Heat dissipation piece, battery module and battery system

Abstract

The utility model relates to the technical field of batteries, and discloses a heat dissipation piece, a battery module and a battery system, the heat dissipation piece is arranged on a battery, the heat dissipation piece comprises a polymer layer and a temperature control layer, and the polymer layer is in contact with the battery. According to the heat dissipation piece, the polymer layer is good in bonding performance, the temperature control layer and the battery can form good contact, when a certain battery is subjected to thermal runaway, heat is rapidly conducted to the temperature control layer, and a large amount of heat generated by thermal runaway is rapidly reduced through the temperature control layer; meanwhile, when the battery expands due to thermal runaway, the polymer layer can also play a certain buffering role, so that the extrusion damage to the adjacent temperature control layer is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, and in particular to a heat sink, a battery module and a battery system. Background Art

[0002] In recent years, lithium-ion batteries have high energy density and long cycle life and have been widely used in new energy vehicles, electrochemical energy storage and other fields. Since the battery generates a lot of heat during the charging and discharging process, coupled with the effects of space limitations and time accumulation, it is easy to cause the temperature of the single battery to rise. When the normal operating temperature range of the battery is exceeded, the single battery is very likely to have thermal runaway. For a long time, the safety hazards such as battery pack fire and explosion caused by battery thermal runaway have been a major obstacle to the large-scale development of lithium-ion batteries in new energy vehicles, electrochemical energy storage and other fields. Therefore, the suppression of thermal runaway is an issue that must be considered in battery design.

[0003] At present, thermal management systems such as liquid cooling and air cooling systems are mostly used to suppress battery thermal runaway. However, simple liquid cooling and air cooling systems cannot effectively and efficiently remove the heat when thermal runaway of lithium-ion batteries occurs, making it difficult to effectively avoid safety accidents. Utility Model Content

[0004] The purpose of the utility model is to overcome the problems existing in the prior art and to provide a heat sink, a battery module and a battery system, wherein the heat sink can quickly reduce a large amount of heat generated by thermal runaway.

[0005] In order to achieve the above objectives, the utility model provides a heat sink on one hand. The heat sink is arranged on a battery. The heat sink comprises a polymer layer and a temperature control layer. The polymer layer is in contact with the battery.

[0006] Preferably, the polymer layer comprises metal particles.

[0007] Preferably, the metal particles include at least one of copper, aluminum, iron, gold, nickel and silver.

[0008] Preferably, the thickness of the polymer layer is 0.1-3 mm.

[0009] Preferably, the temperature control layer comprises a porous heat-conducting skeleton layer and a chemical heat storage material, wherein the porous heat-conducting skeleton layer has pores, and the chemical heat storage material is filled in the pores.

[0010] Preferably, the chemical heat storage material includes at least one of hydroxide, hydrated salt and chloride salt ammonia compound.

[0011] Preferably, the chemical heat storage material includes at least one of magnesium hydroxide, calcium hydroxide, aluminum sulfate 18hydrate, magnesium sulfate heptahydrate, lanthanum chloride heptahydrate, barium hydroxide octahydrate, CaCl2·NH3, BaCl2·NH3 and MnCl2·NH3.

[0012] Preferably, the porous heat-conducting skeleton layer comprises foam metal material or ceramic porous material.

[0013] Preferably, the porous heat-conducting skeleton layer includes at least one of foamed copper, foamed aluminum, foamed nickel, porous alumina ceramic material and porous aluminum nitride ceramic material.

[0014] Preferably, the temperature control layer has a thickness of 0.1 to 10 mm.

[0015] A second aspect of the utility model provides a battery module, which includes a plurality of batteries. A heat insulation layer and the heat dissipation element as described above are provided between two adjacent batteries, and the heat insulation layer is in contact with the temperature control layer.

[0016] Preferably, two heat sinks are provided, and the heat insulation layer is provided between the two heat sinks.

[0017] Preferably, the thickness of the thermal insulation layer is 0.1-15 mm.

[0018] Preferably, the thermal insulation layer comprises aerogel or polyurethane foam.

[0019] A third aspect of the present invention provides a battery system, which includes the battery module as described above.

