Battery monomer, battery and electric device

Abstract

The utility model belongs to the technical field of batteries, and provides a battery monomer, a battery and a power utilization device, the battery monomer comprises an electrode assembly, a pole and a first heat conduction piece; the electrode assembly comprises a tab, the tab is provided with a first surface and a second surface, and the pole is electrically connected with the tab; the first surface is in a sheet shape and is attached to at least one of the first surface and the second surface; or the battery monomer comprises an electrode assembly, a pole, an adapter plate and a second heat conduction piece; the electrode assembly comprises a tab; the switching piece is electrically connected between the pole lug and the pole column, and the switching piece is provided with a first switching surface and a second switching surface; the second heat conduction piece is in a sheet shape and is connected to at least one of the first surface and the second surface, or the second heat conduction piece is connected to at least one of the first adapter surface and the second adapter surface; the first heat conduction piece and the second heat conduction piece respectively comprise a graphite sheet layer or a plurality of stacked graphite sheet layers. The utility model aims to solve the technical problem that the thermal resistance of a low-thermal-resistance channel of a battery cannot be effectively reduced.

Description

Technical Field

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

[0002] Batteries are widely used in various fields of production and life. The electrode assembly in the battery is electrically connected to the pole through the tab. In order to improve the energy density of the electrode assembly, the tab is very thin. Therefore, a lot of heat will be generated on the tab. This heat needs to be transferred or diffused in time. If the heat is not diffused or transferred in time, the thermal resistance of the low thermal resistance channel of the electrode assembly cannot be reduced, and the temperature of the electrode assembly is too high, thereby affecting the service life of the electrode assembly. Utility Model Content

[0003] The purpose of the present application is to provide a battery cell, a battery and an electrical device, aiming to solve the technical problem that the thermal resistance of the low thermal resistance channel of the battery cannot be effectively reduced.

[0004] In a first aspect, the present application provides a battery cell, comprising:

[0005] An electrode assembly includes a tab having a first surface and a second surface;

[0006] A pole, electrically connected to the pole lug;

[0007] The first heat-conducting member is in sheet form and adheres to at least one of the first surface and the second surface. The first heat-conducting member includes a single graphite sheet or multiple stacked graphite sheets.

[0008] In this example, a first heat-conducting member is added to the battery cell. The first heat-conducting member has a high thermal conductivity and can quickly transfer and diffuse heat. The first heat-conducting member is connected to the pole ear. The first heat-conducting member forms a preset contact area with the surface of the pole ear, so that the first heat-conducting member can form a heat-conducting path on the pole ear, thereby increasing the heat-conducting channel and enhancing the heat conduction effect, which is beneficial to reducing the resistance of the heat inside the electrode assembly to be transferred to the external environment, that is, reducing the thermal resistance of the low thermal resistance channel of the electrode assembly. The first heat-conducting member reduces the heat inside the electrode assembly by heat transfer. In addition, the first heat-conducting member has a high thermal conductivity and can absorb the heat on the pole ear and diffuse the heat to the outside. The first heat-conducting member reduces the heat inside the electrode assembly by heat dissipation, so that the thermal resistance of the low thermal resistance channel of the battery is effectively reduced, thereby improving the service life of the battery. The graphite sheet structure can increase the thermal conductivity and heat dissipation performance of the first heat-conducting member, and to a certain extent ensure the thermal conductivity and heat dissipation efficiency of the electrode assembly and the pole ear.

[0009] In one embodiment, when the first heat-conducting member includes a plurality of stacked graphite sheets, a bonding layer is disposed between at least some of the adjacent graphite sheets.

[0010] In this example, the adhesive layer is coated on two oppositely disposed surfaces of two adjacent graphite sheets, thereby bonding and fixing the two graphite sheets together, so that the multiple layers of graphite sheets form a sheet-like whole, thereby forming a first sheet-like heat conductor, so that the first heat conductor has higher thermal conductivity and heat dissipation performance and the overall structure is more solid and reliable.

[0011] In one embodiment, the first heat conducting member is insulated from the tab.

[0012] In this example, the first heat conductor and the pole lug are insulated. It can be seen that current does not flow through the first heat conductor, and the first heat conductor does not play a role in conducting current. The first heat conductor only plays the role of heat conduction and heat dissipation on the surface of the pole lug. Insulating the first heat conductor and the pole lug can reduce the risk of leakage on the first heat conductor and between the first heat conductor and the pole lug, thereby improving the reliability of the battery charging and discharging process.

[0013] In one embodiment, the first heat conductive member further includes a first insulating layer; when the first heat conductive member includes a layer of graphite sheet, the first insulating layer is coated on the outer surface of the graphite sheet; when the first heat conductive member includes multiple layers of graphite sheet, the first insulating layer is coated on the outer surface of the multiple layers of graphite sheet.

[0014] In this example, by insulating the outer surface of the first heat conductor, a first insulating layer is formed on the outer surface of the entire first heat conductor, thereby achieving the effect of insulating the first heat conductor from the pole ear; the storage and use of the first heat conductor are more convenient, the first heat conductor and the pole ear can be quickly connected, and the convenience and reliability of installation are improved.

[0015] In one of the embodiments, a first edge seal is formed on an edge of the first insulating layer avoiding the graphite sheet layer.

[0016] In this example, the first edge sealing can effectively prevent debris from falling off the edge of the graphite sheet and reduce possible environmental pollution; the first edge sealing can also reinforce the edge of the graphite sheet, increase its mechanical strength, prevent edge cracks and wear, and thus improve the durability and stability of the graphite sheet.

[0017] In one embodiment, the first heat conducting member is adhered to the tab.

[0018] In this example, the pasting method does not require operations such as drilling holes in the first heat conductive member and the pole ear, which helps to reduce wear and deformation on the surface of the first heat conductive member and the pole ear, improve the durability of the battery cell, save workload, and improve work efficiency; the pasting method can achieve rapid connection and fixation between the first heat conductive member and the pole ear, thereby improving work efficiency.

[0019] The present application also provides a battery cell, comprising:

[0020] An electrode assembly includes a tab having a first surface and a second surface;

[0021] Pole;

[0022] A transfer plate, electrically connected between the pole lug and the pole, the transfer plate having a first transfer surface and a second transfer surface;

[0023] The second heat-conducting member is in sheet form, and is connected to at least one of the first surface and the second surface, or the second heat-conducting member is connected to at least one of the first transfer surface and the second transfer surface; the second heat-conducting member includes a layer of graphite sheet or multiple layers of stacked graphite sheets.

[0024] In this example, a second heat-conducting member is added to the battery cell. The second heat-conducting member has a high thermal conductivity and can quickly transfer and diffuse heat. The second heat-conducting member is connected to the pole ear and / or the adapter sheet so that the second heat-conducting member forms a preset contact area with the surface of the pole ear and the adapter sheet, so that the second heat-conducting member can form a heat-conducting path on the pole ear and the adapter sheet, thereby increasing the heat-conducting channel and enhancing the heat conduction effect, which is beneficial to reducing the resistance of the heat inside the electrode assembly to be transferred to the external environment, that is, reducing the thermal resistance of the low thermal resistance channel of the electrode assembly. On the one hand, the second heat-conducting member reduces the heat inside the electrode assembly by heat transfer; on the other hand, the second heat-conducting member has a high thermal conductivity and can absorb the heat on the pole ear and the adapter sheet and diffuse the heat to the outside. The second heat-conducting member reduces the heat inside the electrode assembly by heat dissipation, so that the thermal resistance of the low thermal resistance channel of the battery is effectively reduced, thereby improving the service life of the battery. The graphite sheet structure can increase the thermal conductivity and heat dissipation performance of the second heat-conducting member, and to a certain extent ensure the thermal conductivity and heat dissipation efficiency of the electrode assembly, the pole ear and the adapter sheet.

[0025] In one of the embodiments, when the second heat-conducting member includes a plurality of stacked graphite sheets, at least a portion of the adjacent graphite sheets are provided with a bonding layer.

[0026] In this example, the adhesive layer is coated on two oppositely disposed surfaces of two adjacent graphite sheets, thereby bonding and fixing the two graphite sheets together, so that the multiple layers of graphite sheets form a sheet-like whole, thereby forming a second sheet-like heat conductor, so that the second heat conductor has higher thermal conductivity and heat dissipation performance and the overall structure is more solid and reliable.

[0027] In one embodiment, the second heat-conducting member is insulated from the adapter plate; the second heat-conducting member is insulated from the tab.

[0028] In this example, the second heat conducting member, the pole lug and the adapter are insulated, which can reduce the risk of leakage on the second heat conducting member, between the second heat conducting member and the pole lug, and between the second heat conducting member and the adapter, and improve the reliability of the battery cell charging and discharging process.

[0029] In one embodiment, the second heat conductive member further includes a second insulating layer; when the second heat conductive member includes a layer of graphite sheet, the second insulating layer is coated on the outer surface of the graphite sheet; when the second heat conductive member includes multiple layers of graphite sheet, the second insulating layer is coated on the outer surface of the multiple layers of graphite sheet; the second insulating layer is connected to the adapter plate and / or the pole ear.

[0030] In this example, the outer surface of the second heat conductive member is insulated so that a second insulating layer is formed on the outer surface of the entire second heat conductive member, thereby achieving the effect of insulating the second heat conductive member from the pole ear and the adapter plate; the storage and use of the second heat conductive member are more convenient, and the second heat conductive member can be quickly connected to the pole ear and the adapter plate, thereby improving the convenience and reliability of installation.

[0031] In one embodiment, a second edge seal is formed on an edge of the second insulating layer avoiding the graphite sheet layer.

[0032] In this example, the second edge sealing can effectively prevent debris from falling off the edge of the graphite sheet and reduce possible environmental pollution; the second edge sealing can also reinforce the edge of the graphite sheet, increase its mechanical strength, prevent edge cracks and wear, and thus improve the durability and stability of the graphite sheet.

[0033] In one embodiment, the second heat conductive member is adhered to the tab and / or the adapter.

[0034] In this example, the pasting method eliminates the need for operations such as drilling holes in the second heat-conducting member, the pole lug, and the adapter sheet, which helps reduce wear and deformation on the surfaces of the second heat-conducting member, the pole lug, and the adapter sheet, improves the durability of the battery cell, saves workload, and improves work efficiency. The pasting method can achieve rapid connection and fixation between the second heat-conducting member and the pole lug, and between the second heat-conducting member and the adapter sheet, thereby improving work efficiency.

[0035] In one embodiment, the overlapping portion of the electrode tab and the adapter sheet forms a lap portion; the lap portion has a first lap surface and a second lap surface, and the second heat conductive member is connected to at least one of the first lap surface and the second lap surface.

[0036] In this example, the second heat conductor is directly connected to the first overlapping surface and the second overlapping surface of the overlapping part. The surface area of ​​the overlapping part is larger. On the one hand, it is convenient for the installation of the second heat conductor. On the other hand, it can increase the contact area between the second heat conductor and the surface of the overlapping part, thereby increasing the heat transfer area and the heat dissipation area, which is beneficial to improving the efficiency of heat conduction and heat dissipation.

[0037] In one embodiment, the second heat conducting member is adhered to the overlapping portion.

