Cooling fin, cooling device and battery cell cooling method

Abstract

The invention relates to the technical field of lithium battery manufacturing, and discloses a cooling fin, a cooling device and a battery cell cooling method.The cooling fin comprises a body, the body is oppositely provided with a first plane and a second plane, and cooling holes are formed between the first plane and the second plane; the first plane and the second plane are recessed towards the direction of the heat dissipation holes to form a plurality of heat dissipation grooves. The surfaces of the main body, the heat dissipation holes and the heat dissipation grooves form a heat dissipation surface; and the heat radiation coating is coated on the heat dissipation surface and is used for enhancing heat radiation. The heat dissipation area is increased by forming the heat dissipation grooves in the first plane and the second plane of the main body and the heat dissipation holes located between the first plane and the second plane, and the heat dissipation effect of the heat dissipation fin is enhanced by coating the heat dissipation face with the heat dissipation coating, so that the heat dissipation efficiency of the heat dissipation fin is improved.

Description

Technical Field

[0001] The present application relates to the technical field of lithium battery manufacturing, and in particular to a heat sink, a heat dissipation device and a battery cell heat dissipation method. Background Art

[0002] During the laser welding process of the battery cell top cover, a large amount of heat is generated, which is usually absorbed by the positioning blocks on the upper and lower sides. However, the heat dissipation efficiency of the blocks is limited. If the heat cannot be dissipated quickly and efficiently, heat will be retained, causing the battery cell to swell, and even affecting the performance and life of the battery cell.

[0003] In order to improve the heat dissipation efficiency of the positioning block, the number of heat sinks is often increased to increase the heat dissipation area. However, due to the limitation of the internal space of the machine, too many heat sinks will increase the weight and installation area of ​​the entire positioning block, and cannot meet the installation requirements well. In addition, too much installation area will also make the internal heat dissipation space narrower, and the heat cannot be dissipated in time, which will lead to the rapid cooling of the battery cell when the positioning block is overheated. Summary of the invention

[0004] In order to solve the above-mentioned problems existing in the prior art, the present application provides a heat sink, a heat sink device and a battery cell heat dissipation method, which can improve the heat dissipation performance of the heat sink and the heat sink device.

[0005] This application provides the following technical solutions:

[0006] In a first aspect, the present application provides a heat sink, comprising:

[0007] The main body has a first plane and a second plane arranged opposite to each other, a heat dissipation hole is arranged between the first plane and the second plane; the first plane and the second plane are recessed toward the heat dissipation hole to form a plurality of heat dissipation grooves; the surfaces of the main body, the heat dissipation hole and the heat dissipation groove form a heat dissipation surface; and

[0008] The heat radiation coating is applied to the heat dissipation surface to enhance heat radiation.

[0009] In some implementations, the heat dissipation slots on the first plane and the heat dissipation slots on the second plane are arranged opposite to or staggered with each other.

[0010] In some implementations, the heat dissipation holes are disposed through the middle of the main body and extend to the top and bottom of the main body respectively.

[0011] In some implementations, the thermal radiation coating includes the following components by weight percentage: 40% to 60% of a resin base material, 20% to 40% of a nanofiller, 5% to 10% of a curing agent, and the balance is a solvent.

[0012] In some implementations, the thermal radiation coating has a layer thickness of 5 μm-15 μm.

[0013] In a second aspect, the present application provides a heat dissipation device, comprising:

[0014] A heat spreader having a contact surface and a connection surface opposite to each other, wherein the contact surface contacts the battery cell, and the heat spreader is used to conduct heat away from the battery cell; and

[0015] A plurality of heat sinks are arranged in parallel on the connection surface;

[0016] Wherein, the heat sink is the heat sink as mentioned above.

[0017] In some implementations, the vapor chamber further includes a heat conducting layer, and the heat conducting layer is coated on the contact surface.

[0018] In some implementations, the heat spreader further includes a groove and a coolant, the groove is disposed in the heat spreader, and the coolant flows in the groove.

[0019] In some implementations, the groove is a structure formed by a plurality of groove segments continuously penetrating each other, and both ends of the groove are connected to the outside;

[0020] The heat dissipation device further comprises a coolant control system, which is communicated with the groove and is used for flexibly controlling the coolant flowing in the groove according to the temperature of the heat dissipation device.