[0020] In the heat sink described in the utility model, the polymer layer has good bonding performance, which can make the temperature control layer and the battery form good contact. When the battery has thermal runaway, the heat is quickly transferred to the temperature control layer, and the large amount of heat generated by the thermal runaway is quickly reduced through the temperature control layer, thereby extending the life of the battery. Furthermore, when the battery expands due to thermal runaway, the polymer layer can also play a certain buffering role, thereby reducing the extrusion damage to the adjacent temperature control layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of an embodiment of a battery module provided by the utility model.

[0022] Description of Reference Numerals

[0023] 1-battery; 2-heat dissipation element; 3-thermal insulation layer;

[0024] 21- polymer layer; 22- temperature control layer. DETAILED DESCRIPTION

[0025] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0026] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0027] The utility model provides a heat sink 2, please refer to Figure 1 The heat sink 2 is disposed on the battery 1 , and includes a polymer layer 21 and a temperature control layer 22 , and the polymer layer 21 is in contact with the battery 1 .

[0028] In the present invention, the polymer layer 21 is made of a high molecular polymer as a matrix. The present invention does not limit the specific type of the high molecular polymer, which can be a high molecular polymer commonly used in the art, such as a synthetic resin or rubber. In one embodiment, the high molecular polymer is an epoxy resin, a phenolic resin, a styrene-butadiene rubber, a nitrile rubber or a silicone rubber, and the high molecular polymer has good bonding properties and has a certain degree of deformation.

[0029] In one embodiment, the polymer layer 21 includes metal particles. Specifically, the polymer layer 21 has pores, and the metal particles are contained in the pores of the polymer layer 21. Through the design of the polymer layer structure, on the one hand, the polymer layer 21 can play a bonding role, and on the other hand, the metal particle filling can quickly absorb the heat generated by thermal runaway and transfer it to the temperature control layer 22. On the other hand, the polymer layer 21 can also have a certain deformation to protect the adjacent temperature control layer 22.

[0030] Based on the previous embodiment, the polymer layer 21 can be prepared according to the following process: metal particles, polymer matrix, curing agent and solvent are mixed to obtain slurry, the slurry is fully stirred and mixed, and then dried and cured to obtain a polymer layer filled with metal particles.

[0031] In another embodiment, the polymer layer 21 can also be prepared according to the following process: a polymer matrix, a curing agent and a solvent are mixed to obtain a slurry; the slurry is fully stirred, then dried and cured, and then the metal particles are filled into the pores of the polymer layer by ultrasonic dispersion.

[0032] In one embodiment, the particle size of the metal particles is 0.1-10 μm.

[0033] In one embodiment, the mass fraction of the metal particles in the polymer layer 21 is 5-50%.

[0034] The utility model does not particularly limit the specific type of metal particles. In a preferred embodiment, the metal is at least one of copper, aluminum, iron, gold, nickel and silver. The above metals are easily available and have good electrical conductivity.

[0035] In order to improve the buffering and bonding effects of the polymer layer 21 and to transfer the heat generated by thermal runaway to the temperature control layer 22 more quickly, in a preferred embodiment, the thickness of the polymer layer 21 is 0.1-3 mm.

[0036] The present invention does not limit the specific material and structure of the temperature control layer 22, as long as it can quickly reduce the heat generated by thermal runaway. In one embodiment, the temperature control layer 22 includes a porous heat-conducting skeleton layer and a chemical heat storage material, wherein the porous heat-conducting skeleton layer has pores, and the chemical heat storage material is filled in the pores. Furthermore, the chemical heat storage material is contained in the porous heat-conducting skeleton layer. In this embodiment, by filling the chemical heat storage material into the porous heat conductive skeleton layer, the contact area between the porous heat conductive skeleton and the chemical heat storage material can be greatly increased, thereby greatly increasing the heat absorption efficiency of the chemical heat storage material, and then the large amount of heat generated during thermal runaway of the battery can be quickly reduced; at the same time, the porous heat conductive skeleton can better disperse the chemical heat storage material, thereby preventing the chemical heat storage material from failing due to agglomeration during operation, and the filling design can reduce the volume of non-effective components; in addition, the porous heat conductive skeleton can play a role in uniform heat under normal operating conditions of the battery, quickly forming a uniform temperature field, thereby preventing the generation of hot spots; the porous heat conductive skeleton can also play a certain buffering role, thereby further reducing the extrusion damage to adjacent batteries 1 caused by the expansion caused by thermal runaway of the battery.

