Battery monomer, battery and electric device

Abstract

The utility model provides a single battery, a battery and a power utilization device, the single battery comprises a shell and a battery cell, and the inner side wall of the shell is provided with a first heat conduction layer; the battery cell is arranged in the shell, a second heat conduction layer is arranged on the outer side wall of the battery cell, and the second heat conduction layer and the first heat conduction layer are oppositely arranged. In the charging process of the battery monomer, the second heat conduction layer and the first heat conduction layer which are oppositely arranged are close to each other or are in contact with each other along with the volume expansion of the battery cell, heat generated by the battery cell can be quickly conducted to the shell through the first heat conduction layer and the second heat conduction layer, and the battery monomer has good heat dissipation performance.

Description

Technical Field

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

[0002] The statements herein merely provide background information related to the present application and do not necessarily constitute prior art.

[0003] In recent years, as the application scope of batteries has become wider and wider, batteries are widely used in energy storage power supply systems such as hydropower, thermal power, wind power and solar power stations, as well as in many fields such as power tools, electric bicycles, electric motorcycles and electric vehicles.

[0004] As batteries have made great progress, higher requirements have been put forward for their cycle life, high-rate charge and discharge performance, and safety performance. Batteries with higher cycle life, better high-rate charge and discharge performance, and better safety performance have very high requirements for the heat dissipation performance of battery cells.

[0005] Therefore, seeking battery cells with better heat dissipation performance is one of the key areas of focus for those skilled in the art. Summary of the invention

[0006] The present application is made in view of the above-mentioned problems, and one of its purposes is to provide a battery cell having better heat dissipation performance.

[0007] In order to achieve the above-mentioned object, the first aspect of the present application provides a battery cell, comprising:

[0008] a housing, wherein a first heat-conducting layer is disposed on an inner side wall of the housing; and

[0009] The battery core is placed in the shell, and a second heat-conducting layer is arranged on the outer wall of the battery core, and the second heat-conducting layer is arranged opposite to the first heat-conducting layer.

[0010] The above-mentioned battery cell is provided with a first heat-conducting layer on the inner wall of the shell and a second heat-conducting layer on the outer wall of the battery core, and the second heat-conducting layer is arranged opposite to the first heat-conducting layer; during the charging process of the battery cell, as the volume of the battery core expands, the second heat-conducting layer and the first heat-conducting layer arranged opposite to each other approach or contact each other, and the heat generated by the battery core can be quickly conducted to the shell through the first heat-conducting layer and the second heat-conducting layer, and the battery cell has good heat dissipation performance.

[0011] In any embodiment, at least one of the first heat-conducting layer and the second heat-conducting layer is an insulating heat-conducting layer. In this way, leakage due to electrical conduction between the battery cell and the shell can be avoided; and there is no need to set a Mylar sheet on the outer wall of the battery cell, which can reduce costs and improve the energy density of the battery cell.

[0012] In any embodiment, the first heat-conducting layer includes one or more of a heat-conducting silicone rubber layer, a heat-conducting polyimide layer, a heat-conducting epoxy resin layer, a heat-conducting phenolic resin layer, a heat-conducting urea-formaldehyde resin layer, a heat-conducting polyetheretherketone layer, and a heat-conducting polybenzimidazole layer. In this way, the above-mentioned first heat-conducting layer has good thermal conductivity and insulation, which can not only well conduct the heat generated by the battery cell during charging to the shell, but also well avoid electrical conduction between the battery cell and the shell.

[0013] In any embodiment, the second heat-conducting layer includes one or more of a heat-conducting silicone rubber layer, a heat-conducting polyimide layer, a heat-conducting epoxy resin layer, a heat-conducting phenolic resin layer, a heat-conducting urea-formaldehyde resin layer, a heat-conducting polyetheretherketone layer, and a heat-conducting polybenzimidazole layer. In this way, the second heat-conducting layer also has good thermal conductivity and insulation.

[0014] In any embodiment, the thickness ratio of the first heat-conducting layer to the second heat-conducting layer is (0.05-100): 1, and can be (0.5-4): 1. In this way, good heat conduction can be performed between the battery core and the housing.

[0015] In any embodiment, the sum of the thickness of the first heat-conducting layer and the second heat-conducting layer is 20 μm to 1200 μm, and can be 100 μm to 300 μm. In this way, the battery cell can be conveniently loaded into the housing and dissipate heat well, and the volume expansion of the battery cell during charging will not be affected.

[0016] In any embodiment, the thickness of the first heat-conducting layer is 10 μm to 1000 μm, and can be 50 μm to 200 μm, which can not only achieve rapid heat conduction, but also enable the battery to have a suitable group margin, so that the battery cell can be placed in the housing more easily.