[0038] In this example, the pasting method does not require operations such as drilling holes in the second heat-conducting member and the overlapping portion, which helps to reduce wear and deformation on the surfaces of the second heat-conducting member and the overlapping portion, improve the durability of the battery cell, save workload, and improve work efficiency. The pasting method can achieve rapid connection and fixation between the second heat-conducting member and the overlapping portion, thereby improving work efficiency.

[0039] In one embodiment, the electrode assembly includes a plurality of bare cells, each of the bare cells includes the electrode tab, and each of the electrode tabs is electrically connected to the adapter.

[0040] In this example, by configuring multiple bare cells in a battery cell, the total capacity of the battery cell can be increased, so that the battery cell can provide a longer usage time or support devices with higher power requirements; in addition, by using multiple bare cells in a battery cell, it is easier to achieve voltage balance of the battery cell, which helps prevent over-discharge or over-charge of a bare cell in the battery cell, thereby improving the reliability and life of the battery.

[0041] In one embodiment, the battery cell further includes a shell and an end cover, the shell has an inner cavity, the electrode assembly is disposed in the inner cavity, the pole is connected to the end cover, and the end cover is connected to the shell to close the inner cavity.

[0042] In this example, the outer shell is used to protect the outside of the electrode assembly, the pole is connected to the end cover, and the adapter forms a key component connecting the electrode assembly (or pole ear) and the end cover. The pole, adapter, pole ear, bare battery cell, electrolyte, and outer shell form a low thermal resistance channel of the electrode assembly. The heat transfer and heat conduction of the pole ear and the adapter are particularly important. Therefore, a second heat conductive member is arranged on the pole ear and the adapter, and a second heat conductive member is arranged at the overlapping part of the pole ear and the adapter for heat transfer and heat conduction. This can effectively disperse and conduct the heat of the electrode assembly, and to a certain extent avoid overheating that may cause performance degradation or safety problems of the battery cell.

[0043] In a second aspect, the present application provides a battery, which includes the battery cell in the above embodiment.

[0044] In a third aspect, the present application provides an electrical device, which includes the battery in the above embodiment, and the battery is used to provide electrical energy.

[0045] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0047] Figure 1 A schematic diagram of the structure of a vehicle provided in some embodiments of the present application;

[0048] Figure 2 A schematic diagram of the exploded structure of a battery provided in some embodiments of the present application;

[0049] Figure 3 It is a schematic structural diagram of a battery cell in the related art when the first heat conducting member is not provided;

[0050] Figure 4 for Figure 3 axonometric drawing;

[0051] Figure 5 for Figure 3 AA section view;

[0052] Figure 6 The structure of the battery cell of some embodiments of the present application is shown in FIG. Figure 1 ;

[0053] Figure 7 for Figure 6 axonometric drawing;

[0054] Figure 8 The structure of the battery cell of some embodiments of the present application is shown in FIG. Figure 2 ;

[0055] Fig. 9 for Figure 8 axonometric drawing;

[0056] Fig.10 The structure of the battery cell of some embodiments of the present application is shown in FIG. Figure 3 ;

[0057] Fig.11 for Fig.10 axonometric drawing;

[0058] Fig.12 The structure of the battery cell of some embodiments of the present application is shown in FIG. Figure 4 ;

[0059] Fig.13 The structure of the battery cell of some embodiments of the present application is shown in FIG. Figure 5 ;

[0060] Fig.14 A schematic diagram of the three-dimensional structure of a battery cell according to some embodiments of the present application;

[0061] Fig.15 The structure of the battery cell of some embodiments of the present application is shown in FIG. Figure 6 ;

[0062] Fig.16 for Fig.15 axonometric drawing;

[0063] Fig.17 for Fig.15 BB cross-sectional view;

[0064] Fig.18 A schematic diagram of the structure of a first heat-conducting member in a battery cell in some embodiments of the present application;

[0065] Fig.19 for Fig.18 A magnified view of the C position in FIG.

[0066] Fig. 20 for Fig.18 A top view of

[0067] Fig.21 for Fig. 20 axonometric drawing;

[0068] Fig. 22 A schematic diagram of a battery cell structure provided in some embodiments of the present application Figure 7 ;

[0069] Fig.23 for Fig. 22 axonometric drawing;

[0070] Fig.24 A schematic diagram of a battery cell structure provided in some embodiments of the present application Figure 7 ;

[0071] Fig.25 for Fig.24 axonometric drawing;

[0072] Fig.26 for Fig.24DD cross-sectional view;

[0073] Fig. 27 A schematic diagram of the exploded structure of a battery cell provided in some embodiments of the present application is shown.

[0074] Description of reference numerals:

[0075] 1000, vehicle; 100, battery; 10, housing; 11, first part; 12, second part; 20, battery cell; 21, electrode assembly; 211, bare cell; 22, tab; 221, first surface; 222, second surface; 23, first thermal conductor; 231, graphite sheet; 232, adhesive layer; 233, first insulating layer; 234, first edge seal; 24, pole; 25, adapter; 26, welding position; 27, overlapping portion; 271, first overlapping surface; 272, second overlapping surface; 28, second thermal conductor; 281, second insulating layer; 282, second edge seal; 291, housing; 292, end cover; 200, controller; 300, motor. DETAILED DESCRIPTION

[0076] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0077] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0078] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0079] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0080] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0081] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0082] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0083] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0084] The electrode assembly 21 can maintain an appropriate temperature range during operation to improve the reliability, performance and life of the battery. Low thermal resistance channels are an important part of battery design, especially in applications requiring high power and high temperature environments, wherein the electrode assembly 21 can also be understood as a battery cell.

[0085] The low thermal resistance channel of the electrode assembly 21 is intended to promote effective conduction and heat dissipation of heat, thereby improving the heat dissipation performance of the battery. In high-power applications or when long-term high-intensity discharge is required, it is very important to control the temperature of the electrode assembly 21, because excessively high temperatures may affect battery performance and life.

[0086] Figure 3 The structure diagram of the battery cell 20 in the related art is shown; Figure 4 for Figure 3 axonometric drawing; Figure 5 for Figure 3 AA cross-sectional view; in the thermal design of the electrode assembly 21, the low thermal resistance channel of the electrode assembly 21 is the pole 24-pole tab 22-bare cell 211-electrolyte-shell. When there is a transfer sheet 25 in the battery cell 20, the low thermal resistance channel of the electrode assembly 21 is the pole 24-transfer sheet 25-pole tab 22-bare cell 211-electrolyte-shell, wherein the transfer sheet 25 is also called a current collector. It can be seen that the heat transfer and heat conduction of the pole tab 22, or the pole tab 22 and the transfer sheet 25 are particularly important.

[0087] For the pole ear 22, due to the energy density, the thickness of the pole ear 22 needs to be made very thin, which causes the cross-sectional area of ​​the pole ear 22 to be reduced to a minimum, and then causes the temperature of the pole ear 22, the adapter 25 (when the adapter 25 is included), and the pole 24 to be higher, which is not conducive to the heat dissipation of the electrode assembly 21, resulting in an increase in the temperature of the electrode assembly 21; excessively high temperature of the electrode assembly 21 will cause the electrolyte in the electrode assembly 21 to decompose, the gas production of the electrode assembly 21 to increase, and the air pressure inside the electrode assembly 21 to be too high, thereby reducing the energy density of the electrode assembly 21. At the same time, the electrode assembly 21 is subjected to high internal air pressure, which reduces the service life of the electrode assembly 21.

[0088] Therefore, in order to improve the heat dissipation and heat transfer capabilities of the electrode assembly 21, the present application adds a first heat conductor 23. By connecting the first heat conductor 23 to the heat transfer path of the electrode assembly 21, for example, installing it on the pole ear 22, the thermal resistance of the electrode assembly 21 can be effectively reduced, the heat dissipation and heat transfer capabilities of the electrode assembly 21 can be improved, and the current flow capacity of the electrode assembly 21 can be improved, which is beneficial to lowering the temperature of the electrode assembly 21, thereby reducing the risk of overheating of the electrode assembly 21, and ensuring the performance and life of the battery to a certain extent.

[0089] Specifically, the first aspect of the embodiment of the present application provides a battery cell 20, which can improve the heat transfer capacity of the electrode assembly 21, which is conducive to reducing the temperature of the electrode assembly 21; wherein, it should be noted that the battery cell 20 disclosed in the embodiment of the present application can be used for electrical devices that use batteries as power sources or various energy storage systems that use batteries as energy storage elements. Electrical devices can be, but are not limited to, mobile phones, tablets, laptops, electric toys, electric tools, battery cars, electric cars, ships, spacecraft, etc. Among them, electric toys can include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc., and spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0090] For the convenience of description, the following embodiments are described by taking a vehicle 1000 as an example of an electrical device in one embodiment of the present application. Figure 1 , Figure 1A schematic diagram of the structure of a vehicle 1000 provided for some embodiments of the present application. The vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 100 is provided inside the vehicle 1000, and the battery 100 may be provided at the bottom, head or tail of the vehicle 1000. The battery 100 may be used to power the vehicle 1000, for example, the battery 100 may be used as an operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300, and the controller 200 is used to control the battery 100 to power the motor 300, for example, for starting, navigating and driving the vehicle 1000.

[0091] In some embodiments of the present application, the battery 100 can not only serve as an operating power source for the vehicle 1000, but also serve as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0092] Please refer to Figure 2 , Figure 2 An exploded view of a battery 100 provided for some embodiments of the present application. The battery 100 includes a housing 10 and a battery cell 20, and the battery cell 20 is contained in the housing 10. The housing 10 is used to provide a storage space for the battery cell 20, and the housing 10 can adopt a variety of structures. In some embodiments, the housing 10 can include a first part 11 and a second part 12, the first part 11 and the second part 12 cover each other, and the first part 11 and the second part 12 jointly define a storage space for accommodating the battery cell 20; the second part 12 can be a hollow structure with one end open, the first part 11 can be a plate-like structure, and the first part 11 covers the open side of the second part 12, so that the first part 11 and the second part 12 jointly define a storage space; the first part 11 and the second part 12 can also be hollow structures with one side open, and the open side of the first part 11 covers the open side of the second part 12. Of course, the housing 10 formed by the first part 11 and the second part 12 can be in a variety of shapes, such as a cylinder, a cuboid, etc.

[0093] In the battery 100, there may be multiple battery cells 20, and the multiple battery cells 20 may be connected in series, in parallel, or in a mixed connection. A mixed connection means that the multiple battery cells 20 are both connected in series and in parallel. The multiple battery cells 20 may be directly connected in series, in parallel, or in a mixed connection, and then the whole formed by the multiple battery cells 20 is accommodated in the box 10; of course, the battery 100 may also be a battery module formed by connecting multiple battery cells 20 in series, in parallel, or in a mixed connection, and then the multiple battery modules are connected in series, in parallel, or in a mixed connection to form a whole, and accommodated in the box 10. The battery 100 may also include other structures, for example, the battery 100 may also include a busbar component for realizing electrical connection between the multiple battery cells 20.

