Battery cell, battery apparatus and electrical apparatus

Abstract

Provided in the present application are a battery cell, a battery apparatus and an electrical apparatus. The battery cell comprises: a casing; an electrode assembly, located in the casing, the electrode assembly comprising an electrode body and tabs, the electrode body comprising a first end face and a second end face arranged opposite to each other in a first direction, and a side face connected between the first end face and the second end face, and the tabs being connected to the electrode body and extending out of at least one of the first end face and the second end face; and a thermal conduction assembly, comprising a first thermal conduction part, the first thermal conduction part being thermally connected to the side surface, the thermal conductivity of the thermal conduction assembly being greater than that of the casing, and the thermal conduction assembly and the electrode assembly being insulated from each other. The casing comprises an opening in the first direction, and the battery cell further comprises a top cover assembly, the top cover assembly covering the opening. The top cover assembly has electrode terminals, the electrode terminals being connected to the tabs. The thermal conduction assembly further comprises a second thermal conduction part, the second thermal conduction part being thermally connected to the tabs and thermally connected to the first thermal conduction part.

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, in the actual working process, the internal temperature of the battery cell is too high or too low, 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 of the tab of the battery cell, 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 protruding from at least one of the first end face and the second end face; a heat conduction assembly comprising a first heat conduction part, the first heat conduction part being in heat conduction connection with the side face, the heat conduction rate of the heat conduction assembly being greater than the heat conduction rate of the shell, the heat conduction assembly and the electrode assembly being insulated from each other, wherein the shell comprises an opening in the first direction, and the battery cell further comprises a top cover assembly covering the opening, the top cover assembly having an electrode terminal, the electrode terminal being connected to the tab, the heat conduction assembly further comprising a second heat conduction part, the second heat conduction part being in heat conduction connection with the tab, and the second heat conduction part being in heat conduction connection with the first heat conduction part.

[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, and 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 the tab extending from the first end face and / or the second end face and an external component. The heat conduction rate of the heat conduction assembly is greater than that of the shell. The heat conduction assembly comprises a first heat conduction part. The first heat conduction part is connected to the side face of the electrode main body through heat conduction. The first heat conduction part can 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 heat exchange rate 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 adverse effects of the performance and service life of the battery monomer caused by the excessively high or low internal temperature of the battery monomer. The top cover assembly covers the opening of the shell. The tab and the electrode terminal of the top cover assembly are connected to realize electrical connection. The heat conduction assembly further comprises a second heat conduction part in heat conduction connection with the tab. The second heat conduction part is in heat conduction connection with the first heat conduction part, so that the heat conduction assembly can improve the heat conduction rate at the tab, balance the temperature at the tab and the electrode main body, and improve the problem of the performance of the battery monomer affected by the excessively high temperature at the tab.

[0008] In some embodiments, the battery monomer further comprises a switching mechanism connected between the tab and the electrode terminal. The second heat conduction part is further in heat conduction connection with the switching mechanism.

[0009] In the technical scheme of the embodiment of the present application, the battery monomer further comprises a switching mechanism connected between the tab and the electrode terminal. The second heat conduction part is further in heat conduction connection with the switching mechanism, so that the heat conduction assembly can improve the heat conduction rate at the switching mechanism, balance the temperature at the switching mechanism, and improve the problem of the performance of the battery monomer affected by the excessively high temperature at the switching mechanism.

[0010] In some embodiments, the tab comprises a folding section and an extension section. The folding section is connected to the electrode main body. One side of the extension section is connected to the folding section, and the other side of the extension section is connected to the switching mechanism. The second heat conduction part is connected to the side of the extension section facing the folding section, or the second heat conduction part is connected to the side of the extension section facing the switching mechanism.

[0011] In the technical scheme of the embodiment of the present application, the second heat conduction part is connected to the side of the extension section facing the folding section, or the second heat conduction part is connected to the side of the extension section facing the switching mechanism. The second heat conduction part is used to improve the heat conduction rate at the tab, and improve the problem that the excessively high temperature at the tab heats the electrode sheet, causes the electrode main body to heat up, and reduces the performance of the battery monomer.

[0012] In some embodiments, the extension section comprises a first sub-section, a second sub-section and a third sub-section connecting the first sub-section and the second sub-section, the first sub-section is connected to the folding section, the second sub-section is connected to the switching mechanism, and the second heat-conducting part is connected to one side of the first sub-section facing the folding section.

[0013] In the technical scheme of the embodiments of the present application, the extension section comprises a first sub-section, a second sub-section and a third sub-section connecting the first sub-section and the second sub-section, the second sub-section is connected to the switching mechanism, so as to increase the contact area of the switching mechanism and the tab, and the second heat-conducting part is connected to one side of the first sub-section facing the folding section, so as to reduce the connection difficulty of the second heat-conducting part and the tab.

[0014] In some embodiments, the side surface comprises two first side surfaces and two second side surfaces, the two first side surfaces are oppositely arranged in the second direction, the two second side surfaces are oppositely arranged in the third direction, the first direction, the second direction and the third direction intersect with each other, the area of the first side surface is larger than that of the second side surface, the tab comprises two, the two tabs extend from the first end surface and are arranged in the third direction, the first heat-conducting part and the second heat-conducting part each comprise two, the two first heat-conducting parts are arranged on the two second side surfaces respectively, the two second heat-conducting parts are connected to one end of the two first heat-conducting parts facing the tab respectively, and the two second heat-conducting parts are connected to the extension section of the two tabs respectively.

[0015] In the technical scheme of the embodiments of the present application, the two tabs extend from the first end surface and are arranged in the third direction, the two first heat-conducting parts are arranged on the two second side surfaces respectively, so that the thickness of the battery monomer is not increased due to the arrangement of the heat-conducting assembly, and since the expansion of the electrode assembly mainly occurs at the first side surface, when the first heat-conducting part is arranged at the second side surface, the interference of the first heat-conducting part with the expansion of the electrode assembly can be reduced, the two second heat-conducting parts are connected to one end of the two first heat-conducting parts facing the tab respectively, and the two second heat-conducting parts are connected to the extension section of the two tabs respectively, each tab is connected to one second heat-conducting part, so that the heat at the electrode main body and each tab can be transmitted to the first heat-conducting part through the second heat-conducting part, so as to increase the heat-conducting rate at the tab, and improve the problem that the tab is overheated to heat the pole piece, the electrode main body is heated, and the performance of the battery monomer is reduced.

[0016] In some embodiments, the side surface comprises two first side surfaces and two second side surfaces, the two first side surfaces are oppositely arranged in a second direction, the two second side surfaces are oppositely arranged in a third direction, the first direction, the second direction and the third direction are intersected two by two, the area of the first side surface is larger than the area of the second side surface, two first heat conduction parts are respectively arranged, the two first heat conduction parts are respectively arranged on the two first side surfaces, each second heat conduction part is respectively connected to a first heat conduction part, and the two second heat conduction parts are respectively connected to different positions of the extension section of the same lug.

[0017] In the technical scheme of the embodiments of the present application, each second heat conduction part is respectively connected to a first heat conduction part, and the two second heat conduction parts are respectively connected to different positions of the extension section of the same lug, so as to better improve the heat conduction rate at the lug and improve the problem of affecting the performance of the battery monomer due to the excessively high temperature at the lug.

[0018] In some embodiments, the extension section comprises a first sub-section, a second sub-section and a third sub-section connecting the first sub-section and the second sub-section, which are arranged at intervals along the first direction, the first sub-section is connected to the folding section, and the second sub-section is connected to the switching mechanism; one of the two second heat conduction parts is connected to the first sub-section, and the other is connected to the second sub-section.

[0019] In the technical scheme of the embodiments of the present application, one of the two second heat conduction parts is connected to the first sub-section, and the other is connected to the second sub-section, so as to reasonably distribute the connection area of the two second heat conduction parts and the lug, and improve the connection reliability of the second heat conduction part and the lug.

[0020] In some embodiments, the side surface comprises two first side surfaces and two second side surfaces, the two first side surfaces are oppositely arranged in a second direction, the two second side surfaces are oppositely arranged in a third direction, the first direction, the second direction and the third direction are intersected two by two, the area of the first side surface is larger than the area of the second side surface, the switching mechanism comprises a first connecting section and a second connecting section arranged along the third direction, the lug is connected to the first connecting section, and the second heat conduction part is connected to the second connecting section.

[0021] In the technical scheme of the embodiments of the present application, the switching mechanism comprises a first connecting section and a second connecting section, the lug is connected to the first connecting section, and the second heat conduction part is connected to the second connecting section, so as to improve the heat conduction rate at the switching mechanism through the second heat conduction part, and improve the problem that the excessively high temperature at the switching mechanism causes the heating of the pole piece, resulting in the decrease of the performance of the battery monomer.

[0022] In some embodiments, two first heat conduction parts are respectively arranged, the two first heat conduction parts are respectively arranged on the two first side surfaces, each second heat conduction part is respectively connected to a first heat conduction part, and the two second heat conduction parts are respectively connected to different positions of the second connecting section of the same switching mechanism.

[0023] In the technical scheme of the embodiment of the application, the two first heat-conducting parts are respectively arranged on the two first sides, each second heat-conducting part is connected to one first heat-conducting part, and the two second heat-conducting parts are respectively connected to different positions of the second connecting section of the same adapter mechanism, so that the heat conduction rate at the adapter mechanism is improved, and the problem of affecting the performance of the battery monomer due to the excessively high temperature at the adapter mechanism is improved.

