Battery cell, battery device and electric device

Abstract

Provided in the present application are a battery cell, a battery device and an electric device. The battery cell comprises: a casing; an electrode assembly, which is located in the casing, wherein the electrode assembly comprises an electrode body and a tab, the electrode body comprising a first end face and a second end face arranged opposite each other in a first direction, and a side face connecting the first end face and the second end face, and the tab being connected to the electrode body and protruding from at least one of the first end face and the second end face; and a heat-conducting assembly, which comprises an insulating member and a heat-conducting member, wherein at least part of the insulating member forms an accommodating cavity, and the heat-conducting member is arranged in the accommodating cavity; the insulating member covers at least the side face; the heat-conducting member comprises a first heat-conducting sheet, the first heat-conducting sheet being arranged on at least part of the side face and being in thermally conductive connection with the side face; the thermal conductivity of the heat-conducting member is greater than that of the insulating member and that of the casing.

Description

Battery cell, battery device and electric device TECHNICAL FIELD

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

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

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

[0004] SUMMARY

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

[0006] In a first aspect, the present application provides a battery cell, comprising: a shell; an electrode assembly located in the shell, the electrode assembly comprising an electrode body and a tab, the electrode body comprising a first end face and a second end face oppositely arranged in a first direction, and a side face connected between the first end face and the second end face, the tab being connected to the electrode body and extending out of at least one of the first end face and the second end face; a heat conduction assembly comprising an insulating member and a heat conduction member, the insulating member forming a receiving cavity in at least a partial region, the heat conduction member being arranged in the receiving cavity, the insulating member covering at least the side face, the heat conduction member comprising a first heat conduction sheet arranged on at least a partial side face and in heat conduction connection with the side face, the heat conduction rate of the heat conduction member being greater than the heat conduction rate of the insulating member and the heat conduction rate of the shell.

[0007] In the technical scheme of the embodiment of the present application, the battery monomer comprises a shell, an electrode assembly and a heat conduction assembly, the electrode assembly is located inside the shell, the shell provides accommodation and protection for the electrode assembly, the electrode assembly comprises an electrode main body and a tab, the electrode main body comprises a first end face and a second end face oppositely arranged in a first direction, and a side face connected between the first end face and the second end face, the electrode main body forms a loop with an external component through the tab extending from the first end face and / or the second end face, the heat conduction assembly comprises an insulating piece and a heat conduction piece, the insulating piece covers at least the side face, the insulating piece is insulated from the shell and at least part of the electrode assembly, the insulating piece can replace at least part of the Mylar film to reduce the preparation cost of the battery monomer, reduce the thickness of the battery monomer, and improve the energy density of the battery monomer, at least part of the area of the insulating piece forms an accommodation cavity, the heat conduction piece is arranged in the accommodation cavity, the heat conduction piece and the electrode main body can be insulated through the insulating piece, and the heat conduction piece and the electrolyte can be isolated through the insulating piece, so as to improve the problem that the heat conduction piece and the electrolyte are incompatible, the heat conductivity of the heat conduction piece is greater than the heat conductivity of the insulating piece and the heat conductivity of the shell, the heat conduction piece comprises a first heat conduction sheet, the first heat conduction sheet is arranged on at least part of the side face and is in heat conduction connection with the side face, the first heat conduction sheet is used to reduce the thermal resistance of the electrode main body at the side face, improve the temperature uniformity of the electrode main body at the side face, and improve the rate of heat exchange between the electrode main body at the side face and the external environment, so as to balance the internal temperature of the battery monomer and improve the problem that the performance and service life of the battery monomer are adversely affected due to the excessively high or low internal temperature of the battery monomer.

[0008] In some embodiments, the tab extends from the first end face, and the insulating piece covers the second end face and the side face of the electrode main body.

[0009] In the technical scheme of the embodiment of the present application, the insulating piece covers the second end face and the side face of the electrode main body to insulate the shell and the electrode assembly, and no Mylar film is needed, which helps to reduce the preparation cost of the battery monomer, and the thickness of the battery monomer can be reduced and the energy density of the battery monomer can be improved.

[0010] In some embodiments, the side face comprises two first side faces and two second side faces, the two first side faces are oppositely arranged in a second direction, the two second side faces are oppositely arranged in a third direction, the first direction, the second direction and the third direction intersect with each other, the area of the first side face is greater than the area of the second side face, the insulating piece comprises a first insulating part, the first insulating part comprises a body part and a bending part connected with each other, the body part and the bending part are connected, the body parts of the two first insulating parts are arranged on the two first side faces respectively, the two bending parts are arranged on the two second side faces respectively, and the first heat conduction sheet is arranged on at least one of the body part and the bending part.

[0011] In the technical scheme of the embodiment of the present application, the first insulation part comprises a body part and a bent part connected with each other, the body part and the bent part are connected, the body parts of the two first insulation parts are arranged on the two first sides respectively, and the two bent parts are arranged on the two second sides respectively, so as to realize the insulation of the electrode assembly on the circumferential surface and the shell, and the first heat conduction sheet is arranged on at least one of the body part and the bent part, so as to improve the heat conduction rate at the first side and / or the second side of the electrode assembly.

[0012] In some embodiments, the first through hole is arranged on the first insulation part in a penetrating manner, and the first through hole is arranged at intervals with the accommodating cavity.

[0013] In the technical scheme of the embodiment of the present application, the first through hole is arranged on the first insulation part in a penetrating manner, so that the electrolyte can infiltrate the electrode assembly through the first through hole, and the first through hole is arranged at intervals with the accommodating cavity, so as to avoid the contact between the electrolyte and the first heat conduction sheet.

[0014] In some embodiments, the first heat conduction sheet is arranged with a first avoiding hole in a penetrating manner, the first insulation part covers the inner wall of the first avoiding hole, the first through hole is arranged on the first insulation part in a penetrating manner, and the first through hole is located in the first avoiding hole.

[0015] In the technical scheme of the embodiment of the present application, the first heat conduction sheet is arranged with a first avoiding hole in a penetrating manner, the first through hole is arranged on the first insulation part in a penetrating manner, and the first through hole is located in the first avoiding hole, so that the electrolyte can infiltrate the electrode assembly through the first through hole and the first avoiding hole, the first insulation part covers the inner wall of the first avoiding hole, so as to avoid the contact between the electrolyte and the first heat conduction sheet and keep the insulation between the first heat conduction sheet and the electrode assembly.

[0016] In some embodiments, the tab extends from the first end surface, the insulating piece further comprises a second insulation part arranged between the second end surface of the electrode body and the shell, the second insulation part is insulated from the shell and the second end surface of the electrode assembly, and the body parts of the two first insulation parts are connected to the two sides of the second insulation part respectively.

[0017] In the technical scheme of the embodiment of the present application, the insulating piece further comprises a second insulation part arranged between the second end surface of the electrode body and the shell, and the body parts of the two first insulation parts are connected to the two sides of the second insulation part respectively, so as to reduce the alignment difficulty of the second insulation part and the first insulation part and reduce the cooperation difficulty of the insulating piece and the electrode assembly.

[0018] In some embodiments, the heat conduction piece comprises a second heat conduction sheet arranged on the second insulation part.

[0019] In the technical scheme of the embodiment of the present application, the heat conduction piece comprises a second heat conduction sheet arranged on the second insulation part, so as to improve the heat conduction rate at the second end surface.

[0020] In some embodiments, the second insulation part is provided with a second through hole penetrating therethrough, and the second through hole is spaced from the accommodation cavity.

[0021] In the technical scheme of the embodiments of the present application, the second insulation part is provided with a second through hole penetrating therethrough, so that the electrolyte can be soaked into the electrode assembly through the second through hole, and the second through hole is spaced from the accommodation cavity, so as to avoid the electrolyte from contacting the second heat-conducting sheet.

[0022] In some embodiments, the second heat-conducting sheet is provided with a second avoiding hole penetrating therethrough, the second insulation part covers the inner wall of the second avoiding hole, the second insulation part is provided with a second through hole penetrating therethrough, and the second through hole is located in the second avoiding hole.

[0023] In the technical scheme of the embodiments of the present application, the second heat-conducting sheet is provided with a second avoiding hole penetrating therethrough, the second insulation part is provided with a second through hole penetrating therethrough, and the second through hole is located in the second avoiding hole, so that the electrolyte can be soaked into the electrode assembly through the second through hole and the second avoiding hole, the second insulation part covers the inner wall of the second avoiding hole, so as to avoid the electrolyte from contacting the second heat-conducting sheet and keep the second heat-conducting sheet insulated from the electrode assembly.

[0024] In some embodiments, the electrode assembly is provided in plurality, the plurality of electrode assemblies are stacked in the second direction, the insulation member further comprises a middle insulation part, the middle insulation part is arranged between the electrode bodies of adjacent electrode assemblies, the middle insulation part and the second insulation part are connected to each other, the first heat-conducting sheet comprises a middle heat-conducting sheet, and the middle heat-conducting sheet is arranged in the middle insulation part.

[0025] In the technical scheme of the embodiments of the present application, the middle insulation part is arranged between the adjacent electrode bodies, so as to insulate the adjacent electrode bodies, the middle insulation part and the second insulation part are connected to each other, so as to improve the insulation reliability of the middle insulation part, and the middle heat-conducting sheet is arranged in the middle insulation part, so as to improve the heat-conducting rate between the adjacent electrode bodies.

[0026] In some embodiments, the first heat-conducting sheet and the second heat-conducting sheet are connected to each other.

[0027] In the technical scheme of the embodiments of the present application, the heat-conducting member comprises the second heat-conducting sheet arranged in the second insulation part, and the first heat-conducting sheet and the second heat-conducting sheet are connected to each other, so that the heat between the adjacent electrode assemblies can be transferred to the second heat-conducting sheet through the first heat-conducting sheet and exchanged with the external environment, and the heat-conducting rate of the heat-conducting assembly is improved.

[0028] In some embodiments, the body part is connected with a bending part on each side in the third direction, and the two bending parts of the two first insulation parts and located on the same side of the electrode assembly extend towards each other in the second direction.

[0029] In the technical scheme of the embodiment of the present application, the two bending portions on the same side of the electrode assembly of the two first insulating portions extend towards each other in the second direction, and the splicing position of the two bending portions is on the second side surface, and the first side surface with a larger area can be provided with a larger-area heat conduction layer to improve the heat conduction capacity of the heat conduction assembly.

[0030] In some embodiments, the two bending portions extend towards each other in the second direction, and the two bending portions at least partially overlap in the third direction.

[0031] In the technical scheme of the embodiment of the present application, the two bending portions extend towards each other in the second direction, and the two bending portions at least partially overlap in the third direction, so as to improve the insulation reliability of the first insulating portion to the electrode assembly and the shell.