[0021] In a third aspect, the present application provides a method for heat dissipation of a battery cell, the method comprising:

[0022] Control the heat dissipation device to fit the laser-welded battery cell;

[0023] Acquiring temperature data and heat data of the battery cell through a monitor in the heat dissipation device;

[0024] Feeding back the temperature data and the heat data to a coolant control system, wherein the coolant control system determines the type of cooling fluid, the concentration of cooling fluid and the flow rate of cooling fluid selected for cooling the battery core according to a preset cooling scheme;

[0025] The heat dissipation device performs heat dissipation operation on the battery core according to the cooling fluid type, cooling fluid concentration and cooling fluid flow rate;

[0026] Wherein, the heat dissipation device is the heat dissipation device described above.

[0027] In summary, this application has at least the following benefits:

[0028] The heat sink, heat sink device and battery core heat dissipation method provided by the present application increase the heat dissipation area by providing a plurality of heat dissipation slots on the first plane and the second plane of the main body and heat dissipation holes between the first plane and the second plane, and enhance the heat radiation effect of the heat sink by coating the heat radiation coating on the heat dissipation surface, thereby improving the heat dissipation efficiency of the heat sink. In addition, the improvement of the heat dissipation efficiency of the heat sink can also reduce the number of heat sinks used in the heat dissipation device, ensure the internal heat dissipation space, and improve the heat dissipation effect of the heat sink on the battery core. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic diagram of the structure of the heat sink provided in Example 1 of the present application.

[0030] Figure 2 This is a schematic diagram of the structure of the heat dissipation device provided in Example 2 of the present application.

[0031] Figure 3 This is a schematic diagram of the structural cross-section of the heat spreader provided in Example 2 of the present application.

[0032] Markings in the figure:

[0033] 1. heat sink, 11. main body, 111. first plane, 112. second plane, 113. heat dissipation hole, 114. heat dissipation groove; 2. heat spreader, 21. contact surface, 22. connection surface, 23. thermal conductive layer, 24. groove, 241. groove section, 25. mounting hole. DETAILED DESCRIPTION

[0034] In order to facilitate the understanding of the present application, the present application will be described more comprehensively below in conjunction with the accompanying drawings and specific embodiments. The preferred embodiments of the present application are provided in the accompanying drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thoroughly and comprehensively understood.

[0035] Example 1

[0036] Please refer to Figure 1 The heat sink 1 of the present application includes a main body 11 and a heat radiation coating.

[0037] The main body 11 is relatively provided with a first plane 111 and a second plane 112, and a heat dissipation hole 113 is provided between the first plane 111 and the second plane 112; the first plane 111 and the second plane 112 are recessed toward the heat dissipation hole 113 to form a plurality of heat dissipation grooves 114; the surfaces of the main body 11, the heat dissipation holes 113 and the heat dissipation grooves 114 form a heat dissipation surface.

[0038] The heat dissipation holes 113 can increase the contact area between the inside of the main body 11 and the air, and the heat dissipation grooves 114 can increase the contact area between the two sides of the main body 11 and the air, thereby improving the air convection effect and effectively enhancing the heat exchange efficiency. On the other hand, by providing the heat dissipation holes 113 and the heat dissipation grooves 114, a part of the main body 11 is hollowed out, which can reduce the weight of the heat sink 1. Under the requirement of the same heat dissipation performance, the main body 11 is provided with heat dissipation holes 113, which not only increases the contact area with the air, improves the air convection effect, and effectively enhances the heat exchange efficiency, but also effectively reduces the weight of the heat sink 1, and can avoid using a large number of main bodies 11, so that the installation area is small, and the heat dissipation space is effectively increased, thereby achieving rapid cooling.

[0039] The thermal radiation coating is applied to the heat dissipation surface. Specifically, the thermal radiation coating is a cooling coating formed after the nano infrared thermal radiation coating is cured. The thermal radiation coating includes the following components by weight percentage: 40% to 60% of resin base material, 20% to 40% of nano filler, 5% to 10% of curing agent, and the balance is solvent, which can enhance the thermal radiation effect and thus improve heat dissipation.

