Battery cells, battery devices and power-consuming devices

Abstract

The present application provides a battery cell, a battery device and an electric device. The battery cell comprises: a shell; an electrode assembly located in the shell, the electrode assembly comprises an electrode body and a pole ear, the electrode body comprises a first end face and a second end face arranged opposite to each other in a first direction, and a side face connected between the first end face and the second end face, the pole ear is connected to the electrode body and extends out of at least one of the first end face and the second end face; a heat spreader assembly comprises a first heat spreader, the first heat spreader comprises a first chamber and a first capillary structure arranged in the first chamber, the first capillary structure extends in a first direction, a heat exchange medium is contained in the first chamber, the first heat spreader is connected to the side face in a heat-conductive manner, so that the heat exchange medium circulates in the first chamber along the first direction through the first capillary structure, so that the first heat spreader can balance the temperature of the side face in the first direction, enhance the heat dissipation capacity of the battery cell, and improve the performance of the battery cell.

Description

Technical Field

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

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

[0003] However, during actual operation of a battery cell, excessively high internal temperature will have an adverse effect on the service life and performance of the battery cell. Utility Model Content

[0004] In view of the above problems, the present application provides a battery cell, a battery device and an electrical device, which can balance the temperature of the battery cell and enhance the performance of the battery cell.

[0005] In the first aspect, the present application provides a battery cell, comprising: a shell; an electrode assembly, located in the shell, the electrode assembly comprising an electrode body and a pole ear, the electrode body comprising a first end face and a second end face arranged opposite to each other in a first direction, and a side surface connected between the first end face and the second end face, the pole ear is connected to the electrode body and extends out of the first end face; a heat spreading assembly, located in the shell, comprising a first heat spreading part, the first heat spreading part comprising a first chamber and a first capillary structure arranged in the first chamber, the first capillary structure extends along the first direction, a heat exchange medium is accommodated in the first chamber, the first heat spreading part and the side surface are thermally conductively connected, and the first heat spreading part and the electrode assembly are insulated from each other.

[0006] In the scheme of the embodiment of the present application, the battery cell includes a shell, an electrode assembly and a heat spreader assembly. The electrode assembly is located inside the shell, and the shell provides accommodation and protection for the electrode assembly. The electrode assembly includes an electrode body and a pole ear. The electrode body includes a first end face and a second end face arranged opposite to each other in a first direction, and a side surface connected between the first end face and the second end face. The electrode body forms a loop with an external component through the pole ear extending from the first end face. The heat spreader assembly is located inside the shell. The heat spreader assembly includes a first heat spreader portion thermally connected to the side surface. The first heat spreader portion and the electrode assembly are insulated from each other. The first heat spreader portion includes a first chamber for accommodating a heat exchange medium and a first capillary structure. The first capillary structure extends in a first direction so that the heat exchange medium circulates in the first chamber along the first direction through the first capillary structure, so that the first heat spreader portion can balance the temperature of the side surface in the first direction, enhance the heat dissipation capacity of the battery cell, and improve the performance of the battery cell.

[0007] In some embodiments, the side includes two first side surfaces and two second side surfaces, the two first side surfaces are arranged opposite to each other in the second direction, the two second side surfaces are arranged opposite to each other in the third direction, the first direction, the second direction and the third direction intersect each other, the area of ​​the first side surface is greater than the area of ​​the second side surface, and the first heat dissipating portion is arranged on at least one of the two first side surfaces.

[0008] In the solution of the embodiment of the present application, the side includes two first side surfaces and two second side surfaces, the area of ​​the first side surfaces is greater than the area of ​​the second side surfaces, and the first heat equalizing portion is arranged on at least one of the two first side surfaces, which not only helps to increase the contact area between the first heat equalizing portion and the electrode body to enhance the thermal conductivity effect of the first heat equalizing portion, but also better balances the internal temperature of the battery cell and improves the heat dissipation capacity of the battery cell.

[0009] In some embodiments, the heat equalizing assembly also includes a second heat equalizing portion, which is arranged between the shell and at least a portion of the second end surface along the first direction. The second heat equalizing portion includes a second chamber and a second capillary structure arranged in the second chamber. The second chamber contains a heat exchange medium. The first chamber and the second chamber are in communication, and the first capillary structure and the second capillary structure are connected to each other.

[0010] In the scheme of the embodiment of the present application, the heat equalizing component also includes a second heat equalizing portion arranged along the first direction between the shell and at least part of the second end surface. The first heat equalizing portion conducts and equalizes the heat on the side in the first direction. The first chamber and the second chamber are connected. Through the flow of heat exchange medium in the first chamber and the second chamber, the heat on the side can be exchanged to the outside through the second heat equalizing portion and the shell to balance the heat of the battery cells and improve the heat dissipation effect of the battery cells.

[0011] In some embodiments, the side includes two first side surfaces and two second side surfaces, the two first side surfaces are arranged opposite to each other in the second direction, the two second side surfaces are arranged opposite to each other in the third direction, the first direction, the second direction and the third direction intersect each other, the area of ​​the first side surface is greater than the area of ​​the second side surface, the first heat equalizing portion is arranged on at least one of the two first side surfaces, the second heat equalizing portion is connected to the first heat equalizing portion arranged on the first side surface, and the second capillary structure extends along the second direction.

[0012] In the scheme of the embodiment of the present application, the first heat equalizing portion is arranged on the first side to equalize the heat of the first side, and the second capillary structure extends along the second direction to transfer the high-temperature heat exchange medium in the first chamber to the low-temperature area away from the first capillary structure to better equalize the temperature of the first side, and the temperature of the first side is transferred to the outside through the shell through the second heat equalizing portion to equalize the heat of the battery cells and improve the heat dissipation effect of the battery cells.

[0013] In some embodiments, a plurality of electrode assemblies are provided, and the plurality of electrode assemblies are stacked along the second direction. The first heat-spreading portion includes a middle heat-spreading member, and the middle heat-spreading member is provided between two adjacent first sides of two adjacent electrode assemblies. The middle heat-spreading member includes a middle chamber, and a middle capillary structure provided in the middle chamber. The middle capillary structure extends along the first direction, and the middle chamber is connected to the second chamber, and the middle capillary structure and the second capillary structure are connected to each other.

[0014] In the scheme of the embodiment of the present application, the middle heat spreader is arranged between two adjacent first sides of two adjacent electrode assemblies, the heat exchange medium flows in the middle chamber to transfer heat between the adjacent first sides in a first direction, the middle chamber and the second chamber are connected, the middle capillary structure and the second capillary structure are connected to each other, the heat exchange medium is transferred to the second chamber through the middle chamber, and the heat of the adjacent first sides is exchanged through the second heat spreader and the shell and the external environment through the flow of the heat exchange medium in the middle chamber and the second chamber, so as to balance the heat of the battery cells and improve the heat dissipation effect of the battery cells.

[0015] In some embodiments, the middle capillary structure includes two first sub-capillary structures stacked along the second direction, the second capillary structure includes two second sub-capillary structures spaced apart along the second direction, and each second sub-capillary structure is connected to an adjacent first sub-capillary structure.

[0016] In the solution of the embodiment of the present application, two independent capillary structures are formed in the middle chamber and the second chamber through two first sub-capillary structures and the second sub-capillary structures, so as to improve the problem of the decrease in energy density of the battery cell due to the excessive volume of the heat spreader while improving the thermal conductivity rate of the heat spreader.

[0017] In some embodiments, the heat dissipation assembly includes a first wall portion and two second wall portions, the first wall portion is arranged between the shell and at least a portion of the second end surface, the second wall portion includes a first segment and a second segment, the two first segments are arranged between adjacent first side surfaces and are connected to each other to form an intermediate chamber, the second segment is connected to the side of the first segment facing the first wall portion, the two second segments extend back to back and are connected to the first wall portion to form a second chamber.

[0018] In the solution of the embodiment of the present application, the first wall portion and the two second wall portions are covered to form an intermediate chamber and a second chamber, so as to reduce the processing difficulty of the heat spreader component.

[0019] In some embodiments, the first heat equalizing part includes an end heat equalizing member, which is arranged between the first side and the shell, and the end heat equalizing member includes an end chamber, and an end capillary structure arranged in the end chamber, the end capillary structure extends along the first direction, the end chamber is connected to the second chamber, and the end capillary structure and the second capillary structure are connected to each other.

[0020] In the scheme of the embodiment of the present application, the heat exchange medium flows in the middle chamber to transfer heat between adjacent first sides in a first direction, the middle chamber, the second chamber and the end chamber are connected, the middle capillary structure, the second capillary structure and the end capillary structure are connected to each other, and the heat exchange medium is transferred to the second chamber and the end chamber through the middle chamber. The heat exchange medium flows in the middle chamber, the second chamber and the end chamber to exchange the heat of the adjacent first sides through the second heat spreader, the end heat spreader, the shell and the external environment, so as to balance the heat of the battery cells and improve the heat dissipation effect of the battery cells.

[0021] In some embodiments, the heat dissipation assembly includes a third wall portion and two fourth wall portions, the third wall portion includes a third segment and a fourth segment, the third segment is arranged between the shell and the second end face, the two fourth segments are arranged at both ends of the third segment in the second direction and extend between the first side face and the shell, the two fourth wall portions are arranged along the second direction, the fourth wall portion includes a fifth segment and a sixth segment, the two sixth segments are arranged at both ends of the fifth segment in the second direction, one sixth segment is located between the first side face and the fourth segment, the fourth segment and the sixth segment are connected to form an end chamber, the other sixth segment is located between the two first side faces, the sixth segments of the two fourth wall portions are connected to form an intermediate chamber, the fifth segment is arranged between the third segment and the second end face, and the fifth segment and the third segment are connected to form a second chamber.

