CN221201297U - Battery monomer, battery and electric equipment - Google Patents

Abstract

The application belongs to the technical field of battery temperature equalization, and particularly relates to a battery monomer, a battery and electric equipment, wherein the battery monomer comprises a shell, a battery core and a heat conducting piece, and electrolyte is contained in the shell; the battery cell is positioned in the shell and soaked in electrolyte; the heat conducting piece is at least partially positioned inside the battery cell and is used for conducting heat inside the battery cell to the outside of the battery cell; the heat conduction piece can accelerate the heat conduction inside the battery cell to the electrolyte located outside the battery cell, and the electrolyte is transferred to the inside of the whole battery cell, so that uneven temperature distribution inside the battery cell is improved, the uniformity of the temperature distribution inside the battery cell is improved, the performance and the use reliability of the battery cell are improved, and the performance and the use reliability of the battery are improved.

Description

Battery cells, batteries and electrical equipment

Technical Field

The present application belongs to the technical field of battery temperature equalization, and in particular, relates to a battery cell, a battery, and an electrical device.

Background technique

With the development of battery technology, the charging speed of batteries is getting faster and faster. During the rapid charging and discharging of the battery cells in the battery, the cells in the battery cells generate a lot of heat, which increases the temperature inside the battery cells. However, in actual use, the temperature inside the battery cells is unevenly distributed, which affects the performance of the battery cells.

The above statements are only used to provide background information related to the present application and do not necessarily constitute prior art.

Utility Model Content

The purpose of the embodiments of the present application is to provide a battery cell, a battery, and an electrical device, including but not limited to solving the problem in the related art that the temperature distribution inside the battery cell is uneven and affects the performance of the battery cell.

The technical solution adopted in the embodiment of the present application is:

In a first aspect, a battery cell is provided, which includes a shell, a battery core and a heat conductor, wherein the shell contains an electrolyte; the battery core is located in the shell and immersed in the electrolyte; the heat conductor is at least partially located inside the battery core, and is used to conduct heat inside the battery core to the outside of the battery core.

In the battery cell of the embodiment of the present application, the heat conductive member is at least partially located inside the battery cell of the battery cell. The heat conductive member can accelerate the conduction of heat inside the battery cell to the electrolyte located outside the battery cell, and then transfer the heat to the interior of the entire battery cell through the electrolyte, thereby improving the uneven temperature distribution inside the battery cell, improving the uniformity of temperature distribution inside the battery cell, improving the performance and reliability of the battery cell, and improving the performance and reliability of the battery.

In one embodiment, the heat conducting member comprises an insulating layer and a heat conducting layer, and at least one surface of the insulating layer is connected to the heat conducting layer.

By adopting the technical solution of this embodiment, the insulation performance of the insulating layer can reduce the risk of short circuit inside the battery cell and improve the reliability of the battery cell; the setting of the heat conductive layer can accelerate the heat conduction from the inside of the battery cell to the outside, improve the temperature difference between the inside and outside of the battery cell, improve the uniformity of temperature distribution inside the battery cell, improve the performance and reliability of the battery cell, and improve the performance and reliability of the battery. In addition, the heat conductive member adopts the structure of the heat conductive layer and the insulating layer, and the structure of the heat conductive member is simple, which is conducive to reducing the production cost.

In one embodiment, the heat-conducting layer is made by coating a heat-conducting material on the surface of the insulating layer.

By adopting the technical solution of this embodiment, the heat-conducting layer is manufactured by coating, which simplifies the manufacturing process of the heat-conducting component and helps reduce the manufacturing cost.

In one embodiment, at least one of two surfaces of the insulating layer that are opposite to each other along the thickness direction is connected to a heat conducting layer.

By adopting the technical solution of this embodiment, after the heat conductive component is arranged in the battery cell, the surface area of the insulating layer relatively distributed along the thickness direction is large, and the heat conductive layer can be arranged larger, which is beneficial to increase the thermal contact area between the battery cell and the heat conductive component, thereby accelerating the heat extraction inside the battery cell, and can better improve the temperature difference between the inside and outside of the battery cell, improve the uniformity of temperature distribution inside the battery cell, enhance the performance and reliability of the battery cell, and improve the performance and reliability of the battery.

In one embodiment, the thickness of the heat conductive layer is in the range of 0.01 mm to 0.3 mm.

By adopting the technical solution of this embodiment, the thickness of the heat-conducting layer is set in the range of 0.01mm to 0.3mm. The heat-conducting layer has a reasonable thickness, so that the heat-conducting part has good thermal conductivity, and the heat-conducting layer can be stably fixed on the insulating layer. At the same time, the heat-conducting layer will not occupy a large space in the battery cell, which is also beneficial to improving the volume energy density of the battery cell.

In one embodiment, the thickness of the heat conductive layer is in the range of 0.05 mm to 0.15 mm.

By adopting the technical solution of this embodiment, the thickness of the heat-conducting layer is set within the range of 0.05 mm to 0.15 mm. The heat-conducting layer has a more reasonable thickness, which can make the heat-conducting part have better heat conductivity and make the heat-conducting layer stably fixed on the insulating layer. At the same time, the heat-conducting layer will not occupy a large space in the battery cell, which is also beneficial to improving the volume energy density of the battery cell.

In one embodiment, the thermal conductivity of the thermally conductive layer is greater than 150 W/(m·K).

By adopting the technical solution of this embodiment, the thermal conductivity of the heat-conducting layer is greater than 150W/(m·K), the heat-conducting layer has good thermal conductivity, and can effectively conduct heat away from the battery cell, thereby effectively improving the temperature uniformity inside the battery cell, and improving the performance and reliability of the battery cell and the battery.

In one embodiment, the thermal conductivity of the thermally conductive layer is greater than 1700 W/(m·K).

By adopting the technical solution of this embodiment, the thermal conductivity of the heat-conducting layer is greater than 150W/(m·K), the heat-conducting layer has excellent thermal conductivity, and can quickly conduct heat away from the battery cell, thereby effectively improving the temperature uniformity inside the battery cell, and improving the performance and reliability of the battery cell and the battery.

In one embodiment, the heat conductive layer is an annealed pyrolytic graphite layer or a graphene layer.

By adopting the technical solution of this embodiment, the thermal conductive layer is made of annealed pyrolytic graphite or graphene with good thermal conductivity, so that the thermal conductive layer has good thermal conductivity. The thermal conductive layer can quickly conduct the heat inside the battery cell to the electrolyte outside the battery cell, and then transfer it to the interior of the entire battery cell through the electrolyte, effectively improving the uneven temperature distribution inside the battery cell, improving the uniformity of temperature distribution inside the battery cell, improving the performance and reliability of the battery cell, and improving the performance and reliability of the battery.

In one embodiment, the battery cell includes a body and a tab, the tab is connected to an end of the body along a first direction; the heat conductor is at least partially located inside the body, and the portion of the heat conductor located inside the body is a heat conducting portion; the size of the body in the first direction is L ₁ , and the size of the heat conducting portion in the first direction is L ₂ , wherein 0.75≤L ₂ /L ₁ ≤1.

By adopting the technical solution of this embodiment, in the first direction, the heat-conducting part can be located at least in most areas of the main body, so that the middle part of the main body has the heat-conducting part, and the heat-conducting part can quickly conduct the heat in the middle part of the main body with higher temperature to the electrolyte outside the battery cell, and then transfer it to the entire battery cell through the electrolyte, which can effectively improve the uniformity of temperature distribution of the battery cell, and also effectively improve the uneven temperature distribution inside the battery cell, improve the uniformity of temperature distribution inside the battery cell, improve the performance and reliability of the battery cell, and improve the performance and reliability of the battery.

In one embodiment, the tabs include a positive tab and a negative tab, the positive tab and the negative tab are located at the same end of the body, the distance between the heat conductive part and the end surface of the body close to the tab is L ₃ , and the distance between the heat conductive part and the end surface of the body facing away from the tab is L ₄ , wherein L ₃ >L ₄ .

By adopting the technical solution of this embodiment, the design of L ₃ > L ₄ makes the distance between the heat conducting part and the end face of the battery cell facing away from the pole ear shorter, and the heat conducting part can guide more heat in the middle part of the body to the end part of the body facing away from the pole ear with lower temperature, which can better reduce the temperature of the middle part of the body, and is also beneficial to improving the uniformity of the temperature distribution of the battery cell, which is beneficial to improving the performance of the battery cell.

In one embodiment, the battery core includes an electrode assembly, the electrode assembly includes a main body and a tab group, the tab group is connected to an end of the main body along a first direction, and the main body is provided with at least one heat conductive member.