[0032] In some embodiments, the shell comprises an opening in the first direction, the battery monomer further comprises a top cover assembly, the top cover assembly covers the opening and is connected to the tab, and the at least one body portion extends out of the first end surface in the first direction and is connected to the top cover assembly.

[0033] In the technical scheme of the embodiment of the present application, the at least one body portion extends out of the first end surface in the first direction and is connected to the top cover assembly, the top cover assembly plays a role of positioning and fixing the heat conduction assembly, and the stability of the heat conduction assembly in the shell is improved.

[0034] In some embodiments, the size L3 of the body portion extending out of the first end surface in the first direction is greater than or equal to 2 mm.

[0035] In the technical scheme of the embodiment of the present application, the above conditions are met to improve the connection reliability of the heat conduction assembly and the top cover assembly.

[0036] In some embodiments, the minimum distance from the orthogonal projection of the heat conduction member in the thickness direction of the heat conduction assembly to the edge of the orthogonal projection of the insulating member in the thickness direction of the heat conduction assembly is greater than or equal to 2 mm.

[0037] In the technical scheme of the embodiment of the present application, the minimum distance from the orthogonal projection of the heat conduction member in the thickness direction of the heat conduction assembly to the edge of the orthogonal projection of the insulating member in the thickness direction of the heat conduction assembly is greater than or equal to 2 mm, so that there is sufficient plastic sealing area between the heat conduction member and the edge of the insulating member, and the sealing reliability of the accommodating cavity is improved.

[0038] In some embodiments, the thickness D3 of the heat conduction member satisfies 40 μm≤D3≤180 μm.

[0039] In the technical scheme of the embodiment of the present application, when the above conditions are met, the problem of the battery monomer being too large in size and the energy density being reduced due to the heat conduction member being too thick can be improved, and the problem of the heat conduction member being easily damaged due to the heat conduction member being too thin can also be improved.

[0040] In some embodiments, the insulating member includes two sub-insulating layers, the two sub-insulating layers are arranged in a stack and are connected to each other to form the accommodating cavity, and the thickness D1 of the sub-insulating layer satisfies 5 μm≤D1≤100 μm.

[0041] In the technical scheme of the embodiment of the present application, when the above conditions are met, the problem of the battery monomer being too large in size and the energy density being reduced due to the heat conduction member being too thick can be improved, and the problem of the heat conduction member being easily damaged due to the heat conduction member being too thin can also be improved.

[0042] In some embodiments, the insulating member includes polyethylene or polypropylene or polyimide or polyester resin.

[0043] In the technical scheme of the embodiment of the present application, the insulating member includes polyethylene or polypropylene or polyimide or polyester resin, so as to improve the insulation reliability of the insulating member.

[0044] In some embodiments, the heat conduction member includes graphite or graphene or carbon nanotube.

[0045] In the technical scheme of the embodiment of the present application, the heat conduction member includes graphite or graphene or carbon nanotube, so as to improve the heat conduction performance of the heat conduction assembly by using the graphite or graphene or carbon nanotube heat conduction material.

[0046] In some embodiments, the heat conductivity k of the heat conduction member satisfies k>500 W / (m·K).

[0047] In the technical scheme of the embodiment of the present application, when the heat conductivity k of the heat conduction member satisfies the above condition, the heat conduction assembly has sufficient heat conduction performance to conduct the heat of the electrode body.

[0048] In a second aspect, the embodiment of the present application provides a battery device including the battery monomer of any one of the embodiments of the first aspect.

[0049] In a third aspect, the embodiment of the present application provides a power consumption device including the battery device of the embodiment of the second aspect. BRIEF DESCRIPTION OF DRAWINGS

[0050] 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 better understanding of the preferred embodiments and are not to be considered as restrictive of the application. Moreover, in the drawings, like reference numerals refer to similar components throughout the several views. In the drawings:

[0051] FIG. 1 is a structural schematic diagram of a vehicle according to an embodiment of the present application;

[0052] FIG. 2 is a structural schematic diagram of a battery device according to an embodiment of the present application;

[0053] FIG. 3 is a structural schematic diagram of a battery module according to an embodiment of the present application;

[0054] FIG. 4 is an exploded view of a battery cell according to an embodiment of the present application;

[0055] FIG. 5 is a structural schematic diagram of an electrode assembly of a battery cell according to an embodiment of the present application;

[0056] FIG. 6 is a structural schematic diagram of a heat conduction assembly of a battery cell according to an embodiment of the present application;

[0057] FIG. 7 is a sectional view of FIG. 6 at A-A;

[0058] FIG. 8 is an exploded view of a battery cell according to another embodiment of the present application;

[0059] FIG. 9 is a partial structural schematic diagram of a battery cell according to an embodiment of the present application;

[0060] FIG. 10 is a structural schematic diagram of a heat conduction assembly of a battery cell according to an embodiment of the present application;

[0061] FIG. 11 is an expanded view of a heat conduction assembly of a battery cell according to an embodiment of the present application;

[0062] FIG. 12 is a structural schematic diagram of a heat conduction assembly of a battery cell according to an embodiment of the present application;

[0063] FIG. 13 is a structural schematic diagram of a heat conduction assembly of a battery cell according to an embodiment of the present application;

[0064] FIG. 14 is a partial structural schematic diagram of a heat conduction assembly of a battery cell according to an embodiment of the present application;

[0065] FIG. 15 is a structural schematic diagram of a heat conduction assembly of a battery cell according to an embodiment of the present application;

[0066] FIG. 16 is a partial structural schematic diagram of a heat conduction assembly of a battery cell according to another embodiment of the present application;

[0067] FIG. 17 is a structural schematic diagram of a heat conduction assembly of a battery cell according to an embodiment of the present application;

[0068] FIG. 18 is a structural schematic diagram of a heat conduction assembly of a battery cell according to an embodiment of the present application;

[0069] FIG. 19 is a partial structural schematic diagram of a heat conduction assembly of a battery cell according to an embodiment of the present application;

[0070] FIG. 20 is a structural schematic diagram of a heat conduction assembly of a battery cell according to an embodiment of the present application;

[0071] FIG. 21 is a partial structural schematic diagram of a heat conduction assembly of a battery cell according to another embodiment of the present application;

[0072] FIG. 22 is a structural schematic diagram of a heat conduction assembly of a battery cell according to an embodiment of the present application;

[0073] FIG. 23 is an expanded view of a heat conduction assembly of a battery cell according to an embodiment of the present application.

[0074] FIG. 23 is an expanded view of a heat conduction assembly of a battery cell according to an embodiment of the present application. DETAILED DESCRIPTION

[0075] The embodiments of the technical solutions 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 solutions of the present application, and therefore only serve as examples, and cannot limit the protection scope of the present application.

[0076] 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 meanings understood by the skilled person in the field to which the embodiments of the present application belong.

[0077] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship shown in the drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the embodiments of the present application.

[0078] In addition, the technical terms "first", "second" and the like are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. In the description of the embodiments of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified and limited.

[0079] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical terms "mounting", "connecting", "connecting", "fixing" and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0080] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the first feature "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature "above", "above" and "above" the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0081] At present, from the development of market situation, the application of battery device is more and more widely. The battery device is not only applied to the energy storage power supply system of hydropower, thermal power, wind power and solar power station, but also widely applied to electric bicycles, electric motorcycles, electric vehicles and other electric vehicles, military equipment, aerospace and other fields. With the continuous expansion of the application field of battery device, the market demand is also increasing.

[0082] During use of the battery cell, the temperature difference between the inside and outside of the battery cell is too large, which causes the performance and service life of the battery cell to decrease.

[0083] The above problem is caused by the fact that the internal temperature of the battery cell cannot be quickly conducted to the outside, the internal temperature is accumulated and increased, and the electrode assembly is prone to lithium precipitation due to the excessively high temperature; and in a low-temperature environment, the external environment is also difficult to heat the electrode assembly, which causes the battery cell to have the problems of capacity and pulse performance decrease due to low temperature, and affects the performance of the battery cell.

[0084] Based on the above problem, the embodiments of the present application provide a battery cell, which includes a shell, an electrode assembly and a heat conduction assembly, the electrode assembly is located inside the shell, the shell provides accommodation and protection for the electrode assembly, the electrode assembly includes an electrode body and a tab, the electrode body includes a first end face and a second end face oppositely arranged in a first direction, and a side face connected between the first end face and the second end face, the electrode body forms a loop with the tab extending from the first end face and / or the second end face and an external component, the heat conduction assembly includes an insulating piece and a heat conduction piece, the insulating piece covers at least the side face, the insulating piece is insulated from the shell and at least part of the electrode assembly, the insulating piece can replace at least part of the mica film to reduce the manufacturing cost of the battery cell, reduce the thickness of the battery cell, and improve the energy density of the battery cell, at least part of the area of the insulating piece forms an accommodation cavity, the heat conduction piece is arranged in the accommodation cavity, the heat conduction piece and the electrode body can be insulated by the insulating piece, and the heat conduction piece and the electrolyte can be isolated by the insulating piece to improve the problem of incompatibility between the heat conduction piece and the electrolyte, the thermal conductivity of the heat conduction piece is greater than the thermal conductivity of the insulating piece and the thermal conductivity of the shell, the heat conduction piece includes a first heat conduction sheet, the first heat conduction sheet is arranged on at least part of the side face and is in thermal conductive connection with the side face, the first heat conduction sheet is used to reduce the thermal resistance of the electrode body at the side face, improve the temperature uniformity of the electrode body at the side face, and improve the rate of heat exchange between the electrode body at the side face and the external environment, so as to balance the internal temperature of the battery cell and improve the problem of adverse effects on the performance and service life of the battery cell caused by excessively high or low internal temperature of the battery cell.

[0085] The technical solutions described in the embodiments of the present application are suitable for battery devices and electric devices using battery devices.

[0086] 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 electric device is not specially limited in the embodiments of the present application.

[0087] 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.

[0088] The battery cell can be a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel hydrogen battery, a nickel cadmium battery, a lead-acid battery, etc. The embodiments of the present application are not limited thereto. The battery cell can be in the shape of a cylinder, a flat body, a cuboid, or other shapes, etc. The embodiments of the present application are not limited thereto.

[0089] The battery device mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity. For example, the battery device mentioned in the present application can include a battery module or a battery pack, etc. The battery pack generally includes a box for packaging one or more battery cells. The box can avoid the influence of liquid or other foreign matters on the charging or discharging of the battery cell.

[0090] The battery cell includes an electrode assembly and an electrolyte. The electrode assembly includes a positive electrode sheet, a negative electrode sheet, and a separator. The battery cell mainly relies on the movement of metal ions between the positive electrode sheet and the negative electrode sheet to work. The positive electrode sheet includes a positive 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.