[0024] In some embodiments, two electrode assemblies are arranged, the two electrode assemblies are arranged in a stacking manner in the second direction, the adapter mechanism is provided with two first connecting sections, the two first connecting sections are arranged on the two sides of the second connecting section in the second direction, the tabs of the two electrode assemblies are respectively connected to the two first connecting sections, the first heat-conducting part and the second heat-conducting part are respectively provided with two, the two first heat-conducting parts are arranged on the two first sides of the same electrode main body, the two second heat-conducting parts are respectively connected to one end of the two first heat-conducting parts towards the adapter mechanism, and the two second heat-conducting parts are respectively connected to the second connecting section of the adapter mechanism and the tabs.

[0025] In the technical scheme of the embodiment of the application, the two first heat-conducting parts are arranged on the two sides of the electrode main body in the second direction, the two second heat-conducting parts are respectively connected to one end of the two first heat-conducting parts towards the adapter mechanism, and the two second heat-conducting parts are respectively connected to the second connecting section of the adapter mechanism and the tabs, so that the connection difficulty of the second heat-conducting part and the tabs and the adapter mechanism is reduced, and the temperature at the tabs is better stabilized.

[0026] In some embodiments, the tab extends from the first end surface, the heat-conducting assembly further comprises a third heat-conducting part arranged between the shell and at least part of the second end surface in the first direction, and the third heat-conducting part is connected to the first heat-conducting part.

[0027] In the technical scheme of the embodiment of the application, the heat-conducting assembly further comprises a third heat-conducting part arranged between the shell and at least part of the second end surface in the first direction, and the third heat-conducting part is connected to the first heat-conducting part, so that the contact area of the heat-conducting assembly and the shell is increased, the heat conduction rate of the heat-conducting assembly to the heat at the tab is improved, and the problem of affecting the performance of the battery monomer due to the excessively high temperature at the tab is improved.

[0028] In some embodiments, the tab extends from the first end surface, the battery monomer further comprises a first insulating film, and the first insulating film covers the side surface and the second end surface of the electrode main body; wherein the first heat-conducting part is located between the first insulating film and the electrode assembly, or the first heat-conducting part is located between the first insulating film and the shell.

[0029] In the technical scheme of the embodiment of the present application, the first insulating film is wrapped on the side surface and the second end surface of the electrode body to insulate the shell and the electrode assembly, the first heat-conducting part is located between the first insulating film and the electrode assembly, the first insulating film plays a role of supporting and protecting the first heat-conducting part, and the problem of breakage of the first heat-conducting part under external force impact is reduced, or the first heat-conducting part is located between the first insulating film and the shell, so as to improve the insulation reliability between the first heat-conducting part and the electrode assembly and improve the heat conduction efficiency between the first heat-conducting part and the shell.

[0030] In some embodiments, the heat-conducting assembly includes an insulating piece and a heat-conducting piece, the insulating piece forms a containing cavity in at least a partial region, and the heat-conducting piece is arranged in the containing cavity. The heat-conducting piece includes a first heat-conducting sheet and a second heat-conducting sheet. The first heat-conducting part is composed of the first heat-conducting sheet and the insulating piece, and the second heat-conducting part is composed of the second heat-conducting sheet and the insulating piece. The first heat-conducting sheet and the second heat-conducting sheet are connected.

[0031] In the technical scheme of the embodiment of the present application, the heat-conducting assembly includes an insulating piece and a heat-conducting piece. The insulating piece forms a containing cavity in at least a partial region, and the heat-conducting piece is arranged in the containing cavity. The heat-conducting piece includes a first heat-conducting sheet and a second heat-conducting sheet. The first heat-conducting sheet and the insulating piece form a first heat-conducting part, and the second heat-conducting sheet and the insulating piece form a second heat-conducting part. The first heat-conducting sheet and the second heat-conducting sheet are connected. In this way, when the first heat-conducting sheet and the second heat-conducting sheet combine to conduct heat, the first heat-conducting sheet and the second heat-conducting sheet are insulated by the insulating piece and the electrode assembly, and the insulating piece can isolate the heat-conducting piece from the electrolyte. This improves the problem that the heat-conducting piece and the electrolyte are incompatible and affect the performance of the battery monomer.

[0032] In some embodiments, the heat-conducting piece includes graphite, graphene, or carbon nanotubes.

[0033] In the technical scheme of the embodiment of the present application, the heat-conducting piece includes graphite, graphene, or carbon nanotubes. The heat-conducting performance of the heat-conducting piece is improved by using graphite, graphene, or carbon nanotube heat-conducting materials.

[0034] In some embodiments, the thermal conductivity k of the heat-conducting piece satisfies k>500 W / (m·K).

[0035] In the technical scheme of the embodiment of the present application, when the thermal conductivity k of the heat-conducting piece satisfies the above condition, the heat-conducting piece has sufficient heat-conducting performance to conduct the heat of the electrode body.

[0036] In a second aspect, the embodiment of the present application provides a battery device including the battery monomer of any of the embodiments of the first aspect.

[0037] In a third aspect, the embodiment of the present application provides a power utilization device including the battery device of the embodiment of the second aspect. BRIEF DESCRIPTION OF DRAWINGS

[0038] 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 detailed description is made with reference to the accompanying drawings.

[0039] FIG. 1 is a structural schematic diagram of a vehicle according to an embodiment of the present application;

[0040] FIG. 2 is a structural schematic diagram of a battery device according to an embodiment of the present application;

[0041] FIG. 3 is a structural schematic diagram of a battery module according to an embodiment of the present application;

[0042] FIG. 4 is an exploded view of a battery cell according to an embodiment of the present application;

[0043] FIG. 5 is a structural schematic diagram of an electrode assembly of a battery cell according to an embodiment of the present application;

[0044] FIG. 6 is an exploded view of a battery cell according to another embodiment of the present application;

[0045] FIG. 7 is a partial structural schematic diagram of a battery cell according to an embodiment of the present application;

[0046] FIG. 8 is a partial structural schematic diagram of a battery cell according to an embodiment of the present application;

[0047] FIG. 9 is an exploded view of a battery cell according to another embodiment of the present application;

[0048] FIG. 10 is a partial structural schematic diagram of a battery cell according to an embodiment of the present application;

[0049] FIG. 11 is a partial structural schematic diagram of a battery cell according to an embodiment of the present application;

[0050] FIG. 12 is a partial structural schematic diagram of a battery cell according to an embodiment of the present application;

[0051] FIG. 13 is a partial structural schematic diagram of a battery cell according to an embodiment of the present application;

[0052] FIG. 14 is an enlarged structural schematic diagram of B in FIG. 13;

[0053] FIG. 15 is a partial structural schematic diagram of a battery cell according to an embodiment of the present application;

[0054] FIG. 16 is a partial structural schematic diagram of a battery cell according to an embodiment of the present application;

[0055] FIG. 17 is a partial structural schematic diagram of a battery cell according to an embodiment of the present application;

[0056] Fig. 18 is a partial structural schematic diagram of a battery cell according to an embodiment of the present application;

[0057] Fig. 19 is an exploded view of a battery cell according to another embodiment of the present application;

[0058] Fig. 20 is a sectional view at A-A in Fig. 6.

[0059] Reference signs:

[0060] 1, vehicle; 101, motor; 102, controller; 2, battery device; 201, battery module; 202, case; 2021, first case; 2022, second case;

[0061] 3, battery cell;

[0062] 4, housing; 41, opening;

[0063] 5, electrode assembly; 51, tab; 52, electrode body; 521, first end face; 522, second end face; 523, side face; 5231, first side face; 5232, second side face; 511, retracted section; 512, extended section; 5121, first sub-section; 5122, second sub-section; 5123, third sub-section;

[0064] 6, top cover assembly; 61, electrode terminal;

[0065] 7, adapter mechanism;

[0066] 71, first connecting section; 72, second connecting section;

[0067] 8, heat conduction assembly; 81, first heat conduction part; 83, second heat conduction part; 82, third heat conduction part; 84, heat conduction member; 841, first heat conduction sheet; 842, second heat conduction sheet; 85, insulating member; 851, accommodating cavity;

[0068] 91, first insulating film;

[0069] X, first direction; Y, second direction; Z, third direction. DETAILED DESCRIPTION

[0070] 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.

[0071] 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 persons skilled in the art to which the embodiments of the present application belong.

[0072] In the description of the embodiments of the present application, the orientations or positional relationships indicated by the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the embodiments of the present application.

[0073] 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.

[0074] 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, can be fixedly connected, or can be detachably connected, or can be integrated; can be mechanically connected, or can be electrically connected; can be directly connected, or can be indirectly connected through an intermediate medium; 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.

[0075] 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", "over" and "on" the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "under" and "under" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0076] At present, from the development of market situation, the application of battery device is more and more extensive. 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.

[0077] 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.

[0078] The cause of the above problem is that when the battery cell is in a working state, current is output from the tab to the outside through the electrode terminal of the top cover assembly, the temperature of the tab rises due to the current, and the high temperature is transmitted from the tab to the electrode body, causing the temperature of the electrode body to rise, so that the battery cell prematurely reaches the current limiting temperature, causing the performance and service life of the battery cell to decrease.

[0079] 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 conductivity of the heat conduction assembly is greater than that of the shell, the heat conduction assembly includes a first heat conduction part, the first heat conduction part is heat-conductively connected to the side face of the electrode body, which can reduce the thermal resistance of the electrode body at the side face, improve the temperature uniformity of the electrode body at the side face, and improve the rate of heat exchange between the electrode body at the side face and the external environment, to balance the internal temperature of the battery cell and improve the adverse effects on the performance and service life of the battery cell caused by excessively high or low internal temperature of the battery cell, the top cover assembly covers the opening of the shell, the tab and the electrode terminal of the top cover assembly are connected to realize electrical connection, the heat conduction assembly further includes a second heat conduction part heat-conductively connected to the tab, and the second heat conduction part is heat-conductively connected to the first heat conduction part, so that the heat conduction assembly can improve the heat conduction rate at the tab to balance the temperature at the tab and the electrode body, and improve the problem of affecting the performance of the battery cell caused by excessively high temperature at the tab.