[0037] Based on the previous embodiment, the temperature control layer 22 can be prepared according to the following process: solidify the porous thermal conductive skeleton to form a porous thermal conductive skeleton layer, and then use conventional methods (such as sintering, blending, solidification molding, etc.) to embed the chemical heat storage material into the pores of the porous thermal conductive skeleton layer to obtain the temperature control layer 22.

[0038] Obviously, the design of the utility model is not limited to this. The temperature control layer 22 can also be prepared according to the following process: dissolving the chemical heat storage material in a solvent to obtain a slurry; then mixing the slurry with a porous heat conductive skeleton to fill the chemical heat storage material into the pores of the porous heat conductive skeleton; finally drying to remove the solvent to obtain a temperature control layer 22 filled with the chemical heat storage material.

[0039] The utility model does not limit the specific proportion of the chemical heat storage material in the temperature control layer 22, which can be designed according to actual needs, for example, it can be 0.1-99%. In a preferred embodiment, the mass fraction of the chemical heat storage material in the temperature control layer 22 is 20-70%.

[0040] The present invention does not specifically limit the specific thickness of the temperature control layer 22, and the thickness can be designed as required. In one embodiment, the thickness of the temperature control layer 22 is 0.1-10 mm.

[0041] In a preferred embodiment, the temperature control layer 22 has a thickness of 0.5 to 4 mm. Within this thickness range, not only can the heat generated by thermal runaway be quickly reduced, but the impact on battery performance can also be reduced.

[0042] The present invention does not limit the specific type of chemical heat storage material, and it can be a chemical heat storage material commonly used in the art. In one embodiment, the chemical heat storage material includes at least one of hydroxide, hydrated salt and chloride salt ammonia compound. The above chemical heat storage material can not only convert a large amount of heat into chemical energy storage, but also pyrolyze to generate a large amount of water vapor, and the generated water vapor can also evaporate and take away a large amount of heat. Therefore, by selecting the above chemical heat storage material, the total heat generated by thermal runaway can be reduced faster.

[0043] Furthermore, the hydroxide may be magnesium hydroxide or calcium hydroxide; the hydrated salt may be at least one of aluminum sulfate 18hydrate, magnesium sulfate heptahydrate, lanthanum chloride heptahydrate and barium hydroxide 8hydrate; the chloride salt ammonia compound may be CaCl2·NH3, BaCl2·NH 3和 At least one of MnCl2·NH3.

[0044] In a preferred embodiment, the chemical heat storage material includes at least one of magnesium hydroxide, calcium hydroxide, aluminum sulfate 18hydrate, magnesium sulfate heptahydrate, lanthanum chloride heptahydrate, barium hydroxide 8hydrate, CaCl2·NH3, BaCl2·NH3 and MnCl2·NH3.

[0045] The utility model does not limit the specific material and structure of the porous heat-conducting skeleton layer, as long as it has a pore structure and good thermal conductivity. In one embodiment, the porous heat-conducting skeleton layer is a foam metal material or a ceramic porous material.

[0046] Furthermore, the porous thermally conductive skeleton layer includes at least one of foam copper, foam aluminum, foam nickel, porous alumina ceramic material and porous aluminum nitride ceramic material. The above materials are easily available, low in cost, have pores and good thermal conductivity.

[0047] When a lithium battery experiences thermal runaway, its surface temperature can often reach as high as 500-700°C. However, common thermal insulation materials, such as aerogel-type thermal insulation materials, have a high degree of permeability to thermal radiation under thermal runaway conditions, which greatly weakens their thermal insulation capabilities. Therefore, the design of a single thermal insulation material is difficult to achieve a good effect in suppressing heat spread under actual working conditions.

[0048] In view of this, the utility model also provides a battery module, please refer to Figure 1 The battery module includes a plurality of batteries 1 , and a heat insulation layer 3 and the heat sink 2 mentioned above are provided between two adjacent batteries 1 , and the heat insulation layer 3 is in contact with the temperature control layer 22 .