[0022] In the solution of the embodiment of the present application, the third wall portion and the two fourth wall portions are covered to form the middle chamber, the second chamber and the end chamber, so as to reduce the processing difficulty of the heat spreader component.

[0023] In some embodiments, the first capillary structure is disposed around a circumference of the electrode assembly.

[0024] In the solution of the embodiment of the present application, the first capillary structure is arranged around the circumference of the electrode assembly to increase the circulation speed of the heat exchange medium in the first chamber, so that the heat equalizing assembly can better balance the temperature of the electrode assembly.

[0025] In some embodiments, a gap extending along the first direction and penetrating the first heat-leveling portion is formed between two ends of the first heat-leveling portion along the circumference of the electrode body.

[0026] In the scheme of the embodiment of the present application, a gap extending along the first direction and penetrating the first heat equalizing portion is formed between the two ends of the first heat equalizing portion along the circumferential side of the electrode body. By setting the gap, the first heat equalizing portion can be deformed synchronously during the expansion of the electrode assembly, thereby reducing the risk of the first heat equalizing portion being expanded by the electrode body, thereby increasing the service life of the heat equalizing assembly and improving the reliability of the battery cell.

[0027] In some embodiments, the orthographic projection area of ​​the first heat-dissipating portion in the second direction is S1, and the area of ​​the first side surface is S2, where S1 ≥ 0.9*S2.

[0028] In the solution of the embodiment of the present application, when the orthographic projection area S1 of the first heat-scaling portion in the second direction and the area S2 of the first side surface satisfy the above conditions, the heat-scaling component has sufficient thermal conductivity to balance the temperature of the side surface.

[0029] In some embodiments, the electrode assembly includes a pole piece, which includes a current collector and an active material layer. The active material layer is disposed on at least a portion of the surface of the current collector, and the orthographic projection of the active material layer in the second direction is located within the first heat-dissipating portion.

[0030] In the solution of the embodiment of the present application, the orthographic projection of the active material layer in the second direction is located in the first heat-averaging portion to improve the heat conduction efficiency of the first heat-averaging portion.

[0031] In some embodiments, the battery cell further includes an insulating component, at least a portion of the insulating component forms a receiving cavity, and the heat spreader component is disposed in the receiving cavity.

[0032] In the solution of the embodiment of the present application, at least a partial area of ​​the insulating component forms a receiving cavity, and the heat spreader component is arranged in the receiving cavity, so that the heat spreader component can be insulated from the electrode component by the insulating component.

[0033] In some embodiments, the insulating component is coated on the side surface and the second end surface.

[0034] In the solution of the embodiment of the present application, the insulating component is coated on the side and the second end face to insulate the heat spreader component, the shell and the electrode assembly from each other, and there is no need to set up a Mylar film, which helps to reduce the cost of segmented preparation of the battery cell, and can reduce the thickness of the battery cell and improve the energy density of the battery cell.

[0035] In a second aspect, the present application provides a battery device, comprising a battery cell according to the embodiment of the first aspect.

[0036] In a third aspect, the present application provides an electrical device, comprising the battery device of the above-mentioned second aspect embodiment. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Also, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0038] Figure 1 is a structural schematic diagram of a vehicle provided by an embodiment of the present application;

[0039] Figure 2 is a schematic structural diagram of a battery device provided in one embodiment of the present application;

[0040] Figure 3 is a structural schematic diagram of a battery module provided in an embodiment of the application;

[0041] Figure 4 is an exploded view of a battery cell provided in one embodiment of the present application;

[0042] Figure 5 is a schematic structural diagram of an electrode assembly of a battery cell provided in one embodiment of the present application;

[0043] Figure 6 is a partial structural schematic diagram of a battery cell provided in one embodiment of the present application;

[0044] Figure 7 is a partial structural schematic diagram of a battery cell provided in one embodiment of the present application;

[0045] Figure 8 is a partial structural schematic diagram of a battery cell provided in one embodiment of the present application;

[0046] Fig. 9 is a partial structural schematic diagram of a battery cell provided in one embodiment of the present application;

[0047] Fig.10 is a partial structural schematic diagram of a battery cell provided in one embodiment of the present application;

[0048] Fig.11 is an exploded view of a heat spreader assembly of a battery cell provided in one embodiment of the present application;

[0049] Fig.12 is a partial structural schematic diagram of a battery cell provided in one embodiment of the present application;

[0050] Fig.13 is an exploded view of a heat spreader assembly of a battery cell provided in one embodiment of the present application;

[0051] Fig.14 is a partial structural schematic diagram of a battery cell provided in one embodiment of the present application;

[0052] Fig.15 It is a partial structural schematic diagram of a heat spreader assembly of a battery cell provided in one embodiment of the present application;

[0053] Fig.16 It is a partial structural schematic diagram of a heat spreader assembly of a battery cell provided in one embodiment of the present application;

[0054] Fig.17It is a partial structural schematic diagram of a pole piece of a battery cell provided in one embodiment of the present application;

[0055] Fig.18 It is a partial structural schematic diagram of a heat spreader assembly of a battery cell provided in one embodiment of the present application;

[0056] Fig.19 It is a partial structural schematic diagram of a battery cell provided in one embodiment of the present application.

[0057] Reference numerals:

[0058] 1. Vehicle; 101. Motor; 102. Controller; 2. Battery device; 201. Battery module; 202. Box; 2021. First box; 2022. Second box;

[0059] 3. Battery cells;

[0060] 4. Shell;

[0061] 5. electrode assembly; 51. pole ear; 52. electrode body; 521. first end face; 522. second end face; 523. side face; 5231. first side face; 5232. second side face; 53. pole piece; 531. current collector; 532. active material layer; 5311. current collector section; 5312. blank section;

[0062] 6. Top cover assembly; 61. Electrode terminal;

[0063] 7. Heat-saturating assembly; 71. First heat-saturating part; 72. Second heat-saturating part; 73. Middle heat-saturating element; 74. End heat-saturating element; 711. First chamber; 712. First capillary structure; 713. Gap; 721. Second chamber; 722. Second capillary structure; 731. Middle chamber; 732. Middle capillary structure; 741. End chamber; 742. End capillary structure; 751. First sub-capillary structure; 752. Second sub-capillary structure; 761. First wall; 762. Second wall; 7621. First subsection; 7622. Second subsection; 763. Third wall; 7631. Third subsection; 7632. Fourth subsection; 764. Fourth wall; 7641. Fifth subsection; 7642. Sixth subsection;

[0064] 8. Insulation assembly; 81. Accommodation cavity;

[0065] X, first direction; Y, second direction; Z, third direction. DETAILED DESCRIPTION

[0066] 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.

[0067] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in the embodiments of the present application should have the common meanings understood by technicians in the field to which the embodiments of the present application belong.

[0068] In the description of the embodiments of the present application, the orientations or positional relationships indicated by technical terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", and "circumferential" are based on the orientations or positional relationships shown in the accompanying drawings and 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.

[0069] In addition, the technical terms "first", "second", etc. are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number 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.

[0070] 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 ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0071] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0072] At present, from the perspective of market development, the application of battery devices is becoming more and more extensive. Battery devices are not only used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, electric cars, as well as military equipment and aerospace and other fields. With the continuous expansion of the application field of battery devices, the market demand is also constantly expanding.

[0073] During the use of the battery cell, its internal temperature is too high, resulting in a decrease in the performance and service life of the battery cell.

[0074] The reason for the above problems is that during the operation of the battery cell, the electrode assembly undergoes electrochemical reactions and generates heat, which needs to be exchanged between the shell and the external environment. Limited by the thermal conductivity of the shell, the internal temperature of the battery cell cannot be quickly transferred to the outside world, and its internal temperature accumulates and rises. The electrode assembly is prone to lithium deposition due to excessive temperature, affecting the performance of the battery cell.

[0075] Based on the above problems, an embodiment of the present application provides a battery cell, which includes a shell, an electrode assembly and a heat spreader assembly. The electrode assembly is located inside the shell, and the shell provides accommodation and protection for the electrode assembly. The electrode assembly includes an electrode body and a pole ear. The electrode body includes a first end face and a second end face arranged opposite to each other in a first direction, and a side surface connected between the first end face and the second end face. The electrode body forms a loop with an external component through the pole ear extending from the first end face. The heat spreader assembly is located in the shell, and the heat spreader assembly includes a first heat spreader portion thermally connected to the side surface. The first heat spreader portion and the electrode assembly are insulated from each other. The first heat spreader portion includes a first chamber for accommodating a heat exchange medium and a first capillary structure. The first capillary structure extends in a first direction so that the heat exchange medium circulates in the first chamber along the first direction through the first capillary structure, so that the first heat spreader portion can balance the temperature of the side surface in the first direction, enhance the heat dissipation capacity of the battery cell, and improve the performance of the battery cell.

[0076] The technical solutions described in the embodiments of the present application are applicable to battery devices and electrical devices using the battery devices.

[0077] The electrical device may be a vehicle, a mobile phone, a portable device, a laptop computer, a ship, a spacecraft, an electric toy, an electric tool, and the like. The vehicle 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, and the like; the spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, and the like; the electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, and the like; the electric tool may include a metal cutting electric tool, a grinding electric tool, an assembly electric tool, and an electric tool for railways, such as an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact drill, a concrete vibrator, and an electric planer, and the like. The embodiments of the present application do not impose any special restrictions on the above-mentioned electrical devices.