[0080] The technical solutions described in the embodiments of the present application are applicable to battery devices and electric devices using battery devices.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] 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.

[0086] It should be understood that the technical solutions described in the embodiments of the present application are not only limited to the battery device and the electric equipment described above, 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.

[0087] 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 power demand of the vehicle 1 during starting, navigation, and driving.

[0088] 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.

[0089] FIG. 2 shows a structural schematic diagram of a battery device according to an embodiment of the present application.

[0090] 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.

[0091] In some embodiments, the battery cell assembly is generally formed by arranging a plurality of battery cells 3.

[0092] 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.

[0093] 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.

[0094] As an example, the battery cell assembly can be a battery module 201, which can be accommodated in the box by fixing the battery module 201 in the box.

[0095] As an example, the battery cell assembly can also be accommodated in the box 202 by directly fixing a plurality of battery cells 3 to the box 202.

[0096] 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.

[0097] 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.

[0098] 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.

[0099] FIG. 3 shows a structural schematic diagram of the battery module 201 according to an embodiment of the present application.

[0100] 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.

[0101] The plurality of battery cells 3 in the battery module 201 can be electrically connected through the busbar component to achieve parallel connection, series connection or mixed connection of the plurality of battery cells 3 in the battery module 201.

[0102] 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. As shown in FIG. 4, the battery cell 3 includes a top cover assembly 6, a case 4, and an electrode assembly 5.

[0103] 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. The electrode sheet 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.

[0104] The electrode assembly 5 can have a wound structure, a stacked structure, or a hybrid structure of a wound structure and a stacked structure.

[0105] 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.

[0106] 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 are alternately stacked, and a plurality of separators are provided between any adjacent positive electrode sheets or negative electrode sheets. Alternatively, the separators can be continuously provided by being folded between any adjacent positive electrode sheets or negative electrode sheets.

[0107] In some embodiments, the electrode assembly 5 can have a cylindrical shape, a flat shape, or a polygonal shape.

[0108] 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.

[0109] 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.

[0110] 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 battery cell, a multi-prismatic battery cell (such as a hexagonal battery cell, etc.), and the present application is not particularly limited.

[0111] 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.

[0112] 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 mechanism 7.

[0113] Please refer to FIGS. 5 to 8, 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 an exploded view of a battery cell according to another embodiment of the present application; FIG. 7 is a partial structural schematic diagram of a battery cell according to an embodiment of the present application; and FIG. 8 is a partial structural schematic diagram of a battery cell according to an embodiment of the present application.

[0114] In a first aspect, as shown in FIGS. 4-8, the application provides a battery cell 3, the battery cell 3 comprising a housing 4, an electrode assembly 5 and a heat conduction assembly 8, the electrode assembly 5 being located inside the housing 4, the electrode assembly 5 comprising an electrode body 52 and a tab 51, the electrode body 52 comprising a first end face 521 and a second end face 522 oppositely arranged in a first direction X, and a side face 523 connected between the first end face 521 and the second end face 522, the tab 51 being connected to the electrode body 52 and extending out of at least one of the first end face 521 and the second end face 522; the heat conduction assembly 8 comprising a first heat conduction part 81, the first heat conduction part 81 being in heat conduction connection with the side face 523, the heat conductivity of the heat conduction assembly 8 being greater than the heat conductivity of the housing 4, the heat conduction assembly 8 and the electrode assembly 5 being insulated from each other, wherein the housing 4 comprises an opening 41 in the first direction X, the battery cell 3 further comprising a top cover assembly 6, the top cover assembly 6 covering the opening 41, the top cover assembly 6 having an electrode terminal 61, the electrode terminal 61 being connected to the tab 51, the heat conduction assembly 8 further comprising a second heat conduction part 83, the second heat conduction part 83 being in heat conduction connection with the tab 51, the second heat conduction part 83 being in heat conduction connection with the first heat conduction part 81.

[0115] In the scheme of the embodiments of the application, the battery cell 3 comprises a housing 4, an electrode assembly 5 and a heat conduction assembly 8, the electrode assembly 5 being located inside the housing 4, the housing 4 providing accommodation and protection for the electrode assembly 5, the electrode assembly 5 comprising an electrode body 52 and a tab 51, the electrode body 52 comprising a first end face 521 and a second end face 522 oppositely arranged in a first direction X, and a side face 523 connected between the first end face 521 and the second end face 522, the electrode body 52 forming a loop with the tab 51 extending out of the first end face 521 and / or the second end face 522 and external components, the heat conductivity of the heat conduction assembly 8 being greater than the heat conductivity of the housing 4, the heat conduction assembly 8 comprising a first heat conduction part 81, the first heat conduction part 81 being in heat conduction connection with the side face 523 of the electrode body 52, which can reduce the thermal resistance of the electrode body 52 at the side face 523 thereof, improve the temperature uniformity of the electrode body 52 at the side face 523 thereof, and improve 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 adverse effects of excessively high or low internal temperature of the battery cell 3 on the performance and service life of the battery cell 3, the top cover assembly 6 covering the opening 41 of the housing 4, the tab 51 being connected to the electrode terminal 61 of the top cover assembly 6 to realize electrical connection, the heat conduction assembly 8 further comprising a second heat conduction part 83 in heat conduction connection with the tab 51, the second heat conduction part 83 being in heat conduction connection with the first heat conduction part 81, so that the heat conduction assembly 8 can improve the heat conduction rate at the tab 51 to balance the temperature at the tab 51 and improve the adverse effects of excessively high temperature at the tab 51 on the performance of the battery cell 3.

[0116] The electrode body 52 is formed by a separator, a positive electrode sheet and a negative electrode sheet in a winding or stacking manner. The electrode 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.

[0117] Exemplarily, the battery cell 3 further includes a top cover assembly 6 connected with the electrode tab 51, the shell 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 shell 4 includes two openings 41 at two sides in the first direction X, two top cover assemblies 6 cover the openings 41 respectively, and the positive electrode tab and the negative electrode tab extend out of the first end face 521 and the second end face 522 respectively and are connected with the top cover assemblies 6.

[0118] Exemplarily, the first direction X is a height direction of the electrode assembly 5.

[0119] The first heat conduction part 81 is in heat conduction connection with the side face 523 of the electrode body 52, and the first heat conduction part 81 is directly attached to or abuts against the side face 523 of the electrode body 52; or the first heat conduction part 81 is a plating layer arranged on the side face 523; or the first heat conduction part 81 is arranged in a spaced manner with the side face 523, and the first heat conduction part 81 is indirectly connected with the side face 523 through a heat conduction medium, which can be air, metal or heat conduction glue, etc.

[0120] The second heat conduction part 83 is in heat conduction connection with the first heat conduction part 81. Specifically, the heat conduction assembly 8 includes an insulating part (not shown in the figure) and a heat conduction part (not shown in the figure), the insulating part at least partially forms a receiving cavity, and the heat conduction part is arranged in the receiving cavity. Therefore, the heat conduction part in the first heat conduction part 81 and the heat conduction part in the second heat conduction part 83 can be directly connected. Exemplarily, the heat conduction part in the first heat conduction part 81 and the heat conduction part in the second heat conduction part 83 are integrally formed or are mutually adhered or abutted. Alternatively, the heat conduction part in the first heat conduction part 81 and the heat conduction part in the second heat conduction part 83 are indirectly connected through a heat conduction medium, which can be a metal material part or heat conduction glue, etc.

[0121] During the working process of the battery cell 3, the heat generated by the electrode body 52 can be transmitted to the external environment through the heat conduction assembly 8, thereby improving the problem that the electrode body 52 is damaged due to excessively high temperature. Alternatively, in a low-temperature environment, the heat conduction assembly 8 can conduct the heat from the external environment to the electrode body 52 to heat the electrode assembly 5.

[0122] Optionally, the battery device 2 comprises a heat exchange mechanism, the shell of the battery cell 3 is in heat conduction connection with the heat exchange mechanism, the heat conduction assembly 8 can conduct heat between the heat exchange mechanism and the electrode assembly 5, and the heat exchange mechanism can conduct heat into or out of the heat conduction assembly 8.

[0123] 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.

[0124] The first heat conduction part 81 can be in a strip shape or a flat plate shape or a mesh plate shape, and the first heat conduction part 81 can be in a rectangular shape or a circular shape or a rhombic shape, and the specific shape and size of the first heat conduction part 81 can be flexibly designed.

[0125] Optionally, a plurality of first heat conduction parts 81 are arranged at intervals on the side surface 523 of the electrode body 52, which can not only conduct the heat of the electrode body 52 through the first heat conduction part 81, but also reduce the size of the heat conduction assembly 8 and reduce the manufacturing cost of the battery cell 3.

[0126] During the working process of the electrode assembly 5, the temperature of the end of the electrode body 52 close to the tab 51 is relatively high, and the temperature of the end far away from the tab 51 is relatively low, and the first heat conduction part 81 arranged on the side surface 523 of the electrode body 52 can conduct and balance the temperature of the electrode assembly 5 in the first direction X.

[0127] Optionally, in the first direction X, the first heat conduction part 81 extends to both ends of the electrode body 52.

[0128] Optionally, the first heat conduction part 81 covers the entire side surface 523 of the electrode body 52 to improve the heat conduction rate of the first heat conduction part 81.

[0129] The heat conduction rate of the heat conduction assembly 8 is greater than the heat conduction rate of the shell 4, and the heat conduction assembly 8 can comprise graphite, graphene or carbon nanotubes, etc.

[0130] When the battery cell 3 is in a working state, the current is output to the outside through the electrode terminal 61 by the tab 51, and the temperature rises at the tab 51 due to the current, and the high temperature is transmitted from the tab 51 to the electrode body 52, causing the temperature of the electrode body 52 to rise, and the battery cell 3 reaches the current limiting temperature too early, resulting in a decline in the performance of the battery cell 3.