[0091] It should be understood that the technical solutions described in the embodiments of the present application are not only limited to the above-described battery device and electric equipment, but can also be applied to all battery devices including a box body and electric equipment using the battery device. However, for the sake of brevity of description, the following embodiments are described by taking an electric vehicle as an example.

[0092] Please refer to FIG. 1, which is a structural schematic diagram of a vehicle 1 provided by some embodiments of the present application. 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 vehicle, or a range extended vehicle, etc. The vehicle 1 is internally provided with a battery device 2, which can be arranged at the bottom, the head, or the tail of the vehicle 1. The battery device 2 can be used for power supply of the vehicle 1, for example, the battery device 2 can be used as an operating power source of the vehicle 1. The vehicle 1 can further include a controller 102 and a motor 101, and the controller 102 is used to control the battery to supply power to the motor 101, for example, to meet the working power demand of the vehicle 1 during starting, navigation, and driving.

[0093] In some embodiments of the present application, the battery device 2 can not only be used as an operating power source of the vehicle 1, but also be used as a driving power source of the vehicle 1, instead of or partially instead of fuel or natural gas to provide driving power for the vehicle 1.

[0094] FIG. 2 shows a structural schematic diagram of a battery device according to an embodiment of the present application.

[0095] 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.

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

[0097] 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.

[0098] 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.

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

[0100] 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.

[0101] 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 a closed space is formed inside the box 202 to accommodate the battery cell assembly. Here, closed means covered or closed, which can be sealed or unsealed. The first box 2021 can be a top cover or a bottom plate.

[0102] 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 a closed space is formed inside the box 202 to accommodate the battery cell assembly.

[0103] 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.

[0104] FIG. 3 shows a structural schematic diagram of the battery module 201 according to an embodiment of the present application.

[0105] In some embodiments, as shown in FIGS. 2 and 3, the plurality of battery cells 3 are first connected in series, in parallel or in a mixed connection to form a battery module 201. The plurality of battery modules 201 are then connected in series, in parallel or in a mixed connection to form an integral whole and accommodated in the box 202.

[0106] The plurality of battery cells 3 in the battery module 201 can be electrically connected through the busbar components to achieve parallel connection, series connection or mixed connection of the plurality of battery cells 3 in the battery module 201.

[0107] FIG. 4 is an exploded view of a battery cell according to an embodiment of the present application. The battery cell 3 refers to the smallest unit that constitutes a battery device. As shown in FIG. 4, the battery cell 3 includes a top cover assembly 6, a case 4, and an electrode assembly 5.

[0108] The electrode assembly 5 is a component in which electrochemical reactions occur in the battery cell 3. One or more electrode assemblies 5 can be contained in the case 4. The electrode assembly 5 is mainly formed by winding or stacking an electrode sheet, which is divided into a positive electrode sheet and a negative electrode sheet, and a separator is usually provided between the positive electrode sheet and the negative electrode sheet. The positive electrode sheet and the negative electrode sheet each have a portion of an active material that constitutes an electrode body 52, and each have a portion that does not have an active material that constitutes a tab 51. The positive electrode tab and the negative electrode tab can be located at one end of the electrode body 52 or at opposite ends of the electrode body 52. During charging and discharging of the battery cell 3, the positive electrode active material and the negative electrode active material react with an electrolyte, and the tabs 51 connect to electrode terminals to form a current loop.

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

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

[0111] In some embodiments, the electrode assembly 5 has a stacked structure. As an example, a plurality of positive electrode sheets and a plurality of negative electrode sheets can be alternately stacked, and a plurality of separators can be provided between any adjacent positive electrode sheets or negative electrode sheets, or the separators can be continuously provided by being folded between any adjacent positive electrode sheets or negative electrode sheets.

[0112] In some embodiments, the electrode assembly 5 can have a cylindrical shape, a flat shape, or a polygonal shape.

[0113] In some embodiments, the electrode assembly 5 is provided with a tab that can guide current out of the electrode assembly. The tab includes a positive electrode tab and a negative electrode tab.

[0114] The battery cell 3 can include a shell. The shell 4 is a component for fitting the top 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 can be a non-sealed structure. As an example, when the shell 4 is a non-sealed structure, the shell 4 plays a role of protecting the electrode assembly 5, and a sealing bag is further included between the shell 4 and the electrode assembly 5, which is used to 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.

[0115] 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, wherein the prismatic battery cell includes a square battery cell, a blade-shaped battery cell, a multi-prismatic battery cell (such as a hexagonal battery cell, etc.), and the present application is not particularly limited.

[0116] The shell 4 and the top cover assembly 6 can be independent components, one or more openings 41 can be provided on the shell 4, and the one or more top cover assemblies 6 cover the openings 41 to form the internal environment of the battery cell 3. Alternatively, the top cover assembly 6 and the shell 4 can be integrated. Alternatively, the top cover assembly 6 and the shell 4 can form a common connecting surface before other components enter the shell, and then the top cover assembly 6 covers the shell 4 when it is necessary to seal the inside of the shell 4.

[0117] In some embodiments, the electrode terminal 61 can be provided on the top cover assembly 6, or can be provided on the shell 4, and the electrode terminal 61 is electrically connected with the tab 51. The electrode terminal 61 can be directly connected with the tab 51, or can be indirectly connected with the tab 51 through the adapter 7.

[0118] Please refer to FIG. 5, FIG. 6, FIG. 7, and FIG. 8, wherein FIG. 5 is a structural schematic diagram of an electrode assembly of a battery cell according to an embodiment of the present application; FIG. 6 is a structural schematic diagram of a heat-conducting assembly of a battery cell according to an embodiment of the present application; FIG. 7 is a sectional view of A-A in FIG. 6; and FIG. 8 is an exploded view of a battery cell according to another embodiment of the present application.

[0119] In a first aspect, as shown in FIGS. 4-8, the application provides a battery cell 3, which includes a shell 4, an electrode assembly 5, and a heat conduction assembly 8. The electrode assembly 5 is located inside the shell 4. The electrode assembly 5 includes an electrode body 52 and a tab 51. The electrode body 52 includes a first end face 521 and a second end face 522 arranged opposite to each other in a first direction X, and a side face 523 connected between the first end face 521 and the second end face 522. The tab 51 is connected to the electrode body 52 and extends out of at least one of the first end face 521 and the second end face 522. The heat conduction assembly 8 includes an insulating piece 85 and a heat conduction piece 84. The insulating piece 85 forms a receiving cavity 851 in at least a partial region. The heat conduction piece 84 is arranged in the receiving cavity 851. The insulating piece 85 covers at least the side face 523. The heat conduction piece 84 includes a first heat conduction sheet 841 arranged on at least a partial region of the side face 523 and in thermal connection with the side face 523. The heat conduction rate of the heat conduction piece 84 is greater than the heat conduction rates of the insulating piece 85 and the shell 4.

[0120] In the scheme of the embodiments of the application, the battery cell 3 includes a shell 4, an electrode assembly 5, and a heat conduction assembly 8. The electrode assembly 5 is located inside the shell 4. The shell 4 provides accommodation and protection for the electrode assembly 5. The electrode assembly 5 includes an electrode body 52 and a tab 51. The electrode body 52 includes a first end face 521 and a second end face 522 arranged opposite to each other in a first direction X, and a side face 523 connected between the first end face 521 and the second end face 522. The electrode body 52 forms a loop with the tab 51 extending out of the first end face 521 and / or the second end face 522 and an external component. The heat conduction assembly 8 includes an insulating piece 85 and a heat conduction piece 84. The insulating piece 85 covers at least the side face 523. The insulating piece 85 is insulated from the shell 4 and at least a partial region of the electrode assembly 5. The insulating piece 85 can replace at least a partial region of a microporous polypropylene film, thereby reducing the manufacturing cost of the battery cell 3, reducing the thickness of the battery cell 3, and improving the energy density of the battery cell 3. The insulating piece 85 forms a receiving cavity 851 in at least a partial region. The heat conduction piece 84 is arranged in the receiving cavity 851. The insulating piece 85 can insulate the heat conduction piece 84 from the electrode body 52. The insulating piece 85 can also isolate the heat conduction piece 84 from an electrolyte, thereby improving the incompatibility between the heat conduction piece 84 and the electrolyte. The heat conduction rate of the heat conduction piece 84 is greater than the heat conduction rates of the insulating piece 85 and the shell 4. The heat conduction piece 84 includes a first heat conduction sheet 841 arranged on at least a partial region of the side face 523 and in thermal connection with the side face 523. The first heat conduction sheet 841 reduces the thermal resistance of the electrode body 52 at the side face 523, improves the temperature uniformity of the electrode body 52 at the side face 523, and improves the heat exchange rate between the electrode body 52 at the side face 523 and an external environment, thereby balancing the internal temperature of the battery cell 3 and improving the performance and service life of the battery cell 3.

[0121] The electrode body 52 is formed by a separator, a positive electrode sheet 5241 and a negative electrode sheet 5242 in a wound or stacked manner. The tab 51 includes a positive electrode tab and a negative electrode tab, both of which extend out of the first end face 521 or the second end face 522, or one of the positive electrode tab and the negative electrode tab extends out of the first end face 521 and the other extends out of the second end face 522.

[0122] Illustratively, the battery cell 3 further includes a top cover assembly 6 connected with the tab 51, the housing 4 includes an opening 41 at one end close to the first end face 521 or the second end face 522 in the first direction X, the top cover assembly 6 covers the opening 41, and the positive electrode tab and the negative electrode tab extend out of the first end face 521 or the second end face 522 and are connected with the top cover assembly 6; or the housing 4 includes two openings 41 opposite to each other in the first direction X, two top cover assemblies 6 respectively cover the two openings 41, and the positive electrode tab and the negative electrode tab respectively extend out of the first end face 521 and the second end face 522 and are connected with the top cover assemblies 6.

[0123] Illustratively, the first direction X is the height direction of the electrode assembly 5.

[0124] The first heat-conducting sheet 841 is in heat-conducting connection with the side face 523 of the electrode body 52, so that heat can be conducted between the first heat-conducting sheet 841 and the side face 523 of the electrode body 52 through the insulating piece 85.

[0125] During the operation of the battery cell 3, the heat generated by the electrode body 52 can be transferred to the external environment via the heat-conducting assembly 8, thereby improving the problem of damage of the electrode body 52 due to excessively high temperature; or in a low-temperature environment, the heat-conducting assembly 8 can conduct heat from the external environment to the electrode body 52 to heat the electrode assembly 5.