[0040] The thickness of the thermal radiation coating is 5μm-15μm. The thermal radiation coating designed within this thickness range can ensure the stability of the nano-infrared thermal radiation coating after coating, thereby ensuring stable heat dissipation performance. If the thickness is less than 5μm, its heat dissipation capacity will be reduced, and it will be more susceptible to mechanical damage and environmental factors, resulting in reduced durability. In addition, too thin nano-infrared thermal radiation coatings cannot provide sufficient adhesion and are easy to fall off. If the thickness exceeds 15μm, the thermal resistance will increase, affecting the thermal conductivity effect. In addition, thick coatings may dry unevenly, and there may be areas inside that are not fully cured, affecting the overall performance.

[0041] The preparation method of the above nano infrared thermal radiation coating is as follows: add a certain amount of resin base material to a weighed solvent, stir in a 60°C water bath environment, and gradually dissolve the resin base material. Then add nano fillers, curing agents, etc., stir for a period of time, apply the prepared coating to the heat dissipation surface, and cure in a 70°C-80°C oven for 4-5 hours, or cure at room temperature for 24 hours to obtain a thermal radiation coating.

[0042] Specifically, the preparation components of the nano infrared thermal radiation coating are as follows:

[0043] The resin base material accounts for 40%-60% of the total content, and resins with high temperature resistance and good bonding properties are selected, such as epoxy resin, silicone resin, etc.

[0044] The solvent accounts for 10%-20% of the total content, such as n-butanol.

[0045] Nano fillers account for 20%-40% of the total content, and nano materials with high infrared radiation performance are selected, such as one or more of nano alumina, nano zirconium oxide, nano silicon carbide, and nano titanium dioxide. The differences in the various fillers make the infrared active bond vibration composite effect beneficial to infrared radiation, thereby beneficial to cooling. Preferably, the particle size range of nano alumina is 10nm-50nm. The particle size range of nano zirconium oxide is 20nm-100nm. The particle size range of nano silicon carbide is 30nm-500nm. The particle size range of nano titanium dioxide is 20nm-100nm.

[0046] Curing agent, accounting for 5%-10% of the total content.

[0047] The heat sink 1 in this embodiment is provided with a plurality of heat dissipation grooves 114 and heat dissipation holes 113 on the main body 11 to improve the air convection efficiency, and a heat radiation coating is coated on the heat dissipation surface to enhance the heat radiation effect. The combination of structural improvement and the addition of a heat radiation coating with enhanced heat radiation can greatly improve the heat dissipation performance. In addition, due to the provision of a plurality of heat dissipation grooves 114 and heat dissipation holes 113, the weight of the heat sink 1 can also be reduced, making it easier to install and use. Under the requirement of the same heat dissipation performance, it is possible to avoid using a large number of heat sinks 1, and the overall structure is compact, so that the installation area is small, and the heat dissipation space inside the machine is effectively increased, thereby realizing the function of rapid cooling of the battery cell.

[0048] In some embodiments, the heat dissipation slots 114 of the first plane 111 and the second plane 112 are arranged opposite or staggered. This arrangement can be implemented according to the design requirements of the specific heat sink 1 to increase the heat dissipation area and meet customer needs, with high flexibility.

[0049] In some embodiments, the heat dissipation holes 113 are arranged through the middle of the main body 11, and extend respectively to the top and bottom of the main body 11. With this arrangement, the heat dissipation holes 113 are arranged in the middle of the main body 11, which can improve the uniformity of heat dissipation and facilitate rapid heat dissipation; and the heat dissipation holes 113 extend to the top and bottom of the main body 11, and the size of the heat dissipation holes 113 can be designed to be wide, thereby increasing the contact area with the air, increasing the convection rate, and improving the heat dissipation efficiency.

[0050] Embodiment 2:

[0051] See also Figure 2 The heat dissipation device of the present application includes a heat spreader 2 and a plurality of heat sinks 1.

[0052] The heat spreader 2 is provided with a contact surface 21 and a connection surface 22 opposite to each other. The contact surface 21 is in contact with the battery cell. The heat spreader 2 is used to conduct heat away from the battery cell.

[0053] A plurality of heat sinks 1 are arranged in parallel on the connection surface 22, wherein the heat sink 1 is the above-mentioned heat sink 1. Arranging the plurality of heat sinks 1 at a specified interval can effectively increase the contact area with the air and improve the heat dissipation efficiency.