By adopting the technical solution of this embodiment, the main body of the electrode assembly can be provided with one or more heat-conducting parts. In this way, the number of heat-conducting parts can be flexibly distributed according to the temperature distribution of the main body, thereby effectively dissipating the heat in the electrode assembly, making the electrode assembly have better uniformity of temperature distribution, and improving the performance and reliability of the battery cell.

In one embodiment, a heat conducting member is provided on the main body at a middle position of the second direction, and the first direction is perpendicular to the second direction.

By adopting the technical solution of this embodiment, in the second direction of the main body, the temperature of the middle position of the main body is the highest, and the heat conductor is arranged in the middle position of the main body. In this way, the heat at the highest temperature in the middle position of the main body can be effectively exported to the electrolyte located outside the battery cell, and then transferred to the entire battery cell through the electrolyte. In this way, the uniformity of the temperature distribution of the battery cell and the uniformity of the temperature distribution in the battery cell can be effectively improved, and the performance and reliability of the battery cell can be more effectively improved.

In one embodiment, the main body is a winding structure, and a heat conducting member is provided at the winding center of the main body.

By adopting the technical solution of this embodiment, the temperature of the winding center of the electrode assembly is higher, and the heat conductive member is arranged at the winding center of the electrode assembly, so that the heat at the highest temperature of the electrode assembly can be effectively conducted to the electrolyte located outside the battery cell, and transmitted to the entire battery cell through the electrolyte, so that the uniformity of the temperature distribution of the battery cell and the uniformity of the temperature distribution in the battery cell can be effectively improved, and the performance and reliability of the battery cell can be more effectively improved. In addition, in the process of manufacturing the electrode assembly, the positive electrode sheet, the negative electrode sheet and the separator that can be stacked can be wound on the heat conductive member, that is, the electrode assembly with the heat conductive member can be made simply, which is conducive to improving production efficiency.

In one embodiment, the main body is provided with a plurality of heat-conducting members, and the closer to the middle position of the main body in the second direction, the smaller the distance between two adjacent heat-conducting members.

By adopting the technical solution of this embodiment, the temperature in the middle position is high and the number of heat-conducting parts is large, while the temperature on both sides is low and the number of heat-conducting parts is small. The temperature in the middle position is high and the thermal conductivity is strong, while the temperature on both sides is low and the thermal conductivity is weak. In this way, the heat distribution inside the electrode assembly can be better balanced, and the temperature uniformity inside the electrode assembly is better, which is beneficial to improving the temperature uniformity inside the battery cell and the reliability of the battery cell.

In one embodiment, the main body is a laminated structure, and the second direction is a stacking direction of the main body.

By adopting the technical solution of this embodiment, in the process of stacking the positive electrode sheet, the negative electrode sheet and the separator of the electrode assembly layer by layer, multiple heat-conducting members are inserted and stacked between the positive electrode sheet and the separator or between the negative electrode sheet and the separator, so as to form an electrode assembly with multiple heat-conducting members placed at non-equidistant intervals. The whole production process is simple and convenient, which is conducive to improving production efficiency.

In one embodiment, the battery core includes a plurality of electrode assemblies, the plurality of electrode assemblies are stacked, and a heat conductive member is provided between two adjacent electrode assemblies.

By adopting the technical solution of this embodiment, the heat conductive member is arranged between two adjacent electrode assemblies, which can better conduct the heat between the two adjacent electrode assemblies to the outside, thereby effectively reducing the temperature between the two adjacent electrode assemblies and improving the uniformity of the temperature distribution of the battery cell, which is beneficial to improving the uniformity of the temperature distribution inside the battery cell, and is beneficial to improving the performance and reliability of the battery cell.

In one embodiment, the battery cell further includes an insulating member, which is wrapped around the battery core, and at least one side of the insulating layer is connected to the insulating member.

By adopting the technical solution of this embodiment, during the process of charging and discharging the electrode assembly, the electrode assembly will squeeze the heat conductor, and the heat conductor and the insulating member are connected as a whole. The insulating member can support the heat conductor, reduce the risk of the heat conductor moving out of the battery cell, and enable the heat conductor to have a good heat conduction and temperature uniformity inside the battery cell. In addition, in the actual manufacturing process, the insulating member and the heat conductor are connected as a whole, which also facilitates the assembly of the heat conductor, the insulating member and the battery cell.

In one embodiment, the heat conducting member and the insulating member are bonded together by heat conducting adhesive.

By adopting the technical solution of this embodiment, the heat-conducting adhesive can transfer the heat of the battery core through the heat-conducting member to the insulating member, and the insulating member is coated on the outside of the battery core, so that the heat can be transferred to the electrolyte outside the battery core over a large area, thereby helping to improve the uniformity of the temperature distribution inside the battery core and the battery cell, and helping to improve the performance and reliability of the battery cell. In addition, the heat-conducting member and the insulating member are connected by bonding, and the connection operation is simple, which is conducive to improving the production efficiency of the battery cell and reducing the production cost.

In one embodiment, the battery cell further includes a support member, which is located in the housing and is used to support the battery core. The surface of the insulating member facing away from the heat conducting member is connected to the support member.

By adopting the technical solution of this embodiment, the insulating member, the supporting member and the heat conducting member are connected as a whole, which also facilitates the assembly of the battery cell with the heat conducting member, the insulating member and the supporting member, and is beneficial to improving the production efficiency of the battery cell and reducing the production cost.

In a second aspect, a battery is provided, comprising a battery cell as described in the above embodiment.

In a third aspect, an electrical device is provided, comprising a battery as described in the above embodiment.

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

BRIEF DESCRIPTION OF THE DRAWINGS

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

FIG1 is a schematic diagram of the structure of a vehicle provided in one embodiment of the present application.

FIG. 2 is a schematic diagram of the structure of a battery provided in another embodiment of the present application.

FIG. 3 is a schematic diagram of the structure of a battery cell provided in another embodiment of the present application.

FIG. 4 is an exploded schematic diagram of the battery shown in FIG. 3 .

FIG. 5 is a cross-sectional view of the battery shown in FIG. 3 .

FIG. 6 is a cross-sectional view of the heat conducting member shown in FIG. 5 .

FIG. 7 is a cross-sectional view of an electrode assembly and a heat conductor in a laminated arrangement provided in another embodiment of the present application.

FIG. 8 is a cross-sectional view of a battery cell provided in another embodiment of the present application.

FIG. 9 is a schematic diagram of an expanded insulating member and a heat conducting member provided in another embodiment of the present application.

Among them, the reference numerals in the figure are:

1000, vehicle; 1100, battery; 1200, controller; 1300, motor; 10, housing; 11, first part; 12, second part; 20, battery cell; 21, housing; 211, end cover; 2111, electrode terminal; 2112, pressure relief mechanism; 212, housing; 22, battery cell; 221, body; 2211, first end face; 2212, second end face; 222, pole ear; 2221 , positive electrode tab; 2222, negative electrode tab; 223, electrode assembly; 2231, main body; 2232, tab group; 22321, positive electrode tab group; 22322, negative electrode tab group; 2233, positive electrode sheet; 2234, negative electrode sheet; 2235, separator; 23, thermal conductive member; 231, insulating layer; 232, thermal conductive layer; 233, thermal conductive portion; 24, insulating member; 25, thermal conductive adhesive; 26, supporting member.

Detailed ways

In order to make the technical problems, technical solutions and beneficial effects to be solved by this application more clearly understood, this application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not used to limit this application.

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

In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include one or more of the features.

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

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

In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two), and similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces). "Several" means one or more than one, unless otherwise clearly and specifically defined.

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.

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.

In the description of the embodiments of the present application, unless otherwise clearly specified and limited, when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or indirectly connected to the other element.

In the description of the embodiments of the present application, unless otherwise clearly specified and limited, the technical term "adjacent" refers to proximity in position. For example, for three components _A1 , _A2 and B, the distance between _A1 and B is greater than the distance between _A2 and B, then _A2 is closer to B than _A1 , that is _{, A2} is adjacent to B, or B is adjacent to _A2 . For another example, when there are multiple C components, the multiple C components are _C1 , _C2 ... _CN , and when one of the C components, such as _C2, is closer to component B than other C components, then B is adjacent to _C2 , or _C2 is adjacent to B.

A battery usually includes one or more battery cells. A battery cell is the smallest electrical energy storage unit of a battery. A battery cell includes an outer shell and a battery cell disposed in the outer shell. The battery cell undergoes an electrochemical reaction to achieve charging and discharging of the battery cell. However, during the electrochemical reaction of the battery cell, the battery cell will generate a large amount of heat, which will increase the temperature inside the battery cell, affecting the performance of the battery cell and also the reliability of the battery.

