CN221262494U - Battery monomer, battery and power consumption device - Google Patents

Abstract

The application provides a battery monomer, a battery and an electricity utilization device, and belongs to the field of batteries. The battery cell includes a housing, a cell assembly, and a first thermally conductive film. The battery cell assembly is arranged in the shell, and the first heat conducting film is located between the battery cell assembly and the shell, wherein the first heat conducting film is used for dispersing heat transferred to the shell by the battery cell assembly.

Description

Battery monomer, battery and power consumption device

Technical Field

The present application relates to the field of battery technologies, and in particular, to a battery cell, a battery, and an electric device.

Background

Energy conservation and emission reduction are key to sustainable development of the automobile industry, and electric vehicles become an important component of sustainable development of the automobile industry due to the energy conservation and environmental protection advantages of the electric vehicles. For electric vehicles, battery technology is an important factor in the development of the electric vehicles.

In the related art, a plurality of battery monomers are assembled into a module or are arranged in electric equipment after a battery pack is assembled, and because the interval between the battery monomers is smaller, when a certain battery monomer is in thermal runaway, local high temperature is easily caused, so that the performance of the battery monomer is influenced, and even other surrounding battery monomers are caused to be in thermal runaway.

Disclosure of utility model

The present application aims to solve at least one of the technical problems existing in the background art. Therefore, an object of the present application is to provide a battery cell, a battery and an electric device, which can reduce the probability of performance loss or thermal runaway of the battery cell caused by high temperature.

An embodiment of a first aspect of the present application provides a battery cell, comprising: the battery module comprises a shell, a battery cell assembly and a first heat conducting film. The battery cell assembly is arranged in the shell, the first heat conduction film is located between the battery cell assembly and the shell, and the first heat conduction film is used for dispersing heat transferred to the shell by the battery cell assembly.

According to the technical scheme provided by the embodiment of the application, the first heat conducting film is arranged in the battery unit body, so that the heat diffusion capacity of the outer surface of the battery cell assembly can be improved, the locally generated heat can be conducted to the periphery more quickly, the formation of local high temperature can be restrained to a certain extent, and the risk of thermal failure of the battery cell caused by the local high temperature is reduced.

In some embodiments, the housing includes a housing for receiving the cell assembly and an end cap, the housing having an opening; the end cover is connected with the shell and covers the opening, and the first heat conducting film is positioned between the battery cell component and the shell.

In some embodiments, the cell assembly includes opposing first and second end faces, and a side surface connecting the first and second end faces, the first end face having a tab connected to the end cap; at least part of the side surface and/or the second end surface is coated with a first heat conducting film. The side surface and the second end surface without the electrode lugs are relatively flat, the arrangement of the first heat conducting film for heat conduction is facilitated, the arrangement of the first heat conducting film can be simplified, and the capacity loss of the battery cell is reduced.

In some embodiments, the side surface comprises a first plane and a second plane disposed opposite each other, at least a portion of the surface of the first plane and/or the second plane being coated with the first thermally conductive film. Therefore, the first heat conduction film can be better arranged by utilizing the flat surface, so that the heat dissipation can be faster and more uniform, and the probability of local high-temperature formation is reduced.

In some embodiments, the side surface further comprises a connecting surface connecting the first plane and the second plane; the first heat conducting film comprises a first part, a second part and a third part which are connected; the first part is coated on the first plane, the second part is coated on the connecting surface, and the third part is coated on the second plane. The first heat conducting film is connected with the second part of the first connecting surface and/or the second connecting surface through cladding, so that the first heat conducting film can avoid the second end surface of the battery cell assembly, and the risk of short circuit of the pole piece is reduced.

In some embodiments, the ratio K ₁ of the forward projected area of the first portion on the first plane to the area of the first plane satisfies: k ₁ is more than or equal to 0.8 and less than or equal to 1; and/or the ratio K ₂ of the orthographic projection area of the second portion on the second plane to the area of the second plane satisfies: k ₂ is more than or equal to 0.8 and less than or equal to 1. The heat conduction film with enough area is arranged on the large surface of the battery cell assembly, so that heat conduction inside the battery cells can be realized, heat can be more uniformly transferred to surrounding battery cells when the battery cells are distributed, and the probability that the battery performance is reduced or fails due to local high temperature around is reduced.

In some embodiments, the battery cell includes a plurality of cell assemblies; at least part of the outer surface of at least one cell component is coated with a first heat conducting film. Thus, heat transfer among the plurality of battery cell assemblies can be realized, so that the temperature in the battery cell is relatively uniform, and the risk of thermal runaway is reduced.

In some embodiments, the plurality of cell assemblies are arranged along a predetermined direction, and a first heat conductive film is disposed between any two adjacent cell assemblies. Therefore, continuous heat conduction among a plurality of cell assemblies in the battery unit can be realized, heat is more uniformly distributed, and the probability of forming local high temperature is reduced.

In some embodiments, the battery cell further includes a first insulating film located between the housing and the cell assembly. Through setting up first insulating film can reduce the single short circuit risk of battery, improves single reliability of battery.

In some embodiments, the orthographic projection of the first thermally conductive film on the outer surface of the cell assembly falls within the orthographic projection of the first insulating film on the outer surface of the cell assembly. The first heat conducting film is completely covered by the first insulating film, so that the risk of short circuit caused by the first heat conducting film can be effectively reduced, and the reliability of the battery cell is improved.