[0131] Therefore, the tab 51 and the second heat conduction part 83 are in heat conduction connection, so that the heat at the tab 51 can be transmitted to the outside through the first heat conduction part 81 and the second heat conduction part 83, thereby improving the problem of the tab 51 heating the electrode body 52. Or in a low temperature environment, the temperature of the tab 51 can also be raised through the first heat conduction part 81 and the second heat conduction part 83.

[0132] Optionally, as shown in FIG. 7, the second heat-conducting part 83 is connected between the first heat-conducting part 81 and the tab 51, and the first heat-conducting part 81 extends on the first side surface 5231 of the electrode body 52. In this case, the first heat-conducting part 81 can be used to conduct heat at the first side surface 5231 of the electrode body 52 and the tab 51 at the same time. Alternatively, as shown in FIG. 6, the first heat-conducting part 81 extends on the second side surface 5232, which helps to reduce the size of the heat-conducting assembly 8 in the second direction Y. Since the expansion of the electrode assembly 5 mainly occurs at the first side surface 5231, the interference of the first heat-conducting part 81 with the expansion of the electrode assembly 5 can be reduced when the first heat-conducting part 81 is arranged at the second side surface 5232.

[0133] Optionally, the second heat-conducting part 83 can be connected to one first heat-conducting part 81, or the second heat-conducting part 83 can be connected to two or more first heat-conducting parts 81 arranged at intervals.

[0134] Optionally, the electrode body 52 includes a positive tab and a negative tab, and the positive tab and the negative tab are connected to different second heat-conducting parts 83, which helps to reduce the size of a single second heat-conducting part 83 and reduce the risk of interference between the second heat-conducting part 83 and other components of the battery cell 3. Alternatively, the positive tab and the negative tab are connected to the same second heat-conducting part 83, which helps to increase the connection area between the second heat-conducting part 83 and the first heat-conducting part 81 and improve the heat-conducting efficiency of the heat-conducting assembly 8.

[0135] Optionally, the second heat-conducting part 83 and the tab 51 can be connected by abutting, welding, bonding or other connection methods, or the second heat-conducting part 83 and the tab 51 can be connected by a heat-conducting medium.

[0136] Optionally, the first heat-conducting part 81 and the second heat-conducting part 83 are integrally formed to improve the heat-conducting efficiency of the heat-conducting assembly 8.

[0137] Optionally, the positive and negative tabs extend out of the first end surface 521 and the second end surface 522, respectively, and two second heat-conducting parts 83 are connected to the positive tab and the negative tab, respectively. The two second heat-conducting parts 83 can be connected to the same first heat-conducting part 81 to reduce the material cost of the heat-conducting assembly 8, or the two second heat-conducting parts 83 can be connected to two first heat-conducting parts 81 to improve the heat-conducting rate of the heat-conducting assembly 8.

[0138] Please refer to FIG. 9, which is an exploded view of a battery cell according to another embodiment of the present application.

[0139] In some embodiments, as shown in FIG. 9, the battery cell 3 further includes a switching mechanism 7 connected between the tab 51 and the top cover assembly 6, and the second heat-conducting part 83 is also in heat-conducting connection with the switching mechanism 7.

[0140] In the embodiments, the battery cell 3 further comprises a transition mechanism 7 connected between the tab 51 and the top cover assembly 6, and the second heat conduction part 83 is further in heat conduction connection with the transition mechanism 7, so that the heat conduction assembly 8 can improve the heat conduction rate at the transition mechanism 7, balance the temperature at the transition mechanism 7, and improve the problem of affecting the performance of the battery cell 3 due to the excessively high temperature at the transition mechanism 7.

[0141] The second heat conduction part 83 is in heat conduction connection with the transition mechanism 7, that is, the second heat conduction part 83 is directly connected with the transition mechanism 7, or the second heat conduction part 83 is indirectly connected with the transition mechanism 7 through a heat conduction medium, which can be air, metal or heat conduction glue, etc.

[0142] At least one of the tab 51 and the transition mechanism 7 is in heat conduction connection with the second heat conduction part 83.

[0143] The tab 51 is connected with the electrode terminal 61 through the transition mechanism 7, and the high temperature at the electrode terminal 61 can also be transmitted to the electrode body 52 through the tab 51, causing the temperature of the electrode body 52 to rise, and the battery cell 3 to reach the current limiting temperature too early, resulting in the performance of the battery cell 3 being reduced.

[0144] Therefore, the transition mechanism 7 is connected with the second heat conduction part 83, so that the heat at the transition mechanism 7 can be transmitted to the outside through the first heat conduction part 81 and the second heat conduction part 83, thereby improving the problem of the transition mechanism 7 heating the electrode body 52. Or in a low temperature environment, the temperature of the transition mechanism 7 can also be improved through the first heat conduction part 81 and the second heat conduction part 83.

[0145] Optionally, the tab 51 and the transition mechanism 7 are respectively connected with a second heat conduction part 83 to improve the heat conduction rate of the heat conduction assembly 8; or the tab 51 and the transition mechanism 7 are connected with the same second heat conduction part 83 to save the material cost of the heat conduction assembly 8.

[0146] Optionally, the connection mode between the second heat conduction part 83 and the transition mechanism 7 can be abutment, fusion or adhesion, or the second heat conduction part 83 and the transition mechanism 7 are connected through a heat transfer medium.

[0147] Optionally, the electrode terminal 61 and the tab 51 are respectively connected to the two side surfaces of the transition mechanism 7 in the first direction X, the connection area of the second heat conduction part 83 and the transition mechanism 7 is arranged separately from the connection area of the transition mechanism and the electrode terminal 61 and the tab 51, and the second heat conduction part 83 can be arranged on either side of the transition mechanism 7 in the first direction X, or the second heat conduction part 83 can be arranged on both side surfaces of the transition mechanism 7 in the first direction X.

[0148] Please refer to FIG. 10, which is a partial structure schematic diagram of a battery cell provided in an embodiment of the present application.

[0149] In some embodiments, as shown in FIGS. 6, 7 and 10, the tab 51 includes a folding section 511 connected to the electrode body 52 and an extension section 512 connected to one side of the folding section 511 and connected to the adapter mechanism 7 on the other side. The second heat-conducting part 83 is connected to one side of the extension section 512 facing the folding section 511, or the second heat-conducting part 83 is connected to one side of the extension section 512 facing the adapter mechanism 7.

[0150] In these embodiments, the second heat-conducting part 83 is connected to one side of the extension section 512 facing the folding section 511, or the second heat-conducting part 83 is connected to one side of the extension section 512 facing the adapter mechanism 7, so that the second heat-conducting part 83 is used to improve the heat conduction rate at the tab 51, and the problem of excessive temperature at the tab 51 to heat the tab, causing the electrode body 52 to heat up and the performance of the battery monomer 3 to decrease is improved.

[0151] For example, the folding section 511 extends along the first direction X, one end of the extension section 512 is connected to the folding section 511, and the other end extends along the second direction Y. The adapter mechanism 7 is connected to the extension section 512, and the extension section 512 is used to improve the connection area between the tab 51 and the adapter mechanism 7, and improve the connection reliability between the tab 51 and the adapter mechanism 7.

[0152] As shown in FIG. 10, the adapter mechanism 7 is connected to one side of the extension section 512 in the first direction X close to the top cover assembly 6, and the second heat-conducting part 83 is connected to one side of the extension section 512 in the first direction X away from the top cover assembly 6, so that the tab 51 and the second heat-conducting part 83 have sufficient contact area, the connection reliability between the second heat-conducting part 83 and the tab 51 is improved, and the tab 51 and the adapter mechanism 7 have sufficient contact area.

[0153] Alternatively, as shown in FIG. 7, the extension section 512 extends in the third direction Z, and the adapter mechanism 7 and the second heat-conducting part 83 are both connected to the side surface of the extension section 512 facing the top cover assembly 6. The adapter mechanism 7 and the second heat-conducting part 83 are arranged in the third direction Z, so as to reasonably match the positions of the second heat-conducting part 83, the tab 51 and the adapter mechanism 7, and reduce the connection difficulty between the second heat-conducting part 83 and the tab 51.

[0154] In some embodiments, as shown in FIGS. 6 and 10, the extension section 512 includes a first sub-section 5121, a second sub-section 5122 and a third sub-section 5123 connected between the first sub-section 5121 and the second sub-section 5122, which are arranged in the first direction X. The first sub-section 5121 is connected to the folding section 511, the second sub-section 5122 is connected to the adapter mechanism 7, and the second heat-conducting part 83 is connected to one side of the first sub-section 5121 facing the folding section 511.

[0155] In the embodiments, the extending section 512 comprises a first sub-section 5121, a second sub-section 5122 and a third sub-section 5123 connected between the first sub-section 5121 and the second sub-section 5122, the second sub-section 5122 is connected to the adapter 7, so as to increase the contact area between the adapter 7 and the tab 51, and the second heat-conducting part 83 is connected to the side of the first sub-section 5121 facing the folding section 511, so as to reduce the difficulty of connecting the second heat-conducting part 83 and the tab 51.

[0156] The extending section 512 is connected to the adapter 7 at one side, and the second heat-conducting part 83 is connected to the side of the extending section 512 facing the folding section 511, specifically, the adapter 7 is connected to the second sub-section 5122, and the second heat-conducting part 83 is connected to the first sub-section 5121.

[0157] For example, the tabs 51 of the pole pieces are gathered on the folding section 511, and then are bent along the second direction Y to form the first sub-section 5121, then are bent along the first direction X to form the third sub-section 5123, and then are extended along the second direction Y to form the second sub-section 5122.