[0078] In the embodiment of the present application, the battery cell may be a secondary battery. A secondary battery refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0079] The battery cell can be a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel metal hydride battery, a nickel cadmium battery, a lead storage battery, etc., which is not limited in the embodiments of the present application. The battery cell can be cylindrical, flat, rectangular or other shapes, which is not limited in the embodiments of the present application.

[0080] The battery device mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity. For example, the battery device mentioned in the present application may include a battery module or a battery pack. The battery pack generally includes a box for encapsulating one or more battery cells. The box can prevent liquid or other foreign matter from affecting the charging or discharging of the battery cells.

[0081] A battery cell includes an electrode assembly and an electrolyte. The electrode assembly includes a positive electrode sheet, a negative electrode sheet and a separator. A battery cell mainly works by the movement of metal ions between the positive electrode sheet and the negative electrode sheet. The positive electrode sheet includes a positive current collector and a positive active material layer. The positive active material layer is coated on the surface of the positive current collector. The positive current collector includes a positive current collector and a positive electrode ear connected to the positive current collector. The positive current collector is coated with a positive active material layer, and the positive electrode ear is not coated with a positive active material layer. Taking a lithium-ion battery as an example, the material of the positive current collector can be aluminum, and the positive active material layer includes a positive active material. The positive active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganese oxide, etc. The negative electrode sheet includes a negative current collector and a negative active material layer, and the negative active material layer is coated on the surface of the negative current collector; the negative current collector includes a negative current collector and a negative electrode tab connected to the negative current collector, the negative current collector is coated with the negative active material layer, and the negative electrode tab is not coated with the negative active material layer. The material of the negative current collector can be copper, and the negative active material layer includes a negative active material, and the negative active material can be carbon or silicon, etc. The material of the separator can be PP (polypropylene, polypropylene) or PE (polyethylene, polyethylene), etc.

[0082] It should be understood that the technical solutions described in the embodiments of the present application are not limited to the battery devices and electrical equipment described above, but can also be applied to all battery devices including a box and electrical equipment using the battery devices. However, for the sake of simplicity, the following embodiments are described using electric vehicles as examples.

[0083] Please refer to Figure 1 , Figure 1 A schematic diagram of the structure of a vehicle 1 provided for some embodiments of the present application. Vehicle 1 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 device 2 is provided inside the vehicle 1, and the battery device 2 may be provided at the bottom, head or tail of the vehicle 1. The battery device 2 may be used to power the vehicle 1, for example, the battery device 2 may be used as an operating power source for the vehicle 1. The vehicle 1 may also include a controller 102 and a motor 101, and the controller 102 is used to control the battery to power the motor 101, for example, for the starting, navigation and working power requirements of the vehicle 1 during driving.

[0084] In some embodiments of the present application, the battery device 2 can not only serve as an operating power source for the vehicle 1, but also serve as a driving power source for the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0085] Figure 2 A schematic structural diagram of a battery device according to an embodiment of the present application is shown.

[0086] The battery device 2 mentioned in the embodiment of the present application may include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly may include a plurality of battery cells 3, and the plurality of battery cells 3 are connected in series, in parallel or in mixed connection through a busbar.

[0087] In some embodiments, a battery cell assembly is generally formed by arranging a plurality of battery cells 3 .

[0088] As an example, the battery cell assembly may be a battery module 201, and the battery module 201 is formed by arranging and fixing a plurality of battery cells 3 to form an independent module. As an example, the battery module 201 may be formed by bundling a plurality of battery cells 3 by a cable tie.

[0089] In some embodiments, the battery device may be a battery pack, which includes a case 202 and one or more battery cell assemblies, wherein the battery cell assemblies are housed in the case 202 .

[0090] As an example, the battery cell assembly may be a battery module 201 , and the battery cell assembly may be accommodated in the box by fixing the battery module 201 in the box.

[0091] As an example, the battery cell assembly may also be accommodated in the box body 202 by directly fixing the plurality of battery cells 3 to the box body 202 .

[0092] As an example, the box 202 may include a first box 2021 and a second box 2022. The first box 2021 and the second box 2022 are buckled together to form a closed space inside the box 202 to accommodate the battery monomer assembly. The closed space here means covering or closing, which can be sealed or unsealed. The first box 2021 can be a top cover or a bottom plate.

[0093] As an example, the box body 202 may include a top cover, a frame, and a bottom plate. The top cover and the bottom plate are respectively connected to the frame, so that a closed space is formed inside the box body 202 to accommodate the battery cell assembly.

[0094] In some embodiments, the box 202 can be used as a part of the chassis structure of the vehicle. For example, a part of the box 202 can become at least a part of the floor of the vehicle, or a part of the box 202 can become at least a part of the cross beam and the longitudinal beam of the vehicle.

[0095] Figure 3 A schematic structural diagram of a battery module 201 according to an embodiment of the present application is shown.

[0096] In some embodiments, Figure 2 and Figure 3As shown, there are multiple battery cells 3, and the multiple battery cells 3 are first connected in series, parallel or mixed to form a battery module 201. The multiple battery modules 201 are then connected in series, parallel or mixed to form a whole, and are accommodated in the box 202.

[0097] The multiple battery cells 3 in the battery module 201 can be electrically connected through a busbar component to achieve parallel connection, series connection or mixed connection of the multiple battery cells 3 in the battery module 201 .

[0098] In the present application, the battery cell 3 may include a lithium-ion battery cell, a sodium-ion battery cell, a magnesium-ion battery cell, etc., which is not limited in the embodiments of the present application.

[0099] Figure 4 FIG. 1 is an exploded view of a battery cell provided in an embodiment of the present application. A battery cell 3 refers to the smallest unit constituting a battery. Figure 4 The battery cell 3 includes a top cover assembly 6 , a shell 4 and an electrode assembly 5 .

[0100] The electrode assembly 5 is a component in the battery cell 3 where electrochemical reactions occur. One or more electrode assemblies 5 may be included in the housing 4. The electrode assembly 5 is mainly formed by winding or stacking pole sheets, which are divided into positive pole sheets and negative pole sheets, and a separator is usually provided between the positive pole sheet and the negative pole sheet. The parts of the positive pole sheet and the negative pole sheet with active materials constitute the electrode body 52, and the parts of the positive pole sheet and the negative pole sheet without active materials each constitute a pole ear 51. The positive pole ear and the negative pole ear may be located together at one end of the electrode body 52 or at both ends of the electrode body 52, respectively. During the charge and discharge process of the battery cell 3, the positive active material and the negative active material react with the electrolyte, and the pole ear 51 connects the electrode terminal to form a current loop.

[0101] The electrode assembly 5 may be a winding structure, a laminated structure, or a mixed structure of winding and laminated structures.

[0102] In some embodiments, the electrode assembly 5 is a wound structure. The positive electrode sheet and the negative electrode sheet are wound into a wound structure.

[0103] In some embodiments, the electrode assembly 5 is a laminated structure. As an example, a plurality of positive and negative electrodes may be provided, and the plurality of positive and negative electrodes may be alternately stacked, and a plurality of separators may be provided, and each separator may be provided between any adjacent positive or negative electrodes, or the separator may be provided continuously and folded between any adjacent positive or negative electrodes.

[0104] In some embodiments, the shape of the electrode assembly 5 can be cylindrical, flat, or polygonal.

[0105] In some embodiments, the electrode assembly 5 is provided with tabs, which can lead current out of the electrode assembly. The tabs include a positive tab and a negative tab.

[0106] The battery cell may include a shell. The shell 4 is a component used to cooperate with the top cover assembly 6 to form an internal environment of the battery cell 3, wherein the formed internal environment can be used to accommodate the electrode assembly 5, the electrolyte (not shown in the figure) and other components. The shell 4 can be a steel shell, an aluminum shell, a plastic shell (such as polypropylene), a composite metal shell (such as a copper-aluminum composite shell) or an aluminum-plastic film, etc. In some embodiments, the shell 4 can be a sealed structure or a non-sealed structure. As an example, when the shell 4 is a non-sealed structure, the shell 4 plays a role in protecting the electrode assembly 5, and a sealing bag is also included between the shell 4 and the electrode assembly 5, and the sealing bag is used to encapsulate the electrode assembly and the electrolyte. Specifically, the sealing bag can be a bag-shaped insulating member or an aluminum-plastic film. When the shell 4 is a sealed structure, it is used to encapsulate components such as the electrode assembly 5 and the electrolyte.

[0107] As an example, the battery cell 3 can be a cylindrical battery cell, a prismatic battery cell, a soft-pack battery cell or a battery cell of other shapes. The prismatic battery cell includes a square shell battery cell, a blade-shaped battery cell, a polygonal battery, such as a hexagonal battery, etc. There is no special limitation in this application.

[0108] The housing 4 and the top cover assembly 6 may be independent components, and one or more openings may be provided on the housing 4, and one or more top cover assemblies 6 cover the openings to form the internal environment of the battery cell 3. Optionally, the top cover assembly 6 and the housing 4 may be integrated. Optionally, the top cover assembly 6 and the housing 4 may form a common connection surface before other components are placed in the housing, and when the interior of the housing 4 needs to be encapsulated, the top cover assembly 6 covers the housing 4.

[0109] In some embodiments, the electrode terminal 61 may be disposed on the top cover assembly 6 or on the housing 4, and the electrode terminal 61 is electrically connected to the tab 51. The electrode terminal 61 may be directly connected to the tab 51 or indirectly connected to the tab 51 through a switching mechanism.

[0110] See also Figure 5 and Figure 6 , Figure 5 is a schematic structural diagram of an electrode assembly of a battery cell provided in one embodiment of the present application; Figure 6 It is a partial structural schematic diagram of a battery cell provided in one embodiment of the present application.