In some embodiments, the material of the first heat conductive film is graphene. The high heat conduction performance and the mechanical property of the graphene can reduce the thickness of the heat conduction film as much as possible on the basis of meeting the heat conduction requirement, so that the graphene is more beneficial to arrangement in a battery unit body, and the capacity loss of the battery is reduced.

An embodiment of the second aspect of the present application provides a battery including the battery cell of the above embodiment.

In some embodiments, the battery further comprises a second thermally conductive film that is wrapped around at least a portion of the outer surface of the housing of the battery cell. Therefore, heat can be transferred between a plurality of battery monomers more quickly and uniformly, the heat dissipation area is increased, the heat dissipation of the battery is facilitated, and the risk of thermal runaway spreading of the surrounding battery monomers caused by local high temperature is reduced.

In some embodiments, the battery further comprises a second insulating film located between the second heat conducting film and the housing or on a surface of the second heat conducting film remote from the housing, and an orthographic projection of the second heat conducting film on the outer surface of the housing falls within a projection range of the second insulating film on the outer surface of the housing. Through setting up the second insulating film outside the single shell of battery, can reduce the short circuit risk between the single battery, improve the reliability of battery.

An embodiment of a third aspect of the present application provides an electrical device comprising a battery as in the above embodiment for providing electrical energy.

The foregoing description is only an overview of the present application, and is intended to be implemented in accordance with the teachings of the present application in order that the same may be more clearly understood and to make the same and other objects, features and advantages of the present application more readily apparent.

Drawings

In the drawings, the same reference numerals refer to the same or similar parts or elements throughout the several views unless otherwise specified. The figures are not necessarily drawn to scale. It is appreciated that these drawings depict only some embodiments according to the disclosure and are not therefore to be considered limiting of its scope.

FIG. 1 is a schematic illustration of a vehicle according to some embodiments of the application;

fig. 2 is an exploded view of a battery according to some embodiments of the present application;

Fig. 3 is a schematic exploded view of a battery cell according to some embodiments of the present application;

fig. 4 is a schematic structural diagram of a battery cell assembly coated with a first heat conductive film according to some embodiments of the present application;

fig. 5 is a schematic diagram illustrating an exploded structure of a battery cell assembly and a first heat conductive film according to some embodiments of the present application;

FIG. 6 is a cross-sectional view taken along the direction A-A in FIG. 4;

FIG. 7 is a cross-sectional view taken along the direction B-B in FIG. 3;

Fig. 8 is a cross-sectional view taken along the direction C-C in fig. 3.

Reference numerals illustrate:

A vehicle 1000;

battery 100, controller 200, motor 300;

The battery pack includes a case 10, a first portion 11, a second portion 12, battery cells 20, a case 21, a case 211, an end cap 212, a battery cell assembly 22, a first end surface 221, a second end surface 222, a side surface 223, a first plane 2231, a first connection surface 2232, a second plane 2233, a second connection surface 2234, tabs 224, a first heat conductive film 23, a first portion 231, a second portion 232, a third portion 233, a first insulating film 24, a second insulating film 25, and a second heat conductive film 26.

Detailed Description

Embodiments of the technical scheme of the present application will be described in detail below with reference to the accompanying drawings. The following examples are only for more clearly illustrating the technical aspects of the present application, and thus are merely examples, and are not intended to limit the scope of the present application.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "comprising" and "having" and any variations thereof in the description of the application and the claims and the description of the drawings above are intended to cover a non-exclusive inclusion.

In the description of embodiments of the present application, the technical terms "first," "second," and the like are used merely to distinguish between different objects and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated, a particular order or a primary or secondary relationship. In the description of the embodiments of the present application, the meaning of "plurality" is two or more unless explicitly defined otherwise.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those of skill in the art will explicitly and implicitly appreciate that the embodiments described herein may be combined with other embodiments.

In the description of the embodiments of the present application, the term "and/or" is merely an association relationship describing an association object, and indicates that three relationships may exist, for example, a and/or B may indicate: a exists alone, A and B exist together, and B exists alone. In addition, the character "/" herein generally indicates that the front and rear associated objects are an "or" relationship.

In the description of the embodiments of the present application, the term "plurality" means two or more (including two), and similarly, "plural sets" means two or more (including two), and "plural sheets" means two or more (including two).

In the description of the embodiments of the present application, the orientation or positional relationship indicated by the technical terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. are based on the orientation or positional relationship shown in the drawings, and are merely for convenience of description and simplification of the description, and do not indicate or imply that the apparatus or element referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the embodiments of the present application.

In the description of the embodiments of the present application, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured" and the like should be construed broadly and may be, for example, fixedly connected, detachably connected, or integrally formed; or may be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the embodiments of the present application will be understood by those of ordinary skill in the art according to specific circumstances.

Currently, the application of power batteries is more widespread from the development of market situation. The power battery is not only applied to energy storage power supply systems such as hydraulic power, firepower, wind power and solar power stations, but also widely applied to electric vehicles such as electric bicycles, electric motorcycles, electric automobiles and the like. With the continuous expansion of the application field of the power battery, the market demand of the power battery is also continuously expanding.

In order to meet energy requirements, after a plurality of battery monomers are assembled into a module or a battery pack in a serial or parallel mode, the battery pack is powered externally, for example, the battery pack is arranged on a vehicle to provide electric energy for the vehicle, due to the fact that the distance between the battery monomers is smaller, when a certain battery monomer is out of control due to heat, generated heat is difficult to transfer and spread out, particularly when the battery monomer adopts an aluminum shell material, the battery monomers are transmitted to heat through shell contact, the aluminum shell is not high in heat conductivity, heat can be concentrated in a certain area to form local high temperature, and then the battery monomer beside the battery is easy to be influenced by the high temperature, for example, the temperature of the area, close to the local high temperature, of the battery monomer reaches the failure temperature in an electrode material, and further the battery monomer beside the thermal control battery monomer is also out of control.