Generally, a cooling system is provided inside the battery. The coolant in the cooling system exchanges heat with the battery cells and removes the heat from the battery cells, thereby reducing the temperature of the battery cells and improving the performance and reliability of the battery. However, during the actual charging and discharging process of the battery cells, the heat generated inside the cells is not easy to transfer out, causing the temperature inside the cells to be higher than the temperature outside the cells, resulting in uneven temperature distribution inside the battery cells. At the same time, it is difficult for the cooling system to remove the heat generated by the cells in a timely manner, limiting the performance and reliability of the battery cells.

In order to solve the problem of uneven temperature distribution inside a battery cell, an embodiment of the present application provides a battery cell, in which a heat conductor is at least partially located inside the battery cell of the battery cell. The heat conductor can accelerate the conduction of heat inside the battery cell to the electrolyte located outside the battery cell, and then transfer the heat to the interior of the entire battery cell through the electrolyte, thereby improving the uneven temperature distribution inside the battery cell, improving the uniformity of temperature distribution inside the battery cell, improving the performance and reliability of the battery cell, and improving the performance and reliability of the battery.

At present, judging from the development of the market situation, the application of batteries is becoming more and more extensive. Batteries 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 power batteries, the market demand is also constantly expanding.

The battery cells, batteries and electrical devices using the batteries as power sources disclosed in the embodiments of the present application may be, but are not limited to, mobile phones, tablets, laptops, electric toys, electric tools, battery cars, electric cars, ships, spacecraft, etc. Among them, electric toys may include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys and electric airplane toys, etc., and spacecraft may include airplanes, rockets, space shuttles and spacecraft, etc.

For the convenience of description, the following embodiments are described by taking a vehicle 1000 as an example of an electrical device in an embodiment of the present application.

Please refer to Figure 1. Vehicle 1000 can be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 1100 is arranged inside the vehicle 1000. The battery 1100 can be arranged at the bottom, head or tail of the vehicle 1000. The battery 1100 can be used to power the vehicle 1000. For example, the battery 1100 can be used as an operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 1200 and a motor 1300. The controller 1200 is used to control the battery 1100 to power the motor 1300, for example, for the starting, navigation and driving power requirements of the vehicle 1000.

In some embodiments of the present application, the battery 1100 can not only serve as the operating power source of the vehicle 1000, but also serve as the driving power source of the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

Please refer to FIG. 2 , as an embodiment of a battery 1100 , the battery 1100 includes a box 10 and a battery cell 20 , and the battery cell 20 is contained in the box 10 . The box 10 is used to provide a storage space for the battery cell 20 , and the box 10 can adopt a variety of structures. In some embodiments, the box 10 can include a first part 11 and a second part 12 , the first part 11 and the second part 12 cover each other, and the first part 11 and the second part 12 jointly define a storage space for accommodating the battery cell 20 . The second part 12 can be a hollow structure with one end open, the first part 11 can be a plate-like structure, and the first part 11 covers the open side of the second part 12 , so that the first part 11 and the second part 12 jointly define a storage space; the first part 11 and the second part 12 can also be hollow structures with one side open, and the open side of the first part 11 covers the open side of the second part 12. Of course, the box 10 formed by the first part 11 and the second part 12 can be in a variety of shapes, such as a cylinder, a cuboid, etc.

In the battery 1100 , there may be a plurality of battery cells 20 , and the plurality of battery cells 20 may be connected in series, in parallel, or in mixed connection. Mixed connection means that the plurality of battery cells 20 may be connected in series or in parallel.

In one embodiment, multiple battery cells 20 can be directly connected in series, parallel or mixed, and then the whole formed by the multiple battery cells 20 is accommodated in the box 10; of course, the battery 1100 can also be a battery 1100 module in which multiple battery cells 20 are first connected in series, parallel or mixed, and then multiple battery 1100 modules are connected in series, parallel or mixed to form a whole and accommodated in the box 10. The battery 1100 may also include other structures, for example, the battery 1100 may also include a busbar component for realizing electrical connection between the multiple battery cells 20.

Each battery cell 20 may be a secondary battery 1100 or a primary battery 1100, or a lithium-sulfur battery 1100, a sodium-ion battery 1100, or a magnesium-ion battery 1100, but is not limited thereto. The battery cell 20 may be cylindrical, flat, rectangular, or in other shapes.

As another embodiment of the battery 1100, the battery 1100 may not include the housing 10, but may electrically connect a plurality of battery cells 20, and form a whole with necessary fixing structures, and then assemble it into an electrical device.

3 and 4 , the battery cell 20 refers to the smallest unit constituting the battery 1100. As shown in FIG3 , the battery cell 20 includes a housing 21, a battery cell 22 and an electrolyte. The housing 21 is used to enclose a space for accommodating the battery cell 22. The housing 21 includes an end cap 211 and a shell 212. The battery cell 22 includes one or more electrode assemblies 223.

The end cap 211 refers to a component that covers the opening of the shell 212 to isolate the internal environment of the battery cell 20 from the external environment. Without limitation, the shape of the end cap 211 can be adapted to the shape of the shell 212 to match the shell 212. Optionally, the end cap 211 can be made of a material with a certain hardness and strength (such as aluminum alloy), so that the end cap 211 is not easily deformed when squeezed and collided, so that the battery cell 20 can have a higher structural strength and the safety performance can also be improved. Functional components such as electrode terminals 2111 can be provided on the end cap 211. The electrode terminal 2111 can be used to electrically connect to the electrode assembly 223 for outputting or inputting electrical energy of the battery cell 20. In some embodiments, the end cap 211 can also be provided with a pressure relief mechanism 2112 for releasing the internal pressure when the internal pressure or temperature of the battery cell 20 reaches a threshold. The material of the end cap 211 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., which is not particularly limited in the present embodiment. In some embodiments, an insulating component can be provided on the inner side of the end cap 211, and the insulating component can be used to isolate the electrical connection components in the housing 212 from the end cap 211 to reduce the risk of short circuit. Exemplarily, the insulating component can be plastic, rubber, etc.

The shell 212 is a component used to cooperate with the end cap 211 to form the internal environment of the battery cell 20, wherein the formed internal environment can be used to accommodate the electrode assembly 223, the electrolyte and other components. The shell 212 and the end cap 211 can be independent components, and an opening can be set on the shell 212, and the internal environment of the battery cell 20 is formed by covering the opening with the end cap 211 at the opening. Without limitation, the end cap 211 and the shell 212 can also be integrated. Specifically, the end cap 211 and the shell 212 can form a common connection surface before other components are put into the shell, and when it is necessary to encapsulate the interior of the shell 212, the end cap 211 covers the shell 212. The shell 212 can be of various shapes and sizes, such as a rectangular parallelepiped, a cylindrical shape, a hexagonal prism, etc. Specifically, the shape of the shell 212 can be determined according to the specific shape and size of the electrode assembly 223. The shell 212 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiment of the present application does not impose any special limitation on this.

The electrode assembly 223 is a component in the battery cell 20 where an electrochemical reaction occurs. One or more electrode assemblies 223 may be included in the housing 212 to form a battery cell 22. The electrode assembly 223 includes a positive electrode sheet 2233, a negative electrode sheet 2234, and an isolation member 2235. During the charge and discharge process of the battery cell 20, active ions (such as lithium ions) are embedded and removed back and forth between the positive electrode sheet 2233 and the negative electrode sheet 2234. The isolation member 2235 is disposed between the positive electrode sheet 2233 and the negative electrode sheet 2234, which can prevent the positive electrode sheet 2233 and the negative electrode sheet 2234 from short-circuiting, while allowing active ions to pass through.

In some embodiments, the positive electrode sheet 2233 may include a positive electrode current collector and a positive electrode ear. The positive electrode current collector may have a positive electrode active material disposed on at least one surface, and the positive electrode ear may not have a positive electrode active material disposed on it.

In some embodiments, the negative electrode sheet 2234 may include a negative electrode current collector and a negative electrode ear portion, at least one surface of the negative electrode current collector is provided with a negative electrode active material, and the negative electrode ear portion is not provided with a positive electrode active material.

In some embodiments, the isolation member 2235 is an isolation membrane. The present application has no particular limitation on the type of isolation membrane, and any known isolation membrane with a porous structure having good chemical stability and mechanical stability can be selected.