[0126] Optionally, the battery device 2 includes a heat exchange mechanism, the housing of the battery cell 3 is in heat-conducting connection with the heat exchange mechanism, and the heat-conducting assembly 8 can conduct heat between the heat exchange mechanism and the electrode assembly 5, and the heat exchange mechanism can conduct heat into or out of the heat-conducting assembly 8.

[0127] Illustratively, the heat exchange mechanism can be a water-cooled plate or a phase-change heat dissipation plate arranged on the outer surface of the battery cell 3, or a cavity containing a heat exchange medium.

[0128] Illustratively, the material of the insulating piece 85 can be PP or PI (Polyimide) or PET (Polyethylene terephthalate) or the like. The material of the heat-conducting piece 84 can be graphite or graphene or carbon nanotube or the like.

[0129] Optionally, the heat-conducting member 84 is arranged in the accommodating cavity 851, the area of the heat-conducting member 84 matches the area of the accommodating cavity 851, the area of the accommodating cavity 851 can be smaller than the area of the insulating member 85, the heat-conducting member 84 is in contact with the cavity wall of the accommodating cavity 851, and the accommodating cavity 851 plays a limiting role on the heat-conducting member 84.

[0130] Optionally, the heat-conducting member 84 can be in a plate shape or a mesh shape, for example, the accommodating cavity 851 is provided with a mesh-shaped heat-conducting member or one or more plate-shaped heat-conducting members arranged at intervals. The heat-conducting member 84 can be in a rectangular shape, a circular shape, or a diamond shape, etc.

[0131] Optionally, a plurality of first heat-conducting sheets 841 are arranged at intervals in the accommodating cavity 851, which can conduct the heat at the side surface 523 through the first heat-conducting sheet 841 with a larger area, and reduce the overall size of the heat-conducting member 84, thereby reducing the preparation cost of the battery monomer 3.

[0132] Optionally, during the operation of the electrode assembly 5, the temperature of the end of the electrode main body 52 close to the tab 51 is relatively high, and the temperature of the end far from the tab 51 is relatively low, and the first heat-conducting sheet 841 arranged on the side surface 523 of the electrode main body 52 can conduct and balance the temperature of the electrode assembly 5 in the first direction X.

[0133] Optionally, in the first direction X, the accommodating cavity 851 and the first heat-conducting sheet 841 extend to both ends of the electrode main body 52.

[0134] Optionally, the accommodating cavity 851 and the first heat-conducting sheet 841 cover the entire side surface 523 of the electrode main body 52, so as to improve the heat conduction rate of the heat-conducting assembly 8. Optionally, the insulating member 85 covers the entire side surface 523, and the insulating member 85 plays a role of insulating the electrode assembly 5 and the shell 4, and the insulating member 85 can replace part or all of the Mylar film, so that the battery monomer 3 is provided with a smaller size Mylar film or does not need to be separately provided with a Mylar film, thereby reducing the preparation cost of the battery monomer 3, reducing the thickness of the battery monomer 3, and improving the energy density of the battery monomer 3.

[0135] Optionally, the tab 51 extends to both ends of the electrode main body 52 in the first direction X, and the insulating member 85 covering the side surface 523 can completely replace the Mylar film.

[0136] It should be noted that the heat-conducting member 84 is located in the insulating member 85, and the heat-conducting member 84 is covered by the insulating member 85, and in the drawings, the position of the heat-conducting member 84 is shown for convenience, so the heat-conducting member 84 is represented by the shadow on the insulating member 85.

[0137] Optionally, the insulation member 85 is provided with an open-ended accommodating cavity 851, the heat-conducting member 84 is arranged in the accommodating cavity 851 and is bonded or fused to the opening of the insulation member 85, so that the heat-conducting member 84 is located in a sealed accommodating cavity 851; or the insulation member 85 is folded at two ends, the heat-conducting member 84 is located between the two ends of the insulation member 85, and the two ends of the insulation member 85 are bonded or fused together, so that the heat-conducting member 84 is located in a sealed accommodating cavity 851; or the insulation member 85 comprises two oppositely arranged sub-insulation layers 855, the edges of the two sub-insulation layers 855 are bonded or fused, so that the heat-conducting member 84 is located in a sealed accommodating cavity 851.

[0138] Optionally, the side surface of the insulation member 85 facing the electrode body 52 is provided with a bonding layer, so that the heat-conducting assembly 8 and the electrode assembly 5 are bonded and connected. Illustratively, the bonding layer can be an insulating glue, so as to enhance the insulation performance of the heat-conducting assembly 8 and the electrode assembly 5.

[0139] Optionally, the insulation member 85 and the Mylar film are connected with each other, and the insulation member 85 and the Mylar film jointly cover the second end surface 522 and the side surface 523 of the electrode body 52, or the insulation member 85 and the Mylar film jointly cover the side surface 523 of the electrode body 52, so as to realize the insulation between the electrode body 52 and the shell 4 through the combination of the Mylar film and the insulation member 85, which is helpful to reduce the size of the Mylar film, reduce the manufacturing cost of the battery monomer 3, and reduce the thickness of the battery monomer 3 and improve the energy density of the battery monomer 3.

[0140] The side surface 523 comprises two first side surfaces 5231 and two second side surfaces 5232, the two first side surfaces 5231 are oppositely arranged in the second direction Y, the two second side surfaces 5232 are oppositely arranged in the third direction Z, the first direction X, the second direction Y and the third direction Z are intersected with each other, and the area of the first side surface 5231 is greater than that of the second side surface 5232.

[0141] The connection mode of the insulation member 85 and the Mylar film can be bonding or fusing, etc. The specific size of the insulation member 85 and the Mylar film can be flexibly designed. Illustratively, the insulation member 85 covers the first side surface 5231 and the second end surface 522, and the Mylar film covers the second side surface 5232; or the insulation member 85 covers the side surface 523, and the Mylar film covers the second end surface 522.

[0142] Please refer to FIG. 9, which is a partial structure diagram of a battery monomer provided by an embodiment of the present application.

[0143] In some embodiments, as shown in FIG. 5 and FIG. 9, the tab 51 protrudes from the first end surface 521, and the insulation member 85 covers the second end surface 522 and the side surface 523 of the electrode body 52.

[0144] In the embodiments, the insulating member 85 covers the second end surface 522 and the side surface 523 of the electrode body 52 to insulate the shell 4 and the electrode assembly 5, and no Mylar film is needed, which helps to reduce the cost of the battery monomer 3 and reduce the thickness of the battery monomer 3 and improve the energy density of the battery monomer 3.

[0145] In the embodiments, the insulating member 85 insulates the shell 4 and the electrode assembly 5, and no Mylar film is needed, or the insulating member 85 replaces at least part of the Mylar film. The thermal conductivity of the insulating member 85 is similar to that of the Mylar film, so in the embodiments, the replacement of the Mylar film by the insulating member 85 does not greatly affect the heat dissipation of the electrode assembly 5; the heat-conducting member 84 is arranged in the insulating member 85, and the thermal conductivity of the heat-conducting member 84 is greater than that of the Mylar film, so compared with the case where the insulating member 85 or the Mylar film is arranged between the electrode assembly 5 and the shell 4, the arrangement of the heat-conducting member 84 between the electrode assembly 5 and the shell 4 can improve the heat conduction rate between the electrode assembly 5 and the external environment, that is, the heat-conducting assembly 8 can improve the heat conduction efficiency between the electrode assembly 5 and the external environment.

[0146] The thermal conductivity of the heat-conducting assembly 8 can be measured by a heat flow method, a hot plate method, or a hot wire method. When the thermal conductivity of the heat-conducting assembly 8 is tested, the test sample of the heat-conducting assembly 8 should include the heat-conducting member 84 and the insulating member 85 arranged on the outer surface of the heat-conducting member 84.

[0147] The combination of the insulating member 85 and the heat-conducting member 84 enables the insulating member 85 to insulate the electrode body 52 and the shell 4, insulate the heat-conducting member 84 and the electrode body 52, and insulate the heat-conducting member 84 and the electrolyte.

[0148] The insulating member 85 covers the second end surface 522 and the side surface 523 of the electrode body 52, and the insulating member 85 can replace the Mylar film, and the battery monomer 3 does not need to separately arrange the Mylar film. The size of the heat-conducting member 84 arranged in the accommodating cavity 851 can be designed. For example, the heat-conducting member 84 covers at least one of the first side surface 5231, the second side surface 5232, and the second end surface 522 to enhance the ability of the heat-conducting member 84 to conduct heat between the electrode assembly 5 and the external environment.

[0149] Please refer to FIG. 10, FIG. 11, and FIG. 12, FIG. 10 is a structural schematic diagram of a heat-conducting assembly of a battery monomer according to an embodiment of the present application; FIG. 11 is an expanded view of the heat-conducting assembly of the battery monomer according to an embodiment of the present application; and FIG. 12 is a structural schematic diagram of the heat-conducting assembly of the battery monomer according to an embodiment of the present application.

[0150] In some embodiments, as shown in FIGS. 5, 10-12, the side surface 523 includes two first side surfaces 5231 and two second side surfaces 5232, the two first side surfaces 5231 are oppositely arranged in the second direction Y, the two second side surfaces 5232 are oppositely arranged in the third direction Z, the first direction X, the second direction Y and the third direction Z are perpendicular to each other, the area of the first side surface 5231 is greater than the area of the second side surface 5232, the insulating member 85 includes a first insulating part 852, the first insulating part 852 includes a body part 8521 and a bending part 8522 connected to each other, the body part 8521 and the bending part 8522 are connected, the body parts 8521 of the two first insulating parts 852 are arranged on the two first side surfaces 5231 respectively, the two bending parts 8522 are arranged on the two second side surfaces 5232 respectively, and the first heat-conducting sheet 841 is arranged on at least one of the body part 8521 and the bending part 8522.

[0151] In these embodiments, the first insulating part 852 includes the body part 8521 and the bending part 8522 connected to each other, the body parts 8521 of the two first insulating parts 852 are arranged on the two first side surfaces 5231 respectively, the two bending parts 8522 are arranged on the two second side surfaces 5232 respectively, so as to realize the insulation of the electrode assembly 5 on the peripheral surface thereof and the shell 4, and the first heat-conducting sheet 841 is arranged on at least one of the body part 8521 and the bending part 8522, so as to improve the heat-conducting rate at the first side surface 5231 and / or the second side surface 5232 of the electrode assembly 5.

[0152] The first heat-conducting sheet 841 can be arranged on at least one of the body part 8521 and the bending part 8522.

[0153] In the same shell 4, the insulating member 85 includes two first insulating parts 852, and the oppositely arranged two first insulating parts 852 wrap at least part of the peripheral surface of the electrode assembly 5.