In order to alleviate the problem of thermal runaway spread of the battery cells, heat conduction may be optimized in the design of the battery cells so that the generated heat can be transferred from the surroundings quickly and more uniformly. The heat conducting material is arranged in the battery, so that heat can be conducted and dispersed to the periphery in time, thereby reducing the generation of local high temperature as much as possible, and reducing the probability of performance loss or thermal runaway of the battery monomer caused by high temperature.

The battery cell disclosed by the embodiment of the application can be used in electric devices such as vehicles, ships or aircrafts, but is not limited to the electric devices. The power supply system with the battery cells, the batteries and the like which are disclosed by the application can be used for forming the power utilization device, so that the probability of performance loss or thermal runaway of the battery cells caused by high temperature is reduced, and the stability of the battery performance and the service life of the battery are improved.

The embodiment of the application provides an electric device using a battery as a power supply, wherein the electric device can be, but is not limited to, a mobile phone, a tablet, a notebook computer, an electric toy, an electric tool, a battery car, an electric car, a ship, a spacecraft and the like. Among them, the electric toy may include fixed or mobile electric toys, such as game machines, electric car toys, electric ship toys, electric plane toys, and the like, and the spacecraft may include planes, rockets, space planes, and spacecraft, and the like.

For convenience of description, the following embodiment will take an electric device according to an embodiment of the present application as an example of the vehicle 1000.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a vehicle according to some embodiments of the application. The vehicle 1000 may be a fuel oil vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or a range-extended vehicle. The battery 100 is provided in the interior of the vehicle 1000, and the battery 100 may be provided at the bottom or the head or the tail of the vehicle 1000. The battery 100 may be used for power supply of the vehicle 1000, for example, the battery 100 may be used as an operating power source of the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300, the controller 200 being configured to control the battery 100 to power the motor 300, for example, for operating power requirements during start-up, navigation, and travel of the vehicle 1000.

In some embodiments of the present application, battery 100 may not only serve as an operating power source for vehicle 1000, but may also serve as a driving power source for vehicle 1000, instead of or in part instead of fuel oil or natural gas, to provide driving power for vehicle 1000.

Referring to fig. 2, fig. 2 is an exploded view of a battery according to some embodiments of the present application. The battery 100 includes a case 10 and a battery cell 20, and the battery cell 20 is accommodated in the case 10. The case 10 is used to provide an accommodating space for the battery cell 20, and the case 10 may have various structures. In some embodiments, the case 10 may include a first portion 11 and a second portion 12, the first portion 11 and the second portion 12 being overlapped with each other, the first portion 11 and the second portion 12 together defining an accommodating space for accommodating the battery cell 20. The second portion 12 may be a hollow structure with one end opened, the first portion 11 may be a plate-shaped structure, and the first portion 11 covers the opening side of the second portion 12, so that the first portion 11 and the second portion 12 together define a containing space; the first portion 11 and the second portion 12 may be hollow structures each having an opening at one side, and the opening side of the first portion 11 is engaged with the opening side of the second portion 12. Of course, the case 10 formed by the first portion 11 and the second portion 12 may be of various shapes, such as a cylinder, a rectangular parallelepiped, or the like.

In the battery 100, the plurality of battery cells 20 may be connected in series, parallel or a series-parallel connection, wherein the series-parallel connection refers to that the plurality of battery cells 20 are connected in series or parallel. The plurality of battery cells 20 can be directly connected in series or in parallel or in series-parallel, and then the whole formed by the plurality of battery cells 20 is accommodated in the box 10; of course, the battery 100 may also be a battery module formed by connecting a plurality of battery cells 20 in series or parallel or series-parallel connection, and a plurality of battery modules are then connected in series or parallel or series-parallel connection to form a whole and are accommodated in the case 10. The battery 100 may further include other structures, for example, the battery 100 may further include a bus member for making electrical connection between the plurality of battery cells 20.

Wherein each battery cell 20 may be a secondary battery or a primary battery; but not limited to, lithium sulfur batteries, sodium ion batteries, or magnesium ion batteries. The battery cell 20 may be in the shape of a cylinder, a flat body, a rectangular parallelepiped, or other shapes, etc.

Referring to fig. 3, fig. 3 is an exploded view of a battery cell according to some embodiments of the present application. The battery cell 20 refers to the smallest unit constituting the battery.

As shown in fig. 3, an embodiment of the present application provides a battery cell 20, where the battery cell 20 includes a housing 21, a cell assembly 22, and a first heat conductive film 23.

The battery cell assembly 22 is disposed in the housing 21, and the first heat conductive film 23 is disposed between the battery cell assembly 22 and the housing 21, and the first heat conductive film 23 is used for dispersing heat transferred from the battery cell assembly 22 to the housing 21.