[0158] Optionally, the area of the second sub-section 5122 is greater than that of the first sub-section 5121, the second heat-conducting part 83 is connected to the first sub-section 5121, and the adapter 7 is connected to another second heat-conducting part 83 and the second sub-section 5122, so as to increase the contact area between the tab 51 and the adapter 7, and improve the connection reliability between the tab 51 and the adapter 7 and between the tab and the second heat-conducting part 83.

[0159] In some embodiments, as shown in FIGS. 6 and 8, 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 along the second direction Y, and the two second side surfaces 5232 are oppositely arranged along 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 that of the second side surface 5232, the tab 51 is provided with two, the two tabs 51 extend from the first end surface 521 and are arranged along the third direction Z, the first heat-conducting part 81 and the second heat-conducting part 83 are respectively provided with two, the two first heat-conducting parts 81 are respectively arranged on the two second side surfaces 5232, the two second heat-conducting parts 83 are respectively connected to the ends of the two first heat-conducting parts 81 facing the tab 51, and the two second heat-conducting parts 83 are respectively connected to the extending sections 512 of the two tabs 51.

[0160] In the embodiments, the two tabs 51 extend from the first end face 521 and are spaced apart along the third direction Z, and the two first heat conduction parts 81 are arranged on the two second side faces 5232 respectively, so that the thickness of the battery monomer 3 is not increased due to the arrangement of the heat conduction assembly 8, and since the expansion of the electrode assembly 5 mainly occurs at the first side face 5231, when the first heat conduction part 81 is arranged at the second side face 5232, the interference of the first heat conduction part 81 to the expansion of the electrode assembly 5 can be reduced, the two second heat conduction parts 83 are connected to the ends of the two first heat conduction parts 81 respectively and connected to the extension sections 512 of the two tabs 51 respectively, each tab 51 is connected to a second heat conduction part 83, so that the heat at the electrode main body 52 and each tab 51 can be transmitted to the first heat conduction part 81 through the second heat conduction part 83, so as to improve the heat conduction rate at the tab 51, and improve the problem that the temperature at the tab 51 is too high to heat the tab, causing the electrode main body 52 to heat up and the performance of the battery monomer 3 to decrease.

[0161] Optionally, the number of the first heat conduction parts 81 is a plurality, and at least two first heat conduction parts 81 are spaced apart on the same second side face 5232, and the plurality of first heat conduction parts 81 arranged on the same second side face 5232 are connected to the same second heat conduction part 83. The first heat conduction parts 81 arranged at intervals can not only save the material cost of the heat conduction assembly 8, but also improve the problem that the first heat conduction part 81 causes the heat to be too concentrated in some areas of the second side face 5232 when transmitting the temperature of the tab 51, and can balance the temperature at the second side face 5232.

[0162] Optionally, the first heat conduction part 81 and the second heat conduction part 83 are integrally formed, and the first heat conduction part 81 and the second heat conduction part 83 are formed by once bending the base material, so as to reduce the processing difficulty of the first heat conduction part 81 and the second heat conduction part 83.

[0163] Please refer to FIG. 11, which is a partial structure diagram of a battery monomer according to an embodiment of the present application.

[0164] In some embodiments, as shown in FIGS. 6 and 11, the side face 523 includes two first side faces 5231 and two second side faces 5232, the two first side faces 5231 are arranged opposite to each other along the second direction Y, and the two second side faces 5232 are arranged opposite to each other along the third direction Z, the first direction X, the second direction Y and the third direction Z are perpendicular to each other, the area of the first side face 5231 is larger than that of the second side face 5232, the first heat conduction part 81 and the second heat conduction part 83 are provided with two respectively, the two first heat conduction parts 81 are arranged on the two first side faces 5231 respectively, each second heat conduction part 83 is connected to a first heat conduction part 81 respectively, and the two second heat conduction parts 83 are connected to different positions of the extension section 512 of the same tab 51 respectively.

[0165] In some embodiments, each second heat conduction part 83 is connected to a first heat conduction part 81, and two second heat conduction parts 83 are connected to different positions of the extension segment 512 of the same tab 51, so as to improve the heat conduction rate at the tab 51 and solve the problem of affecting the performance of the battery cell 3 due to the excessively high temperature at the tab 51.

[0166] Two second heat conduction parts 83 are connected to different positions of the extension segment 512 of the same tab 51, so that the two second heat conduction parts 83 conduct heat for the same tab 51, so as to better balance the temperature at the tab 51.

[0167] Two second heat conduction parts 83 are connected to different positions of the extension segment 512, and each second heat conduction part 83 can directly contact the extension segment 512. The two second heat conduction parts 83 can be arranged on both sides of the extension segment 512 in the first direction X, or the two second heat conduction parts 83 can be arranged on the same side of the extension segment 512 in the first direction X.

[0168] Optionally, the two second heat conduction parts 83 are connected to both sides of the extension segment 512 of the same tab 51 in the first direction X, which can make each second heat conduction part 83 have sufficient contact area with the extension segment 512 and reduce the connection difficulty of the second heat conduction part 83 and the extension segment 512.

[0169] Optionally, the two second heat conduction parts 83 arranged on both sides of the electrode body 52 in the second direction Y are arranged on one side surface of the extension segment 512 in the first direction X in the second direction Y, for example, the two second heat conduction parts 83 are arranged on the second sub-segment 5122 in the second direction Y.

[0170] Alternatively, the two second heat conduction parts 83 arranged on both sides of the electrode body 52 in the second direction Y are arranged on both sides of the extension segment 512 in the first direction X in the first direction X, for example, the two second heat conduction parts 83 are arranged on the second sub-segment 5122 in the first direction X.

[0171] Optionally, the battery cell 3 includes a plurality of electrode assemblies 5, and one first heat conduction part 81 is arranged between adjacent electrode assemblies 5.

[0172] In some embodiments, as shown in FIGS. 9 and 11, the extension segment 512 includes a first sub-segment 5121, a second sub-segment 5122, and a third sub-segment 5123 connecting the first sub-segment and the second sub-segment, which are arranged in the first direction X, the first sub-segment 5121 is connected to the folding segment 511, and the second sub-segment 5122 is connected to the switching mechanism 7; one of the two second heat conduction parts 83 is connected to the first sub-segment 5121, and the other is connected to the second sub-segment 5122.

[0173] In some embodiments, one of the two second heat-conducting portions 83 is connected to the first sub-portion 5121, and the other is connected to the second sub-portion 5122. The connection areas of the two second heat-conducting portions 83 and the tab 51 are reasonably distributed to improve the connection reliability of the second heat-conducting portions 83 and the tab 51.

[0174] Optionally, one of the second heat-conducting portions 83 is connected to the side surface of the first sub-portion 5121 away from the second sub-portion 5122, and the other is connected to the side surface of the second sub-portion 5122 facing the first sub-portion 5121, so as to reduce the connection difficulty of the tab 51 and the second heat-conducting portions 83.

[0175] Please refer to FIG. 12, which is a schematic diagram of the partial structure of the battery cell according to an embodiment of the present application.

[0176] In some embodiments, as shown in FIG. 9 and FIG. 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 larger than that of the second side surface 5232, the switching mechanism 7 includes a first connecting segment 71 and a second connecting segment 72 arranged in the third direction Z, the tab 51 is connected to the first connecting segment 71, and the second heat-conducting portion 83 is connected to the second connecting segment 72.

[0177] In some embodiments, the switching mechanism 7 includes the first connecting segment 71 and the second connecting segment 72, the tab 51 is connected to the first connecting segment 71, and the second heat-conducting portion 83 is connected to the second connecting segment 72. The second heat-conducting portion 83 is used to improve the heat-conducting rate at the switching mechanism 7 and solve the problem that the temperature at the switching mechanism 7 is too high to heat the electrode tab, which reduces the performance of the battery cell 3.

[0178] The second heat-conducting portion 83 is connected to the second connecting segment 72, or both the second heat-conducting portion 83 and the electrode terminal 61 are connected to the second connecting segment 72. Specifically, the second heat-conducting portion 83 is connected to the second connecting segment 72, and the electrode terminal 61 and the tab 51 are connected to the first connecting segment 71; or both the second heat-conducting portion 83 and the electrode terminal 62 are connected to the second connecting segment 72, the second heat-conducting portion 83 and the electrode terminal 62 are arranged on the two side surfaces of the second connecting segment 72 in the first direction X, or the second heat-conducting portion 83 and the electrode terminal 62 are arranged on one side surface of the second connecting segment 72 in the first direction X.

[0179] Optionally, the specific size and shape of the first connecting segment 71 and the second connecting segment 72 can be designed as needed.

[0180] Optionally, two second connecting segments 72 are arranged on two sides of the first connecting segment 71, and two second heat conduction parts 83 are connected with the two second connecting segments 72 respectively to increase the contact area of the second heat conduction part 83 and the adapter mechanism 7.

[0181] Optionally, a pressure relief valve is arranged on the top cover assembly 6, so that when the pressure inside the shell 4 reaches a threshold value, the pressure is discharged to the outside through the pressure relief valve. The shape and size of the adapter mechanism 7 can be designed as needed, and the adapter mechanism 7 is arranged away from the pressure relief valve to avoid blocking the pressure relief valve.

[0182] Optionally, a single second connecting segment 72 can be connected with two or more second heat conduction parts 83, or the adapter mechanism 7 includes multiple second connecting segments 72 to connect multiple second heat conduction parts 83 to enhance the heat conduction efficiency of the heat conduction assembly 8.

[0183] In some embodiments, as shown in FIGS. 9 and 12, two first heat conduction parts 81 and two second heat conduction parts 83 are arranged respectively, two first heat conduction parts 81 are arranged on two first side surfaces 5231 respectively, each second heat conduction part 83 is connected with a first heat conduction part 81, and two second heat conduction parts 83 are connected with different positions of the second connecting segment 72 of the same adapter mechanism 7.