[0154] As shown in FIG. 11, the first insulating part 852 includes the body part 8521 and the bending part 8522 connected to each other, the body part 8521 and the bending part 8522 are integrally formed, so as to improve the structural strength of the first insulating part 852, there is a folding line between the body part 8521 and the bending part 8522, the body part 8521 covers the first side surface 5231, and the bending part 8522 is bent along the folding line and covers the second side surface 5232, or the body part 8521 and the bending part 8522 are prepared respectively, and the body part 8521 and the bending part 8522 are connected by bonding or fusion.

[0155] The first insulation part 852 comprises a body part 8521 and a bending part 8522 connected to the body part 8521 at one end in the third direction Z, the body part 8521 covers one first side surface 5231 of the electrode assembly 5, one end of the bending part 8522 is connected to the body part 8521, and the other end of the bending part 8522 extends towards the body part 8521 of the other first insulation part 852 in the second direction Y, the bending part 8522 is connected to the two body parts 8521, or the bending part 8522 is arranged separately from the body part 8521, and the two are connected by a Mylar film.

[0156] Alternatively, the first insulation part 852 comprises a body part 8521 and a bending part 8522 connected to the body part 8521 at both ends in the third direction Z, the body part 8521 covers the first side surface 5231 of the electrode assembly 5, the bending parts 8522 of the two oppositely arranged first insulation parts 852 extend oppositely in the second direction Y and are connected to each other, or the bending parts 8522 of the two oppositely arranged first insulation parts 852 extend oppositely in the second direction Y, and the two bending parts 8522 are connected by a Mylar film.

[0157] Optionally, in the same housing 4, the insulation part 85 comprises two first insulation parts 852, the two first insulation parts 852 are integrally formed and surround the outer circumferential surface of the electrode assembly 5.

[0158] Optionally, the body part 8521 covers the first side surface 5231 of the electrode assembly 5, and the bending part 8522 covers the second side surface 5232 of the electrode assembly 5, so that the first insulation part 852 can reliably insulate the electrode assembly 5 and the housing 4.

[0159] Optionally, the heat-conducting part 84 is arranged on the entire body part 8521 or the bending part 8522; or a plurality of heat-conducting parts 84 are arranged separately on the body part 8521 or the bending part 8522.

[0160] Optionally, a plurality of electrode assemblies 5 are provided, the body part 8521 is arranged between the housing 4 and the first side surface 5231 closest to the housing 4, and the bending part 8522 is arranged on one or more second side surfaces 5232.

[0161] Please refer to FIG. 13 and FIG. 14, FIG. 13 is a structural schematic diagram of a heat-conducting assembly of a battery monomer provided by an embodiment of the present application; and FIG. 14 is a partial structural schematic diagram of a heat-conducting assembly of a battery monomer provided by an embodiment of the present application.

[0162] In some embodiments, as shown in FIG. 13 and FIG. 14, a first through hole 815 is arranged through the first insulation part 852, and the first through hole 815 is arranged separately from the accommodating cavity 851.

[0163] In these embodiments, the first insulating portion 852 has a first through hole 815 formed therethrough, and the first through hole 815 is spaced from the accommodating cavity 851 to avoid contact between the electrolyte and the first heat-conducting sheet 841.

[0164] The accommodating cavity (not shown) is formed in a portion of the first insulating portion 852, and the first heat-conducting sheet 841 is arranged in the accommodating cavity 851. The first through hole 815 is formed in another portion of the first insulating portion 852, and the first through hole 815 is not in communication with the accommodating cavity 851. In this way, when the electrolyte infiltrates the electrode assembly 5 through the first through hole 815, the electrolyte cannot enter the accommodating cavity 851 and contact the first heat-conducting sheet 841, and the insulating member 85 can still insulate the first heat-conducting sheet 841 from the electrode assembly 5. The specific shape and size of the first through hole 815 can be designed as desired. For example, the first through hole 815 can be a circular hole or a rectangular hole.

[0165] For example, the insulating member 85 is molded to form the accommodating cavity 851, and the first through hole 815 can be arranged in a molding area 856, or the first through hole 815 can be arranged on a side of the molding area 856 that is away from the accommodating cavity.

[0166] Please refer to FIG. 15 and FIG. 16. FIG. 15 is a schematic structural diagram of a heat-conducting assembly of a battery cell according to another embodiment of the present application, and FIG. 16 is a schematic structural diagram of a heat-conducting assembly of a battery cell according to another embodiment of the present application.

[0167] In some embodiments, as shown in FIG. 15 and FIG. 16, the first heat-conducting sheet 841 has a first avoiding hole 8414 formed therethrough, and the first insulating portion 852 covers an inner wall of the first avoiding hole 8414. The first insulating portion 852 has a first through hole 815 formed therethrough, and the first through hole 815 is located in the first avoiding hole 8414.

[0168] In these embodiments, the first heat-conducting sheet 841 has a first avoiding hole 8414 formed therethrough, and the first insulating portion 852 has a first through hole 815 formed therethrough. The first through hole 815 is located in the first avoiding hole 8414, so that the electrolyte can infiltrate the electrode assembly 5 through the first through hole 815 and the first avoiding hole 8414. The first insulating portion 852 covers an inner wall of the first avoiding hole 8414 to avoid contact between the electrolyte and the first heat-conducting sheet 841 and to insulate the first heat-conducting sheet 841 from the electrode assembly 5.

[0169] The first heat-conducting sheet 841 is provided with a first avoiding hole 8414, and the first insulation part 852 is provided with a first through hole 815. The first through hole 815 is located in the first avoiding hole 8414, or the orthographic projection of the first avoiding hole 8414 in the thickness direction of the insulation part 85 is located in the first through hole 815. In this way, the electrolyte can infiltrate the electrode assembly 5 through the first through hole 815 and the first avoiding hole 8414. The first insulation part 852 covers the inner wall of the first avoiding hole 8414, and is used to isolate the electrolyte passing through the first through hole 815 from contacting the inner wall of the first avoiding hole 8414, and to insulate the electrode assembly 5 and the inner wall of the first avoiding hole 8414. The shape and size of the first avoiding hole 8414 can be designed as needed. For example, the first avoiding hole 8414 is a circular hole or a rectangular hole.

[0170] Optionally, the first avoiding hole 8414 and the first through hole 815 have the same shape, so as to better match each other. For example, the first avoiding hole 8414 and the first through hole 815 are both circular holes.

[0171] For example, the first insulation part 852 is plastic-sealed to form a containing cavity 851, and the first heat-conducting sheet 841 is contained in the containing cavity. Part of the first insulation part 852 is plastic-sealed to be connected to the inside of the first avoiding hole 8414, and the first through hole 815 penetrates the plastic-sealed area 856. The first through hole 815 and the inner wall of the first avoiding hole 8414 are spaced apart by the plastic-sealed area 856.

[0172] Please refer to FIG. 17, which is a structural schematic diagram of a heat-conducting assembly of a battery monomer according to an embodiment of the present application.

[0173] In some embodiments, as shown in FIG. 5, FIG. 9 and FIG. 17, the tab 51 extends out of the first end face 521. The insulation part 85 further includes a second insulation part 853, which is arranged between the second end face 522 of the electrode body 52 and the shell 4. The second insulation part 853 is insulated from the shell 4 and the second end face 522 of the electrode assembly 5, and the body part 8521 of each of the two first insulation parts 852 is connected to one side of the second insulation part 853.

[0174] In these embodiments, the insulation part 85 further includes the second insulation part 853 arranged between the second end face 522 of the electrode body 52 and the shell 4. The body part 8521 of each of the two first insulation parts 852 is connected to one side of the second insulation part 853, which reduces the difficulty of aligning the second insulation part 853 and the first insulation part 852, and reduces the difficulty of matching the insulation part 85 and the electrode assembly 5.

[0175] Optionally, the second insulation part 853 and the first insulation part 852 are bonded or welded to facilitate the size adjustment of the second insulation part 853 and the first insulation part 852; or the second insulation part 853 and the first insulation part 852 are integrally formed to reduce the joint of the insulation part 85 and improve the structural stability of the insulation part 85.

[0176] Optionally, the second insulation part 853 and the first insulation part 852 are integrally formed, the second insulation part 853 covers the second end surface 522, then the body part 8521 is bent and covers the first side surface 5231 of the electrode assembly 5, and then the bent part 8522 is bent and covers the second side surface 5232 of the electrode assembly 5.

[0177] Optionally, a plurality of electrode assemblies 5 are provided, and the second insulation part 853 is arranged between one or more electrode assemblies 5 and the shell 4 in the first direction X.

[0178] In some embodiments, as shown in FIG. 9 and FIG. 17, the heat conduction part 84 includes a second heat conduction sheet 842 arranged on the second insulation part 853.

[0179] In these embodiments, the heat conduction part 84 includes the second heat conduction sheet 842 arranged on the second insulation part 853 to improve the heat conduction rate at the second end surface 522.

[0180] Optionally, the second heat conduction sheet 842 covers the second end surface 522 of the electrode assembly 5 in the first direction X; or the number of electrode assemblies 5 is plural, and the second heat conduction sheet 842 covers the second end surfaces 522 of the plurality of electrode assemblies 5 in the first direction X.

[0181] For example, the size and shape of the second heat conduction sheet 842 can be designed by itself, and the second heat conduction sheet 842 is in the shape of a rectangle or an ellipse, etc.

[0182] Please refer to FIG. 18 and FIG. 19, FIG. 18 is a structural schematic diagram of a heat conduction assembly of a battery monomer provided by an embodiment of the application; and FIG. 19 is a partial structural schematic diagram of a heat conduction assembly of a battery monomer provided by an embodiment of the application.

[0183] In some embodiments, as shown in FIG. 17 to FIG. 19, a second through hole 821 is arranged through the second insulation part 853, and the second through hole 821 and the accommodating cavity 851 are arranged at intervals.

[0184] In the technical scheme of the embodiments of the application, the second through hole 821 is arranged through the second insulation part 853 to enable the electrolyte to soak the electrode assembly 5 through the second through hole 821, and the second through hole 821 and the accommodating cavity 851 are arranged at intervals to avoid the contact between the electrolyte and the second heat conduction sheet 842.

[0185] The accommodating cavity 851 is arranged in a part of the second insulation part 853, the second heat conduction sheet 842 is arranged in the accommodating cavity 851, the second through hole 821 is arranged in another part of the second insulation part 853, and the second through hole 821 and the accommodating cavity 851 are not communicated. In this way, when the electrolyte is infiltrated into the electrode assembly 5 through the first through hole 815, the electrolyte cannot enter the accommodating cavity 851 and contact the second heat conduction sheet 842, and the insulation part 85 can still keep the second heat conduction sheet 842 and the electrode assembly 5 insulated. The specific shape and size of the second through hole 821 can be designed by itself. For example, the second through hole 821 is a circular hole or a rectangular hole.

