Heat dissipation lithium battery
By setting a heat dissipation film on the insulating film of the lithium battery cell to optimize its position and density, the problem of insufficient heat dissipation of large-capacity lithium battery cells is solved, and the consistency of internal temperature and cycling performance of the battery cell are improved.
Patent Information
- Application Number
- CN202421426518.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-21
- Publication Date
- 2025-04-04
- Estimated Expiration
- 2034-06-21
AI Technical Summary
Due to the high energy density of large-capacity lithium battery cells, the existing heat dissipation design is difficult to meet the demand, resulting in inconsistent internal and surface temperatures of the battery cells, affecting the stability of cycling performance.
A heat dissipation film is provided in part of the battery cell insulating film to optimize the position and density of the heat dissipation film, and materials with high heat transfer and strong elastic modulus, such as the combination of graphene and natural rubber, are used as the material of the heat dissipation film.
The heat dissipation speed of lithium batteries is improved, the heat dissipation speed at different positions of the battery cell is adjusted, the internal temperature of the battery cell is maintained consistent, the cycle stability and life are improved, and the safety capability of the battery cell is enhanced.
Smart Images
Figure CN222720518U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of lithium batteries, in particular to a heat dissipation lithium battery. Background Art
[0002] The existing market has increasingly higher requirements for the capacity of energy storage systems and batteries. For large-capacity cells, ordinary heat dissipation designs are difficult to meet the needs of cells due to the high heat dissipation of high-energy-density cells. In addition, the continuous release of heat from the cells during the cycle causes inconsistencies in the internal and surface temperatures of the cells, and the heat released by cells at different locations is also inconsistent, which directly affects the stability of the battery cycle performance. Therefore, it is crucial to design effective heat dissipation structures for large-capacity cells. Utility Model Content
[0003] In order to overcome the defects in the prior art, the embodiment of the utility model provides a heat dissipation lithium battery, which can improve the heat dissipation capacity of high energy density battery cells, improve the consistency of the internal temperature of the battery cells, and improve the safety capability of the battery cells.
[0004] In order to achieve the above purpose, the technical solution adopted by the utility model is:
[0005] The first aspect of the utility model discloses a heat dissipation lithium battery, comprising:
[0006] case;
[0007] A battery cell, wherein the battery cell is arranged in the shell, and an insulating film is arranged on the surface of the battery cell;
[0008] A heat dissipation film is provided on the surface of the battery cell insulation film, and the side of the heat dissipation film away from the insulation film is attached to the shell. At least a part of the surface of the battery cell insulation film is covered with the heat dissipation film. The thickness of the heat dissipation film is 0.1 to 0.5 mm, the length of the heat dissipation film is less than or equal to 0.1 times the thickness of the insulation film, and the width of the heat dissipation film is less than or equal to 0.1 times the thickness of the insulation film.
[0009] The above technical solution can accelerate the heat dissipation speed of the lithium battery and regulate the heat dissipation speed of different positions of the battery cell by setting a heat dissipation film in a partial area of the insulating film, optimizing the setting position of the heat dissipation film, and adjusting the setting density of the heat dissipation film. While improving the heat dissipation capacity of the battery cell, the overall temperature inside the battery cell can be kept consistent, which can improve the cycle stability and life of the battery cell.
[0010] Preferably, at least one heat dissipation film is provided on the insulating film, and the shape of the at least one heat dissipation film is set to be a regular strip or block, and / or an irregular strip or block.
[0011] Since the heat transfer amount of different battery cells is different, heat dissipation films of different shapes can be set according to the heat transfer area. The heat dissipation film can be set to regular or irregular strips or blocks to achieve the heat dissipation effect and maintain the consistency of the internal temperature of the battery cell.
[0012] Preferably, the thickness of the heat dissipation film is 0.2-0.5 mm, the length of the heat dissipation film is 0.5% to 1% times the thickness of the insulating film, and the width of the heat dissipation film is 0.5% to 1% times the thickness of the insulating film. Setting the heat dissipation film according to this thickness can achieve good heat dissipation effect of the heat dissipation film and avoid the heat dissipation film occupying the internal space of the battery cell.
[0013] Preferably, when at least two heat dissipation films are arranged on the same insulating film, the thickness of the at least two heat dissipation films is the same, and the sides of the at least two heat dissipation films away from the insulating film are both in contact with the housing.