[0111] First, as Figures 4 to 6As shown, the present application provides a battery cell 3, which includes a shell 4, an electrode assembly 5 and a heat spreader 7. The electrode assembly 5 is located in the shell 4, and the electrode assembly 5 includes an electrode body 52 and a pole ear 51. The electrode body 52 includes a first end face 521 and a second end face 522 arranged opposite to each other in a first direction X, and a side face 523 connected between the first end face 521 and the second end face 522. The pole ear 51 is connected to the electrode body 52 and extends out of the first end face 521; the heat spreader 7 is located in the shell 4, and the heat spreader 7 includes a first heat spreader 71, the first heat spreader 71 includes a first chamber 711 and a first capillary structure 712 arranged in the first chamber 711, the first capillary structure 712 extends along the first direction X, and the first chamber 711 contains a heat exchange medium. The first heat spreader 71 is thermally connected to the side face 523, and the first heat spreader 71 and the electrode assembly 5 are insulated from each other.

[0112] In the scheme of the embodiment of the present application, the battery cell 3 includes a shell 4, an electrode assembly 5 and a heat spreader 7. The electrode assembly 5 is located inside the shell 4. The shell 4 provides accommodation and protection for the electrode assembly 5. The electrode assembly 5 includes an electrode body 52 and a pole ear 51. The electrode body 52 includes a first end face 521 and a second end face 522 that are arranged opposite to each other in a first direction X, and a side face 523 connected between the first end face 521 and the second end face 522. The electrode body 52 forms a loop with an external component through the pole ear 51 extending from the first end face 521. The heat spreader 7 is located In the shell 4, the heat equalizing component 7 includes a first heat equalizing portion 71 thermally connected to the side 523, the first heat equalizing portion 71 and the electrode assembly 5 are insulated from each other, the first heat equalizing portion 71 includes a first chamber 711 for accommodating a heat exchange medium and a first capillary structure 712, the first capillary structure 712 extends in the first direction X, so that the heat exchange medium circulates in the first chamber 711 along the first direction X through the first capillary structure 712, so that the first heat equalizing portion 71 can equalize the temperature of the side 523 in the first direction X, enhance the heat dissipation capacity of the battery cell 3, and thus improve the performance of the battery cell 3.

[0113] The electrode body 52 is formed by winding or stacking a separator, a positive electrode sheet, and a negative electrode sheet.

[0114] Exemplarily, the battery cell 3 also includes a top cover assembly 6 connected to the pole ear 51, the shell 4 includes an opening close to the first end surface 521 in the first direction X, the top cover assembly 6 covers the opening, and the positive pole ear 51 and the negative pole ear 51 extend out of the first end surface 521 and are connected to the top cover assembly 6.

[0115] Exemplarily, the first direction X is the height direction of the electrode assembly 5 .

[0116] The first heat-averaging portion 71 is thermally connected to the side surface 523 of the electrode body 52, and the first heat-averaging portion 71 is directly attached to or abuts against the side surface 523 of the electrode body 52; or the first heat-averaging portion 71 is a coating arranged on the side surface 523; or the first heat-averaging portion 71 and the side surface 523 of the electrode body 52 are spaced apart, and the first heat-averaging portion 71 is connected to the side surface 523 through a medium, and the medium can be air, metal, thermally conductive glue, etc.

[0117] The first heat equalizing portion 71 includes a first chamber 711 and a first capillary structure 712 disposed in the first chamber 711 . The first chamber 711 contains a heat exchange medium. A flow channel for circulating the gaseous heat exchange medium exists between the first capillary structure 712 and the cavity wall of the first chamber 711 .

[0118] During the operation of the battery cell 3, the temperature of one end of the electrode body 52 close to the pole ear 51 is higher, and the temperature of the end away from the pole ear 51 is lower. During the operation of the battery cell 3, a high-temperature area close to the first end face 521 and a low-temperature area close to the second end face 522 are formed on the side 523 along the first direction X. The heat exchange medium absorbs heat and vaporizes in the high-temperature area to reduce the temperature of the high-temperature area. The gaseous heat exchange medium flows along the flow channel to the low-temperature area to release heat and liquefy. The liquid heat exchange medium flows to the high-temperature area through the siphon effect of the first capillary structure 712. The heat exchange medium circulates through the flow channel and the first capillary structure 712 to balance the temperature of the electrode assembly 5 in the first direction X, so as to improve the heat dissipation capacity of the battery cell 3, improve the problem of heat accumulation in the high-temperature area of ​​the electrode assembly 5, resulting in lithium deposition in the electrode assembly 5 or the battery cell 3 reaching the current limiting temperature prematurely, and improve the performance of the battery cell 3.

[0119] Optionally, the first capillary structure 712 may be a copper mesh or a wire mesh, etc. The first capillary structure 712 includes a plurality of capillary tubes extending along the first direction X to attract liquid heat exchange medium through siphon action.

[0120] Optionally, in the length and width directions of the first heat-averaging portion 71 , the first capillary structure 712 abuts against the cavity wall of the chamber to increase the size of the first capillary structure 712 and improve the thermal conductivity of the first heat-averaging portion 71 .

[0121] Optionally, the first capillary structure 712 and the cavity wall of the first chamber 711 are abutted to be fixed to each other to reduce the processing difficulty of the first heat equalizing part 71; or the first capillary structure 712 and the cavity wall of the first chamber 711 are welded to improve the stability of the first capillary structure 712.

[0122] Optionally, the heat exchange medium may be water, methanol, ethanol or ammonia.

[0123] Optionally, the extension dimension of the first heat-balancing portion 71 in the first direction X is greater than or equal to the dimension of the side surface 523 in the first direction X, so as to improve the heat-balancing capability of the first heat-balancing portion 71 .

[0124] Optionally, the thermal conductivity K of the heat spreader assembly 7 satisfies K≥2000 W / (k·m). Exemplarily, the thermal conductivity of the heat spreader assembly 7 is 2500 W / (k·m) or 3000 W / (k·m) or 5000 W / (k·m) or the like.

[0125] See also Figure 7 , Figure 7 It is a partial structural schematic diagram of a battery cell provided in one embodiment of the present application.

[0126] In some embodiments, Figure 6 and Figure 7 As shown, the side surface 523 includes two first side surfaces 5231 and two second side surfaces 5232. The two first side surfaces 5231 are arranged opposite to each other in the second direction Y, and the two second side surfaces 5232 are arranged opposite to each other in the third direction Z. The first direction X, the second direction Y and the third direction Z intersect each other. The area of ​​the first side surface 5231 is greater than the area of ​​the second side surface 5232. The first heat balancing portion 71 is arranged on at least one of the two first side surfaces 5231.

[0127] In these embodiments, the side 523 includes two first side surfaces 5231 and two second side surfaces 5232, the area of ​​the first side surface 5231 is greater than the area of ​​the second side surface 5232, and the first heat equalizing portion 71 is arranged on at least one of the two first side surfaces 5231, which helps to increase the contact area between the first heat equalizing portion 71 and the electrode body 52 to enhance the thermal conductivity of the first heat equalizing portion 71, better balance the internal temperature of the battery cell 3, and improve the heat dissipation capacity of the battery cell 3.

[0128] Optionally, the second direction Y is the thickness direction of the electrode assembly 5, and the first side surface 5231 is the large surface of the electrode assembly 5. The first direction X is the height direction of the electrode assembly 5, and the third direction Z is the length direction of the electrode assembly 5.

[0129] The electrode body 52 includes a first side surface 5231 and a second side surface 5232 with different areas. Exemplarily, the cross section of the electrode body 52 in the first direction X is rectangular or elliptical.

[0130] The area of ​​the first side surface 5231 is larger than that of the second side surface 5232. Therefore, a first heat-dissipating portion 71 with a larger area can be provided on the first side surface 5231 to improve the heat conduction efficiency of the first heat-dissipating portion 71 to the electrode body 52. ​​The specific areas of the first side surface 5231 and the second side surface 5232 can be designed by the user.

[0131] Optionally, the first heat dissipating portion 71 covers the entire first side surface 5231 to improve the heat conduction efficiency of the first heat dissipating portion 71 .

[0132] Optionally, the first heat-averaging portion 71 is disposed between the first side surface 5231 and the shell 4 , and the first heat-averaging portion 71 is used to enhance the heat exchange rate between the first side surface 5231 and the shell 4 .

[0133] Optionally, in a large-surface water cooling solution, the heat exchange mechanism is thermally connected to the first side surface 5231 , so that the first heat equalizing portion 71 disposed on the first side surface 5231 and the heat exchange mechanism have a smaller distance between them and a larger projected overlapping area, which can better transfer heat between the heat exchange mechanism and the electrode assembly 5 .

[0134] Exemplarily, the heat in the high temperature area is transferred to the low temperature area through the first heat equalizing portion 71, and heat exchange is performed through a portion of the heat exchange mechanism in contact with the low temperature area to better transfer the heat in the high temperature area to the outside.

[0135] In some embodiments, Figure 4 and Figure 7 As shown, the orthographic projection area of ​​the first heat-balancing portion 71 in the second direction Y is S1, and the area of ​​the first side surface 5231 is S2, where S1≥0.9*S2.

[0136] In these embodiments, when the orthographic projection area S1 of the first heat-scaling portion 71 in the second direction Y and the area S2 of the first side surface 5231 meet the above conditions, the heat-scaling component 7 has sufficient thermal conductivity to balance the temperature of the side surface 523 .

[0137] Exemplarily, the orthographic projection area S1 of the first heat-distributing portion 71 on the first side surface 5231 is 0.9*S2 or 0.95*S2, or the orthographic projection areas S1 and S2 of the first heat-distributing portion 71 on the first side surface 5231 are the same.