[0186] For example, the insulation part 85 is plastic encapsulated to form the accommodating cavity 851, and the second through hole 821 can be arranged in the plastic encapsulation area 856 or arranged on the side of the plastic encapsulation area 856 away from the accommodating cavity.

[0187] Please refer to FIG. 20 and FIG. 21, FIG. 20 is a structural schematic diagram of a heat conduction assembly of a battery monomer according to an embodiment of the present application, and FIG. 21 is a partial structural schematic diagram of a heat conduction assembly of a battery monomer according to another embodiment of the present application.

[0188] In some embodiments, as shown in FIG. 20 and FIG. 21, the second heat conduction sheet 842 is arranged with a second avoiding hole 8421, the second insulation part 853 covers the inner wall of the second avoiding hole 8421, and the second insulation part 853 is arranged with a second through hole 821, and the second through hole 821 is located in the second avoiding hole 8421.

[0189] In the technical scheme of the embodiments of the present application, the second heat conduction sheet 842 is arranged with a second avoiding hole 8421, the second insulation part 853 is arranged with a second through hole 821, and the second through hole is located in the second avoiding hole 8421, so that the electrolyte can be infiltrated into the electrode assembly 5 through the second through hole 821 and the second avoiding hole 8421, the second insulation part 853 covers the inner wall of the second avoiding hole 8421, so as to avoid the electrolyte from contacting the second heat conduction sheet 842 and keep the second heat conduction sheet 842 and the electrode assembly 5 insulated.

[0190] The second heat-conductive sheet 842 is provided with a second avoiding hole 8421, and the insulating member 85 is provided with a second through hole 821, the second through hole 821 is located in the second avoiding hole 8421, or the orthographic projection of the second avoiding hole 8421 in the thickness direction of the insulating member 85 is located in the second through hole 821, so that the electrolyte can be infiltrated into the electrode assembly 5 through the second through hole 821 and the second avoiding hole 8421. The second insulating part 853 covers the inner wall of the second avoiding hole 8421, the second insulating part 853 is used to isolate the electrolyte passing through the second through hole 821 from contacting the inner wall of the second avoiding hole 8421 of the second heat-conductive member 84, and the second insulating part 853 insulates the electrode assembly 5 and the second avoiding hole 8421. The shape and size of the second avoiding hole 8421 can be designed by itself, for example, the second avoiding hole 8421 is a circular hole or a rectangular hole.

[0191] Optionally, the shapes of the second avoiding hole 8421 and the second through hole 821 are the same, so that they can better match. For example, the second avoiding hole 8421 and the second through hole 821 are both circular holes.

[0192] For example, the insulating member 85 is plastic-sealed to form a containing cavity 851, the second heat-conductive sheet 842 is contained in the containing cavity, part of the insulating member 85 is plastic-sealed to connect to the inside of the second avoiding hole 8421, the second through hole 821 penetrates through the plastic-sealed area 856, and the inner wall of the second avoiding hole 8421 and the second through hole 821 are spaced apart by the plastic-sealed area 856.

[0193] Please refer to FIG. 22 and FIG. 23, FIG. 22 is a structural schematic diagram of a heat-conductive assembly of a battery monomer provided by an embodiment of the application, and FIG. 23 is an expanded diagram of the heat-conductive assembly of the battery monomer provided by an embodiment of the application.

[0194] In some embodiments, as shown in FIG. 9, FIG. 22 and FIG. 23, the electrode assembly 5 is provided with a plurality of electrode assemblies 5, the plurality of electrode assemblies 5 are stacked along the second direction Y, the insulating member 85 further includes a middle insulating part 854, the middle insulating part 854 is arranged between the electrode main bodies 52 of adjacent electrode assemblies 5, the middle insulating part 854 and the second insulating part 853 are connected to each other, the first heat-conductive sheet 841 includes a middle heat-conductive sheet 8411, and the middle heat-conductive sheet 8411 is arranged in the middle insulating part 854.

[0195] In these embodiments, the middle insulating part 854 is arranged between the adjacent electrode main bodies 52 to insulate the adjacent electrode main bodies 52, the middle insulating part 854 and the second insulating part 853 are connected to each other to improve the insulation reliability of the middle insulating part 854, and the middle heat-conductive sheet 8411 is arranged in the middle insulating part 854 to improve the heat-conduction rate between the adjacent electrode main bodies 52.

[0196] The first heat-conducting sheet 841 further comprises an end heat-conducting sheet 8412 and a side heat-conducting sheet 8413, the middle heat-conducting sheet 8411 is arranged on the middle insulating part 854 to improve the heat-conducting rate between adjacent electrode bodies 52; the end heat-conducting sheet 8412 is arranged on the body part 8521 to improve the heat-conducting rate of the adjacent first side surface 5231; and the side heat-conducting sheet 8413 is arranged on the bending part 8522 to improve the heat-conducting rate of the adjacent second side surface 5232.

[0197] Optionally, the middle insulating part 854 and the second insulating part 853 are bonded or welded, or the middle insulating part 854 and the second insulating part 853 are integrally formed, to improve the connection stability of the middle insulating part 854 and the second insulating part 853.

[0198] Optionally, the middle insulating part 854 and the second insulating part 853 and the bending part 8522 are connected, so that the insulating part 85 can be wrapped on the circumferential surface and the second end surface 522 of the electrode body 52.

[0199] Optionally, the middle insulating part 854 and the second insulating part 853 and the bending part 8522 are connected, so that the insulating part 85 can be wrapped on the circumferential surface and the second end surface 522 of the electrode body 52.

[0200] In some embodiments, as shown in FIG. 9, FIG. 22 and FIG. 23, the first heat-conducting sheet 841 and the second heat-conducting sheet 842 are connected to each other.

[0201] In these embodiments, the heat-conducting part 84 comprises the second heat-conducting sheet 842 arranged on the second insulating part 853, and the first heat-conducting sheet 841 and the second heat-conducting sheet 842 are connected to each other, so that the heat between adjacent electrode assemblies 5 can be transferred to the second heat-conducting sheet 842 through the first heat-conducting sheet 841, and exchanged with the external environment, thereby improving the heat-conducting rate of the heat-conducting assembly 8.

[0202] Optionally, the middle heat-conducting sheet 8411 and the second heat-conducting sheet 842 are connected to each other, and the second insulating part 853 is provided with a first communication hole facing the middle insulating part 854, the middle insulating part 854 is provided with a second communication hole facing the second insulating part 853, and the first heat-conducting sheet 841 of the middle insulating part 854 is connected to the second heat-conducting sheet 842 through the first communication hole and the second communication hole.

[0203] Optionally, the end heat-conducting sheet 8412 and the second heat-conducting sheet 842 are connected to each other. For example, the second insulating portion 853 is provided with a third communication hole facing the body portion 8521, the body portion 8521 is provided with a fourth communication hole facing the second insulating portion 853, the end heat-conducting sheet 8412 is arranged in the body portion 8521, and the end heat-conducting sheet 8412 is connected to the second heat-conducting sheet 842 through the third communication hole and the fourth communication hole.

[0204] Optionally, the side heat-conducting sheet 8413 and the second heat-conducting sheet 842 are connected to each other. For example, the second insulating portion 853 is provided with a fifth communication hole facing the bending portion 8522, the bending portion 8522 is provided with a sixth communication hole facing the second insulating portion 853, the side heat-conducting sheet 8413 is arranged in the bending portion 8522, and the side heat-conducting sheet 8413 is connected to the second heat-conducting sheet 842 through the fifth communication hole and the sixth communication hole.

[0205] Optionally, the second heat-conducting sheet 842 and the first heat-conducting sheet 841 arranged in the middle insulating portion 854 are integrally formed, so as to improve the heat conduction efficiency of the heat conduction assembly 8.

[0206] In some embodiments, as shown in FIGS. 8, 9 and 10, the body portion 8521 is connected with a bending portion 8522 on each side in the third direction Z, and the two bending portions 8522 of the two first insulating portions 852 on the same side of the electrode assembly 5 extend towards each other in the second direction Y.

[0207] In these embodiments, the body portion 8521 is connected with a bending portion 8522 on each side in the third direction Z, and the two bending portions 8522 of the two first insulating portions 852 on the same side of the electrode assembly 5 extend towards each other in the second direction Y, so that the joint of the two bending portions 8522 is located on the second side surface 5232, and the larger first side surface 5231 can be provided with a larger heat-conducting member 84, so as to improve the heat conduction capacity of the heat conduction assembly 8.

[0208] Optionally, the two bending portions 8522 of the two first insulating portions 852 extend towards each other in the second direction Y and are arranged in a spaced manner or abut against each other in the second direction Y, so that the body portion 8521 can cover the entire first side surface 5231, and the heat-conducting member 84 can cover the entire first side surface 5231, so as to improve the heat conduction efficiency of the heat conduction assembly 8; or the two bending portions 8522 of the two first insulating portions 852 extend towards each other in the second direction Y and overlap with each other, so that the overlapping part of the bending portions 8522 in the third direction Z does not increase the size of the battery monomer 3 in the second direction.

[0209] For example, the bent portions 8522 of the two first insulation portions 852 are bent and connected to each other. The insulation member 85 is connected by two sub-insulation layers 855, the two sub-insulation layers 855 are connected to form a containing cavity 851 (not shown in the figure) at the body portion 8521, and each bent portion 8522 includes two sub-insulation layers 855. For the convenience of understanding, part of the sub-insulation layers 855 are folded, and part of the sub-insulation layers 855 are unfolded.

[0210] Optionally, the two bent portions 8522 connected on both sides of the body portion 8521 are the same in size and shape, so as to reduce the processing difficulty of the first insulation portion 852. Specifically, the size and shape of the bent portion 8522 can be designed by oneself. For example, the bent portion 8522 is rectangular.

[0211] In some embodiments, as shown in FIGS. 8, 9 and 10, the two bent portions 8522 extend towards each other in the second direction Y, and the two bent portions 8522 at least partially overlap in the third direction Z.

[0212] In these embodiments, the two bent portions 8522 extend towards each other in the second direction Y, and the two bent portions 8522 at least partially overlap in the third direction Z, so as to improve the insulation reliability of the first insulation portion 852 between the electrode assembly 5 and the shell 4.

[0213] Optionally, the overlapping area of the two bent portions 8522 extends on both ends of the electrode body 52 in the first direction X, so as to improve the insulation reliability of the first insulation portion 852 between the electrode assembly 5 and the shell 4. The shape of the overlapping area of the two bent portions 8522 can be designed by oneself. For example, the overlapping area is rectangular.

[0214] Optionally, the two bent portions 8522 are bonded or plastic-welded in the overlapping area, so as to improve the connection reliability of the bent portion 8522.