[0014] The heat dissipation film is set according to the characteristics of heat transfer inside the battery cell, and the setting position is determined by the amount of heat transfer. Since the heat dissipation film is set between the insulating film and the shell, heat dissipation films of different shapes in the same heat dissipation lithium battery need to be set to the same thickness.
[0015] Preferably, the material of the heat dissipation film includes at least one of a compound of graphene and natural rubber and its derivatives, and a compound of graphene and sodium nanocellulose and its derivatives.
[0016] The heat dissipation film itself is a material with high heat transfer and strong elastic modulus. This type of material has thermal conductivity and certain mechanical properties. It can buffer the expansion of the battery cell and can also restore the deformation after the expansion force becomes smaller. When the battery cell expands due to heat, it can give the battery cell a rebound force to reduce the expansion of the battery cell.
[0017] Preferably, the heat dissipation film is respectively arranged on the insulating film on the two opposite surfaces of the battery core. Arranging the heat dissipation film on the two opposite surfaces of the battery core can speed up the heat dissipation speed and improve the heat dissipation capacity of the battery core.
[0018] Preferably, the thickness of the insulating film is 0.1-1 mm.
[0019] Preferably, the thickness of the insulating film is 0.3-1 mm.
[0020] The applicant found that the insulation effect is better when the thickness of the insulating film is between 0.1 and 1 mm. If it is lower than this range, the insulation effect is poor, and when it is higher than this range, the thermal resistance will also increase. After testing, the performance is best when the thickness of the insulating film is set within the range of 0.3 to 1 mm.
[0021] Preferably, the material of the insulating film includes at least one of polyimide, polyurethane, polyethylene, polypropylene, polyvinylidene fluoride, and polytetrafluoroethylene.
[0022] Due to the application of the above technical solution, the utility model has the following advantages compared with the prior art:
[0023] 1. This application can improve the heat dissipation capacity of high energy density battery cells, reduce the occurrence of thermal runaway of the battery cells, and improve the safety capability of the battery cells by providing a heat dissipation film between the insulating film and the shell.
[0024] 2. According to the characteristics of heat transfer inside the battery cell, the present application sets at least one heat dissipation film in a partial area on the insulating film, and sets at least one heat dissipation film at different positions on the insulating film. The setting density of the heat dissipation film is adjusted, which can improve the consistency of the internal temperature of the battery cell and enhance the cycle performance of the battery cell.
[0025] In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0027] Figure 1 This is a cross-sectional view of the heat dissipation lithium battery of the utility model;
[0028] Figure 2 It is a top view of the heat dissipation film structure of the heat dissipation lithium battery of the utility model.
[0029] The figure numbers of the above drawings are: 1. heat dissipation film; 2. insulation film; 3. shell; 4. battery cell. DETAILED DESCRIPTION
[0030] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. In addition, the drawings of the utility model are only simple schematic illustrations and are not depicted according to actual sizes. Please note in advance.
[0031] In the present utility model, it should be noted that the terms "upper", "lower", "inside", "outside", "forward", "backward", "between", "close to", "far away" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present utility model. It should also be noted that, unless otherwise clearly specified and limited, the terms "installation" and "connection" 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 direct connection or an indirect connection. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to the specific circumstances.
[0032] It should be understood that, although the terms "first", "second", "third", etc. may be used herein to describe various components or signals, these components or signals should not be limited by these terms. These terms are mainly used to distinguish one component from another component, or one signal from another signal. In addition, the term "or" used herein may include any one or more combinations of the associated listed items depending on the actual situation.
[0033] Reference Figure 1 , this application shows a cross-sectional view of a heat dissipation lithium battery. Figure 1 As shown, the heat dissipation lithium battery includes a shell 3, a battery cell 4, an insulating film 2 and a plurality of heat dissipation films 1, wherein the plurality of heat dissipation films in the present application refers to one or more heat dissipation films.
[0034] like Figure 1 As shown, the battery cell 4 is arranged in the shell 3, the insulating film 2 is arranged on the surface of the battery cell 4, and the heat dissipation film 1 is arranged on at least part of the insulating film 2, and the side of the heat dissipation film 1 away from the insulating film 2 is in contact with the shell 3. In a possible embodiment, a plurality of heat dissipation films 1 are arranged on the insulating film 2, and the plurality of heat dissipation films 1 are arranged in different areas on the insulating film 2, and the plurality of heat dissipation films 1 are arranged between the insulating film 2 and the shell 3. When the plurality of heat dissipation films 1 are arranged between the insulating film 2 and the shell 3, the sides of the plurality of heat dissipation films 1 away from the insulating film 2 are all in contact with the shell 3.