[0017] In any embodiment, the thickness of the second heat-conducting layer is 10 μm to 200 μm, and can be 50 μm to 100 μm, so that a good heat-conducting effect can be achieved and the second heat-conducting layer can be effectively prevented from falling off the side wall of the battery cell during the expansion of the battery cell.

[0018] In any embodiment, the thermal conductivity of the first heat-conducting layer and the second heat-conducting layer is ≥ 2 W / m·K. In this way, the first heat-conducting layer and the second heat-conducting layer both have good thermal conductivity and can well conduct the heat of the battery core to the shell.

[0019] In any embodiment, there is a gap between the first heat-conducting layer and the second heat-conducting layer, and the width of the gap is 1mm to 4mm, and can be 1.5mm to 3mm. In this way, when the battery cell expands, the first heat-conducting layer and the second heat-conducting layer can be in close contact to achieve good heat conduction, and a suitable space can be provided for the expansion of the battery cell.

[0020] In any embodiment, there are multiple battery cells, and the multiple battery cells are arranged side by side, and a third heat-conducting layer is provided between adjacent battery cells. In this way, a heat-conducting effect can be played between adjacent battery cells, and heat conduction between multiple battery cells is increased, thereby further improving the heat dissipation effect of the battery cell.

[0021] In any embodiment, the battery cell includes a positive electrode sheet, a separator and a negative electrode sheet stacked in sequence, and the outermost layer of the battery cell is the separator, and the second heat-conducting layer is arranged on the outermost separator. In this way, the mylar sheet on the outer side of the battery cell is eliminated and the second heat-conducting layer is directly arranged on the outermost separator of the battery cell, which can not only improve the heat dissipation effect of the battery cell, but also save costs and reduce weight.

[0022] In any embodiment, the positive electrode plate includes a positive electrode current collector, and the positive electrode current collector includes a first organic support layer and a first conductive layer disposed on at least one surface of the first organic support layer. In this way, the weight of the battery cell can be reduced and the energy density of the battery cell can be increased.

[0023] In any embodiment, the negative electrode plate includes a negative electrode current collector, and the negative electrode current collector includes a second organic support layer and a second conductive layer disposed on at least one surface of the second organic support layer. In this way, the weight of the battery cell can be further reduced and the energy density of the battery cell can be further improved.

[0024] The second aspect of the present application provides a battery, comprising the battery cell of the first aspect of the present application. Thus, the battery has good heat dissipation performance.

[0025] The third aspect of the present application provides an electrical device, comprising the battery of the second aspect of the present application.

[0026] 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

[0027] In order to better describe and illustrate the embodiments or examples provided by the present application, reference may be made to one or more drawings. The additional details or examples used to describe the drawings should not be considered as limiting the scope of the disclosed application, the embodiments or examples currently described, and any of the best modes of these applications currently understood. Moreover, the same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0028] Figure 1 A schematic diagram of the structure of a vehicle according to an embodiment of the present application;

[0029] Figure 2 A schematic diagram of the exploded structure of a battery according to an embodiment of the present application;

[0030] Figure 3 A three-dimensional schematic diagram of a battery cell according to an embodiment of the present application;

[0031] Figure 4 A schematic front view of a battery cell according to an embodiment of the present application;

[0032] Figure 5 For along Figure 4 Schematic diagram of the cross section of the AA surface;

[0033] Figure 6 for Figure 5 A partial enlarged schematic diagram of point B in the middle;

[0034] Figure 7 for Figure 5 A partial enlarged schematic diagram of point C in the middle;

[0035] Figure 8 It is a schematic diagram of the structure of a battery cell in a battery cell according to an embodiment of the present application.

[0036] Description of reference numerals:

[0037] 1000, vehicle; 100, battery; 200, controller; 300, motor; 10, housing; 11, first part; 12, second part; 20, battery cell; 21, end cap; 22, housing; 23, battery cell; 221, first thermal conductive layer; 231, second thermal conductive layer; 24, gap; 25, third thermal conductive layer; 232, positive electrode plate; 233, isolation membrane; 234, negative electrode plate. DETAILED DESCRIPTION

[0038] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0039] 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.

[0040] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0041] 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.

[0042] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0043] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0044] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0045] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0046] The "range" disclosed in the present application can be defined in the form of a lower limit and an upper limit, and a given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundaries of a particular range. The range defined in this way can be inclusive or exclusive of the end values, and any end value can be included or excluded independently, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form a range. For example, if a range of 60 to 120 and 80 to 110 is listed for a specific parameter, it is understood that the range of 60 to 110 and 80 to 120 is also expected. In addition, if the minimum range values ​​1 and 2 are listed, and if the maximum range values ​​3, 4 and 5 are also listed, the following ranges can all be expected: 1 to 3, 1 to 4, 1 to 5, 2 to 3, 2 to 4 and 2 to 5. In the present application, unless otherwise specified, the numerical range "a to b" represents an abbreviation of any real number combination between a and b, where a and b are both real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" are listed in this document, and "0-5" is just an abbreviation of these numerical combinations. In addition, when a parameter is expressed as an integer ≥ 2, it is equivalent to listing the parameter as, for example, integers 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc. For example, when a parameter is expressed as an integer selected from "2-10", it is equivalent to listing the integers 2, 3, 4, 5, 6, 7, 8, 9 and 10.