[0094] The battery cell 20 refers to the smallest unit that constitutes the battery. Each battery cell 20 may be a secondary battery or a primary battery; it may also be a lithium-sulfur battery, a sodium-ion battery or a magnesium-ion battery, but is not limited thereto. The battery cell 20 may be cylindrical, flat, rectangular or in other shapes.

[0095] According to some embodiments of the present application, referring to Figure 6 , Figure 6 The structure schematic diagram of the battery cell 20 in which the first heat conductor 23 is connected to the pole tab 22 when the pole tab 22 is directly electrically connected to the pole column 24 is shown. Figure 7 for Figure 6 The embodiment of the present application provides a battery cell 20, the battery cell 20 includes an electrode assembly 21, a pole 24 and a first heat conductor 23; the electrode assembly 21 includes a pole tab 22, the pole tab 22 has a first surface 221 and a second surface 222, the pole 24 is electrically connected to the pole tab 22; the first heat conductor 23 is connected to the pole tab 22, the first heat conductor 23 is in sheet form and is attached to at least one of the first surface 221 and the second surface 222, and the first heat conductor 23 includes a graphite sheet 231 or multiple stacked graphite sheets 231.

[0096] The electrode assembly 21 is one of the core components of the battery. The electrode assembly 21 can convert chemical energy into electrical energy. The basic structure of the electrode assembly 21 includes a positive electrode sheet, a negative electrode sheet, an electrolyte, a separator and a tab 22. The tab 22 includes a positive tab 22 connected to the positive electrode sheet and a negative electrode connected to the negative electrode sheet. The positive electrode sheet and the negative electrode sheet are separated by an electrolyte and a separator. During the discharge process, the positive electrode sheet and the negative electrode sheet undergo an oxidation-reduction reaction to generate current. The types of electrode assemblies 21 include lithium-ion electrode assemblies (Li-ion), nickel-metal hydride electrode assemblies (NiMH), nickel-cadmium electrode assemblies 21 (NiCd), etc. The lithium-ion electrode assembly 21 has the characteristics of high energy density and light weight.

[0097] The pole lug 22 is a conductive sheet or lead connecting the positive electrode sheet or the negative electrode sheet, and is used to connect the electrode assembly 21 of the battery to the external circuit. The pole lug 22 can be made of a material with good conductivity, such as copper, aluminum, etc. The above materials have good conductivity, which helps to reduce resistance and improve the efficiency of the battery. The pole lug 22 needs to maintain good stability when connected to the positive electrode sheet and the negative electrode sheet to ensure that the battery will not increase resistance or disconnect due to poor connection during use. Therefore, the battery can be connected to the pole lug 22 by welding, or crimping or other connection techniques can be used to ensure the stability of the connection between the pole lug 22 and the positive electrode sheet and the negative electrode sheet to a certain extent. In addition, in a battery pack (or battery module), multiple battery cells 20 are connected together by the pole lug 22 to form the positive and negative electrodes of the battery pack to provide a larger energy storage capacity.

[0098] The pole 24 is the part that connects the inside of the battery cell 20 to the outside. In the battery cell 20, the pole 24 can be considered as an extension of the positive and negative plates. The pole 24 is usually made of metal material. The pole 24 is responsible for outputting the electric energy in the battery cell 20 to the external circuit or inputting the external electric energy into the battery cell 20. The pole 24 has good electrical conductivity to ensure that the current can smoothly enter and exit the battery to provide electric energy or charge. The pole 24 is usually made of metal material, such as copper or aluminum, which has good electrical conductivity and certain corrosion resistance.

[0099] In the battery cell 20, the pole ear 22 of the electrode assembly 21 needs to be electrically connected to the pole 24 so that current can flow during the charging and discharging process of the battery cell 20. When the current flows through the pole ear 22, the pole ear 22 will generate heat, and heat concentration is more likely to occur at the welding position between the pole ear 22 and the electrode assembly 21 (or the bare battery cell 211). The low thermal resistance channel of the electrode assembly 21 cannot be reduced, and the heat accumulation causes the heat inside the electrode assembly 21 to be unable to be effectively transported and diffused, which in turn causes the temperature of the electrode assembly 21 to rise, affecting the performance and life of the battery cell 20.

[0100] Therefore, in the battery cell 20 of this example, a first heat-conducting member 23 is added. The first heat-conducting member 23 has a high thermal conductivity and can quickly transfer and diffuse heat. The first heat-conducting member 23 is connected to the pole ear 22, and the first heat-conducting member 23 forms a preset contact area with the surface of the pole ear 22, so that the first heat-conducting member 23 can form a heat-conducting path on the pole ear 22, thereby increasing the heat-conducting channel and enhancing the heat conduction effect, so as to help reduce the resistance of the internal heat of the electrode assembly 21 to be transferred to the external environment, that is, reduce the thermal resistance of the thermal resistance channel of the electrode assembly 21, and the first heat-conducting member 23 reduces the heat inside the electrode assembly 21 by heat transfer. In addition, the first heat-conducting member 23 has a high thermal conductivity and can absorb the heat on the pole ear 22 and diffuse the heat to the outside. The first heat-conducting member 23 reduces the heat inside the electrode assembly 21 by heat dissipation, so that the thermal resistance of the thermal resistance channel of the battery is effectively reduced, thereby improving the service life of the battery.

[0101] In this example, the first heat conductor 23 needs to have a higher thermal conductivity. Therefore, the first heat conductor 23 can be made of metal materials or non-metallic materials, wherein the metal materials may include ferrous metals, non-ferrous metals and special metal materials, etc. In addition, the metal materials may also include alloy materials, and the metal materials may specifically include aluminum, iron, magnesium, titanium, copper, zinc, lead, silver, gold, platinum, alloy materials, etc., wherein the alloy materials include carbon steel, stainless steel, copper-nickel alloy, iron-nickel alloy, etc.; the non-metallic material may include graphite, and the first heat conductor 23 may be made of graphite sheets or graphite wool or graphite coating, etc.

[0102] The first heat conductor 23 may adopt a sheet structure or a coating structure, etc. The first heat conductor 23 may be insulated from the pole tab 22, or may be conductively connected to the pole tab 22. When the first heat conductor 23 is conductively connected to the pole tab 22, current can still flow through the first heat conductor 23, which is beneficial to improving the conductivity of the electrode assembly 21.

[0103] Combination Figure 8 and Fig. 9 As shown, Figure 8 2 shows a schematic structural diagram of a battery cell 20 in which the first surface 221 and the second surface 222 are both connected to the first heat conducting member 23 . Fig. 9 for Figure 8 In the isometric view, the tab 22 has a first surface 221 and a second surface 222 , and the first heat conductor 23 is connected to at least one of the first surface 221 and the second surface 222 .

[0104] Among them, the first surface 221 and the second surface 222 are two different surfaces of the pole ear 22, and the first surface 221 and the second surface 222 can be planes, curved surfaces, or special-shaped surfaces; the first surface 221 and the second surface 222 can be parallel and coplanar, or oppositely arranged, or at an angle; for example, the pole ear 22 is in the shape of a sheet, and the first surface 221 and the second surface 222 are two oppositely arranged surfaces of the pole ear 22.

[0105] Among them, combined with Figure Figure 6 and Figure 7 As shown, the first heat conductor 23 is connected to at least one of the first surface 221 and the second surface 222, including the first heat conductor 23 being connected to the first surface 221, or the first heat conductor 23 being connected to the second surface 222, or the first heat conductor 23 being connected to the first surface 221 and the second surface 222, that is, the first heat conductor 23 is provided on both the first surface 221 and the second surface 222.

[0106] When the first heat conductor 23 is connected to the first surface 221 or the second surface 222, it can be seen that the first heat conductor 23 is connected to one surface or side of the pole ear 22. This structure is applied to the case where the capacity of the battery cell 20 is not large and the heat generation of the electrode assembly 21 is not high. By connecting a first heat conductor 23 to one side of the pole ear 22, the purpose of heat conduction to the electrode assembly 21 and heat dissipation to the pole ear 22 can be achieved.

[0107] Combination Figure 8 and Fig. 9 As shown, when the first heat conductor 23 is connected to the first surface 221 and the second surface 222, it can be known that the first heat conductor 23 is connected to both surfaces or sides of the pole ear 22. This structure is applied to the case where the capacity of the battery cell 20 is large and the heat generation of the electrode assembly 21 is high. The first heat conductor 23 covers the two sides of the pole ear 22, thereby increasing the contact area with the pole ear 22, which is beneficial to improving the efficiency of heat conduction to the electrode assembly 21 and heat dissipation to the pole ear 22. Among them, the first heat conductor 23 connected to the first surface 221 of the pole lug 22 and the first heat conductor 23 connected to the second surface 222 of the pole lug 22 can be an integrally formed structure, that is, one first heat conductor 23 can cover the first surface 221 and the second surface 222 at the same time; or, the first heat conductor 23 connected to the first surface 221 of the pole lug 22 and the first heat conductor 23 connected to the second surface 222 of the pole lug 22 can be a split structure, for example, the first heat conductor 23 includes a first heat conductor sub-component and a second heat conductor sub-component, the first heat conductor sub-component is connected to the first surface 221, and the second heat conductor sub-component is connected to the second surface 222.

[0108] In this example, the first heat conductor 23 is directly connected to the first surface 221 and the second surface 222 of the pole lug 22. The surface area of ​​the pole lug 22 is large. On the one hand, it is convenient to install the first heat conductor 23. On the other hand, it can increase the contact area between the first heat conductor 23 and the surface of the pole lug 22, thereby increasing the heat transfer area and the heat dissipation area, which is beneficial to improving the efficiency of heat conduction and heat dissipation.

[0109] Combination Figure 6 and Fig.18 As shown, the first heat conductive member 23 is in sheet shape and fits with the pole tab 22, and the thickness of the first heat conductive member 23 is between 0.2 mm and 3 mm; the surface area of ​​the first heat conductive member 23 is less than or equal to the surface area of ​​the pole tab 22, so that the surface of the first heat conductive member 23 can conflict with the first surface 221 or the second surface 222 of the pole tab 22.

[0110] In this example, the sheet-shaped first heat conductor 23 can easily form a larger contact area with the pole lug 22, which is more conducive to increasing the thermal conductivity and heat dissipation efficiency of the first heat conductor 23 and the pole lug 22 without increasing the load on the pole lug 22, which is conducive to achieving lightweight batteries; in addition, the sheet-shaped first heat conductor 23 is conducive to saving space, reducing interference with other components, and improving the rationality of the internal structural space setting of the battery cell 20.

[0111] Combination Figure 18-21 As shown, Fig.18 Schematic diagram of the structure of the first heat conducting member 23 is shown. Fig.19 An enlarged view of the C position is shown, Fig. 20 FIG. 2 shows a schematic diagram of the surface structure of the first heat conducting member 23. Fig.21 Shows Fig. 20 According to the axonometric view, the first heat-conducting member 23 includes a graphite sheet 231 or multiple stacked graphite sheets 231, so that the first heat-conducting member 23 is in a sheet shape.