[0035] In a possible embodiment, the surface of the battery cell 4 is the bottom and top surfaces where heat rises when heat is transferred inside the battery cell 4. In other possible embodiments, the heat dissipation film 1 can be disposed on different surfaces of the insulating film 2 according to actual conditions, and this application does not make specific limitations here.
[0036] The above-mentioned heat dissipation film 1 is fitted with the shell 3, which can accelerate the heat dissipation. Through the above-mentioned structure, the present application can adjust the setting density of the heat dissipation film in the lithium battery, improve the heat dissipation capacity of high energy density battery cells, reduce the occurrence of thermal runaway of the battery cells, improve the safety capability of the battery cells, and improve the consistency of the internal temperature of the battery cells.
[0037] The position of the heat dissipation film 1 on the insulating film 2 is determined by the amount of heat transferred inside the battery cell. There are many ways to determine the amount of heat transferred inside the battery cell. For example, the amount of heat transferred inside the battery cell can be confirmed by thermal simulation. Multiple heat dissipation films 1 set in the same heat dissipation lithium battery can adjust the density of the heat dissipation films. The thickness of the heat dissipation films 1 in the same lithium battery must be the same. Figure 1 and Figure 2 , this application shows a schematic diagram of the heat dissipation film structure in a possible embodiment of a heat dissipation lithium battery. Figure 1 and Figure 2 As shown, when a plurality of heat dissipation films 1 are arranged on the insulating film 2 , the thickness of the plurality of heat dissipation films 1 is the same, the plurality of heat dissipation films 1 are arranged in a block shape, and the distances and sizes between the plurality of heat dissipation films 1 are different.
[0038] The distances between the multiple heat dissipation films 1 and the shapes of the heat dissipation films 1 set in the same heat dissipation lithium battery can be the same or different. In some other possible embodiments, the heat dissipation films 1 can also be set in strips, regular polygons, and / or irregular polygons, the distances between the heat dissipation films 1 can be the same or different, and the distances between the heat dissipation films 1 can also be zero. The specific shape of the heat dissipation film 1 and the distance between the heat dissipation films 1 are set according to the position and amount of heat transfer inside the battery cell, and this application does not make specific limitations here.
[0039] Specifically, the heat dissipation film 1 provided in the present application has a thickness of 0.1-0.5 mm, a length of the heat dissipation film 1 less than or equal to 0.1 times the thickness of the insulating film 2 , and a width of the heat dissipation film 1 less than or equal to 0.1 times the thickness of the insulating film 2 .
[0040] Providing a heat dissipation film between the insulating film and the shell can speed up the heat dissipation speed inside the battery cell. The heat dissipation film can dissipate heat without affecting the utilization of the internal space of the battery cell and reducing the energy density of the battery. The applicant found that when the thickness of the heat dissipation film is 0.1-0.5 mm, the heat dissipation film 1 can not only achieve the effect of heat dissipation, but also make good use of the internal space of the battery cell, avoiding reducing the energy density of the battery due to the heat dissipation film 1 being too thick. When the length and width are less than 0.1 times the thickness of the insulating film, the heat dissipation performance is better and is beneficial to the utilization of the internal space of the battery cell.
[0041] In a possible embodiment, the thickness of the heat dissipation film is 0.2-0.5 mm, the length of the heat dissipation film is 0.5% to 1% times the thickness of the insulating film, and the width of the heat dissipation film is 0.5% to 1% times the thickness of the insulating film. According to the heat dissipation of the battery cell, when the thickness of the heat dissipation film is 0.2-0.5 mm, the heat dissipation performance is optimal, and the heat dissipation demand can be met even if the area of the heat dissipation film is very small.
[0042] The heat dissipation film 1 is used to improve the heat dissipation capacity of the battery cell. Since the battery cell expands due to heat, the heat dissipation film 1 needs to use a material with high heat transfer and strong elastic modulus. When the battery cell expands, the heat dissipation film 1 is squeezed by the battery cell, which can give the battery cell a rebound force and reduce the expansion of the battery cell.
[0043] In a possible embodiment, the heat dissipation film 1 may use one or more materials including a compound of graphene and natural rubber and its derivatives, and a compound of graphene and sodium nanocellulose and its derivatives.