In some embodiments, the electrode assembly 223 is a wound structure. The positive electrode sheet 2233, the negative electrode sheet 2234 and the separator 2235 are wound into a wound structure, and the positive current collector and the negative current collector are wound to form the main body 2231 of the electrode assembly 223, and the main body 2231 is a wound structure; the multiple positive electrode ears of the positive electrode sheet 2233 are stacked and gathered during the winding process to form a positive electrode ear group 22321, and the multiple negative electrode ears of the negative electrode sheet 2234 are stacked and gathered during the winding process to form a negative electrode ear group 22322.

In some embodiments, the electrode assembly 223 is a laminate structure, and multiple positive electrode sheets 2233, multiple negative electrode sheets 2234 and multiple isolation members 2235 are stacked to form a laminate structure. Multiple positive current collectors and multiple negative current collectors are stacked to form the main body 2231 of the electrode assembly 223, and the main body 2231 is a laminate structure; the positive electrode ears of the multiple positive electrode sheets 2233 are stacked and gathered during the stacking process to form a positive electrode ear group 22321, and the negative electrode ears of the multiple negative electrode sheets 2234 are stacked and gathered during the stacking process to form a negative electrode ear group 22322.

In some embodiments, when the battery cell 22 includes one electrode assembly 223, the main body 2231 of the electrode assembly 223 forms the main body 221 of the battery cell 22, the positive electrode tab group 22321 forms the positive electrode tab 2221, and the negative electrode tab group 22322 forms the negative electrode tab 2222; and when the battery cell 22 includes multiple electrode assemblies 223, the main bodies 2231 of the multiple electrode assemblies 223 form the main body 221 of the battery cell 22, the multiple positive electrode tab groups 22321 form the positive electrode tab 2221 of the battery cell 22, and the multiple negative electrode tab groups 22322 form the negative electrode tab 2222 of the battery cell 22. The positive electrode tab 2221 and the negative electrode tab 2222 may be located at the same end of the electrode assembly 223, or may be separately disposed at two opposite ends of the electrode assembly 223. During the charge and discharge process of the battery 1100, the positive electrode active material and the negative electrode active material react with the electrolyte, and the positive electrode tab 2221 and the negative electrode tab 2222 are respectively connected to the two electrode terminals 2111 to form a current loop. The positive electrode tab 2221 and the negative electrode tab 2222 can be connected to the corresponding electrode terminal 2111 through an adapter.

For the convenience of explanation, the positive electrode plate 2233 and the negative electrode plate 2234 are collectively referred to as electrode plates, and the positive electrode tab 2221 and the negative electrode tab 2222 are collectively referred to as tabs 222 .

As shown in Figure 5, in one embodiment of the present application, a battery cell 20 is provided, which includes a shell 21, a battery cell 22 and a heat conductor 23. The shell 21 contains an electrolyte; the battery cell 22 is located in the shell 21 and immersed in the electrolyte; the heat conductor 23 is at least partially located inside the battery cell 22, and the heat conductor 23 is used to transfer the heat inside the battery cell 22 to the outside of the battery cell 22.

The battery cell 22 may refer to a component in the battery cell 20 that can undergo an electrochemical reaction with the electrolyte; the battery cell 22 may include one or more electrode assemblies 223 described above to constitute the battery cell 22 .

The electrolyte may refer to a liquid in the battery cell 20 that can undergo an electrochemical reaction with the battery core 22. The battery core 22 is immersed in the electrolyte, and the electrolyte and the battery cell 22 undergo an electrochemical reaction, thereby realizing the charging and discharging of the battery cell 20. The battery cell 22 may be completely immersed in the electrolyte, or partially immersed in the electrolyte.

The heat conducting member 23 may refer to a component with heat conductivity, and utilizes the heat conductivity of the heat conducting material to accelerate the heat generated inside the battery core 22 to be transferred to the outside of the battery core 22. The heat conducting member 23 may be made of a material with good heat conductivity, such as graphite or graphene.

The heat conductor 23 is at least partially located inside the battery cell 22. It can be understood that a portion of the heat conductor 23 is located inside the battery cell 22, and another portion of the heat conductor 23 is located outside the battery cell 22. During the charging and discharging process of the battery cell 20, the heat generated inside the battery cell 22 is transferred to a portion of the heat conductor 23 located inside the battery cell 22, and then transferred to a portion of the heat conductor 23 located outside the battery cell 22 through the heat conductor 23, thereby transferring the heat generated inside the battery cell 22 to the electrolyte outside the battery cell 22; or, the heat conductor 23 is entirely located inside the battery cell 22, and the heat generated inside the battery cell 22 is transferred to the heat conductor 23, and the heat conduction of the heat conductor 23 accelerates the conduction of the heat inside the battery cell 22 to the electrolyte outside the battery cell 22; when the heat conductor 23 is entirely located inside the battery cell 22, the edge of the heat conductor 23 may be exposed outside the battery cell 22, or the edge of the heat conductor 23 is arranged close to the edge of the battery cell 22, so as to accelerate the conduction of the heat inside the battery cell 22 to the outside.

In the battery cell 20 of the embodiment of the present application, the heat conductive member 23 is at least partially located inside the battery cell 22 of the battery cell 20. The thermal conductivity of the heat conductive member 23 is utilized to accelerate the heat transfer from the battery cell 22 to the electrolyte outside the battery cell 22, and then transfer the heat to the interior of the entire battery cell 20 through the electrolyte, thereby improving the uneven temperature distribution inside the battery cell 20, improving the uniformity of the temperature distribution inside the battery cell 20, improving the performance and reliability of the battery cell 20, and improving the performance and reliability of the battery 1100.

In another embodiment of the present application, as shown in FIG. 6 , the heat conducting member 23 includes an insulating layer 231 and a heat conducting layer 232 , and at least one surface of the insulating layer 231 is connected to the heat conducting layer 232 .

The insulating layer 231 may be a component made of insulating material in the heating element 23 , and the insulating material may be, but is not limited to, plastic materials such as polyethylene terephthalate and polyethylene.

The heat-conducting layer 232 may refer to a heat-conducting portion 233 connected to the surface of the insulating layer 231 . Specifically, the heat-conducting layer 232 may be connected to the surface of the insulating layer 231 by bonding or coating.

By adopting the technical solution of this embodiment, the insulation performance of the insulating layer 231 can reduce the risk of short circuit inside the battery cell 22 and improve the reliability of the battery cell 22; the setting of the heat conductive layer 232 can accelerate the heat conduction from the inside of the battery cell 22 to the outside, improve the temperature difference between the inside and outside of the battery cell 22, improve the uniformity of the temperature distribution inside the battery cell 20, improve the performance and reliability of the battery cell 20, and improve the performance and reliability of the battery 1100. In addition, the heat conductive member 23 adopts the structure of the heat conductive layer 232 and the insulating layer 231, and the structure of the heat conductive member 23 is simple, which is conducive to reducing the manufacturing cost.

In another embodiment of the present application, the heat-conducting layer 232 is made by coating a heat-conducting material on the surface of the insulating layer 231 .

It is understandable that the heat-conducting layer 232 can be manufactured by coating the surface of the insulating layer 231 with a heat-conducting material.

By adopting the technical solution of this embodiment, the heat-conducting layer 232 is manufactured by coating, so that the manufacturing process of the heat-conducting member 23 is simple, which is conducive to reducing the manufacturing cost.

In another embodiment of the present application, as shown in FIG. 5 , at least one of two surfaces of the insulating layer 231 that are opposite to each other along the thickness direction is connected to a heat conducting layer 232 .

It can be understood that one of the two relatively distributed surfaces of the insulating layer 231 along the thickness direction is connected to the heat-conducting layer 232, and the other surface is not connected to the heat-conducting layer 232, or, the two relatively distributed surfaces of the insulating layer 231 along the thickness direction are both connected to the heat-conducting layer 232. The more the heat-conducting layers 232 are, the larger the heat-conducting area of the battery cell 22 to the outside is, and the better the heat-conducting effect of the heat-conducting component 23 is, which is conducive to accelerating the heat dissipation inside the battery cell 22; wherein, the thickness direction of the insulating layer 231 may refer to the stacking direction of the insulating layer 231 and the heat-conducting layer 232. For example, the thickness direction of the insulating layer 231 may refer to the X direction in Figure 6.

By adopting the technical solution of this embodiment, after the heat conductive member 23 is arranged in the battery cell 22, the surface area of the insulating layer 231 relatively distributed along the thickness direction is large, and the heat conductive layer 232 can be arranged larger, which is beneficial to increase the thermal contact area between the battery cell 22 and the heat conductive member 23, thereby accelerating the heat extraction inside the battery cell 22, and can better improve the temperature difference between the inside and outside of the battery cell 22, improve the uniformity of temperature distribution inside the battery cell 20, enhance the performance and reliability of the battery cell 20, and enhance the performance and reliability of the battery 1100.