[0138] Optionally, the orthographic projection of the first heat-spreading portion 71 in the second direction Y covers the entire first side surface 5231 , so as to increase the contact area between the first heat-spreading portion 71 and the first side surface 5231 , thereby increasing the thermal conductivity of the heat-spreading component 7 .

[0139] See also Figure 8 , Figure 8 It is a partial structural schematic diagram of a battery cell provided in one embodiment of the present application.

[0140] In some embodiments, Figure 4 and Figure 8As shown, the heat equalizing component 7 also includes a second heat equalizing portion 72, which is arranged between the shell 4 and at least a portion of the second end surface 522 along the first direction X. The second heat equalizing portion 72 includes a second chamber 721 and a second capillary structure 722 arranged in the second chamber 721. The second chamber 721 contains a heat exchange medium. The first chamber 711 and the second chamber 721 are in communication, and the first capillary structure 712 and the second capillary structure 722 are connected to each other.

[0141] In these embodiments, the heat equalizing component 7 also includes a second heat equalizing portion 72 arranged between the shell 4 and at least a portion of the second end surface 522 along the first direction X, the first heat equalizing portion 71 conducts and equalizes the heat of the side 523 in the first direction X, the first chamber 711 and the second chamber 721 are connected, and the heat exchange medium flows in the first chamber 711 and the second chamber 721, so that the heat of the side 523 can be exchanged to the outside through the second heat equalizing portion 72 and the shell 4, so as to equalize the heat of the battery cell 3 and improve the heat dissipation effect of the battery cell 3.

[0142] Optionally, the second heat-dissipating portion 72 covers the entire second end surface 522 of the electrode assembly 5 to improve the heat conduction rate of the second heat-dissipating portion 72 .

[0143] Optionally, the shape and size of the second heat-dissipating portion 72 can be flexibly designed. For example, the second heat-dissipating portion 72 is rectangular or circular.

[0144] Optionally, the first heat equalizing portion 71 and the second heat equalizing portion 72 are integrally formed to reduce the connection seam between the first heat equalizing portion 71 and the second heat equalizing portion 72, reduce the risk of leakage of the heat exchange medium, and improve the thermal conductivity of the first heat equalizing portion 71 and the second heat equalizing portion 72, or the first heat equalizing portion 71 and the second heat equalizing portion 72 are prepared separately and connected by bonding or welding to facilitate adjustment of the size of the first heat equalizing portion 71 and the second heat equalizing portion 72 to adapt to electrode assemblies 5 of different sizes.

[0145] Optionally, the first capillary structure 712 and the second capillary structure 722 are integrally formed to reduce a joint seam therebetween.

[0146] The first chamber 711 and the second chamber 721 are connected, and the first capillary structure 712 and the second capillary structure 722 are connected to each other, so the high temperature area is located at one end of the side 523 close to the pole ear 51, and the low temperature area is located on the second end face 522. The heat exchange medium circulates in the first chamber 711 and the second chamber 721, and the heat exchange medium can transfer the temperature of the high temperature area to a larger range of the side 523 and the second end face 522 through the second heat equalizing part 72, so as to further reduce the temperature of the high temperature area; and when the heat exchange medium flows in the second chamber 721, the heat is exchanged to the external environment through the shell 4 contacted by the second heat equalizing part 72, so as to improve the heat dissipation capacity of the battery cell 3.

[0147] Exemplarily, in the bottom surface water cooling solution, the heat exchange mechanism and the second end surface 522 are disposed on both sides of the shell 4 , and the battery cells 3 can exchange heat with the heat exchange mechanism through the heat spreader assembly 7 and the shell 4 .

[0148] In some embodiments, Figure 4 and Figure 8 As shown, the side 523 includes two first side surfaces 5231 and two second side surfaces 5232, the two first side surfaces 5231 are arranged opposite to each other in the second direction Y, the two second side surfaces 5232 are arranged opposite to each other in the third direction Z, the first direction X, the second direction Y and the third direction Z intersect each other, the area of ​​the first side surface 5231 is greater than the area of ​​the second side surface 5232, the first heat equalizing portion 71 is arranged on at least one of the two first side surfaces 5231, the second heat equalizing portion 72 is connected to the first heat equalizing portion 71 arranged on the first side surface 5231, and the second capillary structure 722 extends along the second direction Y.

[0149] In these embodiments, the first heat equalizing portion 71 is disposed on the first side surface 5231 to equalize the heat of the first side surface 5231, and the second capillary structure 722 extends along the second direction Y to transfer the high-temperature heat exchange medium in the first chamber 711 to a low-temperature region away from the first capillary structure 712 to better equalize the temperature of the first side surface 5231, and the temperature of the first side surface 5231 is transferred to the outside through the shell 4 through the second heat equalizing portion 72 to equalize the heat of the battery cell 3 and enhance the heat dissipation effect of the battery cell 3.

[0150] The area of ​​the first side surface 5231 is larger than the area of ​​the second side surface 5232. Compared with the case where the second heat equalizing portion 72 is connected to the first heat equalizing portion 71 located on the second side surface 5232, when the second heat equalizing portion 72 is connected to the first heat equalizing portion 71 located on the first side surface 5231, the contact range between the two is larger and the connection strength is higher.

[0151] Optionally, the first heat equalizing portion 71 is arranged between two adjacent first side surfaces 5231 of adjacent electrode assemblies 5 so that the first heat equalizing portion 71 can transfer heat between adjacent first side surfaces 5231, or the first heat equalizing portion 71 is arranged between the first side surface 5231 of the electrode assembly 5 and the shell 4 to reduce the difficulty of setting up the heat equalizing portion 7.

[0152] See also Fig. 9 , Fig. 9 It is a partial structural schematic diagram of a battery cell provided in one embodiment of the present application.

[0153] In some embodiments, Figure 4 and Fig. 9As shown, a plurality of electrode assemblies 5 are provided, and the plurality of electrode assemblies 5 are stacked along the second direction Y. The first heat-averaging portion 71 includes a middle heat-averaging member 73, and the middle heat-averaging member 73 is arranged between two adjacent first side surfaces 5231 of two adjacent electrode assemblies 5. The middle heat-averaging member 73 includes an intermediate chamber 731, and a middle capillary structure 732 arranged in the intermediate chamber 731. The middle capillary structure 732 extends along the first direction X, and the intermediate chamber 731 is connected to the second chamber 721, and the middle capillary structure 732 and the second capillary structure 722 are connected to each other.

[0154] In these embodiments, the middle heat equalizing member 73 is disposed between two adjacent first side surfaces 5231 of two adjacent electrode assemblies 5, and the heat exchange medium flows in the middle chamber 731 to transfer heat between the adjacent first side surfaces 5231 in the first direction X, the middle chamber 731 and the second chamber 721 are connected, the middle capillary structure 732 and the second capillary structure 722 are connected to each other, and the heat exchange medium is transferred to the second chamber 721 through the middle chamber 731, and the heat of the adjacent first side surfaces 5231 is exchanged through the second heat equalizing member 72 and the shell 4 with the external environment through the flow of the heat exchange medium in the middle chamber 731 and the second chamber 721, so as to balance the heat of the battery cells 3 and improve the heat dissipation effect of the battery cells 3.

[0155] The middle capillary structure 732 and the second capillary structure 722 are connected to each other, the middle chamber 731 and the second chamber 721 are connected, the heat exchange medium circulates in the middle chamber 731 and the second chamber 721, and the heat between the adjacent first side surfaces 5231 is transferred to the second heat equalizing portion 72 through the first heat equalizing portion 71. As the heat exchange medium flows in the second chamber 721, the heat is transferred to the external environment through the shell 4.

[0156] Exemplarily, the heat exchange mechanism is disposed on one side of the battery cell 3 close to the second heat equalizing portion 72 in the first direction X, and the heat between adjacent first side surfaces 5231 is transferred to the heat exchange mechanism through the middle heat equalizing member 73 and the second heat equalizing portion 72 .

[0157] Optionally, a plurality of middle heat spreaders 73 may be disposed between adjacent first side surfaces 5231 to improve the heat conduction rate of the heat spreader assembly 7. Exemplarily, one, two, three, etc. middle heat spreaders 73 may be disposed between adjacent first side surfaces 5231.

[0158] Optionally, the shell 4 includes a plurality of electrode assemblies 5 , and a middle heat spreader 73 is disposed between the first side surfaces 5231 of each adjacent electrode assembly 5 to improve the heat conduction rate of the heat spreader 7 .

[0159] Optionally, the middle heat spreader 73 covers the first side surface 5231 to increase the contact area between the middle heat spreader 73 and the electrode assembly 5 and to increase the thermal conductivity of the heat spreader assembly 7 .

[0160] See also Fig.10 , Fig.10 It is a partial structural schematic diagram of a battery cell provided in one embodiment of the present application.

[0161] In some embodiments, Fig. 9 and Fig.10 As shown, the middle capillary structure 732 includes two first sub-capillary structures 751 stacked along the second direction Y, and the second capillary structure 722 includes two second sub-capillary structures 752 spaced apart along the second direction Y, and each second sub-capillary structure 752 is connected to the adjacent first sub-capillary structure 751 .

[0162] In these embodiments, two first sub-capillary structures 751 and a second sub-capillary structure 752 are used to form two independent capillary structures in the middle chamber 731 and the second chamber 721, so as to improve the problem of a decrease in energy density of the battery cell 3 due to the excessive volume of the heat spreader 7 while improving the thermal conductivity rate of the heat spreader 7.