[0184] In these embodiments, two first heat conduction parts 81 are arranged on two first side surfaces 5231 respectively, each second heat conduction part 83 is connected with a first heat conduction part 81, and two second heat conduction parts 83 are connected with different positions of the second connecting segment 72 of the same adapter mechanism 7 to better improve the heat conduction rate at the adapter mechanism 7 and improve the problem of affecting the performance of the battery monomer 3 due to the excessive temperature at the adapter mechanism 7.

[0185] Two second heat conduction parts 83 are connected with different positions of the same second connecting segment 72, and each second heat conduction part 83 can directly contact with the second connecting segment 72. The two second heat conduction parts 83 can be arranged on two sides of the second connecting segment 72 in the first direction X, or the two second heat conduction parts 83 can be arranged on the same side of the second connecting segment 72 in the first direction X; or the two second heat conduction parts 83 can be arranged on two ends of the second connecting segment 72 in the second direction Y; or the two second heat conduction parts 83 can be arranged on one end of the second connecting segment 72 in the second direction Y.

[0186] Optionally, two second heat conduction parts 83 are connected with two sides of the second connecting segment 72 of the same adapter mechanism 7 in the second direction Y, which can reduce the size of the second heat conduction part 83, reduce the material cost of the second heat conduction part 83, and reduce the connection difficulty of the second heat conduction part 83 and the adapter mechanism 7.

[0187] Optionally, two second connecting sections 72 are arranged on two sides of the first connecting section 71 in the second direction Y, and the two second connecting sections 72 are of the same size and are arranged on two sides of the second heat conduction part 83 of the electrode body 52 in the second direction Y, and are connected to the two second connecting sections 72, respectively.

[0188] Optionally, the positive electrode tab of the electrode body 52 and the second heat conduction part 83 are connected to the same switching mechanism 7, or the negative electrode tab of the electrode body 52 and the second heat conduction part 83 are connected to the same switching mechanism.

[0189] Optionally, the number of the electrode assemblies 5 is multiple, one of the two second heat conduction parts 83 arranged on two sides of the electrode body 52 in the second direction Y is arranged between adjacent electrode assemblies 5.

[0190] Please refer to FIG. 13, FIG. 14 and FIG. 15, FIG. 13 is a partial structure schematic diagram of a battery monomer provided by an embodiment of the application; FIG. 14 is an enlarged structure schematic diagram of B in FIG. 13; and FIG. 15 is a partial structure schematic diagram of a battery monomer provided by an embodiment of the application.

[0191] In some embodiments, as shown in FIG. 6 and FIG. 13 to FIG. 15, the electrode assembly 5 is provided with two, the two electrode assemblies 5 are arranged in a stack along the second direction Y, the switching mechanism 7 is provided with two first connecting sections 71, the two first connecting sections 71 are arranged on two sides of the second connecting section 72 in the second direction Y, the electrode tab 51 of the two electrode assemblies 5 is connected to the two first connecting sections 71, respectively, the first heat conduction part 81 and the second heat conduction part 83 are provided with two, respectively, the two first heat conduction parts 81 are arranged on two first sides 5231 of the same electrode body 52, respectively, one end of the two second heat conduction parts 83 connected to the two first heat conduction parts 81 is connected to the two second connecting sections 72 of the switching mechanism 7, respectively, and the two second heat conduction parts 83 are connected to the two second connecting sections 72 of the switching mechanism 7, respectively.

[0192] In these embodiments, the two first heat conduction parts 81 are arranged on two sides of the electrode body 52 in the second direction Y, one end of the two second heat conduction parts 83 connected to the two first heat conduction parts 81 is connected to the two second connecting sections 72 of the switching mechanism 7, respectively, and the two second heat conduction parts 83 are connected to the two second connecting sections 72 of the switching mechanism 7, respectively, so as to reduce the connection difficulty of the second heat conduction part 83 and the electrode tab 51 and the switching mechanism 7; and the two second heat conduction parts 83 are connected to the electrode tab 51 and the switching mechanism 7, respectively, so as to better stabilize the temperature at the electrode tab 51.

[0193] In FIG. 13, in order to facilitate the observation of the connection relationship between the second heat conduction part 83, the electrode tab 51 and the switching mechanism 7, one electrode body 52 is hidden.

[0194] The adapter 7 is provided with two first connecting segments 71, so that the adapter 7 can connect the tabs of two electrode assemblies 5 at the same time, reducing the overall size of the adapter 7 in the battery monomer 3 and improving the energy density of the battery monomer 3.

[0195] The second connecting segment 72 is located between the two first connecting segments 71, so that the second connecting segment 72 is located between the two electrode assemblies 5, and one or more second heat-conducting parts 83 are connected to the second connecting segment 72 to conduct heat at the adapter 7.

[0196] The one or more second heat-conducting parts 83 are located between the shell 4 and the tab 51 along the second direction Y, and the second heat-conducting part 83 is connected to the tab 51 to conduct heat at the tab 51, so as to balance the temperature at the tab 51 and improve the problem of reverse heating of the electrode body 52 by the tab 51. For example, the second heat-conducting part 83 is connected to the first subsegment 5121 of the tab 51.

[0197] Optionally, as shown in FIG. 15, the heat-conducting assembly 8 includes three first heat-conducting parts 81 and three second heat-conducting parts 83 arranged at intervals, two first heat-conducting parts 81 are arranged between the two first sides 5231 of the electrode assembly 5 and the shell 4, and the two first heat-conducting parts 81 are connected to the tab 51 through the two second heat-conducting parts 83; one first heat-conducting part 81 is connected to the second connecting segment 72 through one second heat-conducting part 83, so as to enhance the heat-conducting rate of the heat-conducting assembly 8.

[0198] Please refer to FIG. 16, FIG. 17 and FIG. 18, FIG. 16 is a partial structural schematic diagram of a battery monomer provided by an embodiment of the present application; FIG. 17 is a partial structural schematic diagram of a battery monomer provided by an embodiment of the present application; and FIG. 18 is a partial structural schematic diagram of a battery monomer provided by an embodiment of the present application.

[0199] In some embodiments, as shown in FIG. 6, FIG. 16 to FIG. 18, the heat-conducting assembly 8 further includes a third heat-conducting part 82 arranged between the shell 4 and at least part of the second end surface 522 along the first direction X, and the third heat-conducting part 82 is connected to the first heat-conducting part 81.

[0200] In these embodiments, the heat-conducting assembly 8 further includes a third heat-conducting part 82 arranged between the shell 4 and at least part of the second end surface 522 along the first direction X, and the third heat-conducting part 82 is connected to the first heat-conducting part 81, so as to increase the contact area between the heat-conducting assembly 8 and the shell 4, improve the heat-conducting rate of the heat-conducting assembly 8 to the heat at the tab 51, and improve the problem of affecting the performance of the battery monomer 3 due to the excessively high temperature at the tab 51.

[0201] The third heat conduction part 82 is connected with the first heat conduction part 81. Specifically, the heat conduction assembly 8 comprises an insulating part (not shown in the figure) and a heat conduction part (not shown in the figure). The insulating part forms a containing cavity in at least a partial region, and the heat conduction part is arranged in the containing cavity. Then, the heat conduction part in the first heat conduction part 81 is connected with the heat conduction part in the third heat conduction part 82. For example, the heat conduction part in the first heat conduction part 81 and the heat conduction part in the third heat conduction part 82 are integrally formed or are bonded with each other or are abutted with each other. Alternatively, the heat conduction part in the first heat conduction part 81 and the heat conduction part in the third heat conduction part 82 are arranged in a spaced manner, and the insulating part of the first heat conduction part 81 and the insulating part of the third heat conduction part 82 are connected with each other.

[0202] The heat at the tab 51 can be transferred to the third heat conduction part 82 through the second heat conduction part 83 and the first heat conduction part 81, and then is transferred to the external environment at the third heat conduction part 82. The first heat conduction part and the third heat conduction part 82 connected with each other increase the heat exchange area of the heat conduction assembly 8 and improve the heat conduction rate of the heat conduction assembly 8.

[0203] Optionally, the heat exchange mechanism is arranged at one end of the battery monomer 3 without the tab 51 in the first direction X, and the third heat conduction part 82 can transfer heat between the heat exchange mechanism and the tab 51.

[0204] Optionally, the third heat conduction part 82 covers the entire second end surface 522 of the electrode assembly 5, so as to improve the heat conduction rate of the third heat conduction part 82.

[0205] Optionally, the shape and size of the third heat conduction part 82 can be flexibly designed. For example, the third heat conduction part 82 is in a rectangular or circular shape.

[0206] Optionally, the first heat conduction part 81, the third heat conduction part 82 and the second heat conduction part 83 are integrally formed, so as to improve the heat conduction rate of the heat conduction assembly 8. For example, as shown in FIG. 17, the first heat conduction part 81 is arranged on the first side surface 5231. The first heat conduction part 81 is arranged in a spaced manner with at least two second heat conduction parts 83 at one end in the first direction X. The first heat conduction part 81 is connected with the third heat conduction part 82 at the other end in the first direction X. In this way, the heat conduction efficiency of the heat conduction assembly 8 is improved, and the processing difficulty of the heat conduction assembly 8 is reduced.

[0207] Optionally, as shown in FIG. 16 and FIG. 18, the two first heat conduction parts 81 are arranged in a spaced manner. The two first heat conduction parts 81 are connected with the second heat conduction part 83 at one end in the first direction X. The two first heat conduction parts 81 are connected through the third heat conduction part 82 at the other end in the first direction X, so that the third heat conduction part 82 can balance the heat of the two first heat conduction parts 81.

[0208] Please refer to FIG. 19, which is an exploded view of a battery monomer according to another embodiment of the present application.

[0209] In some embodiments, as shown in FIG. 19, the tab 51 protrudes from the first end face 521, and the battery cell 3 further comprises a first insulating film 91 covering the side face 523 and the second end face 522 of the electrode body 52; wherein the first heat-conducting part 81 is located between the first insulating film 91 and the electrode assembly 5, or the first heat-conducting part 81 is located between the first insulating film 91 and the shell 4.

