell, which comprises a bottom wall, a side wall, and a cavity with an open end in a first direction enclosed by the bottom wall and the side wall; an electrode assembly arranged in the cavity; an end cover assembly covering the open end, the end cover assembly being connected with the electrode assembly; and a heat conduction assembly comprising a first heat conduction part and a second heat conduction part connected with each other, the first heat conduction part being arranged on a side surface of the end cover assembly away from the electrode assembly, and the second heat conduction part being arranged on the side wall, the heat conduction rate of the heat conduction assembly being greater than the heat conduction rate of the end cover assembly and the shell. The side wall comprises two first side walls arranged oppositely in a second direction and two second side walls arranged oppositely in a third direction, the first direction, the second direction and the third direction intersecting with each other, and the area of the first side wall being greater than the area of the second side wall. The second heat conduction part is arranged on the first side wall and / or the second heat conduction part is arranged on the second side wall. The second heat conduction part covers the entire first side wall or the second heat conduction part covers the entire second side wall. The side wall and the end cover assembly are connected with a round corner, and the round corner is spaced apart from the heat conduction assembly.

2. The battery cell of claim 1, wherein, The heat conduction assembly further comprises an adhesive layer, the adhesive layer comprises a first adhesive layer, and the second heat conduction part is adhered to the side wall through the first adhesive layer. The thickness L1 of the adhesive layer satisfies L1 >= 0.5 mm.

3. The battery cell of claim 2, wherein, The first adhesive layer is spaced apart from the edge of the side wall towards one end of the first heat conduction part in the first direction.

4. The battery cell according to any one of claims 1 to 3, characterized in that, The minimum distance between the first adhesive layer towards one end of the first heat conduction part in the first direction and the edge of the side wall is greater than or equal to 10 mm.

5. The battery cell according to any one of claims 1 to 4, characterized in that, The side wall comprises two first side walls arranged oppositely in a second direction and two second side walls arranged oppositely in a third direction, the first direction, the second direction and the third direction intersecting with each other, and the area of the first side wall being greater than the area of the second side wall.

6. The battery cell of claim 5, wherein, The minimum distance L2 between the second heat conduction part arranged on the first side wall and the adjacent second side wall in the third direction satisfies L2 >= 10 mm; and / or 7. The battery cell according to claim 5 or 6, characterized in that The minimum distance L3 between the second heat conduction part arranged on the second side wall and the adjacent first side wall in the second direction satisfies L3 >= 10 mm.

8. The battery cell of claim 7, wherein, The heat conduction assembly further comprises a third heat conduction part, the third heat conduction part being connected with the second heat conduction part, and the third heat conduction part being arranged on the bottom wall.

9. The battery cell of any one of claims 1-8, wherein, The bottom wall comprises a first part and a second part, the third heat conduction part being arranged on the first part, and the second part being used for connecting with a mounting position.

10. The battery cell of claim 9, wherein, The side wall and the bottom wall are connected with a round corner, and the round corner is spaced apart from the heat conduction assembly. ​ 11. The battery cell of any one of claims 1-10, wherein, ​ 12. The battery cell of claim 11, wherein, ​ 13. The battery cell according to claim 11 or 12, characterized in that ​ 14. The battery cell of any one of claims 11 to 13, wherein, The heat conduction assembly further comprises a bonding layer, the bonding layer comprises a second bonding layer, and the third heat conduction part is bonded to the bottom wall through the second bonding layer.

15. The battery cell of claim 14, wherein, The second bonding layer is spaced apart from an end of the second heat conduction part and an edge of the bottom wall.

16. The battery cell of claim 15, wherein, The minimum distance between the second bonding layer and the end of the second heat conduction part and the edge of the bottom wall is greater than or equal to 10 mm.

17. The battery cell of claim 15 or 16, wherein, The heat conduction assembly further comprises a bonding layer, the bonding layer comprises a third bonding layer, and the first heat conduction part is bonded to the end cover assembly through the third bonding layer.

18. The battery cell of claim 17, wherein, The third bonding layer is spaced apart from an end of the second heat conduction part and an edge of the end cover assembly.

19. The battery cell of claim 18, wherein, The minimum distance between the third bonding layer and the end of the second heat conduction part and the edge of the end cover assembly is greater than or equal to 10 mm.