In another embodiment of the present application, the thickness of the heat conductive layer 232 is in the range of 0.01 mm to 0.3 mm.

The thickness direction of the heat-conducting layer 232 may refer to the stacking direction of the insulating layer 231 and the heat-conducting layer 232 . For example, the width direction of the heat-conducting layer 232 may refer to the X direction shown in FIG. 6 .

By adopting the technical solution of this embodiment, the thickness _H1 of the heat-conducting layer 232 is set in the range of 0.01 mm to 0.3 mm. The heat-conducting layer 232 has a reasonable thickness, so that the heat-conducting member 23 has good thermal conductivity, and the heat-conducting layer 232 can be stably fixed on the insulating layer 231. At the same time, the heat-conducting layer 232 will not occupy a large space in the battery cell 20, which is also beneficial to improving the volume energy density of the battery cell 20.

In one embodiment, the thickness of the thermal conductive layer 232 may be, but is not limited to, 0.01 mm, 0.02 mm, 0.04 mm, 0.08 mm, 0.1 mm, 0.12 mm, 0.14 mm, 0.16 mm, 0.18 mm, 0.2 mm, 0.22 mm, 0.24 mm, 0.26 mm, 0.28 mm, or 0.3 mm.

In another embodiment of the present application, the thickness of the heat conductive layer 232 is in the range of 0.05 mm to 0.15 mm.

By adopting the technical solution of this embodiment, the thickness _H1 of the heat-conducting layer 232 is set in the range of 0.05 mm to 0.15 mm. The heat-conducting layer 232 has a more reasonable thickness, which can make the heat-conducting member 23 have better thermal conductivity and also make the heat-conducting layer 232 stably fixed on the insulating layer 231. At the same time, the heat-conducting layer 232 will not occupy a large space in the battery cell 20, which is also beneficial to improve the volume energy density of the battery cell 20.

In one embodiment, the thickness of the thermal conductive layer 232 may be, but is not limited to, 0.05 mm, 0.06 mm, 0.07 mm, 0.08 mm, 0.09 mm, 0.1 mm, 0.11 mm, 0.12 mm, 0.13 mm, 0.14 mm, or 0.15 mm.

In another embodiment of the present application, the thermal conductivity of the heat conductive layer 232 is greater than 150 Watt·meter ⁻¹ ·Kelvin ⁻¹ (150 W/(m·K)).

Thermal conductivity, also known as "thermal conductivity coefficient", refers to the amount of heat transferred per unit horizontal cross-sectional area per unit time when the vertical downward temperature gradient is 1K/m. The thermal conductivity of the thermal conductive layer 232 can be obtained by querying the thermal conductivity corresponding to the thermal conductive material, and can be obtained by using the laser flash method according to the ASTME1461-2013 test standard. Of course, in other embodiments, it can be obtained by other methods.

By adopting the technical solution of this embodiment, the thermal conductivity of the heat-conducting layer 232 is greater than 150W/(m·K), and the heat-conducting layer 232 has excellent thermal conductivity and can quickly conduct heat from the battery cell 22, thereby effectively improving the temperature uniformity inside the battery cell 20, and improving the performance and reliability of the battery cell 20 and the battery 1100.

In another embodiment of the present application, the thermal conductivity of the heat-conducting layer 232 is greater than 1700 W/(m·K).

By adopting the technical solution of this embodiment, the thermal conductivity of the heat-conducting layer 232 is greater than 1700 W/(m·K), and the heat-conducting layer 232 has better thermal conductivity, and can more effectively conduct heat from the battery cell 22, thereby more effectively improving the temperature uniformity inside the battery cell 20, and improving the performance and reliability of the battery cell 20 and the battery 1100.

In another embodiment of the present application, the heat conductive layer 232 is an annealed pyrolytic graphite layer or a graphene layer.

The annealed pyrolytic graphite layer may refer to annealed pyrolytic graphite, which has excellent thermal conductivity. Annealed pyrolytic graphite is an anisotropic pyrolytic graphite material with a microstructure close to that of a graphite crystal. The thermal conductivity in the direction of the graphite sheet (see the Z direction in FIG. 6 ) reaches more than 1700 W/(m·K), and has an ultra-high thermal conductivity. The heat conductive layer 232 uses the annealed pyrolytic graphite layer to effectively conduct the heat inside the battery cell 22 to the external electrolyte, and then transfers it to the entire battery cell 22 through the electrolyte, effectively improving the uniformity of the temperature distribution inside the battery cell 20, improving the performance and reliability of the battery cell 20, and improving the performance and reliability of the battery 1100.

The graphene layer may refer to a layer made of graphene, which has good thermal conductivity. Specifically, the graphene may be, but is not limited to, single-crystal graphene, polycrystalline graphene, graphene oxide, nitrided graphene, and semi-metallic graphene.

By adopting the technical solution of this embodiment, the thermal conductive layer 232 is made of annealed pyrolytic graphite or graphene with good thermal conductivity, so that the thermal conductive layer 232 has good thermal conductivity. The thermal conductive layer 232 can quickly conduct the heat inside the battery cell 22 to the electrolyte outside the battery cell 22, and then transfer it to the interior of the entire battery cell 20 through the electrolyte, effectively improving the uneven temperature distribution inside the battery cell 20, improving the uniformity of temperature distribution inside the battery cell 20, improving the performance and reliability of the battery cell 20, and improving the performance and reliability of the battery 1100.

In another embodiment of the present application, as shown in combination with FIG. 4 and FIG. 5 , the battery cell 22 includes a body 221 and a tab 222, and the tab 222 is connected to the end of the body 221 along the first direction; the heat conductive member 23 is at least partially located inside the body 221, and the portion of the heat conductive member 23 located inside the body 221 is a heat conductive portion 233; the size of the body 221 in the first direction is L ₁ , and the size of the heat conductive portion 233 in the first direction is L ₂ , wherein 0.75≤L ₂ /L ₁ ≤1.

The body 221 may refer to the portion of the battery cell 22 where electrochemical reactions occur, specifically, the portion of the battery cell 22 coated with active materials; for example, the body 221 may refer to a component formed by the main body 2231 of one or more electrode assemblies 223 .

The tab 222 may refer to a portion of the battery cell 22 for outputting or inputting current, specifically, may refer to a portion of the battery cell 22 that is not covered with active materials; for example, a component formed by one or more tab groups 2232 with the same polarity.

The pole ear 222 is connected to the end of the body 221 along the first direction. It can be understood that, of the two ends of the body 221 relatively distributed along the first direction, one end leads to the pole ear 222, and the other end does not lead to the pole ear 222; or, both ends of the body 221 relatively distributed along the first direction have pole ears 222 led out; the first direction can refer to the Z direction in Figure 4, the battery cell 22 is placed vertically, the pole ear 222 is located at the top or bottom of the body 221, and the battery cell 22 has a height direction, a length direction and a width direction, wherein the height direction of the battery cell 22 can refer to the Z direction in Figure 4, the length direction of the battery cell 22 can refer to the Y direction in Figure 4, and the width direction of the battery cell 22 can refer to the X direction in Figure 4, that is, the first direction can refer to the height direction of the battery cell 22; in another embodiment, the battery cell 22 is placed horizontally, the pole ear 222 is located on the side of the body 221, and the first direction can refer to the length direction of the body 221.

The heat conductive member 23 is at least partially located inside the body 221, and the portion of the heat conductive member 23 located inside the body 221 is the heat conductive portion 233; it can be understood that the heat conductive member 23 can be partially located inside the body 221 and the other part is located outside the body 221. In this case, the portion of the heat conductive member 23 located inside the body 221 is the heat conductive portion 233; or, the heat conductive member 23 is entirely located inside the body 221, that is, the entire heat conductive member 23 is the heat conductive portion 233.

The size of the body 221 in the first direction is L ₁ , and the size of the heat conducting portion 233 in the first direction is L ₂ , wherein 0.75≤L ₂ /L ₁ ≤1. It can be understood that, when 0.75≤L ₂ /L ₁ <1, in the first direction, the heat conducting portion 233 can be located in most areas of the body 221, so that the heat conducting portion 233 can be located in the middle of the body 221; when L ₂ /L ₁ =1, in the first direction, the size L ₂ of the heat conducting portion 233 is the same as the size L ₁ of the body 221, and the heat conducting portion 233 runs through the body 221. The heat of the body 221 can be better conducted from both ends of the heat conducting portion 233 to the electrolyte outside the battery cell 22, which is beneficial to improving the temperature uniformity inside the battery cell 22. For example, the first direction is the height direction of the body 221 , the dimension _L1 of the body 221 in the first direction may refer to the height of the body 221 , and the dimension _L2 of the heat conducting portion 233 in the first direction may refer to the height of the heat conducting portion 233 .