[0163] Exemplarily, two first heat-averaging parts 71 are arranged between adjacent electrode assemblies 5, each first heat-averaging part 71 is thermally connected to a first side surface 5231, and two second heat-averaging parts 72 are respectively connected to a first heat-averaging part 71, and each electrode assembly 5 transfers heat through a first heat-averaging part 71 and a second heat-averaging part 72, respectively, so as to improve the thermal conductivity rate of the heat-averaging component 7; and in order to improve the problem of low energy density of the battery cell 3 caused by the large volume of the heat-averaging component 7, in the embodiment of the present application, the two first heat-averaging parts 71 share a first chamber 711, and two first sub-capillary structures 751 are arranged in the first chamber 711 to reduce the total volume of the heat-averaging component 7.

[0164] Optionally, the first sub-capillary structure 751 and the second sub-capillary structure 752 that are connected to each other are integrally formed to facilitate the heat exchange medium to flow smoothly through the first sub-capillary structure 751 and the second sub-capillary structure 752 .

[0165] Optionally, the two first sub-capillary structures 751 are bonded or welded to each other to improve the stability of the middle capillary structure 732 and the second capillary structure 722 .

[0166] Optionally, the two first sub-capillary structures 751 have the same shape and size, and the two second sub-capillary structures 752 have the same shape and size, so as to balance the heat conduction capacity of the heat-spreading component 7 to the two adjacent first side surfaces 5231 .

[0167] See also Fig.11 , Fig.11 It is an exploded view of a heat spreader assembly of a battery cell provided in one embodiment of the present application.

[0168] In some embodiments, Fig. 9 and Fig.11 As shown, the heat equalizing assembly 7 includes a first wall portion 761 and two second wall portions 762, the first wall portion 761 is arranged between the shell 4 and at least part of the second end surface 522, the second wall portion 762 includes a first segment 7621 and a second segment 7622, ​​the two first segments 7621 are arranged between adjacent first side surfaces 5231 and are connected to each other to form an intermediate chamber 731, the second segment 7622 is connected to the side of the first segment 7621 facing the first wall portion 761, and the two second segments 7622 extend back to back and are connected to the first wall portion 761 to form a second chamber 721.

[0169] In these embodiments, the first wall portion 761 and the two second wall portions 762 are covered to form the middle chamber 731 and the second chamber 721 , so as to reduce the processing difficulty of the heat spreader assembly 7 .

[0170] Specifically, the first segments 7621 of the two first wall portions 761 overlap with each other, and their edges are connected to each other to form an intermediate chamber 731. The middle capillary structure 732 is arranged between the two first segments 7621. The second segments 7622 of the two second wall portions 762 overlap with the first wall portion 761, and their edges are connected to each other to form a second chamber 721. The second capillary structure 722 is arranged between the second segment 7622 and the second wall portion 762.

[0171] Optionally, the first wall portion 761 and the second wall portion 762 , and the two first wall portions 761 are connected together by brazing.

[0172] Optionally, the material of the first wall portion 761 may be copper, aluminum, stainless steel, etc. The first wall portion 761 and the second wall portion 762 are made of the same material, which reduces the difficulty of welding between the two.

[0173] Optionally, the thickness of the first wall portion 761 is less than or equal to 0.6 mm, so as to improve the problem that the battery cell 3 is too large and the energy density is too low due to the provision of the heat spreader assembly 7. Exemplarily, the thickness of the first wall portion 761 is 0.6 mm, 0.5 mm, 0.4 mm or 0.2 mm, etc., and the thickness range of the second wall portion 762 is the same as the thickness range of the first wall portion 761.

[0174] Exemplarily, the middle capillary structure 732 and the second capillary structure 722 are integrally formed into a capillary structure member, and the first wall portion 761 and the second wall portion 762 are connected to each other along the capillary structure member to form the heat-spreading component 7 .

[0175] See also Fig.12 , Fig.12 It is a partial structural schematic diagram of a battery cell provided in one embodiment of the present application.

[0176] In some embodiments, Figure 4 and Fig.12 As shown, the first heat equalizing part 71 includes an end heat equalizing member 74, which is arranged between the first side surface 5231 and the shell 4. The end heat equalizing member 74 includes an end chamber 741 and an end capillary structure 742 arranged in the end chamber 741. The end capillary structure 742 extends along the first direction X, the end chamber 741 is connected to the second chamber 721, and the end capillary structure 742 and the second capillary structure 722 are connected to each other.

[0177] In these embodiments, the heat exchange medium flows in the middle chamber 731 to transfer heat between adjacent first sides 5231 in the first direction X, the middle chamber 731 is connected to the second chamber 721 and the end chamber 741, the middle capillary structure 732, the second capillary structure 722 and the end capillary structure 742 are connected to each other, and the heat exchange medium is transferred to the second chamber 721 and the end chamber 741 through the middle chamber 731. By the flow of the heat exchange medium in the middle chamber 731, the second chamber 721 and the end chamber 741, the heat of the adjacent first side 5231 is exchanged with the external environment through the second heat spreader, the end heat spreader 74 and the shell 4, so as to balance the heat of the battery cell 3 and improve the heat dissipation effect of the battery cell 3.

[0178] Optionally, the heat equalizing component 7 includes an end heat equalizing component 74, which is arranged between a first side surface 5231 and the shell 4; or the heat equalizing component 7 includes two end heat equalizing components 74 arranged relatively along the second direction Y, and the two second end heat equalizing components 74 are respectively arranged between the two first side surfaces 5231 and the shell 4.

[0179] A middle heat equalizing member 73 is arranged between the first side surfaces 5231 of adjacent electrode assemblies 5, and the heat of the two adjacent first side surfaces 5231 is transferred to the middle heat equalizing member 73. The middle chamber 731, the second chamber 721 and the end chamber 741 are interconnected, and the heat exchange medium circulates in the middle chamber 731, the second chamber 721 and the end chamber 741, so that the heat is transferred to the second heat equalizing portion 72 and the end heat equalizing member 74 through the middle heat equalizing member 73, and is transferred to the outside through the shell 4.

[0180] Exemplarily, the heat exchange mechanism is arranged on at least one side of the shell 4 close to the end heat equalizer 74 in the second direction Y, and the heat of the middle heat equalizer 73 is transferred to the end heat equalizer 74 through the second heat equalizer 72 and then transferred to the heat exchange mechanism.

[0181] Optionally, the end capillary structure 742 and the second capillary structure 722 are integrally formed to reduce a joint seam between the two and increase the service life of the heat spreader assembly 7 .

[0182] See also Fig.13, Fig.13 It is an exploded view of a heat spreader assembly of a battery cell provided in one embodiment of the present application.

[0183] In some embodiments, Fig.12 and Fig.13 As shown, the heat-saturating assembly 7 includes a third wall portion 763 and two fourth wall portions 764, the third wall portion 763 includes a third segment 7631 and a fourth segment 7632, the third segment 7631 is arranged between the shell 4 and the second end surface 522, the two fourth segments 7632 are respectively arranged at both ends of the third segment 7631 in the second direction Y, and extend between the first side surface 5231 and the shell 4, the two fourth wall portions 764 are arranged along the second direction Y, the fourth wall portion 764 includes a fifth segment 7641 and a sixth segment 7642, the two sixth segments 7642 are respectively arranged at the fifth segment 7641 is at both ends of the second direction Y, a sixth segment 7642 is located between the first side surface 5231 and the fourth segment 7632, the fourth segment 7632 and the sixth segment 7642 are connected to form an end chamber 741, another sixth segment 7642 is located between the two first side surfaces 5231, the sixth segments 7642 of the two fourth wall portions 764 are connected to form an intermediate chamber 731, the fifth segment 7641 is arranged between the third segment 7631 and the second end surface 522, and the fifth segment 7641 and the third segment 7631 are connected to form a second chamber 721.

[0184] In these embodiments, the third wall portion 763 and the two fourth wall portions 764 are covered to form the middle chamber 731 , the second chamber 721 and the end chamber 741 , so as to reduce the processing difficulty of the heat-saturating component 7 .

[0185] Specifically, the sixth segments 7642 of the two fourth wall portions 764 overlap with each other, and their edges are connected to each other to form an intermediate chamber 731, and the middle capillary structure 732 is arranged between the two sixth segments 7642; the sixth segment 7642 of the fourth wall portion 764 and the fourth segment 7632 of the third wall portion 763 overlap with each other, and their edges are connected to each other to form an end chamber 741, and the end capillary structure 742 is arranged between the fourth segment 7632 and the sixth segment 7642; the fifth segment 7641 of the two fourth wall portions 764 and the third segment 7631 of the third wall portion 763 overlap with each other, and their edges are connected to each other to form a second chamber 721, and the second capillary structure 722 is arranged between the fifth segment 7641 and the third segment 7631.

[0186] Optionally, the third wall portion 763 and the fourth wall portion 764 , and the two first wall portions 761 are connected together by brazing.

[0187] Optionally, the third wall portion 763 may be made of copper, aluminum, stainless steel, etc. The third wall portion 763 and the fourth wall portion 764 are made of the same material, which reduces the difficulty of welding between the two.

[0188] Optionally, the thickness of the third wall portion 763 is less than or equal to 0.6 mm, so as to improve the problem that the battery cell 3 is too large and the energy density is too low due to the provision of the heat spreader assembly 7. Exemplarily, the thickness of the third wall portion 763 is 0.6 mm, 0.5 mm, 0.4 mm or 0.2 mm, etc., and the thickness range of the fourth wall portion 764 is the same as the thickness range of the third wall portion 763.

[0189] Exemplarily, the middle capillary structure 732 , the second capillary structure 722 and the end capillary structure 742 are integrally formed into a capillary structure member, and the third wall portion 763 and the fourth wall portion 764 are interconnected along the capillary structure member to form the heat-spreading component 7 .