[0049] In this embodiment, the battery module includes a battery pack formed by connecting a plurality of batteries 1 in series and / or in parallel.

[0050] In this embodiment, a polymer layer 21, a temperature control layer 22 and a heat insulation layer 3 are sequentially arranged between two adjacent batteries 1. The polymer layer 21 has good bonding properties, which can make the temperature control layer 22 form good contact with the battery 1. When a battery 1 has thermal runaway, the heat is quickly transferred to the temperature control layer 22, and the large amount of heat generated by the thermal runaway is quickly reduced by the temperature control layer 22, and the heat is blocked by the heat insulation layer 3 from being transferred to the adjacent battery 1, thereby effectively suppressing the occurrence of heat spread. Furthermore, when the battery 1 expands due to thermal runaway, the polymer layer 21 can also play a certain buffering role, thereby reducing the extrusion damage to the adjacent temperature control layer 22, the heat insulation layer 3 and the adjacent battery 1.

[0051] In a preferred embodiment, two heat sinks 2 are provided, and the heat insulating layer 3 is provided between the two heat sinks 2. That is, the polymer layer 21, the temperature control layer 22, the heat insulating layer 3, the temperature control layer 22 and the polymer layer 21 are sequentially provided along the stacking direction of the battery pack. Through the design of the above symmetrical structure, the heat sink 2 has a better buffering effect and a better effect on suppressing heat spread.

[0052] The utility model does not limit the specific material of the heat insulation layer 3, and it can be a heat insulation material commonly used in the art. In one embodiment, the heat insulation layer 3 includes aerogel or polyurethane foam.

[0053] The present invention does not specifically limit the specific thickness of the heat insulating layer 3, and the thickness can be designed as required. In one embodiment, the thickness of the heat insulating layer 3 is 0.1-15 mm.

[0054] Preferably, the thickness of the heat insulating layer 3 is 0.5-4 mm. Within this thickness range, it can not only effectively prevent heat from being transferred to adjacent batteries 1, but also reduce the impact on the performance of the batteries 1.

[0055] The utility model also provides a battery system, which includes the battery module described above. The battery system can be, for example, a vehicle or an energy storage system. Since the battery system is configured with the battery module described in the utility model, the battery system has good safety.

[0056] The present invention will be described in detail by way of examples below, but the protection scope of the present invention is not limited thereto. In the following examples, the experimental methods in the following examples, unless otherwise specified, are conventional methods in the art. The experimental materials used in the following examples, unless otherwise specified, can all be commercially available.

[0057] Example 1

[0058] The battery module includes a battery pack formed by connecting a plurality of batteries 1 in series, a heat sink 2 and a temperature control layer 3 are provided between two adjacent batteries 1, two heat sinks 2 are provided, and the heat insulation layer 3 is located between the two heat sinks 2, and the stacking method thereof is as follows: Figure 1 As shown, specifically, along the stacking direction of the battery pack, there are 1 mm polymer layer 21, 2 mm temperature control layer 22, 1 mm heat insulation layer 3, 2 mm temperature control layer 22 and 1 mm polymer layer 21;

[0059] The polymer layer 21 is made of epoxy resin (bisphenol A novolac epoxy resin, epoxy value 0.51-0.54) as a matrix, and metal particles are filled in the pores of the polymer layer 21; wherein the particle size of the metal particles is less than 0.1 μm; in the polymer layer 21, the mass fraction of the metal particles is 20%; the metal particles are silver particles;

[0060] The temperature control layer 22 includes a porous heat-conducting skeleton layer and a chemical heat storage material, and the chemical heat storage material is filled in the pores of the porous heat-conducting skeleton layer; wherein, in the temperature control layer 22, the mass fraction of the chemical heat storage material is 60%, the porous heat-conducting skeleton layer is foamed aluminum, and the chemical heat storage material is Ca(OH)2 powder;

[0061] The heat insulation layer 3 is a glass fiber-made silica aerogel heat insulation cotton.