By adopting the technical solution of this embodiment, generally, during the charging and discharging process of the battery cell 22, in the first direction, the heat in the middle of the body 221 relative to the end of the body 221 is difficult to be discharged, so that the temperature in the middle of the body 221 is high and the temperature at the end of the body 221 is low; in the first direction, the heat conducting portion 233 can be located at least in most areas of the body 221, and the middle of the body 221 has the heat conducting portion 233, and the heat conducting portion 233 can quickly discharge the heat in the middle of the body 221 to the electrolyte outside the battery cell 22, and then transfer it to the entire battery cell 22 through the electrolyte, which can effectively improve the uniformity of temperature distribution of the battery cell 22, and also effectively improve the uneven temperature distribution inside the battery cell 20, improve the uniformity of temperature distribution inside the battery cell 20, improve the performance and reliability of the battery cell 20, and improve the performance and reliability of the battery 1100.

In another embodiment of the present application, as shown in combination with FIG. 4 and FIG. 5 , the electrode tab 222 includes a positive electrode tab 2221 and a negative electrode tab 2222, the positive electrode tab 2221 and the negative electrode tab 2222 are located at the same end of the body 221, the distance between the heat conductive member 23 and the end surface of the body 221 close to the electrode tab 222 is L ₃ , and the distance between the heat conductive portion 233 and the end surface of the body 221 facing away from the electrode tab 222 is L ₄ , wherein L ₃ >L ₄ .

The positive electrode tab 2221 may refer to a component consisting of a positive electrode tab extending from a positive electrode sheet 2233 in the battery cell 22 , and the negative electrode tab 2222 may refer to a component consisting of a negative electrode tab extending from a negative electrode sheet 2234 in the battery cell 22 .

The positive electrode tab 2221 and the negative electrode tab 2222 are located at the same end of the body 221. It can be understood that the positive electrode tab 2221 and the negative electrode tab 2222 are located at the same end of the body 221, which can facilitate the connection between the positive electrode tab 2221 and the negative electrode tab 2222 and the corresponding adapter.

The distance between the heat conducting member 23 and the end surface of the body 221 close to the pole ear 222 is L ₃ , and the distance between the heat conducting member 233 and the end surface of the body 221 facing away from the pole ear 222 is L ₄ , wherein L ₃ >L ₄ , it can be understood that the distance L ₃ between the heat conducting member 233 and the end surface of the body 221 close to the pole ear 222 is greater than the distance L ₄ between the heat conducting member 233 and the end surface of the body 221 facing away from the pole ear 222; the body 221 has a first end surface 2211 and a second end surface 2212 arranged opposite to each other, the first end surface 2211 leads out the positive pole ear 2221 and the negative pole ear 2222, the second end surface 2212 does not lead out the positive pole ear 2221 and the negative pole ear 2222, the distance between the first end surface 2211 and the heat conducting member 233 is L ₃ , and the distance between the second end surface 2212 and the heat conducting member 233 is L ₄ , wherein the first end face 2211 may refer to an end face formed after the edge of the electrode leading out of the electrode ear 222 is rolled or stacked, and the second end face 2212 may refer to an end face formed after the edge opposite to the electrode ear 222 is rolled or stacked; for example, if the heat conductor 23 is flush with the second end face 2212 or has a portion protruding from the second end face 2212 to the outside of the battery cell 22, therefore, _L4 is equal to 0; if the heat conductor 23 is located inside the body 221, _L4 is greater than 0.

By adopting the technical solution of this embodiment, generally, the positive pole tab 2221 and the negative pole tab 2222 serve as the output end and the input end of the battery cell 22. During the charging and discharging process, the positive pole tab 2221 and the negative pole tab 2222 generate a large amount of heat, that is, the temperature of the portion of the battery cell 22 close to the tab 222 is greater than the temperature of the end of the battery cell 22 facing away from the tab 222. The design of L ₃ >L ₄ makes the distance between the heat conducting portion 233 and the end surface of the battery cell 22 facing away from the tab 222 shorter. The heat conducting portion 233 can guide more heat from the middle part of the body 221 to the end of the body 221 facing away from the tab 222 with a lower temperature, which can better reduce the temperature of the middle part of the body 221, and is also beneficial to improving the uniformity of the temperature distribution of the battery cell 22, and is beneficial to improving the performance of the battery cell 22.

In another embodiment of the present application, in combination with Figures 4 and 5, the battery cell 22 includes an electrode assembly 223, the electrode assembly 223 includes a main body 2231 and a tab group 2232, the tab group 2232 is connected to the end of the main body 2231 along the first direction, and the main body 2231 is provided with at least one heat conductive member 23.

The main body 2231 may refer to the portion of the electrode assembly 223 coated with active materials, for example, it may refer to the portion composed of the current collector of the electrode sheet. The tab group 2232 may refer to the portion of the electrode assembly 223 that is not coated with active materials, for example, it may refer to the portion formed by the tab stacking led out of the electrode sheet. The tab group 2232 includes a positive tab group 22321 and a negative tab group 22322. The positive tab group 22321 may refer to the portion formed by the stacking of the positive tab portion led out of the positive electrode sheet 2233 of the electrode assembly 223, and the negative tab group 22322 may refer to the portion formed by the stacking of the negative tab portion led out of the negative electrode sheet 2234 of the electrode assembly 223.

By adopting the technical solution of this embodiment, the main body 2231 of the electrode assembly 223 may be provided with one or more heat-conducting parts 23. In this way, the number of heat-conducting parts 23 can be flexibly distributed according to the temperature distribution of the main body 2231, thereby effectively dissipating the heat in the electrode assembly 223, so that the electrode assembly 223 has better uniformity of temperature distribution, thereby improving the performance and reliability of the battery cell 20.

In another embodiment of the present application, as shown in combination with FIG. 4 and FIG. 5 , a heat conducting member 23 is provided at the middle position of the main body 2231 in the second direction, and the first direction is perpendicular to the second direction.

The second direction may refer to a direction perpendicular to the first direction. For example, the second direction may refer to the X direction shown in FIG. 5 , ie, the width direction of the electrode assembly 223 .

By adopting the technical solution of this embodiment, generally, in the second direction, the heat in the middle position of the main body 2231 is difficult to be exported outside the main body 2231, and the temperature of the middle position of the main body 2231 will be greater than the temperature of other positions of the main body 2231. The temperature of the middle position of the main body 2231 is relatively high, and the heat conductor 23 is arranged in the middle position of the main body 2231. In this way, the heat at the highest temperature in the middle position of the main body 2231 can be effectively exported to the electrolyte located outside the battery cell 22, and transferred to the entire battery cell 22 through the electrolyte. In this way, the uniformity of the temperature distribution of the battery cell 22 and the uniformity of the temperature distribution in the battery cell 20 can be effectively improved, and the performance and reliability of the battery cell 20 can be more effectively improved.

In another embodiment of the present application, the main body 2231 is a winding structure, and a heat conducting member 23 is provided at the winding center of the main body 2231 .

The main body 2231 is a winding structure. It can be understood that the electrode assembly 223 is formed by winding a stacked positive electrode sheet 2233, a negative electrode sheet 2234 and an isolation member 2235.

A heat conductive member 23 is disposed at the winding center of the main body 2231 . It can be understood that the stacked positive electrode sheet 2233 , negative electrode sheet 2234 and separator 2235 are wound outside the heat conductive member 23 .

By adopting the technical solution of this embodiment, during the actual charging and discharging process, the temperature of the winding center of the electrode assembly 223 is relatively high, and the heat conductive member 23 is arranged at the winding center of the electrode assembly 223, so that the heat at the highest temperature of the electrode assembly 223 can be effectively conducted to the electrolyte located outside the battery cell 22, and transmitted to the entire battery cell 22 through the electrolyte, so that the uniformity of the temperature distribution of the battery cell 22 and the uniformity of the temperature distribution in the battery cell 20 can be effectively improved, and the performance and reliability of the battery cell 20 can be more effectively improved. In addition, during the manufacturing process of the electrode assembly 223, the positive electrode sheet 2233, the negative electrode sheet 2234 and the separator 2235 which can be stacked can be wound on the heat conductive member 23, that is, the electrode assembly 223 provided with the heat conductive member 23 can be manufactured simply, which is conducive to improving production efficiency.

In another embodiment of the present application, the main body 2231 is provided with a plurality of heat-conducting members 23 , and the closer to the middle position of the main body 2231 in the second direction, the smaller the distance between two adjacent heat-conducting members 23 .