[0215] Optionally, the sum of the extension sizes of the two bent portions 8522 in the second direction Y is L 11 , the size of the electrode assembly 5 in the second direction Y is L2, and L2 11 , so that the two bent portions at least partially overlap in the third direction Z. For example, the difference between L 11 and L2 is between 5mm and 10mm, which can save material cost and improve connection reliability;

[0216] The extension size of the bent portion 8522 in the second direction Y is L1, and the size of the electrode assembly 5 in the second direction Y is L2, which satisfies L1=L2, so as to improve the overlapping area of the two bent portions 8522 and the insulation reliability of the bent portion 8522 on the third side surface 523 of the electrode body 52;

[0217] The extension size of the bending part 8522 in the second direction Y is L1, and the size of the electrode assembly 5 in the second direction Y is L2, which satisfies L2 / 2

[0218] The extension size of the bending part 8522 in the second direction Y is L1, and the size of the electrode assembly 5 in the second direction Y is L2, which satisfies L2 / 2

[0219] In some embodiments, as shown in FIGS. 7, 9 and 12, the shell 4 comprises an opening 41 in the first direction X, and the battery monomer 3 further comprises a top cover assembly 6, which covers the opening 41 and is connected to the tab 51. At least one body part 8521 extends from the first end surface 521 in the first direction X and is connected to the top cover assembly 6.

[0220] In these embodiments, at least one body part 8521 extends from the first end surface 521 in the first direction X and is connected to the top cover assembly 6, which plays a role in positioning and fixing the heat conduction assembly 8, thereby improving the stability of the heat conduction assembly 8 in the shell 4.

[0221] The body part 8521 extends from the first end surface 521 and is fused to the lower plastic of the top cover assembly 6. The first heat conduction sheet 841 is in heat conduction connection with the side surface 523, and the first heat conduction sheet 841 does not exceed the first end surface 521, which can reduce the risk of damage to the first heat conduction sheet 841 and reduce the material cost of the heat conduction assembly 8.

[0222] Optionally, both body parts 8521 are connected to the top cover assembly 6, so as to improve the connection stability of the insulating part 85 and the top cover assembly 6.

[0223] Optionally, the body part 8521 comprises a contact section and a fusion section. The contact section is in contact with the side surface 523 of the electrode body 52. One end of the fusion section is connected to the contact section, and the other end extends from the first end surface 521 and is connected to the top cover assembly 6. The size of the fusion section in the third direction Z is greater than or equal to the size of the contact section, so as to improve the connection reliability of the insulating part 85 and the top cover assembly 6.

[0224] In some embodiments, as shown in FIGS. 9 and 12, the size L3 of the body part 8521 extending from the first end surface 521 in the first direction X is greater than or equal to 2 mm.

[0225] In these embodiments, the above conditions are met to improve the connection reliability of the heat conduction assembly 8 and the top cover assembly 6.

[0226] Optionally, the dimension L3 of the body part 8521 extending out of the first end surface 521 in the first direction X satisfies 2mm≤L3≤7mm to reduce the risk of interference between the excessively long body part 8521 and other components.

[0227] For example, the dimension L3 of the body part 8521 extending out of the first end surface 521 in the first direction X is 2mm or 3mm or 5mm or 7mm, etc.

[0228] In some embodiments, as shown in FIGS. 7 and 8, the minimum distance D2 of the orthographic projection of the heat conduction member 84 in the thickness direction of the heat conduction assembly 8 to the edge of the orthographic projection of the insulation member 85 in the thickness direction of the heat conduction assembly 8 is greater than or equal to 2mm.

[0229] In these embodiments, the minimum distance D2 of the orthographic projection of the heat conduction member 84 in the thickness direction of the heat conduction assembly 8 to the edge of the orthographic projection of the insulation member 85 in the thickness direction of the heat conduction assembly 8 is greater than or equal to 2mm to ensure that there is sufficient plastic sealing area between the heat conduction member 84 and the edge of the insulation member 85 to improve the sealing reliability of the accommodation cavity 851.

[0230] For example, the minimum distance D2 of the orthographic projection of the heat conduction member 84 in the thickness direction of the heat conduction assembly 8 to the edge of the orthographic projection of the insulation member 85 in the thickness direction of the heat conduction assembly 8 is 2mm or 3mm or 5mm, etc.

[0231] Optionally, the insulation member 85 includes two sub-insulation layers 855, which are stacked and connected or bonded in the length and width directions to form the accommodation cavity 851 accommodating the heat conduction member 84, and the minimum distance of the heat conduction member 84 to the edge of the sub-insulation layer 855 is greater than or equal to 2mm.

[0232] Alternatively, the insulation member 85 includes two sub-insulation layers 855 integrally formed and connected to each other, which are folded against each other, and then the edges of the length or width thereof are plastic sealed to form the accommodation cavity 851, and the minimum distance of the heat conduction member 84 to the edge of the sub-insulation layer 855 that needs to be plastic sealed or bonded is greater than or equal to 2mm.

[0233] Optionally, the two sub-insulation layers 855 have different areas, and the sub-insulation layer 855 with a smaller area is heat fused to the sub-insulation layer 855 with a larger area to form the accommodation cavity 851, thereby reducing the volume of the insulation member 85 and the volume of the heat conduction assembly 8 to improve the energy density of the battery monomer 3.

[0234] In some embodiments, as shown in FIGS. 7 and 8, the thickness D3 of the heat conduction member 84 satisfies 40μm≤D3≤180μm.

[0235] In these embodiments, when the above condition is met, the problem of the battery monomer 3 having a large volume and a low energy density caused by the thermal conduction member 84 being too thick can be improved, and the problem of the thermal conduction member 84 being easily damaged caused by the thermal conduction member 84 being too thin can also be improved.

[0236] For example, the thickness D3 of the thermal conduction assembly 8 is 40 μm or 50 μm or 110 μm or 180 μm, etc.

[0237] In some embodiments, as shown in FIGS. 7 and 8, the insulating member 85 includes two sub-insulating layers 855, which are stacked and connected to each other to form the accommodation cavity 851, and the thickness D1 of the sub-insulating layer 855 satisfies 5 μm≤D1≤100 μm.

[0238] In these embodiments, when the above condition is met, the problem of the battery monomer 3 having a large volume and a low energy density caused by the sub-insulating layer 855 being too thick can be improved, and the problem of the sub-insulating layer 855 being easily damaged caused by the sub-insulating layer 855 being too thin can also be improved.

[0239] For example, the thickness D1 of the sub-insulating layer 855 is 5 μm or 10 μm or 50 μm or 100 μm, etc.

[0240] Optionally, the two sub-insulating layers 855 have the same thickness, so as to reduce the processing difficulty of the insulating member 85.

[0241] In some embodiments, as shown in FIGS. 7 and 8, the insulating member 85 includes polyethylene or polypropylene or polyimide or polyester resin.

[0242] In these embodiments, the insulating member 85 includes polyethylene or polypropylene or polyimide or polyester resin, so as to improve the insulation reliability of the insulating member 85.

[0243] Optionally, the insulating member 85 should have the characteristics of insulation and high-temperature resistance, so that the insulating member 85 can be used to insulate the thermal conduction member 84 and the electrode assembly 5, and the risk of the insulating member 85 being damaged by melting under high-temperature conditions can be reduced.

[0244] In some embodiments, as shown in FIG. 7, the thermal conduction member 84 includes graphite or graphene or carbon nanotube.

[0245] In these embodiments, graphite is generally composed of parallel arranged layered carbon atoms, and presents a planar sheet shape. Graphene is generally a two-dimensional crystal composed of carbon atoms with only one side of atomic thickness, and belongs to the shape of fibers. Carbon nanotube is generally a tubular structure formed by rolling one or more graphite layers. The material of the thermal conduction member 84 includes graphite or graphene or carbon nanotube, and the thermal conduction performance of the thermal conduction member 84 is improved by using graphite or graphene or carbon nanotube as the thermal conduction material.

[0246] Optionally, the material of the heat conduction member 84 is super-crystal graphite, which has a larger crystal grain size than ordinary graphite, and a significantly improved thermal conductivity compared with ordinary graphite, so as to make the heat conduction member 84 have better heat conduction capacity.

[0247] Optionally, the heat conduction member 84 adopts a graphite heat conduction technology, which is a heat conduction technology based on graphite material and micro-porous structure. The principle is to quickly transfer heat to the heat conduction sheet through the high-efficiency heat conduction performance of the graphite material, and then quickly dissipate the heat to the external environment through the micro-porous structure, so as to achieve the heat exchange effect.

[0248] In some embodiments, as shown in FIG. 7, the thermal conductivity k of the heat conduction member 84 satisfies k≥500 W / (m·K).

[0249] In these embodiments, the thermal conductivity k of the heat conduction member 84 satisfies the above condition, so that the heat conduction member 84 has sufficient heat conduction performance to conduct the heat of the electrode body 52. Optionally, the thermal conductivity k of the heat conduction member 84 satisfies 500 W / (m·K)≤k≤1600 W / (m·K), and the thermal conductivity of the heat conduction member 84 is 500 W / (m·K) or 550 W / (m·K) or 1050 W / (m·K) or 1550 W / (m·K) or 1600 W / (m·K), etc.

[0250] Optionally, the thermal conductivity k of the heat conduction member 84 satisfies k≥1000 W / (m·K).

[0251] Optionally, the density of the heat conduction member 84 is 2.1±0.05 g / cm 3 , the insulation resistance is greater than 1 GΩ, the withstand voltage strength is 5400 V, and the bending resistance is greater than 10,000 times.

[0252] In a second aspect, the embodiments of the present application provide a battery device, which includes the battery monomer of any of the embodiments of the first aspect.

[0253] In a third aspect, the embodiments of the present application provide a power consumption device, which includes the battery device of the embodiments of the second aspect.