[0112] Graphite material has good thermal conductivity and can effectively transfer and disperse heat. Therefore, the first heat conductor 23 made of graphite material can better transfer the heat of the electrode assembly 21 and disperse the heat on the pole ear 22, thereby improving the thermal conductivity and heat dissipation efficiency of the first heat conductor 23 to the electrode assembly 21 and the pole ear 22; the thermal conductivity coefficient of the graphite layer 231 in the horizontal direction is as high as 1500W / (M*K), which is much greater than the thermal conductivity of copper of 400W / (M*K).

[0113] The graphite material is made into a sheet shape, that is, a graphite sheet 231 is formed, which is beneficial to increase the contact area between the graphite sheet 231 and the pole ear 22, thereby increasing the contact area between the first heat conductor 23 and the pole ear 22, increasing the heat conduction area and the heat dissipation area, and is beneficial to improving the heat conduction and heat dissipation efficiency.

[0114] According to parameters such as the capacity of the battery cell 20, the heat generation of the electrode assembly 21 can be known, and the number of graphite sheets 231 in the first heat conductive member 23 can be selected accordingly. When the capacity of the battery cell 20 is not large, the first heat conductive member 23 can include only one layer of graphite sheet 231 to meet the requirements of heat conduction and heat dissipation of the electrode assembly 21 and the tab 22. When the capacity of the battery cell 20 is large, the number of graphite sheets 231 can be increased, and multiple layers of graphite sheets 231 can be arranged in parallel and stacked to form a sheet structure with a certain thickness. The multi-layer graphite sheet 231 structure can increase the heat conduction and heat dissipation performance of the first heat conductive member 23, and to a certain extent ensure the heat conduction and heat dissipation efficiency of the electrode assembly 21 and the tab 22.

[0115] In addition, the graphite material has high chemical stability and corrosion resistance, so that it can maintain stable performance in the high temperature of the battery and the corrosive environment of the electrolyte; furthermore, the graphite material has relatively high mechanical strength and hardness. The graphite is made into a graphite sheet 231 and attached to the surface of the pole ear 22, so that the first heat conductor 23 can also provide good structural support and durability for the pole ear 22; in addition, the graphite material is a lightweight material, and when connected to the pole ear 22, it will not generate a weight burden on the pole ear 22, which helps to reduce the weight of the battery cell 20.

[0116] In some examples, combined Fig.19 As shown, in the case where the first heat conducting member 23 includes multiple stacked graphite sheets 231 , a bonding layer 232 is disposed between at least some adjacent graphite sheets 231 , and the bonding layer 232 is used to make the adjacent graphite sheets 231 adhere to each other.

[0117] The bonding layer 232 may be a combination of one or more of polymer, conductive glue, graphene, silica gel, epoxy resin, nanomaterials, etc.; wherein the polymer may include polyvinyl alcohol (PVA), polyacrylic acid (PPA), etc. The polymer bonding layer may provide good adhesion and elasticity, and enhance the bonding firmness between adjacent graphite sheets 231. The conductive glue may contain conductive particles, such as carbon black or metal particles, to improve the conductivity, and the conductive glue can ensure the effective transmission of current between the graphite sheets 231. Graphene has excellent conductivity and mechanical strength. Using graphene as a bonding layer material can improve the overall performance of the first heat conductor 23. Silica gel has good elasticity and high temperature resistance. The graphite sheets 231 are connected by silica gel, so that the first heat conductor 23 can be used in a high temperature environment. Epoxy resin can bond adjacent graphite sheets 231 while also improving the mechanical strength and chemical resistance of the first heat conductor 23. The nanomaterial may include nanoparticles or nanofibers, etc., which can improve the performance of the adhesive layer and enhance the strength and conductivity between adjacent graphite sheets 231 .

[0118] In this example, the bonding layer 232 uses double-sided tape, and two adjacent graphite sheets 231 are arranged opposite to each other to form two opposite surfaces. The bonding layer 232 is coated on the two oppositely configured surfaces of the two adjacent graphite sheets 231, so as to bond and fix the two graphite sheets 231, so that the multi-layer graphite sheets 231 form a sheet-like whole, and then form a sheet-like first heat conductor 23, so that the first heat conductor 23 has higher thermal conductivity and heat dissipation performance and the overall structure is more firm and reliable.

[0119] In some examples, combined Fig.19 As shown, the first heat conducting member 23 is insulated from the pole tab 22 so that current cannot be transmitted between the first heat conducting member 23 and the pole tab 22, thereby achieving a non-conductive connection.

[0120] The insulation arrangement between the first heat conductor 23 and the pole lug 22 includes adding an insulating interlayer between the first heat conductor 23 and the pole lug 22, wherein the insulating interlayer is made of insulating material so that the current on the pole lug 22 cannot be transmitted to the first heat conductor 23 during charging and discharging; the insulation arrangement between the first heat conductor 23 and the pole lug 22 also includes forming an insulating coating layer on the surface of the first heat conductor 23 or the pole lug 22, thereby achieving an insulation effect between the first heat conductor 23 and the pole lug 22.

[0121] In this example, the first heat conductor 23 and the pole lug 22 are insulated. It can be seen that no current will flow through the first heat conductor 23, and the first heat conductor 23 does not play a role in conducting current. The first heat conductor 23 only plays a role in conducting and dissipating heat on the surface of the pole lug 22. Insulating the first heat conductor 23 and the pole lug 22 can reduce the risk of leakage on the first heat conductor 23 and between the first heat conductor 23 and the pole lug 22, thereby improving the reliability of the battery charging and discharging process.

[0122] In some examples, combined Fig.19 As shown, the first heat conductor 23 also includes a first insulating layer 233; when the first heat conductor 23 includes a layer of graphite sheet 231, the first insulating layer 233 is coated on the outer surface of the graphite sheet 231; when the first heat conductor 23 includes multiple layers of graphite sheet 231, the first insulating layer 233 is coated on the outer surface of the multiple layers of graphite sheet 231.

[0123] The first insulating layer 233 may be a sealing film made of insulating material. The sealing film forms a physical isolation between the graphite sheet 231 and the tab 22 . The sealing film can provide insulation and protection for the graphite sheet 231 .

[0124] Since the first heat-conducting member 23 includes one or more layers of graphite sheet 231, it can be known that when the first heat-conducting member 23 includes one layer of graphite sheet 231, the first insulating layer 233 is wrapped around the outside of the graphite sheet 231, and when the second heat-conducting member 28 includes multiple layers of graphite sheet 231 bonded and stacked together, the first insulating layer 233 is wrapped around the outer surface of the outermost graphite sheet 231, thereby playing an insulating role on the outer surface of the entire multi-layer graphite sheet 231.

[0125] In this example, the outer surface of the first heat conductor 23 is insulated so that a first insulating layer 233 is formed on the outer surface of the entire first heat conductor 23, thereby achieving the effect of insulating the first heat conductor 23 from the pole lug 22; in addition, after the first heat conductor 23 has the first insulating layer 233 on the outside, the storage and use of the first heat conductor 23 are more convenient. When the first heat conductor 23 and the pole lug 22 are assembled, it is only necessary to take out one or more first heat conductors 23 and fit them with the pole lug 22. There is no need to consider the conductivity problem between the first heat conductor 23 and the pole lug 22, so that the first heat conductor 23 and the pole lug 22 can be quickly connected, and the convenience and reliability of installation are improved.

[0126] In some examples, combined Figure 19-21 As shown, the edge of the first insulating layer 233 avoiding the graphite sheet 231 forms a first edge seal 234, and the first edge seal 234 is the portion of the first insulating layer 233 extending outside the graphite sheet 231. The first edge seal 234 is formed by the first insulating layer 233 extending outward from the outside of the graphite sheet 231 on one surface of the graphite sheet 231 and the first insulating layer 233 extending outward from the outside of the graphite sheet 231 on the other surface of the graphite sheet 231 being bonded and superimposed.

[0127] In this example, the first edge seal 234 can effectively prevent the debris at the edge of the graphite sheet from falling off, reducing possible environmental pollution; the first edge seal 234 can also reinforce the edge of the graphite sheet 231, increase its mechanical strength, prevent edge cracks and wear, and thus improve the durability and stability of the graphite sheet 231. Since the battery cell 20 has a high temperature during charging and discharging, and the battery cell 20 is corrosive, the first edge seal 234 is formed on the periphery of the graphite sheet 231, which can effectively prevent oxidation and corrosion of the graphite sheet 231 by oxygen, moisture, etc., and extend its service life.

[0128] In some examples, the first thermal conductor 23 is pasted on the pole lug 22, that is, the first thermal conductor 23 and the pole lug 22 are connected by pasting. The first thermal conductor 23 can be adhered to the surface of the pole lug 22 by double-sided tape, and the double-sided tape can be adhered to the outer surface of the first insulating layer 233 of the first thermal conductor 23.

[0129] In this example, the pasting method does not require operations such as drilling holes in the first heat conductive member 23 and the pole lug 22, which helps to reduce wear and deformation on the surfaces of the first heat conductive member 23 and the pole lug 22, improve the durability of the battery cell 20, save workload, and improve work efficiency; the pasting method can achieve rapid connection and fixation between the first heat conductive member 23 and the pole lug 22, thereby improving work efficiency.

[0130] According to other embodiments of the present application, Figure 10-17 As shown, Fig.10 2 shows a schematic structural diagram of a battery cell 20 provided with an adapter sheet 25. Fig.11 for Fig.10 axonometric drawing; Fig.12 A schematic diagram showing the structure of the battery cell 20 when the first heat conducting member 23 is connected to the adapter sheet 25 is shown; Fig.13 A schematic diagram showing the structure of the adapter sheet 25 connected to the overlapping portion 27; Fig.14 for Fig.13 axonometric drawing; Fig.15 is a schematic structural diagram of a battery cell 20 with a pole 24 connected; Fig.16 for Fig.15 axonometric drawing; Fig.17 for Fig.15 The embodiment of the present application provides a battery cell 20, the battery cell 20 includes an electrode assembly 21, a pole 24, a transfer sheet 25 and a second heat conductive member 28; the electrode assembly 21 includes a pole lug 22, the pole lug 22 has a first surface 221 and a second surface 222, the transfer sheet 25 is electrically connected between the pole lug 22 and the pole 24, and the transfer sheet 25 has a first transfer surface and a second transfer surface; the second heat conductive member 28 is in the form of a sheet, the second heat conductive member 28 is connected to at least one of the first surface 221 and the second surface 222, or the second heat conductive member 28 is connected to at least one of the first transfer surface and the second transfer surface; the second heat conductive member 28 includes a layer of graphite sheet 231 or multiple layers of stacked graphite sheet 231.

[0131] The adapter 25 is connected between the pole ear 22 and the pole 24 to guide the current. The adapter is also called a current collector. When the pole 24 is connected to the upper cover of the battery cell 20, the adapter 25 can connect the electrode assembly 21 to the end cover (which can be called the upper cover). The adapter 25 and the pole ear 22 and the pole 24 can usually be connected and fixed by welding. A welding position 26 for welding with the pole 24 is formed on the adapter 25.

[0132] When the adapter 25 is provided in the battery cell 20, the low thermal resistance channel of the electrode assembly 21 is the pole 24-adapter 25-tab 22-bare cell 211-electrolyte-housing. It can be seen that the heat transfer and heat conduction of the tab 22 and the adapter 25 are particularly important.