The housing 21 is an assembly that forms the internal environment of the battery cell 20 that may be used to house the components of the cell assembly 22, it being understood that the internal environment formed by the housing 21 may also house electrolyte and other components. The housing 21 may be of various shapes and various sizes, such as rectangular parallelepiped, cylindrical, hexagonal prism, etc. In particular, the shape of the housing may be determined according to the specific shape and size of the cell assembly 22. The material of the housing 21 may be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

The cell assembly 22 is the component of the battery cell 20 where the electrochemical reaction occurs. One or more of the cell assemblies 22 may be contained within the housing 211. The cell assembly 22 is formed primarily of a positive and negative electrode sheet wound or stacked together, and typically has a separator disposed between the positive and negative electrode sheets. The portions of the positive and negative electrode sheets having active material constitute the main body of the cell assembly, and the portions of the positive and negative electrode sheets having no active material constitute the tabs 224, respectively. The positive electrode tab and the negative electrode tab may be located at one end of the main body portion together or located at two ends of the main body portion respectively. During charge and discharge of the battery, the positive electrode active material and the negative electrode active material react with the electrolyte, and the tab 224 is connected to the corresponding electrode terminal to form a current loop.

The first heat conducting film 23 is in a film state structure, and the first heat conducting film 23 is arranged between the housing 21 and the cell assembly 22, for example, on the outer surface of the cell assembly 22 or on the inner surface of the housing 21. The heat generated in the cell assembly 22 is typically diffused through the housing 21 to the surroundings. In some examples, the first thermally conductive film 23 may directly or indirectly cover at least a portion of the outer surface of the cell assembly 22. The first heat conducting film 23 of the coating means herein is directly or indirectly attached to the outer surface of the cell assembly 22, so as to be capable of absorbing and conducting heat generated by the cell assembly 22. The first heat conducting film 23 can be made of a material with better heat conducting property. In some examples, the heat conducting property of the first heat conducting film 23 is better than that of the housing 211, for example, the first heat conducting film 23 may be made of a material with a higher heat conducting coefficient than that of the housing 211. The thickness of the first heat conductive film 23 may be determined according to the heat conductive property, mechanical property, and arrangement space in the case, and the smaller the thickness, the less space occupation in the battery cell, and the smaller the resulting capacity loss. The first heat conductive film 23 is disposed between the housing 21 and the cell assembly 22, and can spread heat generated from the cell assembly 22 to a larger area before being transferred to the housing, thereby conducting the heat to the housing 11 in a larger area.

It will be appreciated that the first heat conductive film 23 needs to be offset from the tab 224 when wrapping the outer surface of the battery module 22, so as to allow the tab 224 to be connected to the housing.

By arranging the first heat conducting film 23 in the battery unit body, the heat diffusion capability of the outer surface of the battery cell assembly 22 can be improved, heat generated locally by the battery cell assembly 22 is conducted to the periphery more quickly, the formation of local high temperature can be restrained to a certain extent, and the risk of thermal failure of the battery cell caused by the local high temperature is reduced.

In some embodiments, housing 21 includes a housing 211 and an end cap 212, housing 211 for housing cell assembly 22, housing 211 having an opening; the end cap 212 is connected with the housing 211 and covers the opening, and the first heat conducting film 23 is located between the cell assembly 22 and the housing 211.

The housing 21 includes a case 211 having an opening and an end cap 212 connected to the case and covering the opening. The inner space formed by the case 211 may be used to accommodate the battery cell assembly 22, and the opening is an opening communicating with the inner space formed by the case 211, for example, the opening may be located at one end of the accommodating space of the case 211, and the end cap 212 refers to a member that covers the opening of the case 211 to isolate the inner environment of the battery cell 20 from the outer environment. Without limitation, the shape of the end cap 212 may be adapted to the shape of the housing 211 to fit the housing 211. Optionally, the end cap 212 may be made of a material having a certain hardness and strength (such as an aluminum alloy), so that the end cap 212 is not easy to deform when being extruded and collided, so that the battery cell 20 can have a higher structural strength, and the safety performance can be improved. The end cap 212 may be provided with functional parts such as electrode terminals. The electrode terminals may be used to electrically connect with the cell assembly 22 for outputting or inputting electric power of the battery cell 20. In some embodiments, the end cap 212 may also be provided with a pressure relief mechanism for relieving the internal pressure of the battery cell 20 when the internal pressure or temperature reaches a threshold. The end cap 212 may also be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

The case 211 and the end cap 212 may be separate members, and an opening may be provided in the case 211, and the interior of the battery cell 20 may be formed by closing the opening with the end cap 212 at the opening. The end cap 212 and the housing 22 may be integrated, and specifically, the end cap 212 and the housing 211 may form a common connection surface before other components are put into the housing, and when the interior of the housing 211 needs to be sealed, the end cap 212 is covered on the housing 211.

In some examples, taking square batteries as an example, the tabs of the battery cell assembly 22 are located at the same end, after the battery cell assembly 22 is placed in the housing 211, one end of the tab faces the opening of the housing 211 so as to be connected with the end cover 212, the other end of the pole piece of the battery cell assembly 22 away from the tab and the side surface of the pole piece are opposite to the inner surface of the housing 211, the surface area of the portion is relatively large, and the first heat conducting film 23 is located between the housing 211 and the battery cell assembly 22, so that heat dissipation is more facilitated in time, and the first heat conducting film can be staggered with the tab. The first heat conducting film 23 may be attached to at least part of the inner surface of the housing 211, or may be coated on at least part of the outer surface of the cell assembly 22 opposite to the housing 211.

The first heat conducting film 23 is arranged between the shell 211 and the battery cell assembly 22, so that heat generated by the battery cell assembly 22 can be timely dispersed, the first heat conducting film 23 and the electrode lugs are staggered, the risk of short circuit inside the battery is reduced, and the reliability of the battery is improved.

Referring to fig. 4-6, fig. 4 is a schematic structural diagram of a battery cell assembly coated with a first heat conductive film according to some embodiments of the present application; fig. 5 is a schematic diagram illustrating an exploded structure of a battery cell assembly and a first heat conductive film according to some embodiments of the present application; fig. 6 is a cross-sectional view taken along A-A in fig. 4.