[0047] In the present application, in the open technical features or technical solutions described by the words "contain", "include", "comprise", etc., unless otherwise specified, additional members other than the listed members are not excluded, and it can be regarded as providing both closed features or solutions consisting of the listed members and open features or solutions including additional members in addition to the listed members. For example, A includes a1, a2 and a3. Unless otherwise specified, it may also include other members or may not include additional members. It can be regarded as providing both the feature or solution of "A consists of a1, a2 and a3" and the feature or solution of "A not only includes a1, a2 and a3, but also includes other members". In the present application, unless otherwise specified, A (such as B) means that B is a non-limiting example of A, and it can be understood that A is not limited to B.

[0048] In this application, "optionally", "optional", and "optional" mean optional, that is, any one of the two parallel schemes of "yes" or "no". If there are multiple "options" in a technical solution, unless otherwise specified and there is no contradiction or mutual restriction, each "option" is independent.

[0049] For the convenience of description, the following embodiments are described by taking a vehicle 1000 as an example of an electrical device according to an embodiment of the present application.

[0050] See also Figure 1 , Figure 1 A schematic diagram of the structure of a vehicle 1000 provided for one embodiment of the present application. The vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 100 is provided inside the vehicle 1000, and the battery 100 may be provided at the bottom, head or tail of the vehicle 1000. The battery 100 may be used to power the vehicle 1000, for example, the battery 100 may be used as an operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300, and the controller 200 is used to control the battery 100 to power the motor 300, for example, for starting, navigating and driving the vehicle 1000.

[0051] In some embodiments of the present application, the battery 100 can not only serve as an operating power source for the vehicle 1000, but also serve as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0052] See also Figure 2 , Figure 2 The schematic diagram of the exploded structure of the battery 100 provided in one embodiment of the present application. The battery 100 includes a box 10 and a battery cell 20, and the battery cell 20 is contained in the box 10. Among them, 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 may include a first part 11 and a second part 12, and 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, and 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.

[0053] In the battery 100, there may be multiple battery cells 20, and the multiple battery cells 20 may be connected in series, in parallel, or in a mixed connection. A mixed connection means that the multiple battery cells 20 are both connected in series and in parallel. The multiple battery cells 20 may be directly connected in series, in parallel, or in a mixed connection, and then the whole formed by the multiple battery cells 20 is accommodated in the box 10; of course, the battery 100 may also be a battery module formed by connecting multiple battery cells 20 in series, in parallel, or in a mixed connection, and then the multiple battery modules are connected in series, in parallel, or in a mixed connection to form a whole, and accommodated in the box 10. The battery 100 may also include other structures, for example, the battery 100 may also include a busbar component for realizing electrical connection between the multiple battery cells 20.

[0054] Each battery cell 20 may be a secondary battery or a primary battery, or a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto. The battery cell 20 may be cylindrical, flat, rectangular, or in other shapes.

[0055] The battery cell 20 refers to the smallest unit constituting the battery and includes an end cap 21, a housing 22, a battery cell 23 and other functional components.

[0056] The end cap 21 refers to a component that covers the opening of the shell 22 to isolate the internal environment of the battery cell 20 from the external environment. Without limitation, the shape of the end cap 21 can be adapted to the shape of the shell 22 to match the shell 22. Optionally, the end cap 21 can be made of a material with a certain hardness and strength (such as aluminum alloy), so that the end cap 21 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 can be provided on the end cap 21. The electrode terminal can be used to electrically connect to the battery cell 23 for outputting or inputting electrical energy of the battery cell 20. In some embodiments, the end cap 21 can also be provided with a pressure relief mechanism 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 21 can also be a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiments of the present application do not impose special restrictions on this. In some embodiments, an insulating member may be provided inside the end cap 21, and the insulating member may be used to isolate the electrical connection components in the housing 22 from the end cap 21 to reduce the risk of short circuit. For example, the insulating member may be plastic, rubber, or the like.

[0057] The shell 22 is a component used to cooperate with the end cap 21 to form the internal environment of the battery cell 20, wherein the formed internal environment can be used to accommodate the battery cell 23, the electrolyte and other components. The shell 22 and the end cap 21 can be independent components, and an opening can be set on the shell 22, and the internal environment of the battery cell 20 is formed by covering the opening with the end cap 21 at the opening. Without limitation, the end cap 21 and the shell 22 can also be integrated. Specifically, the end cap 21 and the shell 22 can form a common connection surface before other components are put into the shell, and when the interior of the shell 22 needs to be encapsulated, the end cap 21 covers the shell 22. The shell 22 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 22 can be determined according to the specific shape and size of the battery cell 23. The material of the shell 22 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiment of the present application does not impose any special restrictions on this.