[0133] The adapter 25 has the function of conducting current. As the main channel of current, the adapter 25 can provide a low-resistance current conduction path to ensure efficient transmission of electric energy between the battery cells 20. The adapter 25 can also reduce the loss of current during transmission and improve the overall efficiency of the battery. The adapter 25 can maintain stable contact between the pole ear 22 and the pole 24, so that the pole ear 22 and the pole 24 are not prone to loosening, falling off or poor contact, thereby reducing resistance and heat accumulation, and reducing the risk of heating and damage to the battery cell 20. In addition, the adapter 25 can also play a role in heat dissipation and thermal balance. During the high-power discharge or charging process of the battery cell 20, the electrode assembly 21 will generate heat. The adapter 25 can help to effectively disperse and conduct the heat, and to a certain extent avoid overheating that causes performance degradation or safety problems of the battery cell 20.

[0134] The adapter sheet 25 is generally made of a metal material with good conductive properties, and the adapter sheet 25 is usually in a sheet shape; it should be pointed out that when the electrode assembly 21 includes multiple bare cells 211, the adapter sheet 25 is also used to electrically connect the multiple bare cells 211 to ensure that current can flow between the multiple bare cells 211, thereby forming a circuit for the entire battery cell 20 (see below for details).

[0135] However, when the adapter 25 is installed and the battery capacity is large, a lot of heat will still be generated on the pole tab 22 and the adapter 25 during the charge and discharge process, and heat concentration is more likely to occur at the welding position between the pole tab 22 and the bare battery cell 211, and at the welding position between the adapter 25, the pole tab 22 and the pole 24. The low thermal resistance channel of the electrode assembly 21 cannot be reduced, and the heat accumulation causes the heat inside the electrode assembly 21 to be unable to be effectively transported and diffused, which in turn causes the temperature of the electrode assembly 21 to rise, affecting the performance and life of the battery cell 20.

[0136] Therefore, in order to improve the heat dissipation and heat transfer capabilities of the electrode assembly 21, the present application adds a second heat conductor 28, and connects the second heat conductor 28 to the heat transfer path of the electrode assembly 21, specifically, installs the second heat conductor 28 on the pole ear 22, or installs it on the adapter 25, or installs the second heat conductor 28 on both the pole ear 22 and the adapter 25, which can effectively reduce the thermal resistance of the electrode assembly 21, improve the heat dissipation and heat transfer capabilities of the electrode assembly 21, reduce the thermal resistance of the low thermal resistance channel of the electrode assembly 21, and improve the current flow capacity of the electrode assembly 21, which is beneficial to reduce the temperature of the electrode assembly 21, so as to reduce the overheating risk of the electrode assembly 21, and to ensure the performance and life of the battery to a certain extent; wherein, it should be noted that when the second heat conductor 28 is connected to the adapter 25, the second heat conductor 28 needs to avoid the welding position 26 on the adapter 25 to facilitate the welding of the adapter 25 and the pole 24.

[0137] Specifically, in the battery cell 20 of this example, a second heat conducting member 28 is added, and the second heat conducting member 28 has a high thermal conductivity and can quickly transfer and diffuse heat; in one case, combined with Fig.10 and Fig.11 As shown, the second heat conductor 28 is connected to the pole lug 22, and the second heat conductor 28 forms a preset contact area with the surface of the pole lug 22, so that the second heat conductor 28 can form a heat conduction path on the pole lug 22, thereby increasing the heat conduction channel and enhancing the heat conduction effect, which is beneficial to reduce the resistance of the internal heat of the electrode assembly 21 to be transferred to the external environment, that is, the thermal resistance of the low thermal resistance channel of the electrode assembly 21 is reduced. On the one hand, the second heat conductor 28 reduces the heat inside the electrode assembly 21 by heat transfer; on the other hand, the second heat conductor 28 has a high thermal conductivity coefficient, which can absorb the heat on the pole lug 22 and diffuse the heat to the outside. The second heat conductor 28 reduces the heat inside the electrode assembly 21 by heat dissipation, so that the thermal resistance of the low thermal resistance channel of the battery is effectively reduced, thereby improving the service life of the battery.

[0138] In another case, combined with Fig.12 As shown, the second heat conductor 28 is connected to the adapter sheet 25, and a preset contact area is formed between the second heat conductor 28 and the surface of the adapter sheet 25, so that the second heat conductor 28 can form a heat conduction path on the adapter sheet 25, thereby increasing the heat conduction channel and enhancing the heat conduction effect, which is beneficial to reduce the resistance of the internal heat of the electrode assembly 21 to be transferred to the external environment, that is, the thermal resistance of the electrode assembly 21 is reduced. On the one hand, the second heat conductor 28 reduces the heat inside the electrode assembly 21 by heat transfer; on the other hand, the second heat conductor 28 has a high thermal conductivity coefficient, which can absorb the heat on the adapter sheet 25 and diffuse the heat to the outside. The second heat conductor 28 reduces the heat inside the electrode assembly 21 by heat dissipation.

[0139] In another case, combined with Fig.13 and Fig.14As shown, the pole ear 22 and the adapter sheet 25 are both connected to the second heat-conducting member 28, and the second heat-conducting member 28 connected to the pole ear 22 and the second heat-conducting member 28 connected to the adapter sheet 25 can be integrally formed or independently arranged; the second heat-conducting member 28 forms a preset contact area with the surface of the pole ear 22 and the adapter sheet 25 respectively, so that the second heat-conducting member 28 can form a heat-conducting path on the pole ear 22 and the adapter sheet 25, thereby increasing the heat-conducting channel and enhancing the heat conduction effect, so as to help reduce the resistance of the internal heat of the electrode assembly 21 to be transferred to the external environment, that is, reduce the thermal resistance of the electrode assembly 21. On the one hand, the second heat-conducting member 28 reduces the heat inside the electrode assembly 21 by heat transfer; on the other hand, the second heat-conducting member 28 has a high thermal conductivity, can absorb the heat on the pole ear 22 and the adapter sheet 25, and diffuse the heat to the outside, and the second heat-conducting member 28 reduces the heat inside the electrode assembly 21 by heat dissipation.

[0140] In this example, the second heat conductor 28 needs to have a higher thermal conductivity coefficient. Therefore, the second heat conductor 28 can be made of the same material as the first heat conductor 23, and can be made of metal material or non-metal material. For details, please refer to the introduction of the first heat conductor 23 above, which will not be repeated here.

[0141] The second heat conductive member 28 may adopt a sheet structure or a coating structure, etc. The second heat conductive member 28 may be insulated from both the pole ear 22 and the adapter plate 25, or may be conductively connected to the pole ear 22 or the adapter plate 25. When the second heat conductive member 28 is conductively connected to both the pole ear 22 and the adapter plate 25, current can still flow through the second heat conductive member 28, which is beneficial to improving the conductivity of the electrode assembly 21.

[0142] Combination Fig.10 and Fig.11 As shown, when the second heat conductive member 28 is connected to the tab 22 , the tab 22 has a first surface 221 and a second surface 222 , and the second heat conductive member 28 is connected to at least one of the first surface 221 and the second surface 222 .

[0143] Among them, the first surface 221 and the second surface 222 are two different surfaces of the pole lug 22, and the first surface 221 and the second surface 222 can be planes or curved surfaces; the first surface 221 and the second surface 222 can be parallel and coplanar, or oppositely arranged, or at an angle; for example, the pole lug 22 is in the shape of a sheet, and the first surface 221 and the second surface 222 are two oppositely arranged surfaces of the pole lug 22.

[0144] Among them, the second heat conductor 28 is connected to at least one of the first surface 221 and the second surface 222, including the second heat conductor 28 connected to the first surface 221, or the second heat conductor 28 connected to the second surface 222, or the second heat conductor 28 connected to the first surface 221 and the second surface 222, that is, the second heat conductor 28 is arranged on both the first surface 221 and the second surface 222.

[0145] When the second heat conductor 28 is connected to the first surface 221 or the second surface 222, it can be seen that the second heat conductor 28 is connected to one surface or side of the pole ear 22. This structure is applied to the case where the capacity of the battery cell 20 is not large and the heat generation of the electrode assembly 21 is not high. By connecting a second heat conductor 28 to one side of the pole ear 22, the purpose of heat conduction to the electrode assembly 21 and heat dissipation of the pole ear 22 can be achieved.

[0146] When the second heat conductor 28 is connected to the first surface 221 and the second surface 222, it can be seen that the second heat conductor 28 is connected to both surfaces or sides of the pole ear 22. This structure is applied to the case where the capacity of the battery cell 20 is large and the heat generation of the electrode assembly 21 is high. The second heat conductor 28 covers the two sides of the pole ear 22, thereby increasing the contact area with the pole ear 22, which is beneficial to improving the efficiency of heat conduction to the electrode assembly 21 and heat dissipation to the pole ear 22. Among them, the second heat-conducting member 28 connected to the first surface 221 of the pole lug 22 and the second heat-conducting member 28 connected to the second surface 222 of the pole lug 22 can be an integrally formed structure, that is, one second heat-conducting member 28 can cover the first surface 221 and the second surface 222 at the same time; or, the second heat-conducting member 28 connected to the first surface 221 of the pole lug 22 and the second heat-conducting member 28 connected to the second surface 222 of the pole lug 22 can be a split structure, for example, the second heat-conducting member 28 includes a first heat-conducting sub-member and a second heat-conducting sub-member, the first heat-conducting sub-member is connected to the first surface 221, and the second heat-conducting sub-member is connected to the second surface 222.

[0147] In this example, the second heat conductor 28 is directly connected to the first surface 221 and the second surface 222 of the pole lug 22. The surface area of ​​the pole lug 22 is large. On the one hand, it is convenient to install the second heat conductor 28. On the other hand, it can increase the contact area between the second heat conductor 28 and the surface of the pole lug 22, thereby increasing the heat transfer area and the heat dissipation area, which is beneficial to improving the efficiency of heat conduction and heat dissipation.

[0148] Combination Fig.12 As shown, when the second heat conducting member 28 is connected to the adapter plate 25 , the adapter plate 25 has a first adapter surface and a second adapter surface, and the second heat conducting member 28 is connected to at least one of the first adapter surface and the second adapter surface.

[0149] Among them, the first transfer surface and the second transfer surface are two different surfaces of the transfer plate 25, and the first transfer surface and the second transfer surface can be a plane or a curved surface; the first transfer surface and the second transfer surface can be parallel and coplanar, or configured opposite to each other, or configured at an angle; for example, the pole ear 22 is in the shape of a sheet, and the first transfer surface and the second transfer surface are two oppositely disposed surfaces of the transfer plate 25.

[0150] Among them, the second heat conductor 28 is connected to at least one of the first transfer surface and the second transfer surface, including the second heat conductor 28 connected to the first transfer surface, or the second heat conductor 28 connected to the second transfer surface, or the second heat conductor 28 connected to the first transfer surface and the second transfer surface, that is, the second heat conductor 28 is arranged on both the first transfer surface and the second transfer surface.