[0190] Optionally, during the process of connecting the third wall portion 763 and the fourth wall portion 764 to the capillary structure, the two fourth wall portions 764 can be first connected together through two adjacent sixth segments 7642; or the two fourth wall portions 764 are integrally formed and connected together through the sixth segment 7642.

[0191] See also Fig.14 , Fig.15 and Fig.16 As shown, Fig.14 is a partial structural schematic diagram of a battery cell provided in one embodiment of the present application; Fig.15 It is a partial structural schematic diagram of a heat spreader assembly of a battery cell provided in one embodiment of the present application; Fig.16 It is a partial structural schematic diagram of a heat spreader assembly of a battery cell provided in one embodiment of the present application.

[0192] In some embodiments, Figures 14 to 16 As shown, the first capillary structure 712 is arranged around the circumference of the electrode assembly 5 .

[0193] In these embodiments, the first capillary structure 712 is disposed around the circumference of the electrode assembly 5 to increase the circulation speed of the heat exchange medium in the first chamber 711 , so that the heat equalizing assembly 7 can better equalize the temperature of the electrode assembly 5 .

[0194] The first capillary structure 712 is disposed around the circumference of the electrode assembly 5 , and the first heat-averaging portion 71 is disposed around the circumference of the electrode assembly 5 .

[0195] The first heat averaging portion 71 disposed on the side 523 of the electrode body 52 can transfer heat in the first direction X to balance the temperature of the electrode assembly 5 in the first direction X and reduce the temperature difference of the electrode assembly 5 in the first direction X; or the first heat averaging portion 71 extends to the two first side surfaces 5231 of the electrode assembly 5, so that the heat exchange medium circulates between the first side surface 5231 with a higher temperature and the first side surface 5231 with a lower temperature to transfer heat. Exemplarily, one end of the first heat averaging portion 71 is located between two adjacent first side surfaces 5231, and the other end of the first heat averaging portion 71 is located between the shell 4 and the first side surface 5231.

[0196] The electrode assembly 5 is cylindrical, and the first heat-dissipating portion 71 surrounds the peripheral surface of the electrode assembly 5 ; or the electrode assembly 5 is flat, and the first heat-dissipating portion 71 surrounds the first side surface 5231 and the second side surface 5232 .

[0197] Optionally, the first heat-averaging portion 71 covers the entire side surface 523 of the electrode assembly 5 to increase the contact area between the first heat-averaging portion 71 and the electrode assembly 5 and to increase the thermal conductivity of the first heat-averaging portion 71 .

[0198] In some embodiments, Figures 14 to 16 As shown, a gap 713 extending along the first direction X and penetrating the first heat-averaging portion 71 is formed between two ends of the first heat-averaging portion 71 along the circumference of the electrode body 52 .

[0199] In these embodiments, a gap 713 extending along the first direction X and penetrating the first heat-averaging portion 71 is formed between the two ends of the first heat-averaging portion 71 along the circumferential side of the electrode body 52. ​​The gap 713 is provided so that the first heat-averaging portion 71 can be deformed synchronously during the expansion of the electrode assembly 5, thereby reducing the risk of the first heat-averaging portion 71 being expanded by the electrode body 52, thereby improving the service life of the heat-averaging assembly 7 and the reliability of the battery cell 3.

[0200] A gap 713 is formed between the two ends of the first heat-averaging portion 71 along the circumference of the electrode body 52, so that the first heat-averaging portion 71 can be elastically deformed. In this way, during the charging and discharging process of the battery cell 3, when the electrode assembly 5 expands, the distance between the two ends of the first heat-averaging portion 71 increases, reducing the risk of the first heat-averaging portion 71 being squeezed and damaged by the electrode assembly 5. When the electrode assembly 5 shrinks, the distance between the two ends of the first heat-averaging portion 71 decreases, and the first heat-averaging portion 71 fits the electrode assembly 5 to maintain a good thermal conductivity. The specific size of the gap 713 can be designed by yourself.

[0201] Optionally, as shown in the figure, the first side 5231 and the second side 5232 are connected by a rounded transition, and a gap 713 is set at the rounded connection between the first side 5231 and the second side 5232, so that as large a heat dissipation component 7 as possible can be set on the flat part of the first side 5231 and / or the second side 5232.

[0202] Optionally, the gap 713 extends linearly along the first direction X, reducing the size of the gap 713 .

[0203] See also Fig.17 , Fig.17 It is a partial structural schematic diagram of a pole piece of a battery cell provided in one embodiment of the present application.

[0204] In some embodiments, Figure 4 and Fig.17 As shown, the electrode assembly 5 includes a pole piece 53, and the pole piece 53 includes a current collector 531 and an active material layer 532. The active material layer 532 is arranged on at least a portion of the surface of the current collector 531, and the orthographic projection of the active material layer 532 in the second direction Y is located in the first heat equalizing portion 71.

[0205] In these embodiments, the orthographic projection of the active material layer 532 in the second direction Y is located within the first heat-dissipating portion 71 to improve the heat conduction efficiency of the first heat-dissipating portion 71 .

[0206] The pole piece 53 includes a current collector 531 and an active material layer 532. The current collector 531 includes a current collecting section 5311 and a pole lug 51. The active material layer 532 is disposed on the current collecting section 5311. The pole piece 53 includes a positive pole piece and a negative pole piece. Considering the overhang design, the current collector 531 of the positive pole piece also includes a blank section 5312 disposed between the current collecting section 5311 and the pole lug 51.

[0207] When the positive electrode sheet is arranged at the outermost layer of the electrode assembly 5 in the first direction X, the heat generated by the current collecting section 5311 is more serious than that generated by the blank section 5312. Therefore, the positive projection of the first heat equalizing part 71 is covered on the active material layer 532, which can improve the thermal conductivity of the first heat equalizing part 71 and reduce the material cost of the heat equalizing component 7.

[0208] See also Fig.18 and Fig.19 , Fig.18 It is a partial structural schematic diagram of a heat spreader assembly of a battery cell provided in one embodiment of the present application; Fig.19 It is a partial structural schematic diagram of a battery cell provided in one embodiment of the present application.

[0209] In some embodiments, Fig.18 and Fig.19As shown, the battery cell 3 further includes an insulating component 8 , at least a portion of the insulating component 8 forms a receiving cavity 81 , and the heat spreader component 7 is disposed in the receiving cavity 81 .

[0210] In these embodiments, at least a portion of the insulating component 8 forms a receiving cavity 81 , and the heat spreader component 7 is disposed in the receiving cavity 81 , so that the heat spreader component 7 can be insulated from the electrode component 5 by the insulating component 8 .

[0211] Exemplarily, the material of the insulating component 8 may be PP, PI, or PET.

[0212] Optionally, the insulating component 8 is provided with a accommodating cavity 81 with an opening at one end, the heat equalizing component 7 is arranged in the accommodating cavity 81, and the opening of the insulating component 8 is glued or welded so that the heat equalizing component 7 is located in a sealed accommodating cavity 81; or the two ends of the insulating component 8 are folded in half, the heat equalizing component 7 is located between the two ends of the insulating component 8, and the two ends of the insulating component 8 are glued or welded together so that the heat equalizing component 7 is located in a sealed accommodating cavity 81; or the insulating component 8 includes two sub-insulating layers arranged opposite to each other, and the edges of the two sub-insulating layers are glued or welded so that the heat equalizing component 7 is located in a sealed accommodating cavity 81.

[0213] Optionally, a bonding layer is provided on the surface of the insulating component 8 facing the electrode body 52 to bond the heat spread component 7 to the electrode body 52. ​​Exemplarily, the bonding layer can be an insulating colloid to enhance the insulation performance of the heat spread component 7 and the electrode component 5.

[0214] Optionally, the thickness of the insulating component 8 is between 5um and 200um. Exemplarily, the thickness of the insulating component 8 is 5um, 100um or 200um, etc.

[0215] Optionally, when the heat-spreading component 7 is disposed in the accommodating cavity 81 , even if the heat-spreading component 7 is broken and the heat exchange medium leaks, the insulating component 8 can separate the heat exchange medium and the electrolyte.

[0216] Optionally, the heat-scaling component 7 is disposed in the accommodating cavity 81, and the area of ​​the heat-scaling component 7 matches the area of ​​the accommodating cavity 81. The area of ​​the accommodating cavity 81 may be smaller than the area of ​​the insulating component 8. The heat-scaling component 7 is in contact with the cavity wall of the accommodating cavity 81, and the accommodating cavity 81 serves to limit the heat-scaling component 7.

[0217] In some embodiments, Fig.18 and Fig.19 As shown, the insulating component 8 is covered on the side surface 523 and the second end surface 522 .

[0218] In these embodiments, the insulating component 8 is coated on the side surface 523 and the second end surface 522 to insulate the heat spreader component 7, the shell 4 and the electrode assembly 5 from each other, and there is no need to set a Mylar film, which helps to reduce the segmented preparation cost of the battery cell 3, and can reduce the thickness of the battery cell 3 and improve the energy density of the battery cell 3.

[0219] In the embodiment of the present application, the shell 4 and the electrode assembly 5 are insulated by the insulating assembly 8, and there is no need to provide a Mylar film, or the Mylar film is replaced by the insulating assembly 8.

[0220] Optionally, the insulating component 8 extends out of the first end surface 521 along the first direction X to be thermally melt-connected with the top cover component 6 , so that the insulating component 8 and the heat-spreading component 7 remain stable in the shell 4 .

[0221] Optionally, the dimension of the insulating component 8 extending beyond the first end surface 521 along the first direction X is greater than or equal to 2 mm. Exemplarily, the dimension of the insulating component 8 extending beyond the first end surface 521 along the first direction X is 2 mm, 3 mm, 5 mm, 7 mm, etc.