[0058] The battery cell 23 is a component in the battery cell 20 where electrochemical reactions occur. One or more battery cells 23 may be contained in the housing 22. The battery cell 23 is mainly formed by winding or stacking positive and negative electrode sheets, and a separator is usually provided between the positive and negative electrode sheets. The parts of the positive and negative electrode sheets with active materials constitute the main body of the battery cell 23, and the parts of the positive and negative electrode sheets without active materials each constitute a tab. The positive tab and the negative tab may be located together at one end of the main body or respectively at both ends of the main body. During the charge and discharge process of the battery, the positive active material and the negative active material react with the electrolyte, and the tabs connect the electrode terminals to form a current loop.

[0059] At present, as batteries have made great progress, higher requirements have been put forward for the cycle life, high-rate charge and discharge performance, and safety performance of batteries. Batteries with high cycle life, good high-rate charge and discharge performance, and good safety performance have very high requirements for the heat dissipation performance of battery cells. If the heat dissipation performance of the battery cell is poor, the temperature rise of the battery will be high during the battery charging and discharging process, especially during the high-rate charge and discharge process, which will seriously affect the cycle life and safety performance of the battery. In this regard, the present application provides a battery cell, which can effectively improve the heat dissipation performance of the battery cell by improving the structure of the battery cell.

[0060] See also Figures 3 to 7 In some embodiments, the first aspect of the present application provides a battery cell 20, which includes a shell 22 and a battery cell 23. A first heat-conducting layer 221 is provided on the inner wall of the shell 22; the battery cell 23 is placed in the shell 22, and a second heat-conducting layer 231 is provided on the outer wall of the battery cell 23, and the second heat-conducting layer 231 is arranged opposite to the first heat-conducting layer 221.

[0061] During the charging and discharging process of the traditional battery cell 20, the heat generated by the battery cell 23 cannot be well conducted to the outside of the battery cell 20 through the shell 22, resulting in poor heat dissipation effect of the battery cell 20; especially during the high-rate charging process of the battery, the temperature of the battery cell 23 is high, and the heat of the battery cell 23 cannot be well dissipated to the outside through the shell 22, resulting in a high temperature rise of the battery cell 20 during the high-rate charging process, affecting the cycle life and safety of the battery.

[0062] The present application sets a first heat-conducting layer 221 on the inner wall of the shell 22, sets a second heat-conducting layer 231 on the outer wall of the battery cell 23, and sets the second heat-conducting layer 231 opposite to the first heat-conducting layer 221; in this way, during the charging process of the battery cell 20, as the volume of the battery cell 23 expands, the oppositely set second heat-conducting layer 231 and the first heat-conducting layer 221 contact each other, and the heat generated by the battery cell 23 can be quickly conducted to the shell 22 through the first heat-conducting layer 221 and the second heat-conducting layer 231, thereby improving the heat dissipation performance of the battery cell 20.

[0063] In addition, the present application adopts a structure in which a first heat-conducting layer 221 is provided on the inner wall of the shell 22, and a second heat-conducting layer 231 is provided on the outer wall of the battery core 23; when the battery core 23 is placed in the shell 22, the first heat-conducting layer 221 and the second heat-conducting layer 231 have little interference with the battery core 23, and the battery core 23 can be placed in the shell 22 very conveniently; and, during the process of volume expansion of the battery core 23, heat conduction can be achieved by only making the adjacent surfaces of the first heat-conducting layer 221 and the second heat-conducting layer 231 contact, and the reliability of heat conduction is high.

[0064] In some embodiments, the first heat-conducting layer 221 may be a coating containing a heat-conducting filler formed by coating a slurry containing a heat-conducting filler on the inner side wall of the housing 22 to form a slurry layer, and then curing the slurry layer. Similarly, the second heat-conducting layer 231 may be a coating containing a heat-conducting filler formed by coating a slurry containing a heat-conducting filler on the outer side wall of the battery core 23 to form a slurry layer, and then curing the slurry layer.

[0065] In some embodiments, the first heat-conducting layer 221 and the second heat-conducting layer 231 may be heat-conducting sheets containing heat-conducting fillers that are respectively bonded to the inner wall of the housing 22 and the outer wall of the battery core 23 .

[0066] The thermally conductive filler may be thermally conductive particles commonly used in the art. For example, the thermally conductive filler may be one or more of silicon carbide particles, aluminum nitride particles, and boron nitride particles.

[0067] In some embodiments, at least one of the first heat-conducting layer 221 and the second heat-conducting layer 231 is an insulating heat-conducting layer. In this way, when the battery expands during charging and makes the first heat-conducting layer 221 and the second heat-conducting layer 231 contact each other, since at least one of the first heat-conducting layer 221 and the second heat-conducting layer 231 is an insulating heat-conducting layer, the battery cell 23 and the housing 22 are electrically connected and thus leakage can be avoided.