20. The battery cell of any one of claims 1-19, wherein, The end cover assembly comprises a cover plate and an electrode terminal arranged on the cover plate, the electrode terminal is connected with the electrode assembly, and the first heat conduction part is connected with the electrode terminal.

21. The battery cell of any one of claims 1-20, wherein, The battery monomer further comprises a first insulating layer arranged on the outer surface of the shell and the end cover assembly, and the heat conduction assembly is arranged on the side of the first insulating layer away from the shell and the end cover assembly.

22. The battery cell of any one of claims 1-21, wherein, The heat conduction assembly comprises an insulating piece and a heat conduction piece, at least a part of the insulating piece forms a containing cavity, and the heat conduction piece is arranged in the containing cavity. The heat conduction piece comprises a first heat conduction sheet and a second heat conduction sheet connected with each other, the first heat conduction sheet is arranged on the end cover assembly, the second heat conduction sheet is arranged on the side wall, the first heat conduction part is composed of the first heat conduction sheet and the insulating piece, and the second heat conduction part is composed of the second heat conduction sheet and the insulating piece.

23. The battery cell of claim 22, wherein, The insulating piece is arranged on the outer surface of the end cover assembly and the shell.

24. The battery cell of claim 22, wherein, The battery monomer further comprises a second insulating layer connected with the insulating piece, and the insulating piece and the second insulating layer jointly cover the outer surface of the shell and the end cover assembly.

25. The battery cell of claim 24, wherein, The end cover assembly comprises a cover plate and a pressure relief mechanism arranged on the cover plate, the insulating piece is provided with a first opening, and the pressure relief mechanism is exposed to the first opening.

26. The battery cell of any one of claims 22-25, wherein, The side wall comprises two first side walls and two second side walls, the two first side walls are arranged opposite to each other in a second direction, the two second side walls are arranged opposite to each other in a third direction, the first direction, the second direction and the third direction intersect with each other, the area of the first side wall is greater than that of the second side wall, and at least two second heat conduction sheets are arranged on the first side wall and the second side wall, wherein the second heat conduction sheets arranged on the first side wall and the second side wall are independent of each other.

27. The battery cell of any one of claims 22-26, wherein, The heat conduction piece further comprises a third heat conduction sheet, the third heat conduction sheet is connected with the second heat conduction sheet, and the second heat conduction sheet is arranged on the bottom wall.

28. The battery cell of any one of claims 22-27, wherein, The thickness D1 of the heat conduction piece satisfies 40 μm≤D1≤180 μm.

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

30. The battery cell of any one of claims 22-29, wherein, The heat conduction piece comprises graphite, graphene or carbon nanotube.

31. The battery cell of any one of claims 22-30, wherein, The heat conductivity k of the heat conduction piece satisfies k≥500 W / (m·K).

32. A battery device, characterized by The battery device further comprises a heat exchange mechanism arranged in the box, and the heat conduction assembly and the heat exchange mechanism are in thermal conduction connection.

33. The battery device of claim 32, wherein, The side wall comprises two first side walls and two second side walls, the two first side walls are oppositely arranged in a second direction, the two second side walls are oppositely arranged in a third direction, the first direction, the second direction and the third direction intersect with each other, and the area of the first side wall is greater than that of the second side wall.

34. The battery device of claim 33, wherein, The heat exchange mechanism and the first side wall are spaced apart along the second direction, and at least one second heat conduction part is arranged between the first side wall and the heat exchange mechanism, or the heat exchange mechanism and the second side wall are spaced apart along the third direction, and at least one second heat conduction part is arranged between the second side wall and the heat exchange mechanism. The heat conduction assembly further comprises a third heat conduction part, the third heat conduction part is connected with the second heat conduction part, the third heat conduction part is arranged on the bottom wall, and the heat exchange mechanism is arranged on the side of the third heat conduction part away from the bottom wall.

35. The battery device of claim 33, wherein, At least two battery cells are in thermal conduction connection with the same heat conduction assembly.

36. The battery device of claim 33, wherein, The battery device comprises any one of the battery devices in claims 32-36.

37. An electrical device, comprising: ​

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