The main body 2231 is provided with a plurality of heat-conducting members 23 . It is understandable that the number of the heat-conducting members 23 provided on the main body 2231 may be, but is not limited to, two, three, four, or five.

The closer to the middle position of the main body 2231 in the second direction, the smaller the distance between two adjacent heat-conducting parts 23. It can be understood that the multiple heat-conducting parts 23 are non-equidistantly distributed in the second direction, and the number of heat-conducting parts 23 distributed from the middle position to both sides of the main body 2231 becomes smaller and smaller, and the distance between two adjacent heat-conducting parts 23 becomes larger and larger.

By adopting the technical solution of this embodiment, during the actual charging and discharging process of the battery cell 22, in the second direction, the temperature of the main body 2231 becomes lower and lower from the middle position to both sides, and the closer to the middle position of the main body 2231 in the second direction, the smaller the distance between two adjacent heat-conducting parts 23, that is, the temperature in the middle position is high and the number of heat-conducting parts 23 is large, while the temperature on both sides is low and the number of heat-conducting parts 23 is small. The temperature in the middle position is high and the thermal conductivity is strong, while the temperature on both sides is low and the thermal conductivity is weak. In this way, the heat distribution inside the electrode assembly 223 can be better balanced, and the temperature uniformity inside the electrode assembly 223 is better, which is beneficial to improving the temperature uniformity inside the battery cell 20 and improving the reliability of the battery cell 20.

In another embodiment of the present application, as shown in combination with FIG. 5 and FIG. 7 , the main body 2231 is a laminated structure, and the second direction is the stacking direction of the main body 2231 .

It can be understood that the positive electrode sheet 2233, the separator 2235, the negative electrode sheet 2234 and the separator 2235 are stacked in sequence to form the electrode assembly 223, wherein the stacking direction of the main body 2231 may refer to the stacking direction of the positive electrode sheet 2233, the separator 2235, the negative electrode sheet 2234 and the separator 2235 in sequence; for example, refer to the X direction in Figure 7, that is, the thickness direction of the heat conductor 23, wherein the heat conductor 23 may be located between the negative electrode sheet 2234 and the separator 2235, and may also be located between the positive electrode sheet 2233 and the separator 2235.

The closer to the middle position of the main body 2231 in the stacking direction of the main body 2231, the smaller the distance between two adjacent heat-conducting parts 23. It can be understood that the multiple heat-conducting parts 23 are non-equidistantly distributed in the stacking direction of the main body 2231. The number of heat-conducting parts 23 distributed from the middle position to both sides of the main body 2231 becomes smaller and smaller, and the distance between two adjacent heat-conducting parts 23 becomes larger and larger.

By adopting the technical solution of this embodiment, during the actual charging and discharging process of the electrode assembly 223, in the stacking direction of the main body 2231, the temperature of the main body 2231 from the middle position to the two sides becomes lower and lower, and the closer to the middle position of the main body 2231 in the stacking direction, the smaller the distance between two adjacent heat-conducting parts 23, that is, the temperature in the middle position is high and the number of heat-conducting parts 23 is large, and the temperature on both sides is low and the number of heat-conducting parts 23 is small. The temperature in the middle position is high and the thermal conductivity is strong, while the temperature on both sides is low and the thermal conductivity is weak. In this way, the heat distribution inside the electrode assembly 223 can be better balanced, and the temperature uniformity inside the electrode assembly 223 is better, which is beneficial to improving the temperature uniformity inside the battery cell 20 and improving the reliability of the battery cell 20. In addition, in the process of stacking the positive electrode sheet 2233, the negative electrode sheet 2234 and the isolation member 2235 of the electrode assembly 223, multiple heat conductive members 23 are inserted and stacked between the positive electrode sheet 2233 and the isolation member 2235 or between the negative electrode sheet 2234 and the isolation member 2235, so as to form an electrode assembly 223 with multiple heat conductive members 23 placed at non-equidistant intervals. The whole production process is simple and convenient, which is conducive to improving production efficiency.

In another embodiment of the present application, as shown in FIG. 8 , the battery cell 22 includes a plurality of electrode assemblies 223 , the plurality of electrode assemblies 223 are stacked, and a heat conductive member 23 is provided between two adjacent electrode assemblies 223 .

By adopting the technical solution of this embodiment, multiple electrode assemblies 223 are stacked. During the charging and discharging process of the battery cell 22, the heat generated by the electrode assembly 223 is difficult to dissipate from between two adjacent electrode assemblies 223. The temperature between two adjacent electrode assemblies 223 is relatively high. The heat conductor 23 is arranged between two adjacent electrode assemblies 223, which can better conduct this part of heat to the outside, thereby effectively reducing the temperature at this position, improving the uniformity of the temperature distribution of the battery cell 22, and helping to improve the uniformity of the temperature distribution inside the battery cell 20, which is beneficial to improving the performance and reliability of the battery cell 20.

In another embodiment of the present application, as shown in FIG. 8 and FIG. 9 , the battery cell 20 further includes an insulating member 24 , the insulating member 24 is coated on the outside of the battery core 22 , and at least one side of the heat conductive member 23 is connected to the insulating member 24 .

The insulating member 24 may refer to an insulating component wrapped around the battery core 22. The insulating member 24 is made of insulating material, which may be, but is not limited to, plastic materials such as polyethylene terephthalate and polyethylene. For example, the insulating member 24 may be a blue film or a mylar film. The state of the insulating member 24 after unfolding can be seen in FIG9 .

At least one side of the heat conductor 23 is connected to the insulating member 24. It can be understood that the sides electrically connected to the heat conductor 23 and the insulating member 24 can be but are not limited to one, two, or three; specifically, the side of the heat conductor 23 exposed outside the battery cell 22 can be connected to the insulating member 24, so that the heat inside the battery cell 22 can be transferred to the electrolyte outside the battery cell 22 through the side of the heat conductor 23 exposed outside the battery cell 22, which is beneficial to accelerate the outward conduction of the battery cell 22 and to improve the uniformity of temperature distribution inside the battery cell 20; the heat conductor 23 and the insulating member 24 can be connected by bonding, clamping, screwing, integral molding, etc., wherein the integral molding can refer to that the insulating layer 231 of the heat conductor 23 and the insulating member 24 are an integral structure, and the insulating layer 231 and the insulating member 24 can be made by an integral molding process by integral injection molding, integral cutting, etc.

By adopting the technical solution of this embodiment, during the process of charging and discharging the electrode assembly 223, the electrode assembly 223 will squeeze the heat conductor 23, and the heat conductor 23 and the insulating member 24 are connected as a whole. The insulating member 24 can support the heat conductor 23, reduce the risk of the heat conductor 23 moving out of the battery cell 22, and enable the heat conductor 23 to have a good heat conduction and temperature uniformity inside the battery cell 20. In addition, in the actual manufacturing process, the insulating member 24 and the heat conductor 23 are connected as a whole, which also facilitates the assembly of the heat conductor 23, the insulating member 24 and the battery cell 22.

In one embodiment, the insulating layer 231 may be made of the same material as the insulating member 24 to reduce the manufacturing cost of the battery cell 20. Of course, in other embodiments, the insulating layer 231 may be made of a different material than the insulating member 24.

In another embodiment of the present application, as shown in combination with FIG. 8 and FIG. 9 , the heat conducting member 23 and the insulating member 24 are bonded together by a heat conducting adhesive 25 .

The thermal conductive adhesive 25 may refer to a component that can bond the thermal conductive member 23 and the insulating member 24 and transfer the heat of the thermal conductive member 23 to the insulating member 24. Specifically, the thermal conductive adhesive 25 may be, but is not limited to, silicone thermal conductive adhesive 25, epoxy resin AB adhesive, acrylic thermal conductive adhesive 25, and polyurethane thermal conductive adhesive 25.

By adopting the technical solution of this embodiment, the heat-conducting adhesive 25 can transfer the heat of the battery cell 22 through the heat-conducting member 23 to the insulating member 24, and the insulating member 24 is coated on the outside of the battery cell 22, so that the heat can be transferred to the electrolyte outside the battery cell 22 over a large area, thereby facilitating the improvement of the uniformity of the temperature distribution inside the battery cell 22 and the battery cell 20, and facilitating the improvement of the performance and reliability of the battery cell 20. In addition, the heat-conducting member 23 and the insulating member 24 are connected by bonding, and the connection operation is simple, which is conducive to improving the production efficiency of the battery cell 20 and reducing the production cost.

In another embodiment of the present application, as shown in FIG. 8 and FIG. 9 , the battery cell 20 further includes a support member 26 , which is located in the housing 21 and is used to support the battery cell 22 . The surface of the insulating member 24 facing away from the heat conducting member 23 is connected to the support member 26 .