According to some embodiments of the present application, the cell assembly 22 includes opposing first 221 and second 222 end faces, and side surfaces 223 connecting the first 221 and second 222 end faces,

The first end surface 221 is provided with a tab 224 connected with the end cover 212; at least a portion of the side surface 223 and/or the second end surface 222 is coated with the first thermally conductive film 23.

The first end face 221 and the second end face 222 are two end faces of the cell assembly 22, respectively, and the side surface 223 is a sidewall outer surface therebetween. Taking a winding cell or a cylindrical cell as an example, the first end surface 221 and the second end surface 222 are end surfaces perpendicular to the winding center, and the tab 224 may be located at the first end surface 221 entirely or at the first end surface 221 partially or at the second end surface 222 partially.

The first heat conducting film 23 may cover at least part of the surface of the side surface 223, or cover at least part of the surface of the second end surface 222 when the tab 224 is located on the first end surface 221, or cover at least part of the surfaces of the side surface 223 and the second end surface 222 at the same time. It will be appreciated that when the material of the first heat conductive film 23 is an electrically conductive material, the first heat conductive film 23 needs to be insulated from the second end surface 222 when coated on the second end surface 222, for example, an insulating layer capable of conducting heat may be disposed therebetween to prevent the plurality of pole pieces from forming an electrical connection through the first heat conductive film 23.

Since the side surfaces 223 and the second end surfaces 222 where the tabs are not arranged are relatively flat, the arrangement of the first heat conductive film 23 for conducting heat is facilitated, the arrangement of the first heat conductive film 23 can be simplified, and the capacity loss of the battery cell can be reduced.

According to some embodiments of the present application, as shown in fig. 6, the side surface 223 includes a first plane 2231 and a second plane 2233 disposed opposite to each other, and at least a portion of a surface of the first plane 2231 and/or the second plane 2233 is coated with the first heat conductive film 23.

The cell assemblies 22 may be wound cells, and the side surfaces 223 have two large faces that are disposed opposite and substantially parallel, namely, a first plane 2231 and a second plane 2233, and generally, adjacent cell assemblies 22 are disposed with large faces opposite to or abutting each other, or adjacent cells are disposed with large faces opposite to each other. This may increase the contact area and heat transfer area between the cell assemblies 22 or between the cells.

The first heat conductive film 23 is coated on at least part of the surface of the first plane 2231 and/or the second plane 2233, so that the first heat conductive film 23 can be better arranged by using the flat surface, thereby realizing faster and more uniform heat dissipation and reducing the probability of local high temperature formation.

According to some embodiments of the present application, as shown in fig. 6, side surface 223 further includes first and second connection surfaces 2232 and 2234 that connect first and second planes 2231 and 2233, respectively; the first heat conductive film 23 includes a first portion 231, a second portion 232, and a third portion 233 connected in sequence; the first portion 231 is coated on the first plane 2231, the second portion 232 is coated on the first connecting surface 2232 and/or the second connecting surface 2234, and the third portion 233 is coated on the second plane 2233.

The connection surface 2232 is located between the first plane 2231 and the second plane 2233, and the first connection surface 2232 may be curved or planar, and may be specifically determined according to the structural form of the pole piece. The second portion 232 may cover either one of the first connection surface 2232 and the second connection surface 2234, or both the first connection surface 2232 and the second connection surface 2234 may be covered. The second end face of the battery cell assembly 22 has one end of the positive electrode plate and one end of the negative electrode plate at the same time, and when the first heat conducting film 23 is made of an electrically conductive material, the first heat conducting film is directly coated on the second end face, so that short circuit risk may exist.

In one example, the first thermally conductive film 23 has the same or similar shape as the side surface 223 and is wrapped 360 ° around the outer surface of the cell assembly 22 along the outer circumference of the side surface 223.

The heat conductive film disposed on the first plane 2231 and the second plane 2233 may be closer to the active material area of the pole piece of the cell assembly 22, and may rapidly conduct heat using the large surface of the cell assembly 22, thereby improving the heat transfer effect. The first conductive film 23 is disposed to be connected by the second portion 232 wrapping the first connection surface 2232 and/or the second connection surface 2234, so that the first conductive film 23 can avoid the second end surface of the cell assembly 22, thereby reducing the risk of short-circuiting the pole pieces.

According to some embodiments of the present application, the ratio K ₁ of the forward projected area of the first portion 231 on the first plane 2231 to the area of the first plane 2231 satisfies: k ₁ is more than or equal to 0.8 and less than or equal to 1; in some embodiments, the ratio K ₂ of the forward projected area of the third portion 233 on the second plane 2233 to the area of the second plane 2233 satisfies: k ₂ is more than or equal to 0.8 and less than or equal to 1.

The orthographic projection area of the first portion 231 on the first plane 2231 refers to the area of the projection area of the first portion 231 projected onto the first plane 2231 along the direction perpendicular to the first plane 2231, and it can be understood that the area of the first plane 2231 covered by the first portion 231 is similar to the orthographic projection area of the third portion 233 on the second plane 2233, and will not be repeated here. Since the larger the area covered by the first heat conductive film, the larger the area where rapid heat conduction can be achieved, and the more rapid heat conduction to the surroundings.

The heat conduction film with enough area is arranged on the large surface of the battery cell assembly, so that heat conduction inside the battery cells can be realized, heat can be more uniformly transferred to surrounding battery cells when the battery cells are distributed, and the probability that the battery performance is reduced or fails due to local high temperature around is reduced.