[0151] When the second heat conductor 28 is connected to the first transfer surface or the second transfer surface, it can be known that the second heat conductor 28 is connected to a transfer surface or side surface of the transfer sheet 25. The above structure is applied to the case where the capacity of the battery cell 20 is not large and the heat generation of the electrode assembly 21 is not high. By connecting a second heat conductor 28 to one side surface of the transfer sheet 25, the purpose of heat conduction to the electrode assembly 21 and heat dissipation to the electrode ear 22 can be achieved.

[0152] When the second heat conductor 28 is connected to the first adapter surface and the second adapter surface, it can be seen that the second heat conductor 28 is connected to both adapter surfaces or side surfaces of the adapter sheet 25. The above structure is applied to the case where the capacity of the battery cell 20 is large and the heat generation of the electrode assembly 21 is high. The second heat conductor 28 covers the two side surfaces of the adapter sheet 25, thereby increasing the contact area with the adapter sheet 25, which is beneficial to improving the efficiency of heat conduction to the electrode assembly 21 and heat dissipation of the adapter sheet 25. Among them, the second heat-conducting component 28 connected to the first transfer surface of the transfer plate 25 and the second heat-conducting component 28 connected to the second transfer surface of the transfer plate 25 can be an integrally formed structure, that is, one second heat-conducting component 28 can cover the first transfer surface and the second transfer surface at the same time; or, the second heat-conducting component 28 connected to the first transfer surface of the transfer plate 25 and the second heat-conducting component 28 connected to the second transfer surface of the transfer plate 25 can be a split structure, for example, the second heat-conducting component 28 includes a third heat-conducting sub-component and a fourth heat-conducting sub-component, the third heat-conducting sub-component is connected to the first transfer surface, and the fourth heat-conducting sub-component is connected to the second transfer surface.

[0153] In this example, the second heat conductor 28 is directly connected to the first adapter surface and the second adapter surface of the adapter plate 25. The surface area of ​​the adapter plate 25 is large. On the one hand, it is convenient for the installation of the second heat conductor 28. On the other hand, it can increase the contact area between the second heat conductor 28 and the surface of the adapter plate 25, thereby increasing the heat transfer area and the heat dissipation area, which is beneficial to improving the efficiency of heat conduction and heat dissipation.

[0154] Combination Fig.12 As shown, the second heat-conducting member 28 is in sheet shape, and the thickness of the second heat-conducting member 28 is between 0.2 mm and 3 mm; the surface area of ​​the second heat-conducting member 28 is less than or equal to the surface area of ​​the adapter plate 25, so that the surface of the second heat-conducting member 28 can be in conflict with the first adapter surface or the second adapter surface of the adapter plate 25.

[0155] In this example, the sheet-shaped second heat conductor 28 can easily form a larger contact area with the adapter plate 25, which is more conducive to increasing the thermal conductivity and heat dissipation efficiency of the second heat conductor 28 and the adapter plate 25 without increasing the weight on the adapter plate 25, which is conducive to achieving lightweight batteries; in addition, the sheet-shaped second heat conductor 28 is conducive to saving space, reducing interference with other components, and improving the rationality of the internal structural space setting of the battery cell 20.

[0156] Combination Figure 18-21 As shown, the second heat conducting member 28 includes a single graphite sheet layer 231 or multiple stacked graphite sheet layers 231 .

[0157] Graphite material has good thermal conductivity and can effectively transfer and disperse heat. Therefore, the second heat conductor 28 made of graphite material can better transfer the heat of the electrode assembly 21 and disperse the heat on the pole ear 22 and the adapter plate 25, thereby improving the thermal conductivity and heat dissipation efficiency of the second heat conductor 28 to the electrode assembly 21, the pole ear 22 and the adapter plate 25.

[0158] The graphite material is made into a sheet shape, that is, a graphite sheet 231 is formed, which is beneficial to increase the contact area between the graphite sheet 231 and the pole ear 22 and the adapter plate 25, thereby increasing the contact area between the second heat conductor 28 and the pole ear 22 and the adapter plate 25, increasing the heat conduction area and the heat dissipation area, which is beneficial to improve the heat conduction and heat dissipation efficiency.

[0159] In this example, the heat generation of the electrode assembly 21 can be known based on parameters such as the capacitance of the battery cell 20, and the number of graphite sheets 231 in the second heat-conducting member 28 can be selected accordingly. When the capacitance of the battery cell 20 is not large, the second heat-conducting member 28 can include only one layer of graphite sheet 231 to meet the requirements of heat conduction and heat dissipation of the electrode assembly 21, the tab 22, and the adapter 25; when the capacitance of the battery cell 20 is large, the number of graphite sheets 231 can be increased, and multiple layers of graphite sheets 231 can be arranged in parallel and stacked to form a sheet structure with a certain thickness. The multi-layer graphite sheet 231 structure can increase the thermal conductivity and heat dissipation performance of the second heat-conducting member 28, and to a certain extent ensure the thermal conduction and heat dissipation efficiency of the electrode assembly 21, the tab 22, and the adapter 25.

[0160] In addition, the graphite material has high chemical stability and corrosion resistance, so that it can maintain stable performance under the high temperature of the battery and the corrosive environment of the electrolyte; furthermore, the graphite material has relatively high mechanical strength and hardness, and the graphite is made into a graphite sheet layer 231 and attached to the surface of the pole lug 22 and the adapter plate 25, so that the second heat conductor 28 can also provide good structural support and durability for the pole lug 22 and the adapter plate 25; in addition, the graphite material is a lightweight material, and when connected to the pole lug 22 and the adapter plate 25, it will not generate a weight burden on the pole lug 22 and the adapter plate 25, which helps to reduce the weight of the battery cell 20.

[0161] In some examples, combined Fig.19 As shown, in the case where the second heat-conducting member 28 includes multiple stacked graphite sheets 231 , a bonding layer 232 is disposed between at least some adjacent graphite sheets 231 , and the bonding layer 232 is used to make the adjacent graphite sheets 231 adhere to each other.

[0162] The characteristics of the adhesive layer 232 may refer to the description in the above embodiment and will not be described in detail here.

[0163] In this example, the bonding layer 232 uses double-sided tape, and two adjacent graphite sheets 231 are arranged opposite to each other to form two opposite surfaces. The bonding layer 232 is coated on the two oppositely configured surfaces of the two adjacent graphite sheets 231, so as to bond and fix the two graphite sheets 231, so that the multi-layer graphite sheets 231 form a sheet-like whole, and then form a sheet-like second heat conductor 28, so that the second heat conductor 28 has higher thermal conductivity and heat dissipation performance and the overall structure is more firm and reliable.

[0164] In some examples, combined Fig.19 As shown, the second heat conductor 28 is insulated from the adapter plate 25 so that current cannot be transmitted between the second heat conductor 28 and the adapter plate 25, thereby achieving an insulated, non-conductive connection between the second heat conductor 28 and the adapter plate 25; the second heat conductor 28 is insulated from the pole ear 22 so that current cannot be transmitted between the first heat conductor 23 and the pole ear 22, thereby achieving an insulated, non-conductive connection between the second heat conductor 28 and the adapter plate 25.

[0165] The insulation arrangement between the second heat-conducting member 28 and the pole lug 22 includes adding an insulating interlayer between the second heat-conducting member 28 and the pole lug 22, wherein the insulating interlayer is made of insulating material so that the current on the pole lug 22 cannot be transmitted to the second heat-conducting member 28 during charging and discharging; the insulation arrangement between the second heat-conducting member 28 and the pole lug 22 also includes forming an insulating coating layer on the surface of the second heat-conducting member 28 or the pole lug 22, thereby achieving an insulation effect between the second heat-conducting member 28 and the pole lug 22.

[0166] The insulation arrangement between the second heat-conducting member 28 and the adapter plate 25 includes adding an insulating interlayer between the second heat-conducting member 28 and the adapter plate 25, wherein the insulating interlayer is made of insulating material so that the current on the adapter plate 25 cannot be transmitted to the second heat-conducting member 28 during charging and discharging; the insulation arrangement between the second heat-conducting member 28 and the adapter plate 25 also includes forming an insulating coating layer on the surface of the second heat-conducting member 28 or the adapter plate 25, thereby achieving an insulation effect between the second heat-conducting member 28 and the adapter plate 25.

[0167] In this example, the second heat conductor 28 is insulated from the adapter plate 25 and the pole lug 22. It can be seen that no current will flow through the second heat conductor 28, and the second heat conductor 28 does not play a role in conducting current. The second heat conductor 28 only plays a role in conducting and dissipating heat on the surfaces of the pole lug 22 and the adapter plate 25. Insulating the second heat conductor 28 from the pole lug 22 and the adapter plate 25 can reduce the risk of leakage on the second heat conductor 28, between the second heat conductor 28 and the pole lug 22, and between the second heat conductor 28 and the adapter plate 25, thereby improving the reliability of the charging and discharging process of the battery cell 20.

[0168] In some examples, combined Fig.19 As shown, the second heat-conducting member 28 also includes a second insulating layer 281; when the second heat-conducting member 28 includes a layer of graphite sheet 231, the second insulating layer 281 is coated on the outer surface of the graphite sheet 231; when the second heat-conducting member 28 includes multiple layers of graphite sheet 231, the second insulating layer 281 is coated on the outer surface of the multiple layers of graphite sheet 231.

[0169] The second insulating layer 281 may be a sealing film made of insulating material, which forms a physical isolation between the graphite sheet 231 and the tab 22 and between the graphite sheet 231 and the adapter 25 . The sealing film can provide insulation and protection for the graphite sheet 231 .

[0170] Since the second heat-conducting member 28 includes one or more layers of graphite sheet 231, it can be known that when the second heat-conducting member 28 includes one layer of graphite sheet 231, the second insulating layer 281 is wrapped around the outside of the graphite sheet 231, and when the second heat-conducting member 28 includes multiple layers of graphite sheet 231 bonded and stacked together, the second insulating layer 281 is wrapped around the outer surface of the outermost graphite sheet 231, thereby playing an insulating role on the outer surface of the entire multi-layer graphite sheet 231.

[0171] In this example, the outer surface of the second heat-conducting member 28 is insulated so that a second insulating layer 281 is formed on the outer surface of the entire second heat-conducting member 28, thereby achieving the effect of insulating the second heat-conducting member 28 from the pole lug 22 and the adapter plate 25; in addition, after the second heat-conducting member 28 has the second insulating layer 281 on the outside, the storage and use of the second heat-conducting member 28 are more convenient. When the second heat-conducting member 28 is assembled with the pole lug 22 and the adapter plate 25 respectively, it is only necessary to take out one or more second heat-conducting members 28 and fit them with the pole lug 22 or the adapter plate 25. There is no need to consider the electrical conductivity problem between the second heat-conducting member 28 and the pole lug 22 and the adapter plate 25, and the second heat-conducting member 28 can be quickly connected with the pole lug 22 and the adapter plate 25, thereby improving the convenience and reliability of installation.

[0172] In some examples, combined Figure 19-21 As shown, the edge of the second insulating layer 281 avoiding the graphite sheet 231 forms a second edge seal 282, and the second edge seal 282 is the portion of the second insulating layer 281 extending outside the graphite sheet 231. The second edge seal 282 is formed by the second insulating layer 281 extending outward from the outside of the graphite sheet 231 on one surface of the graphite sheet 231 and the second insulating layer 281 extending outward from the outside of the graphite sheet 231 on the other surface of the graphite sheet 231, which are bonded and superimposed.