[0068] It is understandable that only the first heat-conducting layer 221 may be an insulating heat-conducting layer, only the second heat-conducting layer 231 may be an insulating heat-conducting layer, or both the first heat-conducting layer 221 and the second heat-conducting layer 231 may be insulating heat-conducting layers. In a specific example, both the first heat-conducting layer 221 and the second heat-conducting layer 231 are insulating heat-conducting layers, which can better avoid electrical conduction between the battery cell 23 and the shell 22.

[0069] In some embodiments, the first heat-conducting layer 221 includes one or more of a heat-conducting silicone rubber layer, a heat-conducting polyimide layer, a heat-conducting epoxy resin layer, a heat-conducting phenolic resin layer, a heat-conducting urea-formaldehyde resin layer, a heat-conducting polyetheretherketone layer, and a heat-conducting polybenzimidazole layer; similarly, the second heat-conducting layer 231 includes one or more of a heat-conducting silicone rubber layer, a heat-conducting polyimide layer, a heat-conducting epoxy resin layer, a heat-conducting phenolic resin layer, a heat-conducting urea-formaldehyde resin layer, a heat-conducting polyetheretherketone layer, and a heat-conducting polybenzimidazole layer. The above-mentioned heat-conducting layer has good thermal conductivity and insulation, which can not only well export the heat generated by the battery cell 23 during charging to the shell 22, but also well avoid electrical conduction between the battery cell 23 and the shell 22.

[0070] It is understandable that the thermally conductive silicone rubber layer may be a thermally conductive insulating layer formed by filling a thermally conductive filler in a silicone rubber substrate; the thermally conductive polyimide layer may be a thermally conductive insulating layer formed by filling a thermally conductive filler in a polyimide substrate; the thermally conductive epoxy resin layer may be a thermally conductive insulating layer formed by filling a thermally conductive filler in an epoxy resin substrate; the thermally conductive phenolic resin layer may be a thermally conductive insulating layer formed by filling a thermally conductive filler in a phenolic resin substrate; the thermally conductive urea-formaldehyde resin layer may be a thermally conductive insulating layer formed by filling a thermally conductive filler in a urea-formaldehyde resin substrate; the thermally conductive polyetheretherketone layer may be a thermally conductive insulating layer formed by filling a thermally conductive filler in a polyetheretherketone substrate; and the thermally conductive polybenzimidazole layer may be a thermally conductive insulating layer formed by filling a thermally conductive filler in a polybenzimidazole substrate. It should be noted that each of the above-mentioned thermally conductive insulating layers may be made of existing materials in the art.

[0071] In some embodiments, the thickness ratio of the first heat-conducting layer 221 and the second heat-conducting layer 231 is (0.05-100):1. The thickness ratio of the first heat-conducting layer 221 and the second heat-conducting layer 231 is within the above range, and good heat conduction can be performed between the battery cell 23 and the shell 22. It can be understood that the thickness ratio of the first heat-conducting layer 221 and the second heat-conducting layer 231 can be but not limited to 0.05:1, 0.1:1, 0.5:1, 1:1, 4:1, 5:1, 10:1, 15:1, 20:1, 30:1, 50:1, 60:1, 80:1, 90:1, 100:1. In some specific examples, the thickness ratio of the first heat-conducting layer 221 and the second heat-conducting layer 231 is (0.5-4):1.

[0072] In some of the embodiments, the sum of the thicknesses of the first heat-conducting layer 221 and the second heat-conducting layer 231 is 20μm to 1200μm. Generally speaking, after the battery cell 23 is placed in the shell 22, a certain gap needs to be left between the inner wall of the shell 22 and the outer wall of the battery cell 23 to reserve space for the volume expansion of the battery cell 23 during charging. Moreover, the width of the gap between the shell 22 and the battery cell 23 may be different in different types of battery cells 20. By setting the sum of the thicknesses of the first heat-conducting layer 221 and the second heat-conducting layer 231 to 20μm to 1200μm, it can be applicable to most battery cells 20, and the battery cell 23 can be easily loaded into the shell 22 and dissipate heat well without affecting the volume expansion of the battery cell 23. It is understandable that the sum of the thicknesses of the first heat conducting layer 221 and the second heat conducting layer 231 may be, but is not limited to, 20 μm, 30 μm, 50 μm, 100 μm, 200 μm, 300 μm, 500 μm, 600 μm, 800 μm, 1000 μm, 1100 μm, or 1200 μm.