[0054] The relationship between the number, height, thickness, spacing, etc. of the heat sink 1 and the overall heat dissipation performance of the heat dissipation device in this embodiment can be estimated based on the formula of convection heat dissipation: Q = h × A × (T1-T2), where Q is the heat dissipation (W), h is the heat transfer coefficient (W / m2·K), A is the heat dissipation area (m2), T1 is the heat source temperature (K), T2 is the ambient temperature (K), and T1-T2 is the temperature difference between the heat source temperature (K) and the ambient temperature (K). Heat dissipation area A = L × (N × τ + B × (N-1)), where L is the length of the base of the heat sink 1 (m), N is the number of heat sinks 1, τ is the thickness of the heat sink 1 (m), and B is the spacing between the heat sinks 1 (m). In combination with the heat dissipation device of the present application, formulas can be used to evaluate and optimize the heat dissipation performance of the heat sink 1 assembly under different parameter combinations, such as the number, height, thickness, spacing, etc. of the heat sink 1. The optimal parameter combination can be obtained based on the results, and then the shape, size and quantity of the heat sink 1 can be designed to achieve the best heat dissipation performance.

[0055] In the heat dissipation device of this embodiment, the battery cell contacts the contact surface 21, and the heat of the battery cell is conducted from the contact surface 21 to the connection surface 22, so that the heat can be better conducted to the heat sink 1, avoiding heat retention and causing the battery cell to swell, and effectively ensuring the quality of the battery cell. Then, multiple heat sinks 1 are used to increase the contact area with the air, improve the air convection effect, enhance the heat exchange efficiency, and then quickly dissipate the heat into the air. Since the heat dissipation performance of a single heat sink 1 is good, when the same heat dissipation performance is required, a smaller number of heat sinks 1 can be used in this application, so that the overall installation area is small, thereby increasing the heat dissipation space and realizing the function of rapid cooling.

[0056] In addition, mounting holes 25 are provided at the corners of the heat spreader 2, and conventional fasteners are used to fix the pressing block at the mounting hole 25 to ensure that the pressing block is positioned during the laser welding process of the battery cell top cover to ensure welding stability.

[0057] In some embodiments, the heat spreader 2 also includes a thermal conductive layer 23, which is coated on the contact surface 21. Preferably, the thermal conductive layer 23 is a thermal conductive layer 23 formed by thermal conductive silicone grease. The thermal conductive layer 23 can more effectively transfer the heat of the battery cell to the heat spreader 2, thereby achieving rapid heat dissipation of the battery cell. Specifically, the coating thickness of the thermal conductive silicone grease is 0.01mm-0.2mm, which can ensure that the thermal conductive silicone grease is evenly coated on the tiny gaps on the heat spreader 2, so that the heat spreader 2 is evenly heated and effectively provides thermal conductivity. If the coating thickness of the thermal conductive silicone grease exceeds 0.2mm, the thermal resistance of the heat spreader 2 will increase, reducing the heat dissipation efficiency.

[0058] The preparation method of the above-mentioned thermal grease is: put the basic silicone oil, auxiliary additives and structural improvers in a blender in proportion for preliminary mixing to ensure that all ingredients are evenly distributed, put the obtained premix into a grinder, add thermal conductive filler and grind it, and stir and mix the ground mixture again. During the mixing process, the bubbles in the mixture need to be removed by a vacuum degassing machine, and finally the large particles and impurities that are not fully ground can be removed by a filtering device.

[0059] Specifically, the preparation components of thermal conductive silicone grease are as follows:

[0060] The base silicone oil accounts for 30%-50% of the total content. As the carrier of silicone grease, silicone oil with moderate viscosity and good chemical stability is usually selected.

[0061] The thermal conductive filler accounts for 50%-70% of the total content, and the thermal conductive filler can be one or more of aluminum oxide, aluminum nitride, silicon carbide, and diamond powder.

[0062] The structure improver accounts for 5%-10% of the total content. The structure improver can be a silicone resin. The structure of the silicone resin contains both "organic groups" and "inorganic structures". This special composition and molecular structure makes it combine the characteristics of organic matter with the functions of inorganic matter. When the structure improver is a silicone resin, the mechanical properties and viscosity of the silicone grease can be improved.