[0222] Optionally, the minimum distance from the orthographic projection of the heat spreader component 7 in the thickness direction to the edge of the insulating component 8 is greater than or equal to 2 mm, so that there is a sufficient plastic sealing area between the heat spreader component 7 and the edge of the insulating component 8 to improve the sealing reliability of the accommodating cavity 81.

[0223] Exemplarily, the minimum distance from the heat spreader component 7 to the edge of the insulating component 8 is 2 mm, 3 mm, 5 mm, etc.

[0224] In a second aspect, an embodiment of the present application provides a battery, comprising a battery cell according to an embodiment of the first aspect.

[0225] In a third aspect, an embodiment of the present application provides an electrical device, comprising the battery of the embodiment of the second aspect above.

[0226] In some embodiments, Figures 1 to 19As shown, the present application provides a battery cell 3, the battery cell 3 includes a shell 4, an electrode assembly 5, a heat spreader assembly 7 and an insulating assembly 8, the electrode assembly 5 is located in the shell 4, the electrode assembly 5 includes an electrode body 52 and a pole ear 51, the electrode body 52 includes a first end face 521 and a second end face 522 arranged opposite to each other in a first direction X, and a side face 523 connected between the first end face 521 and the second end face 522, the side face 523 includes two first side faces 5231 and two second side faces 5232, the two first side faces 5231 are arranged opposite to each other in a second direction Y, the two second side faces 5232 are arranged opposite to each other in a third direction Z, the first direction X, the second direction Y and the third direction Z intersect each other, the area of ​​the first side face 5231 is greater than the area of ​​the second side face 5232, the pole ear 51 is connected to the electrode body 52 and extends out of the first end face 521; at least a part of the area of ​​the insulating assembly 8 forms a capacitor The housing 81, the heat-averaging component 7 is arranged in the housing 81, the insulating component 8 is covered on the side surface 523 and the second end surface 522, the heat-averaging component 7 includes a first heat-averaging portion 71 and a second heat-averaging portion 72, the first heat-averaging portion 71 includes a first chamber 711 and a first capillary structure 712 arranged in the first chamber 711, the first capillary structure 712 extends along the first direction X, the first heat-averaging portion 71 and the first side surface 5231 are thermally connected, the second heat-averaging portion 72 is arranged between the shell 4 and at least part of the second end surface 522 along the first direction X, the second heat-averaging portion 72 includes a second chamber 721 and a second capillary structure 722 arranged in the second chamber 721, the second capillary structure 722 extends along the second direction Y, the first chamber 711 and the second chamber 721 contain heat exchange medium, the first chamber 711 and the second chamber 721 are connected, and the first capillary structure 712 and the second capillary structure 722 are connected to each other.

[0227] In these embodiments, the battery cell 3 includes a shell 4, an electrode assembly 5 and a heat spreader 7. The electrode assembly 5 is located inside the shell 4. The shell 4 provides accommodation and protection for the electrode assembly 5. The electrode assembly 5 includes an electrode body 52 and a pole ear 51. The electrode body 52 includes a first end face 521 and a second end face 522 that are arranged opposite to each other in a first direction X, and a side face 523 connected between the first end face 521 and the second end face 522. The electrode body 52 forms a loop with an external component through the pole ear 51 extending from the first end face 521. The heat spreader 7 is located in the shell. 4, the heat-spreading assembly 7 includes a first heat-spreading portion 71 thermally connected to the side surface 523, the first heat-spreading portion 71 and the electrode assembly 5 are insulated from each other, the first heat-spreading portion 71 includes a first chamber 711 for accommodating a heat exchange medium and a first capillary structure 712, the first capillary structure 712 extends in a first direction X, so that the heat exchange medium circulates in the first chamber 711 along the first direction X through the first capillary structure 712, so that the first heat-spreading portion 71 can balance the temperature of the side surface 523 in the first direction X, enhance the heat dissipation capacity of the battery cell 3, and improve the performance of the battery cell 3.

[0228] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery cell, characterized in that: include: case; an electrode assembly, located in the housing, the electrode assembly comprising an electrode body and a tab, the electrode body comprising a first end face and a second end face arranged opposite to each other in a first direction, and a side face connected between the first end face and the second end face, the tab being connected to the electrode body and extending beyond the first end face; A heat-spreading assembly is located in the shell, and includes a first heat-spreading portion, the first heat-spreading portion includes a first chamber and a first capillary structure arranged in the first chamber, the first capillary structure extends along the first direction, the first chamber contains a heat exchange medium, the first heat-spreading portion is thermally connected to the side, and the first heat-spreading portion and the electrode assembly are insulated from each other.

2. The battery cell according to claim 1, characterized in that: The side surfaces include two first side surfaces and two second side surfaces, the two first side surfaces are arranged opposite to each other in the second direction, the two second side surfaces are arranged opposite to each other in the third direction, the first direction, the second direction and the third direction intersect each other, the area of ​​the first side surface is greater than the area of ​​the second side surface, and the first heat equalizing portion is arranged on at least one of the two first side surfaces.

3. The battery cell according to claim 1, characterized in that: The heat-spreading assembly also includes a second heat-spreading portion, which is arranged between the shell and at least a portion of the second end surface along the first direction. The second heat-spreading portion includes a second chamber and a second capillary structure arranged in the second chamber. The second chamber contains a heat exchange medium. The first chamber and the second chamber are connected, and the first capillary structure and the second capillary structure are connected to each other.

4. The battery cell according to claim 3, characterized in that: The side surfaces include two first side surfaces and two second side surfaces, the two first side surfaces are arranged opposite to each other in the second direction, the two second side surfaces are arranged opposite to each other in the third direction, the first direction, the second direction and the third direction intersect each other, the area of ​​the first side surface is greater than the area of ​​the second side surface, the first heat equalizing portion is arranged on at least one of the two first side surfaces, the second heat equalizing portion is connected to the first heat equalizing portion arranged on the first side surface, and the second capillary structure extends along the second direction.

5. The battery cell according to claim 4, characterized in that: There are multiple electrode assemblies, and the multiple electrode assemblies are stacked along the second direction. The first heat-averaging part includes a middle heat-averaging piece, and the middle heat-averaging piece is arranged between two adjacent first side surfaces of two adjacent electrode assemblies. The middle heat-averaging piece includes an intermediate chamber, and a middle capillary structure arranged in the intermediate chamber. The middle capillary structure extends along the first direction, and the intermediate chamber is connected to the second chamber, and the middle capillary structure and the second capillary structure are connected to each other.

6. The battery cell according to claim 5, characterized in that: The middle capillary structure includes two first sub-capillary structures stacked along the second direction, and the second capillary structure includes two second sub-capillary structures spaced apart along the second direction, and each of the second sub-capillary structures is connected to the adjacent first sub-capillary structure.

7. The battery cell according to claim 5, characterized in that: The heat equalizing assembly includes a first wall portion and two second wall portions, the first wall portion is arranged between the shell and at least part of the second end surface, the second wall portion includes a first segment and a second segment, the two first segments are arranged between adjacent first side surfaces and are connected to each other to form the intermediate chamber, the second segment is connected to the side of the first segment facing the first wall portion, the two second segments extend back to back and are connected to the first wall portion to form the second chamber.

8. The battery cell according to claim 5, characterized in that: The first heat equalizing part includes an end heat equalizing member, which is arranged between the first side and the shell, and the end heat equalizing member includes an end chamber and an end capillary structure arranged in the end chamber, the end capillary structure extends along the first direction, the end chamber is connected to the second chamber, and the end capillary structure and the second capillary structure are connected to each other.

9. The battery cell according to claim 8, characterized in that: The heat equalizing assembly includes a third wall portion and two fourth wall portions, the third wall portion includes a third section and a fourth section, the third section is arranged between the shell and the second end face, the two fourth sections are arranged at both ends of the third section in the second direction and extend between the first side face and the shell, the two fourth wall portions are arranged along the second direction, the fourth wall portion includes a fifth section and a sixth section, two sixth sections are arranged at both ends of the fifth section in the second direction, one sixth section is located between the first side face and the fourth section, the fourth section and the sixth section are connected to form the end chamber, the other sixth section is located between the two first side faces, the sixth sections of the two fourth wall portions are connected to form the intermediate chamber, the fifth section is arranged between the third section and the second end face, the fifth section and the third section are connected to form the second chamber.

10. The battery cell according to claim 2, characterized in that: The first capillary structure is disposed around a circumference of the electrode assembly.

11. The battery cell according to claim 10, characterized in that: A gap extending along the first direction and penetrating the first heat-averaging portion is formed between two ends of the first heat-averaging portion along the circumference of the electrode body.

12. The battery cell according to claim 2, characterized in that: The orthographic projection area of ​​the first heat-averaging portion in the second direction is S1, and the area of ​​the first side surface is S2, where S1≥0.9*S2.

13. The battery cell according to claim 2, characterized in that: The electrode assembly includes a pole piece, which includes a current collector and an active material layer. The active material layer is arranged on at least a portion of the surface of the current collector, and the orthographic projection of the active material layer in the second direction is located in the first heat-averaging portion.

14. The battery cell according to claim 1, characterized in that: The battery cell further includes an insulating component, at least a portion of the insulating component forms a receiving cavity, and the heat distribution component is disposed in the receiving cavity.

15. The battery cell according to claim 14, characterized in that: The insulating component is coated on the side surface and the second end surface.

16. A battery device, characterized in that: A battery cell comprising any one of claims 1 to 15.

17. An electrical device, characterized in that: A battery device comprising the battery device described in claim 16 above.

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