[0210] In these embodiments, the first insulating film 91 covers the side face 523 and the second end face of the electrode body 52 to insulate the shell 4 and the electrode assembly 5, the first heat-conducting part 81 is located between the first insulating film 91 and the electrode assembly 5, the first insulating film 91 serves to support and protect the first heat-conducting part 81, reducing the problem of breakage of the first heat-conducting part 81 under external force impact, or the first heat-conducting part 81 is located between the first insulating film 91 and the shell 4 to improve the insulation reliability between the first heat-conducting part 81 and the electrode assembly 5, and improve the heat conduction efficiency between the first heat-conducting part 81 and the shell 4.

[0211] For example, the material of the first insulating film 91 can be PP or PI (Polyimide) or PET (Polyethylene terephthalate), etc.

[0212] The first heat-conducting part 81 is located between the first insulating film 91 and the electrode assembly 5, which helps to reduce the distance between the first heat-conducting part 81 and the electrode assembly 5, and improve the heat conduction rate between the electrode assembly 5 and the first heat-conducting part 81.

[0213] Optionally, the first insulating film 91 is formed with a groove, and the first heat-conducting part 81 is accommodated in the groove to reduce the overall thickness of the first insulating film 91 and the first heat-conducting part 81.

[0214] The first heat-conducting part 81 is located between the first insulating film 91 and the shell 4, and at least one of the first insulating film 91 and the shell 4 is bonded to the first heat-conducting part 81 to keep the first heat-conducting part 81 stable in the shell 4.

[0215] Please refer to FIG. 20, which is a structural schematic diagram of a heat-conducting assembly of a battery cell according to an embodiment of the present application.

[0216] In some embodiments, as shown in FIG. 6 and FIG. 20, the heat-conducting assembly 8 comprises an insulating piece 85 and a heat-conducting piece 84, the insulating piece 85 at least partially forms an accommodating cavity 851, and the heat-conducting piece 84 is arranged in the accommodating cavity 851; the heat-conducting piece 84 comprises a first heat-conducting sheet 841 and a second heat-conducting sheet 842, the first heat-conducting part 81 is composed of the first heat-conducting sheet 841 and the insulating piece 85, the second heat-conducting part 83 is composed of the second heat-conducting sheet 842 and the insulating piece 85, and the first heat-conducting sheet 841 and the second heat-conducting sheet 842 are connected.

[0217] In the embodiments, the heat-conducting assembly 8 comprises an insulating piece 85 and a heat-conducting piece 84, the insulating piece 85 at least partially forms a containing cavity 851, the heat-conducting piece 84 is arranged in the containing cavity 851, the heat-conducting ability of the heat-conducting assembly 8 is improved by the heat-conducting piece 84, the heat-conducting piece 84 comprises a first heat-conducting sheet 841 and a second heat-conducting sheet 842, the first heat-conducting sheet 841 and the insulating piece 85 form the first heat-conducting part 81, the second heat-conducting sheet 842 and the insulating piece 85 form the second heat-conducting part 83, the first heat-conducting sheet 841 and the second heat-conducting sheet 842 are connected, so that when the first heat-conducting sheet 841 and the second heat-conducting sheet 842 combine to conduct heat, the first heat-conducting sheet 841 and the second heat-conducting sheet 842 are insulated by the insulating piece 85 and the electrode assembly 5, and the insulating piece 85 can isolate the heat-conducting piece 84 and the electrolyte, so as to improve the problem that the heat-conducting piece 84 and the electrolyte are incompatible and affect the performance of the battery monomer 3.

[0218] For example, the insulating piece 85 can be PP or PI or PET or the like. The material of the heat-conducting piece 84 includes graphite or graphene or carbon nanotube or the like. The heat conductivity of the heat-conducting piece 84 is greater than that of the shell 4.

[0219] Optionally, the heat-conducting piece 84 can be in the form of a plate or a strip or a mesh or the like. For example, the containing cavity 851 is provided with a plate-shaped heat-conducting piece or a mesh-shaped heat-conducting piece or one or more spaced strip-shaped heat-conducting pieces.

[0220] Optionally, the insulating piece 85 is provided with the containing cavity 851 with an open end 41, the heat-conducting piece 84 is arranged in the containing cavity 851 and is bonded or fused to the open end of the insulating piece 85, so that the heat-conducting piece 84 is located in a sealed containing cavity 851; or the insulating piece 85 is folded at both ends, the heat-conducting piece 84 is located between the two ends of the insulating piece 85, and the two ends of the insulating piece 85 are bonded or fused together, so that the heat-conducting piece 84 is located in a sealed containing cavity 851; or the insulating piece 85 comprises two relatively arranged independent sub-insulating layers, the edges of the two sub-insulating layers are bonded or fused, so that the heat-conducting piece 84 is located in a sealed containing cavity 851.

[0221] Optionally, the side surface of the insulating piece 85 towards the electrode body 52 is provided with a bonding layer, so as to bond and connect the heat-conducting assembly 8 and the electrode body 52. For example, the bonding layer can be an insulating adhesive, so as to enhance the insulation performance of the heat-conducting assembly 8 and the electrode assembly 5.

[0222] At least part of the insulating piece 85 extends to the side surface 523, the first heat-conducting sheet 841 is arranged on the side surface 523 and is in heat-conducting connection with the electrode assembly 5, and the first heat-conducting part 81 is composed of the first heat-conducting sheet 841 and the insulating piece 85. For example, the first heat-conducting sheet 841 covers the entire side surface 523, so as to improve the heat-conducting rate of the first heat-conducting part 81.

[0223] In some embodiments, as shown in FIG. 6 and FIG. 20, the heat-conducting member 84 includes graphite or graphene or carbon nanotubes.

[0224] Graphite is generally composed of parallel arranged layered carbon atoms, showing a planar sheet shape. Graphene is generally a two-dimensional crystal composed of carbon atoms with only one side atomic thickness, belonging to the shape of fibers. Carbon nanotubes are generally tubular structures formed by curling one or more graphite layers.

[0225] In these embodiments, the material of the heat-conducting member 84 includes graphite or graphene or carbon nanotubes, and the heat-conducting performance of the heat-conducting member 84 is improved by the graphite or graphene or carbon nanotube heat-conducting material.

[0226] Optionally, the heat-conducting member 84 is supercrystalline graphite, which has a larger grain size than ordinary graphite and a significantly improved thermal conductivity compared to ordinary graphite, so as to have better heat-conducting capacity.

[0227] Optionally, the heat-conducting member 84 adopts graphite heat-conducting technology, which is a heat-conducting technology based on graphite material and microporous structure. The principle is to quickly transfer heat to the heat-conducting sheet through the high-efficiency heat-conducting performance of graphite material, and then quickly dissipate heat to the external environment through the microporous structure, so as to achieve the effect of heat exchange.

[0228] In some embodiments, as shown in FIG. 6 and FIG. 20, the thermal conductivity k of the heat-conducting member 84 satisfies k≥500 W / (m·K).

[0229] In these embodiments, the thermal conductivity k of the heat-conducting member 84 satisfies the above condition, so as to have sufficient heat-conducting performance to conduct the heat of the electrode body 52.

[0230] Optionally, the thermal conductivity k of the heat-conducting member 84 satisfies 500 W / (m·K)≤k≤1600 W / (m·K), and exemplarily, the thermal conductivity of the heat-conducting member 84 is 500 W / (m·K) or 550 W / (m·K) or 1050 W / (m·K) or 1550 W / (m·K) or 1600 W / (m·K), etc.

[0231] Optionally, the thermal conductivity k of the heat-conducting member 84 satisfies k≥1000 W / (m·K).

[0232] Optionally, the density of the heat-conducting member 84 is 2.1±0.05 g / cm3, the insulation resistance is greater than 1 GΩ, the withstand voltage strength is 5400 V, and the bending resistance is greater than 10000 times.

[0233] 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.

[0234] In a third aspect, the embodiments of the present application provide a power utilization device comprising the battery device of the second aspect.

[0235] In some embodiments, as shown in FIGS. 1-20, the battery cell 3 comprises a housing 4, an electrode assembly 5 and a heat-conducting assembly 8, the electrode assembly 5 is located in the housing 4, the electrode assembly 5 is of a jelly-roll type or a stacked type, the electrode assembly 5 comprises an electrode body 52 and a tab 51, the electrode body 52 comprises a first end face 521 and a second end face 522 oppositely arranged in a first direction X, and a side face 523 connected between the first end face 521 and the second end face 522, the side face 523 comprises two first side faces 5231 oppositely arranged in a second direction Y and two second side faces 5232 oppositely arranged in a third direction Z, the first direction X, the second direction Y and the third direction Z are perpendicular to each other in pairs, the area of the first side face 5231 is greater than that of the second side face 5232, the tab 51 is connected to the electrode body 52 and extends out of the first end face 521; the heat-conducting assembly 8 comprises a first heat-conducting part 81, a second heat-conducting part 83 and a third heat-conducting part 82, the heat-conducting assembly 8 comprises an insulating piece 85 and a heat-conducting piece 84, the insulating piece 85 at least partially forms an accommodating cavity 851, the heat-conducting piece 84 is arranged in the accommodating cavity 851, the heat-conducting piece 84 comprises a first heat-conducting sheet 841 and a second heat-conducting sheet 842, the first heat-conducting part 81 is composed of the first heat-conducting sheet 841 and the insulating piece 85, the second heat-conducting part 83 is composed of the second heat-conducting sheet 842 and the insulating piece 85, the first heat-conducting sheet 841 and the second heat-conducting sheet 842 are connected, the first heat-conducting part 81 is in thermal conduction with the first side face 5231, the thermal conductivity of the heat-conducting assembly 8 is greater than that of the housing 4, the third heat-conducting part 82 is arranged between the housing 4 and at least part of the second end face 522 along the first direction X, and the third heat-conducting part 82 is connected with the first heat-conducting part 81.