Referring to fig. 7, fig. 7 is a cross-sectional view taken along the direction B-B in fig. 3.

According to some embodiments of the present application, the battery cell 20 includes a plurality of cell assemblies 22; at least a portion of the outer surface of at least one of the cell assemblies 22 is coated with a first thermally conductive film 23.

A plurality of cell assemblies 22 may be disposed within the battery cell 20, and the plurality of cell assemblies 22 may be electrically connected to the end cap 212 via a transfer tab. Only part of the outer surfaces of the plurality of cell assemblies 22 may be coated with the first heat conducting film 23, or each cell assembly 22 may be coated with one first heat conducting film 23.

As shown in fig. 3 and 7, 2 cell assemblies 22 may be disposed inside the battery cell 20, and a side surface of each cell assembly 22 is coated with a first heat conductive film 23. In some embodiments, the first heat conductive film 23 may cover all of the side surface of the cell assembly 22, only a portion of the side surface, and the second end surface of the cell assembly 22 where no tab is disposed.

When a plurality of cell assemblies 22 are disposed in the battery unit 20, the surface of at least one cell assembly 22 is coated with the first heat conducting film 23 capable of conducting heat, so that heat transfer between the plurality of cell assemblies 22 can be realized, the temperature in the battery unit is relatively uniform, and the risk of thermal runaway is reduced.

According to some embodiments of the present application, the plurality of cell assemblies 22 are arranged along a predetermined direction, and the first heat conductive film 23 is disposed between any two adjacent cell assemblies 22.

The plurality of wound cell assemblies 22 may be arranged with the side surfaces thereof being in contact with or facing each other, with the first thermally conductive film 23 disposed between the opposing surfaces (e.g., side surfaces) of any adjacent cell assemblies 22. As shown in fig. 7, the first heat conductive films 23 may be equal in number to the cell assemblies 22 to cover the outer surface (e.g., side surface) of each cell assembly 22, respectively, such that the first heat conductive films 23 are disposed between the adjacent outer surfaces of the plurality of cell assemblies 22 when arranged. In some embodiments, the first heat-conducting film 23 may also be continuously coated on a part of the side surfaces of the plurality of battery cell assemblies 22 in an "S" shape, so as to realize heat conduction between the plurality of battery cell assemblies 22, and reduce the space occupied by the heat-conducting film and the capacity loss of the battery cell.

By arranging the first heat conducting film 23 between two adjacent cell assemblies 22, continuous heat conduction among the plurality of cell assemblies 22 in the battery unit can be realized, heat can be more uniformly distributed, and the formation probability of local high temperature is reduced.

According to some embodiments of the present application, the battery cell 20 further includes a first insulating film 24, the first insulating film 24 being located between the housing 211 and the cell assembly 22.

The first insulating film 24 is a thin film made of an insulating material, and since the case 211 of the battery cell 20 is generally made of a conductive metal material, the cell assembly 22 is inevitably disposed in the case 211 to be in contact with the case 211, thereby causing a short circuit. The first insulating film 24 may be a mylar film, i.e., a mylar film. The first insulating film 24 may be coated on the outer surface of the cell assembly 22 or the inner surface of the housing 211.

In some examples, when the outer surface of the battery cell assembly 22 is coated with the first heat conductive film 23 and the first insulating film 24 at the same time, the first insulating film 24 may be located on a side surface of the first heat conductive film 23 away from the battery cell assembly 22, or may be located on a side surface of the first heat conductive film 23 facing the battery cell assembly 22. That is, the outer surface of the battery cell assembly 22 may sequentially cover the first heat conductive film 23 and the first insulating film 24. It should be noted that, when the material of the first heat conductive film 23 is an electrically conductive material and is located between the first insulating film 24 and the battery cell assembly 22, the first heat conductive film 23 may avoid the second end face 222 of the battery cell assembly 22, or may be covered on the second end face 222 in an insulating manner by other means, so as to reduce the risk of short circuit.

In some embodiments, as shown in fig. 7, a plurality of battery cell assemblies 22 are disposed in the battery cell 20, and a side surface of each battery cell assembly 22 is covered with a first heat conducting film 23, and a first insulating film 24 is covered with a plurality of battery cell assemblies 22 with the first heat conducting films 23, so as to insulate the battery cell assemblies 22 between the housings 211. In another embodiment, the plurality of battery cell assemblies 22 in the battery cell 20 may be sequentially covered with a first insulating film 24, and then arranged in a predetermined direction in the housing 211.

By providing the first insulating film 24, insulation between the battery cell assembly 22 and the inner surface of the housing 211 can be more reliably achieved, the risk of short circuit of the battery cell 20 is reduced, and the reliability of the battery cell 20 is improved.

According to some embodiments of the present application, the orthographic projection of the first thermally conductive film 23 on the outer surface of the cell assembly 22 falls within the orthographic projection of the first insulating film 24 on the outer surface of the cell assembly 22.

The first heat conducting film 23 may be disposed between the first insulating film 24 and the battery cell assembly 22, or may be disposed on the outer surface of the first insulating film 24 away from the battery cell assembly 22, but the orthographic projection of the first heat conducting film 23 on the outer surface of the battery cell assembly 22 falls completely within the coating range of the first insulating film 24, so that even if the first heat conducting film 23 is made of an electrically conductive material, the electrical connection between the battery cell assembly 22 and the housing 211 can be prevented by the insulating effect of the first insulating film 24.