[0044] In some other possible embodiments, the material of the heat dissipation film 1 can also be a thermally conductive silicone material, such as thermally conductive gel, thermally conductive potting glue, thermally conductive silicone grease, etc. This type of material has thermal conductivity and certain mechanical properties, can buffer the expansion of the battery cell, and can also restore deformation after the expansion force becomes smaller.
[0045] The insulating film 2 mainly plays the role of isolation and maintaining the overall stability of the battery. The material used needs to have good isolation performance, mechanical strength and thermal stability. This type of material needs to have excellent high temperature resistance, wear resistance, and chemical resistance, and can be used in a variety of corrosive media, high temperature and high pressure environments.
[0046] In an embodiment of the present application, the material of the insulating film 2 can be selected from one or more of polyimide, polyurethane, polyethylene, polypropylene, polyvinylidene fluoride, and polytetrafluoroethylene. In some other possible embodiments, the insulating film 2 can also be other insulating materials, such as various inorganic insulating materials or organic insulating materials, which are not described in detail in the present application.
[0047] The thickness of the insulating film 2 is set to 0.1-1 mm. According to experiments, when the thickness of the insulating film 2 is set within the range of 0.1-1 mm, the insulating film 2 can ensure the insulation effect and avoid the increase of thermal resistance due to excessive thickness.
[0048] In a possible embodiment, the thickness of the insulating film may be set to 0.3-1 mm, at which point the performance of the insulating film can be optimized.
[0049] The present application can optimize the setting position of the heat dissipation film according to the heat transferred inside the battery cell, and adjust the setting density of the heat dissipation film in the lithium battery, which can not only achieve rapid heat dissipation inside the battery cell, but also improve the consistency of the temperature inside the battery cell, improve the cycle performance of the battery cell, reduce the occurrence of thermal runaway of the battery cell, and improve the safety capability of the battery cell.
[0050] The present invention uses specific embodiments to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method and core idea of the present invention. At the same time, for those skilled in the art, according to the idea of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.
Claims
1. A heat dissipation lithium battery, characterized in that: include: case; A battery cell, wherein the battery cell is arranged in the shell, and an insulating film is arranged on the surface of the battery cell; A heat dissipation film is provided on the surface of the battery cell insulation film, and the side of the heat dissipation film away from the insulation film is attached to the shell. At least a part of the surface of the battery cell insulation film is covered with the heat dissipation film. The thickness of the heat dissipation film is 0.1 to 0.5 mm, the length of the heat dissipation film is less than or equal to 0.1 times the thickness of the insulation film, and the width of the heat dissipation film is less than or equal to 0.1 times the thickness of the insulation film.
2. A heat dissipation lithium battery according to claim 1, characterized in that: At least one heat dissipation film is provided on the insulating film, and the shape of the at least one heat dissipation film is set to be a regular strip or block, and / or an irregular strip or block.
3. A heat dissipation lithium battery according to claim 1, characterized in that: The thickness of the heat dissipation film is 0.2-0.5 mm, the length of the heat dissipation film is 0.5% to 1% times the thickness of the insulating film, and the width of the heat dissipation film is 0.5% to 1% times the thickness of the insulating film.
4. A heat dissipation lithium battery according to claim 2, characterized in that: When at least two heat dissipation films are arranged on the same insulating film, the thickness of the at least two heat dissipation films is the same, and the sides of the at least two heat dissipation films away from the insulating film are both in contact with the housing.
5. A heat dissipation lithium battery according to claim 1, characterized in that: The material of the heat dissipation film includes at least one of a compound of graphene and natural rubber and its derivatives, and a compound of graphene and sodium nanocellulose and its derivatives.
6. A heat dissipation lithium battery according to claim 1, characterized in that: The heat dissipation films are respectively arranged on the insulating films on two opposite surfaces of the battery core.
7. A heat dissipation lithium battery according to claim 1, characterized in that: The thickness of the insulating film is 0.1-1 mm.
8. A heat dissipation lithium battery according to claim 7, characterized in that: The thickness of the insulating film is 0.3-1 mm.
9. A heat dissipating lithium battery according to claim 1, characterized in that: The material of the insulating film includes at least one of polyimide, polyurethane, polyethylene, polypropylene, polyvinylidene fluoride, and polytetrafluoroethylene.