[0254] In some embodiments, as shown in FIGS. 1-23, the battery cell 3 comprises a housing 4, an electrode assembly 5 located within the housing 4, and a thermally conductive assembly 8, the electrode assembly 5 is of a jelly-roll type or a stacked type, the electrode assembly 5 comprises an electrode body 52 and a tab 51, the electrode body 52 comprises a first end face 521 and a second end face 522 oppositely arranged in a first direction X, and a side face 523 connected between the first end face 521 and the second end face 522, the side face 523 comprises two first side faces 5231 oppositely arranged in a second direction Y and two second side faces 5232 oppositely arranged in a third direction Z, the first direction X, the second direction Y and the third direction Z are perpendicular to each other in pairs, and an area of the first side face 5231 is greater than an area of the second side face 5232;

[0255] The heat conduction assembly 8 comprises an insulating piece 85 and a heat conduction piece 84, the insulating piece 85 at least partially forms a containing cavity 851, the heat conduction piece 84 is arranged in the containing cavity 851, the heat conduction piece 84 comprises a first heat conduction sheet 841 and a second heat conduction sheet 842, the tab 51 extends from the first end surface 521, the insulating piece 85 comprises a first insulating part 852, a second insulating part 853 and a middle insulating part 854, the first insulating part 852 comprises a body part 8521 and a bent part 8522 connected with each other, the body part 8521 and the bent part 8522 are connected, the body part 8521 of the two first insulating parts 852 is arranged on the two first side surfaces 5231 respectively, the two bent parts 8522 are arranged on the two second side surfaces 5232 respectively, the first heat conduction sheet 841 comprises a middle heat conduction sheet 8411, an end heat conduction sheet 8412 and a side heat conduction sheet 8413, the second insulating part 853 is arranged between the second end surface 522 of the electrode body 52 and the shell 4, the second insulating part 853 is insulated from the shell 4 and the second end surface 522 of the electrode assembly 5, the body part 8521 of the two first insulating parts 852 is connected to the two sides of the second insulating part 853 respectively, the second heat conduction sheet 842 is arranged on the second insulating part 853, the electrode assembly 5 is arranged in plurality, the plurality of electrode assemblies 5 are arranged in a stacking mode along the second direction Y, the middle insulating part 854 is arranged between the adjacent electrode bodies 52, the middle insulating part 854 and the second insulating part 853 are connected with each other, the middle heat conduction sheet 8411 is arranged on the middle insulating part 854, the end heat conduction sheet 8412 is arranged on the body part 8521, the side heat conduction sheet 8413 is arranged on the bent part 8522, the first heat conduction sheet 841 and the second heat conduction sheet 842 are connected with each other, the body part 8521 has one bent part 8522 connected on each side in the third direction Z, the two bent parts 8522 of the two first insulating parts 852 on the same side of the electrode assembly 5 extend towards each other in the second direction Y and at least partially overlap, at least one body part 8521 extends from the first end surface 521 in the first direction X and is connected to the top cover assembly 6, the size L3 of the body part 8521 extending from the first end surface 521 in the first direction X is greater than or equal to 2mm, the minimum distance between the orthographic projection of the heat conduction piece 84 in the thickness direction of the heat conduction assembly 8 and the edge of the orthographic projection of the insulating piece 85 in the thickness direction of the heat conduction assembly 8 is greater than or equal to 2mm, the thickness D3 of the heat conduction piece 84 satisfies 40μm≤D3≤180μm, the insulating piece 85 comprises two sub-insulating layers 855, the two sub-insulating layers 855 are arranged in a stacking mode and connected with each other to form the containing cavity 851, the thickness D1 of the sub-insulating layer 855 satisfies 5μm≤D1≤100μm, the insulating piece 85 comprises polyethylene or polypropylene or polyimide or polyester resin, the first insulating part 852 is provided with a first through hole 815, the second insulating part 853 is provided with a second through hole 821, the second through hole 821 and the first through hole 815 are arranged separately from the containing cavity 851, the heat conduction piece 84 comprises graphite or graphene or carbon nanotube, the heat conductivity k of the heat conduction piece 84 satisfiesk>500W / (m·K), the thermal conductivity of the thermal conductive member 84 is greater than the thermal conductivity of the insulating member 85 and the shell 4.

[0256] In these embodiments, the battery cell 3 comprises a shell 4, an electrode assembly 5 and a thermal conductive assembly 8, the electrode assembly 5 is located inside the shell 4, the shell 4 provides accommodation and protection for the electrode assembly 5, the electrode assembly 5 comprises an electrode body 52 and a tab 51, the electrode body 52 comprises a first end face 521 and a second end face 522 oppositely arranged in the first direction X, and a side face 523 connected between the first end face 521 and the second end face 522, the electrode body 52 forms a loop with the tab 51 and external components extending from the first end face 521 and / or the second end face 522, the thermal conductive assembly 8 comprises an insulating member 85 and a thermal conductive member 84, the insulating member 85 covers at least the side face 523, the insulating member 85 is insulated from the shell 4 and at least part of the electrode assembly 5, the insulating member 85 can replace at least part of the mica film to reduce the manufacturing cost of the battery cell 3, reduce the thickness of the battery cell 3, and improve the energy density of the battery cell 3, at least part of the insulating member 85 forms an accommodation cavity 851, the thermal conductive member 84 is arranged in the accommodation cavity 851, the thermal conductive member 84 and the electrode body 52 can be insulated by the insulating member 85, and the thermal conductive member 84 and the electrolyte can be isolated by the insulating member 85, so as to improve the problem of incompatibility between the thermal conductive member 84 and the electrolyte, the thermal conductivity of the thermal conductive member 84 is greater than the thermal conductivity of the insulating member 85 and the thermal conductivity of the shell 4, the thermal conductive member 84 comprises a first thermal conductive sheet 841, the first thermal conductive sheet 841 is arranged on at least part of the side face 523 and is in thermal conductive connection with the side face 523, the first thermal conductive sheet 841 reduces the thermal resistance of the electrode body 52 at the side face 523 thereof, improves the temperature uniformity of the electrode body 52 at the side face 523 thereof, and improves the rate of heat exchange between the electrode body 52 at the side face 523 thereof and the external environment, so as to balance the internal temperature of the battery cell 3 and improve the problem of adverse effects on the performance and service life of the battery cell 3 due to excessively high or low internal temperature of the battery cell 3.

[0257] 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 for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should be covered in the scope of the claims and 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 herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, comprising: a housing; an electrode assembly located in the housing, the electrode assembly comprising an electrode body and a tab, the electrode body comprising a first end face and a second end face oppositely arranged in a first direction, and a side face connected between the first end face and the second end face, the tab being connected to the electrode body and protruding from at least one of the first end face and the second end face; a heat conduction assembly comprising an insulating member and a heat conduction member, the insulating member at least partially forming a receiving cavity, the heat conduction member being arranged in the receiving cavity, the insulating member at least covering the side face, the heat conduction member comprising a first heat conduction sheet, the first heat conduction sheet being arranged on at least part of the side face and being in heat conduction connection with the side face, the heat conduction rate of the heat conduction member being greater than the heat conduction rate of the insulating member and the housing.

2. The battery cell of claim 1, wherein, The tab protrudes from the first end face, and the insulating member covers the second end face and the side face of the electrode body.

3. The battery cell of claim 2, wherein, The side face comprises two first side faces and two second side faces, the two first side faces being oppositely arranged in a second direction, and the two second side faces being oppositely arranged in a third direction, the first direction, the second direction and the third direction intersecting with each other, the area of the first side face being greater than the area of the second side face. The insulating member comprises two first insulating portions, each of the first insulating portions comprising a body portion and a bent portion connected to each other, the body portion and the bent portion being connected, the body portions of the two first insulating portions being arranged on the two first side faces respectively, and the bent portions being arranged on the two second side faces respectively, the first heat conduction sheet being arranged on at least one of the body portion and the bent portion.

4. The battery cell of claim 3, wherein, A first through hole is arranged through the first insulating portion, and the first through hole and the receiving cavity are arranged in a spaced manner.

5. The battery cell of claim 3, wherein, A first avoiding hole is arranged through the first heat conduction sheet, and the first insulating portion covers the inner wall of the first avoiding hole, a first through hole is arranged through the first insulating portion, and the first through hole is located in the first avoiding hole.

6. The battery cell of any one of claims 3 to 5, wherein, The insulating member further comprises a second insulating portion, the second insulating portion being arranged between the second end face of the electrode body and the housing, and the body portions of the two first insulating portions being connected to two sides of the second insulating portion respectively.

7. The battery cell of claim 6, wherein, The heat conduction member further comprises a second heat conduction sheet, the second heat conduction sheet being arranged on the second insulating portion.

8. The battery cell of claim 7, wherein, A second through hole is arranged through the second insulating portion, and the second through hole and the receiving cavity are arranged in a spaced manner.

9. The battery cell of claim 8, wherein, A second avoiding hole is arranged through the second heat conduction sheet, and the second insulating portion covers the inner wall of the second avoiding hole, a second through hole is arranged through the second insulating portion, and the second through hole is located in the second avoiding hole.

10. The battery cell of any one of claims 7 to 9, wherein, The first heat conduction sheet and the second heat conduction sheet are connected to each other.

11. The battery cell of any one of claims 6 to 10, wherein, A plurality of electrode assemblies are arranged, and the plurality of electrode assemblies are arranged in a stacked manner in the second direction. The insulation member further comprises a middle insulation part arranged between the electrode bodies of adjacent electrode assemblies, the middle insulation part and the second insulation part are connected to each other, the first heat conduction piece comprises a middle heat conduction piece arranged in the middle insulation part.

12. The battery cell of any one of claims 3 to 11, wherein, The body part is connected with one of the bending parts on each side in the third direction, and the two bending parts on the same side of the electrode assemblies extend towards each other in the second direction.

13. The battery cell of claim 12, wherein, The two bending parts extend towards each other in the second direction, and the two bending parts at least partially overlap in the third direction.

14. The battery cell of any one of claims 3 to 13, wherein, The shell comprises an opening in the first direction, the battery monomer further comprises a top cover assembly, the top cover assembly covers the opening and is connected to the tab, and at least one of the body parts extends out of the first end surface in the first direction and is connected to the top cover assembly.

15. The battery cell of claim 14, wherein, The size L3 of the body part extending out of the first end surface in the first direction is greater than or equal to 2mm.

16. The battery cell of any one of claims 1 to 15, wherein, The minimum distance from the orthographic projection of the heat conduction piece in the thickness direction of the heat conduction assembly to the edge of the orthographic projection of the insulation member in the thickness direction of the heat conduction assembly is greater than or equal to 2mm.

17. The battery cell of any one of claims 1 to 16, wherein, The thickness D3 of the heat conduction piece satisfies 40μm≤D3≤180μm.

18. The battery cell of any one of claims 1 to 17, wherein, The insulation member comprises two sub-insulation layers, the two sub-insulation layers are arranged in layers and connected to each other to form the accommodating cavity, and the thickness D1 of the sub-insulation layer satisfies 5μm≤D1≤100μm.

19. The battery cell of any one of claims 1 to 18, wherein, The insulation member comprises polyethylene or polypropylene or polyimide or polyester resin.

20. The battery cell of any one of claims 1 to 19, wherein, The heat conduction piece comprises graphite or graphene or carbon nanotube.

21. The battery cell of any one of claims 1 to 20, wherein, The thermal conductivity k of the heat conduction piece satisfies k≥500W / (m·K).

22. A battery device comprising the battery monomer of any one of claims 1-21.

23. An electric device comprising the battery device of claim 22.

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