The support member 26 may refer to a component for being located in the housing 21 and supporting the battery cell 22 .

The surface of the insulating member 24 facing away from the heat conducting member 23 is connected to the supporting member 26 . It can be understood that the insulating member 24 is located between the heat conducting member 23 and the supporting member 26 .

By adopting the technical solution of this embodiment, the insulating member 24, the supporting member 26 and the heat conducting member 23 are connected as a whole, which also facilitates the assembly of the battery cell 22 with the heat conducting member 23, the insulating member 24 and the supporting member 26, thereby improving the production efficiency of the battery cell 20 and reducing the production cost.

The following describes the invention in combination with some embodiments.

Embodiment 1

In this embodiment, in combination with Figures 1 to 6 and Figure 9, the battery cell 20 includes an outer shell 21 and a battery cell 22, the outer shell 21 includes an end cover 211 and a shell 212, the end cover 211 is covered at the upper end opening of the shell 212, the end cover 211 and the shell 212 are surrounded to form a accommodating space, the battery cell 22 is located in the accommodating space, the end cover 211 is provided with two electrode terminals 2111 and a pressure relief mechanism 2112 for pressure relief; the battery cell 22 includes two electrode assemblies 223, and the upper ends of the two electrode assemblies 223 are both led out with a positive electrode tab group 22321 and a negative electrode tab group 22322. The two positive electrode tab groups 22321 form a positive electrode tab 2221, and the two positive electrode tab groups 22321 are bent relative to each other to facilitate electrical connection with an electrode terminal 2111 on the end cover 211; the two negative electrode tab groups 22322 form a negative electrode tab 2222, and the two negative electrode tab groups 22322 are bent relative to each other to facilitate electrical connection with another electrode terminal 2111 on the end cover 211; the main bodies 2231 of the two electrode assemblies 223 are stacked and form the body 221 of the battery cell 22.

In this embodiment, a heat conducting member 23 is provided at the middle position of the two main bodies 2231 along the width direction, the distance between the upper end of the heat conducting member 23 and the upper end surface of the main body 2231 (i.e., the first end surface 2211) is L ₃ , and the distance between the lower end of the heat conducting member 23 and the lower end surface of the main body 2231 is 0, that is, the heat conducting member 23 is completely inserted into the main body 2231, the heat conducting member 23 is a heat conducting portion 233, the height of the main body 2231 is L ₁ , the height of the heat conducting member 23 is L ₂ , 0.75≤L ₂ /L ₁ ≤1, and the lower end of the heat conducting member 23 (i.e., the second end surface 2212) is connected to the insulating member 24 wrapped around the outside of the battery core 22 through the thermal conductive adhesive 25.

In this embodiment, the heat conducting member 23 includes an insulating layer 231 and two heat conducting layers 232. The two heat conducting layers 232 are respectively connected to two surfaces of the insulating layer 231 that are opposite to each other along the thickness direction. The heat conducting layer 232 is an annealed pyrolytic graphite layer.

In this embodiment, a support member 26 is provided between the insulating member 24 and the bottom wall of the housing 21 , and the support member 26 is bonded to the insulating member 24 .

During the assembly process of the battery cell 20, the bottom of the heat conductive part 23 is coated with a thermal conductive adhesive 25 and bonded to the insulating part 24 to form a T-shaped structure; after the pole ear 222 and the adapter are laser welded, the heat conductive part 23 is placed between the two electrode assemblies 223, and the insulating part 24 is coated on the surface of the electrode assembly 223. The bottom of the insulating part 24 is bonded to the support part 26 by hot melting or gluing to achieve insulation of the battery cell 22, and finally the coated electrode assembly 223 is placed in the outer shell 21.

Embodiment 2

The difference between this embodiment and the first embodiment is that, as shown in FIG. 8 , the heat conducting member 23 is between the two main body portions 2231 .

Embodiment 3,

The difference between this embodiment and the first embodiment is that: as shown in Figure 7, the electrode assembly 223 is a laminated structure, the positive electrode plate 2233, the negative electrode plate 2234 and the isolation member 2235 in the electrode assembly 223 are stacked, and the heat conductive member 23 can be inserted between the negative electrode plate 2234 and the isolation member 2235.

In another embodiment of the present application, in combination with FIG. 2 , a battery 1100 is provided, comprising the battery cell 20 of the above embodiment.

In another embodiment of the present application, in combination with FIG. 1 , an electrical device is provided, including a battery 1100 as in the above embodiment.

The above description of various embodiments tends to emphasize the differences between the various embodiments. The same or similar parts can be referenced to each other, and for the sake of brevity, they will not be repeated in this article.

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 (22)

1. A battery cell, characterized in that: it comprises: A shell containing an electrolyte; a battery cell, located in the housing and immersed in the electrolyte; and A heat conductive member, wherein the heat conductive member is at least partially located inside the battery core, and the heat conductive member is used to conduct heat inside the battery core to the outside of the battery core. 2 . The battery cell according to claim 1 , wherein the heat-conducting member comprises an insulating layer and a heat-conducting layer, and at least one surface of the insulating layer is connected to the heat-conducting layer. 3 . The battery cell according to claim 2 , wherein the heat-conducting layer is made by coating a heat-conducting material on the surface of the insulating layer. 4 . The battery cell according to claim 2 , wherein the heat conducting layer is connected to at least one of two surfaces of the insulating layer that are opposite to each other in the thickness direction. 5 . The battery cell according to claim 2 , wherein the thickness of the heat conductive layer is in the range of 0.01 mm to 0.3 mm. 6 . The battery cell according to claim 4 , wherein the thickness of the heat conductive layer is in the range of 0.05 mm to 0.15 mm. 7 . The battery cell according to claim 5 , wherein the thermal conductivity of the thermal conductive layer is greater than 150 W/(m·K). 8 . The battery cell according to claim 6 , wherein the thermal conductivity of the heat-conducting layer is greater than 1700 W/(m·K). 9 . The battery cell according to claim 2 , wherein the heat conductive layer is an annealed pyrolytic graphite layer or a graphene layer. 10. The battery cell according to any one of claims 1 to 9, characterized in that: the battery cell comprises a body and a tab, the tab is connected to an end of the body along a first direction; the heat conductive member is at least partially located inside the body, and the portion of the heat conductive member located inside the body is a heat conductive portion; A dimension of the main body in the first direction is L ₁ , and a dimension of the heat conducting portion in the first direction is L ₂ , wherein 0.75≤L ₂ /L ₁ ≤1. 11. The battery cell according to claim 10, characterized in that: the tabs include a positive tab and a negative tab, the positive tab and the negative tab are located at the same end of the body, the distance between the heat conductive member and the end surface of the body close to the tab is _L3 , and the distance between the heat conductive part and the end surface of the body facing away from the tab is _L4 , wherein _L3 > _L4 . 12. The battery cell according to any one of claims 1 to 9, characterized in that: the battery core comprises an electrode assembly, the electrode assembly comprises a main body and a tab group, the tab group is connected to an end of the main body along a first direction, and the main body is provided with at least one of the heat conducting members. 13 . The battery cell according to claim 12 , wherein the heat conducting member is disposed at a middle position of the main body in the second direction, and the first direction is perpendicular to the second direction. 14 . The battery cell according to claim 13 , wherein the main body is a winding structure, and the heat conducting member is disposed at the winding center of the main body. 15 . The battery cell according to claim 12 , wherein the main body is provided with a plurality of the heat conducting members, and the closer to the middle position of the main body in the second direction, the smaller the distance between two adjacent heat conducting members. 16 . The battery cell according to claim 15 , wherein the main body is a laminated structure, and the second direction is a stacking direction of the main body. 17 . The battery cell according to claim 1 , wherein the battery core comprises a plurality of electrode assemblies, the plurality of electrode assemblies are stacked, and the heat conductive member is disposed between two adjacent electrode assemblies. 18 . The battery cell according to claim 2 , wherein the battery cell further comprises an insulating member, the insulating member is coated on the outside of the battery core, and at least one side of the insulating layer is connected to the insulating member. 19 . The battery cell according to claim 18 , wherein the heat conductive member and the insulating member are bonded together by heat conductive adhesive. 20 . The battery cell according to claim 19 , wherein the battery cell further comprises a support member, the support member is located in the housing, the support member is used to support the battery core, and a surface of the insulating member facing away from the heat conductive member is connected to the support member. 21. A battery, characterized by comprising the battery cell according to any one of claims 1 to 20. 22. An electrical device, characterized in that it comprises the battery according to claim 21.