[0062] Example 2

[0063] The method described in Example 1 is implemented, except that there is one heat sink 2, specifically, a 1 mm polymer layer 21, a 2 mm temperature control layer 22 and a 1 mm heat insulation layer 3 are provided in sequence along the stacking direction of the battery pack.

[0064] Comparative Example 1

[0065] The method described in Example 1 is implemented, except that the heat sink 2 does not contain the polymer layer 21. Specifically, along the stacking direction of the battery pack, there are a 2 mm temperature control layer 22, a 1 mm heat insulation layer 3 and a 2 mm temperature control layer 22.

[0066] Comparative Example 2

[0067] The method described in Example 1 is used for implementation, except that only a 5 mm thick heat insulation layer 3 is included between the batteries 1 .

[0068] The battery modules of the above-mentioned embodiments and comparative examples were subjected to the thermal propagation test of the modules in GB / T 36276-2018 "Lithium-ion Batteries for Power Energy Storage", and the test results are shown in Table 1 below.

[0069] Table 1

[0070]

[0071] It can be seen from Table 1 that after the thermal runaway of one of the batteries in the battery module is triggered, a large amount of heat generated will be transferred to the adjacent battery, and the adjacent battery will be continuously heated, thereby inducing thermal runaway of the adjacent battery. The utility model, through the design of the structure of the heat sink, quickly absorbs the heat generated by the thermal runaway through the polymer layer and transfers it to the temperature control layer, and then quickly conducts the large amount of heat generated through the porous heat-conducting skeleton in the temperature control layer, and converts the large amount of heat into chemical energy storage through the chemical heat storage material. In addition, the large amount of water vapor generated in the chemical heat storage material can evaporate and take away a large amount of heat, and then the heat transfer is further blocked through the heat-blocking layer, thereby inhibiting the occurrence of heat spread.

[0072] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including combining various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A heat sink, characterized in that: The heat sink (2) is arranged on the battery (1), and the heat sink (2) comprises a polymer layer (21) and a temperature control layer (22), and the polymer layer (21) is in contact with the battery (1).

2. The heat sink according to claim 1, characterized in that: The thickness of the polymer layer (21) is 0.1 to 3 mm.

3. The heat sink according to claim 1, characterized in that: The temperature control layer (22) comprises a porous heat-conducting skeleton layer and a chemical heat storage material, wherein the porous heat-conducting skeleton layer has pores, and the chemical heat storage material is filled in the pores.

4. The heat sink according to claim 3, characterized in that: The chemical heat storage material includes one of hydroxide, hydrated salt and chloride salt ammonia compound.

5. The heat sink according to claim 3 or 4, characterized in that: The chemical heat storage material includes one of magnesium hydroxide, calcium hydroxide, aluminum sulfate 18hydrate, magnesium sulfate heptahydrate, lanthanum chloride heptahydrate, barium hydroxide 8hydrate, CaCl2·NH3, BaCl2·NH3 and MnCl2·NH3.

6. The heat sink according to claim 3, characterized in that: The porous heat-conducting skeleton layer includes foam metal material or ceramic porous material.

7. The heat sink according to claim 3 or 6, characterized in that: The porous heat-conducting skeleton layer comprises one of foam copper, foam aluminum, foam nickel, porous alumina ceramic material and porous aluminum nitride ceramic material.

8. The heat sink according to claim 1 or 3, characterized in that: The thickness of the temperature control layer (22) is 0.1-10 mm.

9. A battery module, characterized in that: The battery module comprises a plurality of batteries (1), a heat insulation layer and a heat sink (2) according to any one of claims 1 to 8 are provided between two adjacent batteries (1), and the heat insulation layer (3) is in contact with the temperature control layer (22).

10. The battery module according to claim 9, characterized in that: Two heat sinks (2) are provided, and the heat insulation layer (3) is provided between the two heat sinks (2).

11. The battery module according to claim 9 or 10, characterized in that: The thickness of the heat insulation layer (3) is 0.1 to 15 mm.

12. The battery module according to claim 9 or 10, characterized in that: The thermal insulation layer (3) comprises aerogel or polyurethane foam.

13. A battery system, characterized in that: The battery system comprises the battery module according to any one of claims 9 to 12.

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