[0073] It should be noted that the sum of the thickness of the first heat-conducting layer 221 and the second heat-conducting layer 231 can be specifically determined according to the size of the gap between the shell 22 and the battery cell 23 in different types of battery cells 20. If the gap between the shell 22 and the battery cell 23 is small, the thickness of the first heat-conducting layer 221 and the second heat-conducting layer 231 is set to be thinner; otherwise, the thickness of the first heat-conducting layer 221 and the second heat-conducting layer 231 can be set to be thicker. In some specific examples, the sum of the thickness of the first heat-conducting layer 221 and the second heat-conducting layer 231 is 100μm to 300μm.

[0074] See also Figure 6In some embodiments, the thickness d of the first heat-conducting layer 221 is 10 μm to 1000 μm. The thickness d of the first heat-conducting layer 221 on the inner wall of the shell 22 is within the range of 10 μm to 1000 μm, which can not only play a role in rapid heat conduction, but also enable the battery to have a suitable group margin, so that the battery cell 23 can be placed in the shell 22 more easily. Among them, the group margin refers to the ratio of the diameter of the battery cell 23 to the inner diameter of the shell 22. It can be understood that the thickness d of the first heat-conducting layer 221 can be, but is not limited to, 10 μm, 20 μm, 50 μm, 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm, 900 μm, 1000 μm.

[0075] In some embodiments, the thickness d of the first heat-conducting layer 221 is 50 μm to 200 μm. In this way, the thermal conductivity and the battery group margin can be better balanced.

[0076] See also Figure 6 In some embodiments, the thickness e of the second heat-conducting layer 231 is 10 μm to 200 μm. Since the battery cell 23 will expand in volume during the charging process, the thickness of the second heat-conducting layer 231 on the side wall of the battery cell 23 should not be too thick, otherwise the second heat-conducting layer 231 will easily fall off from the outer side wall of the battery cell 23. Controlling the thickness e of the second heat-conducting layer 231 to 10 μm to 200 μm can play a good heat-conducting role and effectively alleviate the shedding of the second heat-conducting layer 231. It can be understood that the thickness e of the second heat-conducting layer 231 can be but is not limited to 10μm, 20μm, 30μm, 40μm, 50μm, 60μm, 70μm, 80μm, 90μm, 100μm, 110μm, 120μm, 130μm, 140μm, 150μm, 160μm, 170μm, 180μm, 190μm, 200μm.

[0077] In some embodiments, the thickness e of the second heat-conducting layer 231 is 50 μm to 100 μm. In this way, the thermal conductivity and the bonding stability between the second heat-conducting layer 231 and the battery cell 23 can be better balanced.

[0078] In some embodiments, the thermal conductivity of the first heat-conducting layer 221 and the second heat-conducting layer 231 is ≥ 2 W / m·K. In this way, the first heat-conducting layer 221 and the second heat-conducting layer 231 both have good thermal conductivity, and can well conduct the heat of the battery core 23 to the housing 22, thereby dissipating the heat of the battery cell 20 well.

[0079] See also Figure 6In some embodiments, there is a gap 24 between the first heat-conducting layer 221 and the second heat-conducting layer 231, and the width f of the gap 24 is 1mm to 4mm. During the charging process of the battery cell 20, the volume of the battery cell 23 will expand. The width f of the gap 24 between the first heat-conducting layer 221 and the second heat-conducting layer 231 is set to 1mm to 4mm, which can not only make the first heat-conducting layer 221 and the second heat-conducting layer 231 in close contact when the battery cell 23 expands, but also provide a suitable space for the expansion of the battery cell 23. It can be understood that the width f of the gap 24 can be but not limited to 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm.

[0080] In some embodiments, the width f of the gap 24 between the first heat-conducting layer 221 and the second heat-conducting layer 231 is 1.5 mm to 3 mm. In this way, the thermal conductivity and the volume expansion of the battery cell 23 can be better balanced.

[0081] See also Figure 5 and Figure 7 In some embodiments, the number of the battery cells 23 is multiple, and the multiple battery cells 23 are arranged side by side, and a third heat-conducting layer 25 is provided between adjacent battery cells 23. In this way, by providing the third heat-conducting layer 25 between adjacent battery cells 23, a heat-conducting effect can be played between adjacent battery cells 23, and the heat conduction between the multiple battery cells 23 is increased, so that the heat of the battery cell 23 located in the middle of the battery cell 20 can also be better conducted to the housing 22 for heat dissipation, thereby further improving the heat dissipation effect of the battery cell 20.

[0082] It should be noted that the third heat-conducting layer 25 can be the same as the second heat-conducting layer 231, and can be pre-arranged on the outer wall of the battery core 23 before the battery cell 20 is assembled; or the third heat-conducting layer 25 can be sandwiched between two adjacent battery cores 23 when the battery core 23 is placed in the housing 22. The material of the third heat-conducting layer 25 can be the same as that of the first heat-conducting layer 221 and the second heat-conducting layer 231.