The first insulating film 24 is used to completely cover the first heat conducting film 23, so that the risk of short circuit caused by the first heat conducting film 23 can be effectively reduced, and the reliability of the battery cell 20 can be improved.

According to some embodiments of the present application, the material of the first heat conductive film 23 is graphene.

Graphene has very good heat conduction properties. The thermal conductivity of the pure nondefective single-layer graphene is up to 5300 watts per meter Kelvin (W/(mK)), and the graphene has good toughness and can be bent to be made into a thin film with smaller thickness to be coated on the outer surface of the cell assembly 22, so that the rapid conduction of heat is realized. The first heat conducting film 23 can be made into a film to directly cover the outer surface of the battery cell assembly 22, or can be directly or indirectly covered on the outer surface of the battery cell assembly 22 by spraying and pasting.

The high heat conduction performance and the mechanical property of the graphene can reduce the thickness of the heat conduction film as much as possible on the basis of meeting the heat conduction requirement, so that the graphene is more beneficial to arrangement in a battery unit body, and the capacity loss of the battery is reduced.

The embodiment of the present application provides a battery 100 including the battery cell 20 described in the above embodiment.

The battery 100 may include a case 10 forming a receiving chamber, and one or more battery cells 20 disposed within the receiving chamber. The plurality of battery cells 20 may be arranged in a predetermined direction.

By providing the first heat conductive film 23 in the battery cell 20, heat conduction in the battery cell 20 can be improved, so that internal temperature distribution is relatively uniform, formation of local high temperature is reduced, probability of thermal runaway of the battery cell 20 is reduced, and reliability of the battery 100 is improved.

Referring to fig. 8, fig. 8 is a cross-sectional view taken along the direction C-C in fig. 3. According to some embodiments of the present application, the battery 100 further includes a second heat conductive film 26, where the second heat conductive film 26 is wrapped around at least a portion of the outer surface of the housing 21 of the battery cell 20.

The second heat conductive film 26 may be made of the same material as the first heat conductive film 23, for example, graphene, or may be different. The second heat conducting film 26 is coated on the outer surface of the housing 21, which means that the second heat conducting film 26 is directly or indirectly attached to the outer surface of the housing 21, and other film layers or components can be arranged between the second heat conducting film 26 and the outer surface, so long as the heat conducting requirements can be met. The second heat conductive film 26 may cover only a portion of the outer surface of the housing 211, for example, the second heat conductive film 26 covers the side surface of the housing 211 of the case 21. It is also possible to completely cover the entire outer surface of the housing 211. In some embodiments, the second thermally conductive film 26 is wrapped around at least a portion of the outer surface of the housing 211.

By coating the second heat conductive film 26 on the outer surface of the housing 211, heat can be transferred between the plurality of battery cells 20 more quickly and uniformly, the heat dissipation area is increased, the heat dissipation of the battery is facilitated, and the risk of thermal runaway spread of the surrounding battery cells caused by local high temperature is reduced.

According to some embodiments of the present application, the battery 100 further includes a second insulating film 25, the second insulating film 25 is located between the second heat conductive film 26 and the case 21 or on a surface of the second heat conductive film 26 remote from the case 21, and an orthographic projection of the second heat conductive film 26 on the outer surface of the case 21 falls within an orthographic projection range of the second insulating film 25 on the outer surface of the case 21.

The second insulating film 25 may be the same material as the first insulating film 24 or may be different. The second insulating film 25 may cover the surface of the second heat conductive film 26 away from the housing 21 to cover both the housing 21 and the second heat conductive film 26, or may be disposed between the second heat conductive film 26 and the housing 21.

Alternatively, the second insulating film 25 may be provided on the outer surface of the housing 211, and the second insulating film 25 may cover only a portion of the outer surface of the housing 211 or may cover the entire outer surface of the housing 211. The orthographic projection of the second heat conductive film 26 on the outer surface of the case 211 falls within the projection range of the second insulating film 25 on the outer surface of the case 21, which means that the orthographic projection area range of the second insulating film 25 on the case 21 is larger than and completely covers the projection range of the second heat conductive film 26 on the case 21, so that the second insulating film 25 can isolate the second heat conductive film 26 from the case 21 or isolate the second heat conductive film 16 from other adjacent battery cells 20.

By providing the second insulating film 25, particularly, the orthographic projection range of the second insulating film 25 on the case 11 completely includes the orthographic projection range of the second heat conductive film 26 on the case 211, the conductive path formed between adjacent battery cells by the second heat conductive film 26 can be suppressed to some extent, the risk of short circuit of the battery can be reduced, and the reliability of the battery can be improved.

The embodiment of the application provides an electric device, which comprises a battery as described above, wherein the battery is used for providing electric energy.

The battery cell and the battery of the present application will be described in further detail with reference to specific examples.

As shown in fig. 3 to 8, the battery cell 20 includes a case 21, two cell assemblies 22, and two first heat conductive films 23, a first insulating film 24.

The housing 21 includes a case 211 having an opening and an end cap 212 connected to the case and covering the opening. The cell assembly 22 is disposed within the housing 211.

The cell assembly 22 includes opposing first and second end faces 221, 222, and a side surface 223 connecting the first and second end faces 221, 222, the first end face 221 being provided with a tab 224 connected to the end cap 212.

The side surface 223 includes first and second planes 2231 and 2233 disposed opposite each other, and first and second connection planes 2232 and 2234 connecting the first and second planes 2231 and 2233.