[0173] In this example, the second edge seal 282 can effectively prevent the debris at the edge of the graphite sheet from falling off, reducing possible environmental pollution; the second edge seal 282 can also reinforce the edge of the graphite sheet 231, increase its mechanical strength, prevent edge cracks and wear, and thus improve the durability and stability of the graphite sheet 231. Since the battery cell 20 has a high temperature during charging and discharging, and the battery cell 20 is corrosive, the second edge seal 282 is formed on the periphery of the graphite sheet 231, which can effectively prevent oxygen, moisture, etc. from oxidizing and corroding the graphite sheet 231, thereby extending its service life.

[0174] In some examples, the second thermal conductor 28 is adhered to the pole tab 22 and / or the adapter sheet 25, that is, the second thermal conductor 28 and the pole tab 22, and the second thermal conductor 28 and the adapter sheet 25 are connected by pasting. The second thermal conductor 28 can be adhered to the surface of the pole tab 22 and the adapter sheet 25 by double-sided tape, and the double-sided tape can be adhered to the outer surface of the second insulating layer 281 of the second thermal conductor 28.

[0175] In this example, the pasting method does not require operations such as drilling holes in the second heat conductive member 28, the pole lug 22, and the adapter plate 25, which helps to reduce wear and deformation on the surfaces of the second heat conductive member 28, the pole lug 22, and the adapter plate 25, improve the durability of the battery cell 20, save workload, and improve work efficiency; the pasting method can achieve rapid connection and fixation between the second heat conductive member 28 and the pole lug 22 and the second heat conductive member 28 and the adapter plate 25, thereby improving work efficiency.

[0176] In some examples, combined Fig.13 and Fig.14 As shown, a lap portion 27 is formed between the pole ear 22 and the adapter plate 25 ; and the second heat conducting member 28 is connected to the lap portion 27 .

[0177] The overlapping portion 27 is the portion where the pole ear 22 and the adapter plate 25 overlap. For example, the pole ear 22 and the adapter plate 25 are both in sheet shape. When the pole ear 22 is connected to the adapter plate 25, the protruding end of the pole ear 22 is overlapped on the adapter plate 25, so that the connecting position between the pole ear 22 and the adapter plate 25 forms an overlapping portion 27. The overlapping portion 27 can be welded to connect and fix the pole ear 22 and the adapter plate 25; the pole ear 22 overlaps the adapter plate 25 to achieve electrical connection and conduction between the pole ear 22 and the adapter plate 25.

[0178] The adapter plate 25 overlapped on the pole ear 22 can enhance the stability of the connection between the adapter plate 25 and the pole ear 22, and can reduce the possibility of loosening or disconnection between the pole ear 22 and the pole 24 during use; in addition, the pole ear 22 and the adapter plate 25 overlap can increase the conductive path of the current, thereby improving the conductive performance, which helps to reduce resistance and ensure that electrical energy can be transmitted more efficiently.

[0179] During the charging and discharging process of the battery cell 20, current will also flow through the overlapping portion 27, so heat will also be generated on the overlapping portion 27. In addition, the pole ear 22 and the adapter plate 25 are welded at the overlapping portion 27. The welding position is more likely to generate heat accumulation, so that the low thermal resistance channel of the electrode assembly 21 cannot be reduced. The heat accumulation causes the heat inside the electrode assembly 21 to be unable to be effectively transported and diffused, which in turn causes the temperature of the electrode assembly 21 to rise, affecting the performance and life of the battery cell 20.

[0180] Therefore, in the battery cell 20 of this example, a second heat-conducting member 28 is added. The second heat-conducting member 28 has a high thermal conductivity and can quickly transfer and diffuse heat. The second heat-conducting member 28 is connected to the overlapping portion 27, and the second heat-conducting member 28 forms a preset contact area with the surface of the overlapping portion 27, so that the second heat-conducting member 28 can form a heat-conducting path on the overlapping portion 27, thereby increasing the heat-conducting channel and enhancing the heat conduction effect, so as to help reduce the resistance of the internal heat of the electrode assembly 21 to be transferred to the external environment, that is, reduce the thermal resistance of the low thermal resistance channel of the electrode assembly 21, and the second heat-conducting member 28 reduces the heat inside the electrode assembly 21 by heat transfer. In addition, the second heat-conducting member 28 has a high thermal conductivity and can absorb the heat on the overlapping portion 27 and diffuse the heat to the outside. The second heat-conducting member 28 reduces the heat inside the electrode assembly 21 by heat dissipation, so that the thermal resistance of the low thermal resistance channel of the battery is effectively reduced, thereby improving the service life of the battery.

[0181] In some examples, combined Fig.13 As shown, the overlapping portion 27 has a first overlapping surface 271 and a second overlapping surface 272 , and the second heat conducting member 28 is connected to at least one of the first overlapping surface 271 and the second overlapping surface 272 .

[0182] Among them, the first lap surface 271 and the second lap surface 272 are two different surfaces of the lap portion 27, and the first lap surface 271 and the second lap surface 272 are combined surfaces, which include a partial surface of the pole ear 22 and a partial surface of the adapter plate 25. For example, the combined surface is a step surface formed by combining a partial surface of the pole ear 22 and a partial surface of the adapter plate 25. The partial surface of the pole ear 22 and the partial surface of the adapter plate 25 can be a plane or a curved surface or a special-shaped surface; the first lap surface 271 and the second lap surface 272 can be arranged opposite to each other at the two ends of the lap portion 27 in the thickness direction; for example, the lap portion 27 is in a sheet shape, and the first lap surface 271 and the second lap surface 272 are two step surfaces of the lap portion 27 arranged opposite to each other.

[0183] Among them, the second heat conductive member 28 is connected to at least one of the first lap joint surface 271 and the second lap joint surface 272, including the second heat conductive member 28 being connected to the first lap joint surface 271, or the second heat conductive member 28 being connected to the second lap joint surface 272, or the second heat conductive member 28 being connected to the first lap joint surface 271 and the second lap joint surface 272, that is, the second heat conductive member 28 is arranged on both the first lap joint surface 271 and the second lap joint surface 272.

[0184] When the second heat conductor 28 is connected to the first lap joint surface 271 or the second lap joint surface 272, it can be seen that the second heat conductor 28 is connected to an lap joint surface or side surface of the lap joint portion 27. This structure is applied to the case where the capacity of the battery cell 20 is not large and the heat generation of the electrode assembly 21 is not high. By connecting a second heat conductor 28 to an lap joint surface of the lap joint portion 27, the purpose of heat conduction to the electrode assembly 21 and heat dissipation of the lap joint portion 27 can be achieved.

[0185] When the second heat conductor 28 is connected to the first lap joint surface 271 and the second lap joint surface 272, it can be seen that the second heat conductor 28 is connected to both lap joint surfaces or side surfaces of the lap joint 27. This structure is applied to the case where the capacity of the battery cell 20 is large and the heat generation of the electrode assembly 21 is high. The second heat conductor 28 covers the two side surfaces of the lap joint 27, increasing the contact area with the lap joint 27, which is beneficial to improving the efficiency of heat conduction to the electrode assembly 21 and heat dissipation of the lap joint 27. Among them, the second heat-conducting component 28 connected to the first lap surface 271 of the lap joint 27 and the second heat-conducting component 28 connected to the second lap surface 272 of the lap joint 27 can be an integrally formed structure, that is, one second heat-conducting component 28 can cover the first lap surface 271 and the second lap surface 272 at the same time; or, the second heat-conducting component 28 connected to the first lap surface 271 of the lap joint 27 and the second heat-conducting component 28 connected to the second lap surface 272 of the lap joint 27 can be a split structure, for example, the second heat-conducting component 28 includes a fifth heat-conducting sub-component and a sixth heat-conducting sub-component, the fifth heat-conducting sub-component is connected to the first lap surface 271, and the sixth heat-conducting sub-component is connected to the second lap surface 272.

[0186] In this example, the second heat conductor 28 is directly connected to the first overlapping surface 271 and the second overlapping surface 272 of the overlapping portion 27. The overlapping portion 27 has a larger surface area. On the one hand, it is convenient for the second heat conductor 28 to be installed. On the other hand, it can increase the contact area between the second heat conductor 28 and the surface of the overlapping portion 27, thereby increasing the heat transfer area and the heat dissipation area, which is beneficial to improving the efficiency of heat conduction and heat dissipation.

[0187] In some examples, the second thermal conductor 28 is adhered to the overlapping portion 27, that is, the second thermal conductor 28 and the overlapping portion 27 are connected by pasting. The second thermal conductor 28 can be adhered to the surface of the overlapping portion 27 by double-sided tape, and the double-sided tape can be adhered to the outer surface of the second insulating layer 281 of the second thermal conductor 28.

[0188] In this example, the gluing method eliminates the need to perform operations such as drilling holes in the second heat-conducting member 28 and the overlapping portion 27, which helps reduce wear and deformation on the surfaces of the second heat-conducting member 28 and the overlapping portion 27, improves the durability of the battery cell 20, saves workload, and improves work efficiency. The gluing method can achieve rapid connection and fixation between the second heat-conducting member 28 and the overlapping portion 27, thereby improving work efficiency.

[0189] In some examples, combined Figure 22-26 As shown, Fig. 22 FIG. 2 shows a schematic structural diagram of a battery cell 20 in which an electrode assembly 21 has two bare cells 211. Fig.23 Shows Fig. 22 axonometric drawing; Fig.24 A schematic diagram of the structure of a battery cell 20 with a pole 24 connected is shown; Fig.25 for Fig.24 axonometric drawing; Fig.26 for Fig.24 Cross-sectional view at position D in the middle; the electrode assembly 21 includes a plurality of bare cells 211 , each of the bare cells 211 includes a pole ear 22 , and each pole ear 22 is electrically connected to the adapter 25 .

[0190] The electrode assembly 21 may include at least one bare cell 211. When the electrode assembly 21 includes one bare cell 211, a battery cell 20 with a simple structure and flexible use can be formed. For some situations where large capacity is required, the electrode assembly 21 may include multiple bare cells 211, and each of the multiple bare cells 211 has an outwardly extending pole ear 22. The pole ears 22 of the multiple bare cells 211 are all connected to the adapter 25, and the adapter 25 is further connected to the pole 24. The adapter 25 can electrically connect and conduct the multiple bare cells 211.

[0191] Since the pole ears 22 of multiple bare cells 211 are connected to the adapter 25, it can be seen that heat accumulation is very likely to occur on the adapter 25. Therefore, it is very necessary to connect the second heat conductor 28 to the adapter 25 and to connect the second heat conductor 28 to the overlapping portion 27. In addition, heat is also easily accumulated on the pole ears 22 of each bare cell 211, resulting in the inability to reduce the low thermal resistance channel of the electrode assembly 21. Therefore, a second heat conductor 28 can be further connected to the pole ears 22 to enhance heat conduction and diffusion.