[0083] See also Figure 8In some embodiments, the battery cell 23 includes a positive electrode sheet 232, a separator 233, and a negative electrode sheet 234 which are stacked in sequence, and the outermost layer of the battery cell 23 is the separator 233, and the second heat-conducting layer 231 is arranged on the outermost separator 233 of the battery cell 23. Usually, before the battery cell 23 is installed in the housing 22, a layer of mylar sheet needs to be arranged on the outermost large surface of the battery cell 23 to insulate the battery cell 23 from the housing 22. The material of the mylar sheet is usually a plastic material such as polyethylene terephthalate (PET), which has a very low thermal conductivity, affecting the heat dissipation of the battery cell 23. The present application sets a second heat-conducting layer 231 on the outer wall of the battery cell 23 and sets a first heat-conducting layer 221 on the inner wall of the shell 22; when at least one of the first heat-conducting layer 221 and the second heat-conducting layer 231 is an insulating heat-conducting layer, the battery cell 23 and the shell 22 can be insulated, so the Mylar sheet can be eliminated and the second heat-conducting layer 231 can be directly set on the outermost isolation film 233 of the battery cell 23. In this way, not only the heat dissipation effect of the battery cell 20 can be improved, but also the cost can be saved and the weight can be reduced.

[0084] In some embodiments, the positive electrode plate 232 includes a positive electrode current collector, which includes a first organic support layer and a first conductive layer disposed on at least one surface of the first organic support layer. That is, the positive electrode current collector may be a composite current collector. In this way, the weight of the battery cell 23 can be reduced and the energy density of the battery cell 23 can be increased.

[0085] Specifically, the first organic support layer can be made of an organic polymer material such as PET, the first conductive layer can be made of aluminum foil, and the first conductive layer can be formed on the first organic support layer by evaporation or other methods. The thickness of the first organic support layer can be 1 μm to 30 μm; further, it can be 3 μm to 7 μm. The thickness of the first conductive layer can be 0.03 μm to 3 μm. It can be understood that the thickness of the first organic supporting layer can be but not limited to 1μm, 2μm, 5μm, 8μm, 10μm, 12μm, 14μm, 16μm, 18μm, 20μm, 22μm, 24μm, 26μm, 28μm, 30μm; the thickness of the first conductive layer can be but not limited to 0.03μm, 0.05μm, 0.08μm, 0.1μm, 0.12μm, 0.15μm, 0.18μm, 0.2μm, 0.22μm, 0.24μm, 0.26μm, 0.28μm, 3μm.

[0086] In some embodiments, the negative electrode plate 234 includes a negative electrode current collector, and the negative electrode current collector includes a second organic support layer and a second conductive layer disposed on at least one surface of the second organic support layer. That is, the negative electrode current collector can be a composite current collector. In this way, the weight of the battery cell 23 can be further reduced, and the energy density of the battery cell 23 can be further improved.

[0087] Specifically, the second organic support layer can be made of an organic polymer material such as PET, the second conductive layer can be made of copper foil, and the second conductive layer can be formed on the second organic support layer by evaporation or other methods. The thickness of the second organic support layer can be 1 μm to 30 μm; further, it can be 3 μm to 7 μm. The thickness of the second conductive layer can be 0.03 μm to 3 μm. It can be understood that the thickness of the second organic supporting layer can be but not limited to 1μm, 2μm, 5μm, 8μm, 10μm, 12μm, 14μm, 16μm, 18μm, 20μm, 22μm, 24μm, 26μm, 28μm, 30μm; the thickness of the second conductive layer can be but not limited to 0.03μm, 0.05μm, 0.08μm, 0.1μm, 0.12μm, 0.15μm, 0.18μm, 0.2μm, 0.22μm, 0.24μm, 0.26μm, 0.28μm, 3μm.

[0088] In some embodiments, the battery cell 20 can be prepared by the following method:

[0089] The positive electrode active material, the binder, and the conductive agent are mixed in a certain weight ratio, and a solvent is added, and the slurry is stirred in a vacuum state until it is uniform. The obtained slurry is coated on the positive electrode current collector, and the positive electrode sheet 232 is obtained after drying, cold pressing, and cutting;

[0090] The negative electrode active material, conductive agent, binder and dispersant are dissolved in deionized water solvent according to a certain weight ratio, and stirred and mixed to prepare a negative electrode slurry. The negative electrode slurry is evenly coated on the negative electrode current collector, and the negative electrode sheet 234 is obtained after drying, cold pressing and cutting;

[0091] In an argon atmosphere glove box (H2O<0.1ppm, O2<0.1ppm), organic solvents ethylene carbonate (EC) / ethyl methyl carbonate (EMC) are mixed uniformly according to a certain volume ratio, electrolyte lithium salt is added and dissolved in the above organic solvent, and stirred uniformly to obtain an electrolyte solution;

[0092] A commercially available PP-PE copolymer microporous film was used as the separator 233;

[0093] The positive electrode sheet 232, the separator 233, and the negative electrode sheet 234 are stacked in order, so that the separator 233 is located between the positive and negative electrodes to play a role of isolation, and are wound to obtain the battery cell 23, and the second heat-conducting layer 231 is formed on the outermost separator 233 of the battery cell 23. The first heat-conducting layer 221 is formed on the inner side wall of the shell 22, and the battery cell 23 is installed in the shell 22 to assemble into a battery cell 20.