[0236] The shell 4 comprises an opening 41 in the first direction X, the battery cell 3 further comprises a top cover assembly 6 and an adapter mechanism 7, the top cover assembly 6 covers the opening 41, the top cover assembly 6 has an electrode terminal 61, the adapter mechanism 7 is connected between the tab 51 and the top cover assembly 6, at least one of the tab 51 and the adapter mechanism 7 is connected with the second heat conduction part 83, the second heat conduction part 83 is connected with the first heat conduction part 81, the electrode assembly 5 is provided with two, the two electrode assemblies 5 are stacked in the second direction Y, the adapter mechanism 7 is provided with two first connecting segments 71, the two first connecting segments 71 are respectively arranged on both sides of the second connecting segment 72 in the second direction Y, the tabs 51 of the two electrode assemblies 5 are respectively connected with the two first connecting segments 71, the first heat conduction part 81 and the second heat conduction part 83 are respectively provided with two, the two first heat conduction parts 81 are respectively arranged on both sides of the electrode body 52 in the second direction Y, the two second heat conduction parts 83 are respectively connected with one end of the two first heat conduction parts 81 towards the adapter mechanism 7, and the two second heat conduction parts 83 are respectively connected with the two second connecting segments 72 of the adapter mechanism 7, the extension segment 512 comprises a first sub-segment 5121, a second sub-segment 5122 and a third sub-segment 5123 connected between the first sub-segment 5121 and the second sub-segment 5122, the first sub-segment 5121 is connected with the folding segment 511, the second sub-segment 5122 is connected with the adapter mechanism 7, the second heat conduction part 83 is connected with one side of the first sub-segment 5121 towards the folding segment 511, the heat conduction piece 84 comprises graphite or graphene or carbon nanotubes, the thermal conductivity k of the heat conduction piece 84 satisfies k>500 W / (m·K).

[0237] In the embodiments, the battery cell 3 comprises a shell 4, an electrode assembly 5 and a heat-conducting assembly 8, the electrode assembly 5 is located inside the shell 4, the shell 4 provides accommodation and protection for the electrode assembly 5, the electrode assembly 5 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 heat-conducting assembly 8 has a heat conductivity greater than that of the shell 4, the heat-conducting assembly 8 comprises a first heat-conducting part 81, the first heat-conducting part 81 is heat-conductively connected to the side face 523 of the electrode body 52, so as to reduce the thermal resistance of the electrode body 52 at the side face 523 thereof, improve the temperature uniformity of the electrode body 52 at the side face 523 thereof, and improve the heat exchange rate between the electrode body 52 at the side face 523 thereof and the external environment, so as to balance the temperature inside the battery cell 3, and improve the performance and service life of the battery cell 3 which are adversely affected by excessively high or low temperature inside the battery cell 3, the top cover assembly 6 covers the opening 41 of the shell 4, the tab 51 and the electrode terminal 61 of the top cover assembly 6 are connected to realize electrical connection, the heat-conducting assembly 8 further comprises a second heat-conducting part 83 heat-conductively connected to the tab 51, and the second heat-conducting part 83 is heat-conductively connected to the first heat-conducting part 81, so that the heat-conducting assembly 8 can improve the heat-conducting rate at the tab 51, so as to balance the temperature at the tab 51, and improve the performance of the battery cell 3 which is affected by excessively high temperature at the tab 51.

[0238] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should be covered in the scope of the claims and the specification of the present application. In particular, as long as there is no structural conflict, each technical feature mentioned in each embodiment can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, comprising: a housing; an electrode assembly located in the housing, the electrode assembly comprising an electrode body and a tab, the electrode body comprising a first end face and a second end face oppositely arranged in a first direction, and a side face connected between the first end face and the second end face, the tab being connected to the electrode body and protruding from at least one of the first end face and the second end face; a heat conduction assembly comprising a first heat conduction part, the first heat conduction part being in thermal conduction with the side face, the heat conduction assembly having a thermal conductivity greater than that of the housing, the heat conduction assembly and the electrode assembly being insulated from each other, wherein the housing comprises an opening in the first direction, the battery cell further comprising a top cover assembly covering the opening, the top cover assembly having an electrode terminal connected to the tab, the heat conduction assembly further comprising a second heat conduction part, the second heat conduction part being in thermal conduction with the tab, the second heat conduction part being in thermal conduction with the first heat conduction part.

2. The battery cell of claim 1, wherein, The battery cell further comprises an adapter connected between the tab and the electrode terminal, the second heat conduction part being further in thermal conduction with the adapter.

3. The battery cell of claim 2, wherein, The tab comprises a folding section connected to the electrode body and an extension section connected to the folding section on one side and to the adapter on the other side, the second heat conduction part being connected to the extension section on a side facing the folding section or the second heat conduction part being connected to the extension section on a side facing the adapter.

4. The battery cell of claim 3, wherein, The extension section comprises a first sub-section, a second sub-section and a third sub-section connecting the first sub-section and the second sub-section, the first sub-section being connected to the folding section, the second sub-section being connected to the adapter, the second heat conduction part being connected to the first sub-section on a side facing the folding section.

5. The battery cell of claim 3, wherein, The side face comprises two first side faces oppositely arranged in a second direction and two second side faces oppositely arranged in a third direction, the first direction, the second direction and the third direction intersecting with each other, the first side face having a larger area than the second side face, the tab being provided with two tabs, the two tabs protruding from the first end face and being spaced apart in the third direction, the first heat conduction part and the second heat conduction part being provided with two, respectively, the two first heat conduction parts being provided on the two second side faces, respectively, the two second heat conduction parts being connected to the two first heat conduction parts on an end facing the tab, respectively, and the two second heat conduction parts being connected to the extension sections of the two tabs, respectively.

6. The battery cell of claim 3, wherein, The side face comprises two first side faces oppositely arranged in a second direction and two second side faces oppositely arranged in a third direction, the first direction, the second direction and the third direction intersecting with each other, the first side face having a larger area than the second side face, The first heat-conducting part and the second heat-conducting part are respectively provided with two, two first heat-conducting parts are respectively arranged on two first side surfaces, and each second heat-conducting part is respectively connected to a first heat-conducting part, and two second heat-conducting parts are respectively connected to different positions of the extension section of the same tab.

7. The battery cell of claim 6, wherein, The extension section includes a first sub-section, a second sub-section, and a third sub-section connecting the first sub-section and the second sub-section, which are arranged at intervals along the first direction, the first sub-section is connected to the folding section, and the second sub-section is connected to the switching mechanism. One of the two second heat-conducting parts is connected to the first sub-section, and the other is connected to the second sub-section.

8. The battery cell of claim 2, wherein, The side surface includes two first side surfaces and two second side surfaces, the two first side surfaces are arranged opposite to each other in a second direction, the two second side surfaces are arranged opposite to each other in a third direction, the first direction, the second direction, and the third direction intersect with each other, and the area of the first side surface is greater than that of the second side surface. The switching mechanism includes a first connecting section and a second connecting section arranged along the third direction, the tab is connected to the first connecting section, and the second heat-conducting part is connected to the second connecting section.

9. The battery cell of claim 8, wherein, The first heat-conducting part and the second heat-conducting part are respectively provided with two, two first heat-conducting parts are respectively arranged on two first side surfaces, and each second heat-conducting part is respectively connected to a first heat-conducting part, and two second heat-conducting parts are respectively connected to different positions of the extension section of the same tab.

10. The battery cell of claim 8, wherein, The electrode assembly is provided with two, two electrode assemblies are arranged in layers along the second direction, the switching mechanism is provided with two first connecting sections, two first connecting sections are arranged on both sides of the second connecting section in the second direction, and the tabs of two electrode assemblies are respectively connected to two first connecting sections. The first heat-conducting part and the second heat-conducting part are respectively provided with two, two first heat-conducting parts are arranged on two first side surfaces of the same electrode body, two second heat-conducting parts are respectively connected to one end of two first heat-conducting parts towards the switching mechanism, and two second heat-conducting parts are respectively connected to the second connecting section of the switching mechanism and the tab.

11. The battery cell of any one of claims 1 to 10, wherein, The tab extends from the first end surface, the heat-conducting assembly further includes a third heat-conducting part, the third heat-conducting part is arranged between the shell and at least part of the second end surface along the first direction, and the third heat-conducting part is connected to the first heat-conducting part.

12. The battery cell of any one of claims 1 to 11, wherein, The tab extends from the first end surface, the battery monomer further includes a first insulating film, the first insulating film covers the side surface and the second end surface of the electrode body; wherein the first heat-conducting part is located between the first insulating film and the electrode assembly, or the first heat-conducting part is located between the first insulating film and the shell.

13. The battery cell of any one of claims 1 to 12, wherein, The heat-conducting assembly includes an insulating part and a heat-conducting part, the insulating part at least partially forms a receiving cavity, and the heat-conducting part is arranged in the receiving cavity. The heat-conducting member comprises a first heat-conducting sheet and a second heat-conducting sheet, the first heat-conducting part is composed of the first heat-conducting sheet and the insulating member, the second heat-conducting part is composed of the second heat-conducting sheet and the insulating member, and the first heat-conducting sheet and the second heat-conducting sheet are connected.

14. The battery cell of claim 13, wherein, The heat-conducting member comprises graphite or graphene or carbon nanotubes.

15. The battery cell of claim 13, wherein, The heat-conducting rate k of the heat-conducting member satisfies k≥500 W / (m·K).

16. A battery device comprising the battery cell according to any one of claims 1-15.

17. An electric device comprising the battery device according to claim 16.

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