[0192] In this example, by configuring multiple bare cells 211 in the battery cell 20, the total capacity of the battery cell 20 can be increased, so that the battery cell 20 can provide a longer service time or support devices with higher power requirements; in addition, by using multiple bare cells 211 in the battery cell 20, it is easier to achieve voltage balance of the battery cell 20, which helps prevent over-discharge or over-charge of a bare cell 211 in the battery cell 20, thereby improving the reliability and life of the battery; it can be seen that the battery cell 20 is provided with multiple bare cells 211 can improve the overall performance, flexibility and reliability of the battery cell 20, so that it can better adapt to different application scenarios.

[0193] In some examples, combined Fig. 27 As shown, Fig. 27A schematic diagram of the exploded structure of a battery cell 20 in an embodiment is shown; the battery cell 20 also includes a shell 291 and an end cover 292, the shell 291 has an inner cavity, the electrode assembly 21 is arranged in the inner cavity, the pole 24 is connected to the end cover 292, and the end cover 292 is connected to the shell 291 to close the inner cavity.

[0194] The outer shell 291 forms the outer shell structure of the battery cell 20. The outer shell 291 is at least partially hollow to form an inner cavity. The outer shell 291 is provided with an opening, and the opening is connected to the inner cavity. The outer shell 291 is a component used to cooperate with the end cap 292 to form the internal environment of the battery cell 20, wherein the formed internal environment can be used to accommodate the electrode assembly 21, the electrolyte and other components. The outer shell 291 and the end cap 292 can be independent components, and a receiving opening can be set on the outer shell 291, and the internal environment of the battery cell 20 is formed by covering the opening with the end cap 292 at the receiving opening.

[0195] The shell 291 can be in various shapes and sizes, such as a rectangular parallelepiped, a cylindrical shape, a hexagonal prism shape, etc. Specifically, the shape of the shell 291 can be determined according to the specific shape and size of the electrode assembly 21. The shell 291 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc. The materials of the shell 291 in the embodiment of the present application include but are not limited to the above materials.

[0196] The end cap 292 refers to a component that covers the opening of the outer shell 291 to isolate the internal environment of the battery cell 20 from the external environment. Without limitation, the shape of the end cap 292 can be adapted to the shape of the outer shell 291 to match the outer shell 291. Optionally, the end cap 292 can be made of a material with a certain hardness and strength (such as aluminum alloy), so that the end cap 292 is not easily deformed when squeezed and collided, so that the battery cell 20 can have a higher structural strength and improved reliability. Functional components such as the pole 24 are provided on the end cap 292. The pole 24 can be used to be electrically connected to the electrode assembly 21 for outputting or inputting electrical energy of the battery cell 20.

[0197] Without limitation, the end cap 292 and the outer shell 291 may be integrated. Specifically, the end cap 292 and the outer shell 291 may form a common connection surface before other components are inserted into the shell. When the interior of the outer shell 291 needs to be encapsulated, the end cap 292 is covered on the outer shell 291.

[0198] The electrode assembly 21 is installed in the inner cavity. The electrode assembly 21 can be a wound structure or a stacked structure. The electrode assembly 21 can be placed in the inner cavity of the outer shell 291 through the opening on the outer shell 291. The pole ear 22 of the electrode assembly 21 can be directly connected to the pole 24, or it can be connected to the pole 24 through the adapter 25. The electrode assembly 21 is the component where the electrochemical reaction occurs in the battery cell 20. The electrode assembly 21 may include one or more bare cells 211. The bare cell 211 is mainly formed by winding or stacking the positive electrode sheet and the negative electrode sheet, and a separator is usually provided between the positive electrode sheet and the negative electrode sheet.

[0199] In this example, the shell 291 is used to protect the outside of the electrode assembly 21, the pole 24 is connected to the end cover 292, and the adapter 25 forms a key component connecting the electrode assembly 21 (or the pole ear 22) and the end cover 292. The pole 24, the adapter 25, the pole ear 22, the bare battery cell 211, the electrolyte, and the shell 291 form a low thermal resistance channel for the electrode assembly 21. The heat transfer and heat conduction of the pole ear 22 and the adapter 25 are particularly important. Therefore, a second heat conductor 28 is arranged on the pole ear 22, the adapter 25, and on the overlapping portion 27 between the pole ear 22 and the adapter 25 for heat transfer and heat conduction, which can effectively disperse and conduct the heat of the electrode assembly 21, and to a certain extent avoid overheating that causes performance degradation or safety problems of the battery cell 20.

[0200] In a specific embodiment, the battery cell 20 includes an electrode assembly 21, a pole 24 and a first heat-conducting member 23, the electrode assembly 21 includes a pole ear 22, and the first heat-conducting member 23 is connected to the pole ear 22; or, the battery cell 20 includes an electrode assembly 21, a pole 24, a transfer plate 25 and a second heat-conducting member 28; the electrode assembly 21 includes a pole ear 22, and the transfer plate 25 is electrically connected between the pole ear 22 and the pole 24; the second heat-conducting member 28 is connected to the pole ear 22 and / or the transfer plate 25; the electrode assembly 21 includes one or more bare cells 211, each bare cell 211 includes The pole lugs 22 are each electrically connected to the adapter plate 25; a lap joint 27 is formed between the pole lugs 22 and the adapter plate 25; a second heat conductor 28 is connected to the lap joint 27; the first heat conductor 23 and the second heat conductor 28 each include a graphite sheet 231 or multiple stacked graphite sheets 231, and adjacent graphite sheets 231 are bonded by an adhesive layer 232, and the outer surface of the graphite sheets 231 has an insulating layer, so that the first heat conductor 23 is insulated from the pole lugs 22, and the second heat conductor 28 is insulated from the pole lugs 22, the adapter plate 25 and the lap joint 27.

[0201] Based on the above battery cell 20, the present application further proposes an example of a battery 100. The battery 100 includes the battery cell 20 as described in any of the above examples.

[0202] The battery 100 in this example may include a box body 10, and a battery cell 20 is installed in the box body 10. The battery 100 may include one battery cell 20, or may include multiple battery cells 20. When multiple battery cells 20 are provided in the battery 100, the multiple battery cells 20 may be arranged according to a preset rule. The multiple battery cells 20 may be arranged in a row of multiple columns or multiple rows of multiple columns. The multiple battery cells 20 may be connected in series, in parallel, or in series-parallel hybrid.

[0203] It is understandable that in this example, only the battery 100 including the above-mentioned battery cell 20 is described, and the battery 100 may also include other functional components, which will not be described in detail.

[0204] The example of the battery 100 in the present application is based on the example of the battery cell 20 described above. The example of the battery 100 includes all the technical effects of the example of the battery cell 20 described above, which will not be described in detail.

[0205] In some examples, an example of an electrical device is disclosed, the electrical device including the battery cell 20 described in any of the above examples, or the battery 100 described in any of the above examples.

[0206] The electrical devices in this example include, but are not limited to: mobile phones, portable devices, laptop computers, electric vehicles, electric vehicles 1000, ships, spacecraft, electric toys and electric tools, etc. The battery cells 20 described in any of the above examples can be installed separately in the electrical devices, and the above-mentioned battery 100 can also be installed in the electrical devices.

[0207] The examples of the electrical device in the present application are based on the examples of the battery cell 20 or the battery 100 described above, and the examples of the electrical device include all the technical effects of the examples of the battery cell 20 or the battery 100 described above, which will not be repeated.

[0208] The above are only preferred embodiments of the present application, and only specifically describe the technical principles of the present application. These descriptions are only for explaining the principles of the present application and cannot be interpreted as limiting the scope of protection of the present application in any way. Based on the explanation here, any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application, and other specific implementation methods of the present application that can be associated with the technicians in this field without creative work, should be included in the scope of protection of the present application.

Claims

1. A battery cell, characterized in that: include: An electrode assembly includes a tab having a first surface and a second surface; A pole, electrically connected to the pole lug; The first heat-conducting member is in sheet form and adheres to at least one of the first surface and the second surface. The first heat-conducting member includes a single graphite sheet or multiple stacked graphite sheets.

2. The battery cell according to claim 1, characterized in that: In the case where the first heat conducting member comprises a plurality of stacked graphite sheets, a bonding layer is disposed between at least some of the adjacent graphite sheets.

3. The battery cell according to claim 1 or 2, characterized in that: The first heat conducting member is insulated from the tab.

4. The battery cell according to claim 3, characterized in that: The first heat conductor also includes a first insulating layer; when the first heat conductor includes a layer of graphite sheet, the first insulating layer is coated on the outer surface of the graphite sheet; when the first heat conductor includes multiple layers of graphite sheet, the first insulating layer is coated on the outer surface of the multiple layers of graphite sheet.

5. The battery cell according to claim 4, characterized in that: The edge of the first insulating layer avoiding the graphite sheet forms a first edge seal.

6. The battery cell according to claim 1 or 2, characterized in that: The first heat conducting member is adhered to the pole lug.

7. A battery cell, characterized in that: include: An electrode assembly includes a tab having a first surface and a second surface; Pole; A transfer plate, electrically connected between the pole lug and the pole, the transfer plate having a first transfer surface and a second transfer surface; The second heat-conducting member is in sheet form, and is connected to at least one of the first surface and the second surface, or the second heat-conducting member is connected to at least one of the first transfer surface and the second transfer surface; the second heat-conducting member includes a layer of graphite sheet or multiple layers of stacked graphite sheets.

8. The battery cell according to claim 7, characterized in that: In the case where the second heat conducting member comprises a plurality of stacked graphite sheets, at least a portion of adjacent graphite sheets are provided with a bonding layer.

9. The battery cell according to claim 7 or 8, characterized in that: The second heat-conducting member is insulated from the adapter sheet; the second heat-conducting member is insulated from the tab.

10. The battery cell according to claim 9, characterized in that: The second heat conductive member also includes a second insulating layer; when the second heat conductive member includes a layer of graphite sheet, the second insulating layer is coated on the outer surface of the graphite sheet; when the second heat conductive member includes multiple layers of graphite sheet, the second insulating layer is coated on the outer surface of the multiple layers of graphite sheet; the second insulating layer is connected to the adapter and / or the tab.

11. The battery cell according to claim 10, characterized in that: The edge of the second insulating layer avoiding the graphite sheet forms a second edge seal.

12. The battery cell according to claim 7 or 8, characterized in that: The second heat conducting member is adhered to the tab and / or the adapter.

13. The battery cell according to claim 7 or 8, characterized in that: The overlapping portion of the electrode tab and the adapter sheet forms a lap portion; the lap portion has a first lap surface and a second lap surface, and the second heat conducting member is connected to at least one of the first lap surface and the second lap surface.

14. The battery cell according to claim 13, characterized in that: The second heat conducting member is adhered to the overlapping portion.

15. The battery cell according to claim 7 or 8, characterized in that: The electrode assembly includes a plurality of bare cells, each of the bare cells includes a pole tab, and each of the pole tabs is electrically connected to the adapter.

16. A battery, characterized in that: Comprising a battery cell as claimed in any one of claims 1 to 15.

17. An electrical device, characterized in that: Comprising the battery monomer according to any one of claims 1 to 15, or, comprising the battery according to claim 16.

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