[0063] The auxiliary additives account for 1%-5% of the total content. The auxiliary additives may be one or more of antioxidants, anti-settling agents, and tackifiers, and are used to improve the specific properties of silicone grease.

[0064] The ratio of the above basic raw materials can be flexibly adjusted according to the performance of the prepared thermal conductive silicone grease, and the specific optimal ratio can be verified by actual performance testing and adjusting the raw material ratio, which is not limited in this application. The performance targets include thermal conductivity, thermal stability, mechanical properties, compatibility with contact materials, and mechanical properties such as viscosity, elasticity, yield stress, etc.

[0065] The heat conducting layer 23 in this embodiment facilitates the rapid conduction of the heat of the battery cell to the heat spreader 2 , effectively avoiding the retention of heat in the battery cell, thereby ensuring the performance and life of the battery cell.

[0066] In some embodiments, see Figure 3 The heat spreader 2 also includes a groove 24 and a coolant.

[0067] The groove 24 is provided in the heat spreader 2. The groove 24 is a structure formed by a plurality of groove sections 241 that are continuously connected, and both ends of the groove sections 241 are connected to the outside. The groove sections 241 can be U-shaped groove sections, V-shaped groove sections, or straight groove sections, and can be flexibly arranged according to customer needs, and this application does not limit this.

[0068] Preferably, the groove section 241 adopts a U-shaped groove section, which can form a more uniform pressure distribution in the cooling fluid, making the fluid flow more uniform and improving the cooling efficiency; secondly, it can increase the contact area between the fluid and the solid surface, and the structural strength is high; finally, it helps to guide the fluid to form a more stable laminar flow inside the groove 24, reduce the generation of turbulence and eddy currents, and reduce the fluid flow resistance.

[0069] The coolant flows in the groove 24 to quickly cool the heat sink. The heat sink also includes a coolant control system, which is connected to the groove 24 and is used to flexibly control the coolant flowing in the groove 24 according to the temperature of the heat sink. The coolant is injected into the groove 24 through an external coolant control system and flows in the groove 24.

[0070] In the coolant control system, the type, concentration, flow rate, etc. of the coolant can be automatically adjusted according to the temperature change and the amount of heat generated. The circulation of the coolant can be controlled in a closed loop by a control program, specifically, data collection is performed on the temperature of the heat spreader 2, and the collected data is analyzed to determine the type, concentration and flow rate of the coolant, and the corresponding coolant is injected into the groove 24, while the heat dissipation effect is monitored and fed back in real time to achieve closed loop control.

[0071] The above data collection can be performed by installing a temperature sensor on one side of the heat spreader 2 and a thermocouple, thermistor or other type of sensor on the other side to monitor temperature changes and heat size.

[0072] The above-mentioned coolant execution is first transmitted to the coolant control system through the monitored data, and then the coolant control system sets different cooling schemes according to the preset temperature threshold and heat level, determines the type, concentration, and flow rate of the required cooling fluid, and finally controls the execution of the scheme. Specifically, the coolant control system is designed as a multi-channel cooling fluid supply system, each channel is equipped with a valve, and the coolant control system adjusts the switch of each valve according to the cooling scheme, and supplies different types of cooling fluids into the groove 24 in the heat spreader 2. For the concentration adjustment, an injection pump can be used to accurately control the flow rate. The cooling fluid can be water, ethylene glycol solution, cold air, etc.

[0073] The above monitoring feedback is to monitor the heat dissipation effect after adjustment in real time, and optimize and adjust the type, concentration and flow rate of the coolant according to historical data to achieve the best cooling effect and realize closed-loop control.

[0074] In this embodiment, the groove 24 and the coolant cooperate with each other to achieve rapid cooling of the heat dissipation device. That is, when the temperature is too high, the coolant is introduced into the groove 24, and the coolant transfers and cools the heat of the heat dissipation device, thereby achieving rapid cooling of the heat dissipation device and greatly improving the heat dissipation efficiency.