[0094] The second aspect of the present application provides a battery 100, including the battery cell 20 of the first aspect of the present application. Thus, by using the battery cell 20 of the first aspect of the present application, the battery 100 can have good heat dissipation performance, thereby improving the service life and safety of the battery 100.

[0095] A third aspect of the present application provides an electrical device, comprising the battery 100 of the second aspect of the present application.

[0096] The embodiment of the present application provides an electric device using a battery 100 as a power source, and the electric device may be, but is not limited to, a mobile phone, a tablet, a laptop, an electric toy, an electric tool, a battery car, an electric car, a ship, a spacecraft, etc. Among them, the electric toy may include a fixed or mobile electric toy, for example, a game console, an electric car toy, an electric ship toy, an electric airplane toy, etc., and the spacecraft may include an airplane, a rocket, a space shuttle, a spacecraft, etc.

[0097] The above description of various embodiments tends to emphasize the differences between the various embodiments. The same or similar aspects can be referenced to each other, and for the sake of brevity, they will not be repeated herein.

[0098] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and the embodiments having the same structure as the technical idea and exerting the same effect within the scope of the technical solution of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the main purpose of the present application, various modifications that can be thought of by those skilled in the art to the embodiments and other methods of combining some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A battery cell, characterized in that: include: a housing, wherein a first heat-conducting layer is disposed on an inner side wall of the housing; and The battery core is placed in the shell, and a second heat-conducting layer is provided on the outer wall of the battery core, and the second heat-conducting layer is arranged opposite to the first heat-conducting layer.

2. The battery cell according to claim 1, characterized in that: At least one of the first heat-conducting layer and the second heat-conducting layer is an insulating heat-conducting layer.

3. The battery cell according to claim 2, characterized in that: Satisfy at least one of the following (1) to (2): (1) The first heat-conducting layer includes any one of a heat-conducting silicone rubber layer, a heat-conducting polyimide layer, a heat-conducting epoxy resin layer, a heat-conducting phenolic resin layer, a heat-conducting urea-formaldehyde resin layer, a heat-conducting polyetheretherketone layer, and a heat-conducting polybenzimidazole layer; (2) The second thermally conductive layer includes any one of a thermally conductive silicone rubber layer, a thermally conductive polyimide layer, a thermally conductive epoxy resin layer, a thermally conductive phenolic resin layer, a thermally conductive urea-formaldehyde resin layer, a thermally conductive polyetheretherketone layer, and a thermally conductive polybenzimidazole layer.

4. The battery cell according to claim 1, characterized in that: The thickness ratio of the first heat-conducting layer to the second heat-conducting layer is (0.05-100):

1.

5. The battery cell according to claim 1, characterized in that: The sum of the thicknesses of the first heat-conducting layer and the second heat-conducting layer is 20 μm to 1200 μm.

6. The battery cell according to claim 1, characterized in that: The thickness of the first heat conducting layer is 10 μm-1000 μm.

7. The battery cell according to claim 1, characterized in that: The thickness of the second heat-conducting layer is 10 μm to 200 μm.

8. The battery cell according to claim 1, characterized in that: The thermal conductivity of the first heat-conducting layer and the second heat-conducting layer are both ≥2 W / m·K.

9. The battery cell according to claim 1, characterized in that: There is a gap between the first heat-conducting layer and the second heat-conducting layer, and the width of the gap is 1 mm to 4 mm.

10. The battery cell according to claim 1, characterized in that: There are multiple battery cells, which are arranged side by side, and a third heat-conducting layer is provided between adjacent battery cells.

11. The battery cell according to any one of claims 1 to 10, characterized in that: The battery cell comprises a positive electrode sheet, a separator and a negative electrode sheet which are stacked in sequence, and the outermost layer of the battery cell is the separator, and the second heat-conducting layer is arranged on the outermost separator.

12. The battery cell according to claim 11, characterized in that: Satisfy at least one of the following (3) to (4): (3) The positive electrode sheet includes a positive electrode current collector, and the positive electrode current collector includes a first organic support layer and a first conductive layer provided on at least one surface of the first organic support layer; (4) The negative electrode plate includes a negative electrode current collector, and the negative electrode current collector includes a second organic supporting layer and a second conductive layer provided on at least one surface of the second organic supporting layer.

13. A battery, characterized in that: A battery cell comprising the battery cell according to any one of claims 1 to 12.

14. An electrical device, characterized in that: Comprising the battery of claim 13.

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