The first heat conducting film 23 is arranged between the housing 21 and the cell assembly 22, and the first heat conducting film 23 comprises a first part 231, a second part 232 and a third part 233 which are sequentially connected; the first portion 231 is coated on the first plane 2231, the second portion 232 is coated on the first connecting surface 2232 and/or the second connecting surface 2234, and the third portion 233 is coated on the second plane 2233. The two first heat conductive films 23 are respectively coated on the side surfaces 223 of the two cell assemblies 22. Optionally, the first heat conductive film 23 is a graphene film.

The ratio K ₁ of the orthographic projection area of the first portion 231 on the first plane 2231 to the area of the first plane 2231 satisfies: k ₁ is more than or equal to 0.8 and less than or equal to 1. The ratio K ₂ of the orthographic projection area of the third portion 233 on the second plane 2233 to the area of the second plane 2233 satisfies: k ₂ is more than or equal to 0.8 and less than or equal to 1.

The first insulating film 24 covers the outer surfaces of the two cell assemblies 22 and the first heat conducting film 25, and the orthographic projection of the first heat conducting film 23 on the outer surface of the cell assembly 22 falls within the orthographic projection range of the first insulating film 24 on the outer surface of the cell assembly 22. Alternatively, the first insulating film 24 is a mylar film.

The battery 10 may include a plurality of battery cells 20, and at least a portion of an outer surface of a case of each battery cell 20 may be coated with a second insulating film 25 and/or a second heat conductive film 26. In some embodiments, the second insulating film 25 is located between the second heat conducting film 26 and the housing 21 or on a surface of the second heat conducting film 26 remote from the housing 21, and an orthographic projection of the second heat conducting film 26 on the outer surface of the housing 21 falls within an orthographic projection range of the second insulating film 25 on the outer surface of the housing 21.

Through set up first heat conduction membrane 23 in battery monomer 20 inside, can make the heat transfer of battery monomer inside more smooth and easy for temperature distribution is more even, reduces the formation of local high temperature, reduces the risk that the battery takes place thermal runaway, improves the reliability of battery. The second heat conducting film 26 is arranged on the outer surface of the shell 21 of the battery unit 20, so that rapid heat transfer among a plurality of battery units can be realized, the formation of local high temperature can be reduced, and the risk of thermal runaway of the battery is reduced.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present application, and not for limiting the same; although the application has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the application, and are intended to be included within the scope of the appended claims and description. In particular, the technical features mentioned in the respective embodiments may be combined in any manner as long as there is no structural conflict. The present application is not limited to the specific embodiments disclosed herein, but encompasses all technical solutions falling within the scope of the claims.

Claims (15)

1. A battery cell, comprising:

a housing;

the battery cell component is arranged in the shell,

The first heat conduction film is positioned between the battery cell assembly and the shell and is used for dispersing heat transferred from the battery cell assembly to the shell.

2. The battery cell of claim 1, wherein the housing comprises

A housing for receiving the battery cell assembly, the housing having an opening; and

An end cover connected with the shell and covered on the opening;

The first heat conducting film is located between the battery cell assembly and the shell.

3. The battery cell of claim 2, wherein the battery cell comprises a plurality of cells,

The cell assembly includes opposing first and second end faces, and side surfaces connecting the first and second end faces,

The first end face is provided with a tab connected with the end cover;

at least part of the surface of the side surface and/or the second end surface is/are coated with the first heat conducting film.

4. The battery cell of claim 3, wherein the battery cell comprises a plurality of cells,

The side surface includes oppositely disposed first and second planar surfaces,

At least part of the surface of the first plane and/or the second plane is coated with the first heat conducting film.

5. The battery cell of claim 4, wherein the side surface further comprises a connecting surface connecting the first plane and the second plane;

the first heat conducting film comprises a first part, a second part and a third part which are connected;

The first part is coated on the first plane, the second part is coated on the connecting surface, and the third part is coated on the second plane.

6. The battery cell of claim 5, wherein a ratio K ₁ of an orthographic projected area of the first portion on the first plane to an area of the first plane satisfies: k ₁ is more than or equal to 0.8 and less than or equal to 1; and/or the ratio K ₂ of the orthographic projection area of the second portion on the second plane to the area of the second plane satisfies: k ₂ is more than or equal to 0.8 and less than or equal to 1.

7. The battery cell of any one of claims 1-6, wherein the battery cell comprises a plurality of the cell assemblies; at least part of the outer surface of at least one cell assembly is coated with the first heat conducting film.

8. The battery cell according to claim 7, wherein a plurality of the cell assemblies are arranged in a predetermined direction, and the first heat conductive film is disposed between any adjacent two of the cell assemblies.

9. The battery cell of any one of claims 1-6, further comprising

And the first insulating film is positioned between the shell and the battery cell component.

10. The battery cell of claim 9, wherein the battery cell comprises a plurality of cells,

The orthographic projection of the first heat conducting film on the outer surface of the battery cell assembly falls into the orthographic projection range of the first insulating film on the outer surface of the battery cell assembly.

11. The battery cell according to any one of claims 1 to 6, wherein,

The material of the first heat conduction film comprises graphene.

12. A battery comprising a battery cell according to any one of claims 1-11.

13. The battery of claim 12, further comprising

And the second heat conduction film is coated on at least part of the outer surface of the shell of the battery cell.

14. The battery of claim 13, further comprising

The second insulating film is positioned between the second heat conducting film and the shell or positioned on the surface of the second heat conducting film far away from the shell, and the orthographic projection of the second heat conducting film on the outer surface of the shell falls into the projection range of the second insulating film on the outer surface of the shell.

15. An electrical device comprising a battery according to any one of claims 12-14 for providing electrical energy.