[0075] Embodiment 3:

[0076] Based on the above embodiments, this embodiment provides a method for cooling the battery cell, including controlling the heat dissipation device to fit the battery cell after laser welding; obtaining the temperature data and heat data of the battery cell through the monitor in the heat dissipation device; feeding back the temperature data and heat data to the coolant control system, and the coolant control system determines the type of cooling fluid, the concentration of cooling fluid and the flow rate of cooling fluid selected for cooling the battery cell according to the preset heat dissipation scheme; the heat dissipation device performs heat dissipation operations on the battery cell according to the type of cooling fluid, the concentration of cooling fluid and the flow rate of cooling fluid. Among them, the heat dissipation device can be the heat dissipation device mentioned in any of the above embodiments, and the specific structure and setting method will not be repeated here.

[0077] The battery cell heat dissipation method in this embodiment generates a large amount of heat during the laser welding process of the battery cell top cover. The heat in the battery cell can be transferred to the heat dissipation device through the contact between the battery cell and the heat dissipation device, thereby avoiding heat retention in the battery cell, accelerating the heat dissipation of the battery cell, avoiding battery cell swelling, and effectively ensuring the performance and life of the battery cell.

[0078] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be an intermediate element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element at the same time.

[0079] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0080] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0081] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0082] The above contents are merely examples and explanations of the structure of the present application, and the descriptions are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present application, and these obvious replacement forms all belong to the protection scope of the present application.

Claims

1. A heat sink, characterized in that: include: The main body (11) is provided with a first plane (111) and a second plane (112) opposite to each other, a heat dissipation hole (113) is provided between the first plane (111) and the second plane (112); the first plane (111) and the second plane (112) are recessed in the direction of the heat dissipation hole (113) to form a plurality of heat dissipation grooves (114); the surfaces of the main body (11), the heat dissipation hole (113) and the heat dissipation grooves (114) form a heat dissipation surface; as well as The heat radiation coating is applied to the heat dissipation surface to enhance heat radiation.

2. The heat sink according to claim 1, characterized in that: The heat dissipation grooves (114) of the first plane (111) and the second plane (112) are arranged opposite to or staggered with each other.

3. The heat sink according to claim 1, characterized in that: The heat dissipation hole (113) is arranged through the middle of the main body (11) and extends to the top and bottom of the main body (11) respectively.

4. The heat sink according to claim 1, characterized in that: The heat radiation coating comprises the following components by weight percentage: 40% to 60% of a resin base material, 20% to 40% of a nano filler, 5% to 10% of a curing agent, and the balance is a solvent.

5. The heat sink according to claim 1, characterized in that: The thickness of the heat radiation coating is 5 μm-15 μm.

6. A heat dissipation device, characterized in that: include: A heat spreader (2) is provided with a contact surface (21) and a connection surface (22) opposite to each other, the contact surface (21) is used to contact the battery cell, and the heat spreader (2) is used to conduct heat from the battery cell; and A plurality of heat sinks (1) are arranged in parallel on the connection surface (22); Wherein, the heat sink (1) is the heat sink (1) according to any one of claims 1 to 5.

7. The heat dissipation device according to claim 6, characterized in that: The heat sink (2) further comprises a heat conducting layer (23), wherein the heat conducting layer (23) is coated on the contact surface (21).

8. The heat dissipation device according to claim 6, characterized in that: The heat spreader (2) further comprises a groove (24) and a cooling liquid. The groove (24) is arranged inside the heat spreader (2), and the cooling liquid flows in the groove (24).

9. The heat dissipation device according to claim 8, characterized in that: The groove (24) is a structure formed by a plurality of groove segments (241) that are continuously connected, and both ends of the groove are connected to the outside. The heat dissipation device further comprises a coolant control system, which is in communication with the groove (24) and is used to flexibly control the coolant flowing in the groove (24) according to the temperature of the heat dissipation device.

10. A method for dissipating heat from a battery cell, characterized in that: The method comprises: Control the heat dissipation device to fit the laser-welded battery cell; Acquiring temperature data and heat data of the battery cell through a monitor in the heat dissipation device; Feeding back the temperature data and the heat data to a coolant control system, wherein the coolant control system determines the type of cooling fluid, the concentration of cooling fluid and the flow rate of cooling fluid selected for cooling the battery core according to a preset cooling scheme; The heat dissipation device performs heat dissipation operation on the battery core according to the cooling fluid type, cooling fluid concentration and cooling fluid flow rate; Wherein, the heat dissipation device is the heat dissipation device as described in any one of claims 6-9.

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