Composite heat dissipation device for lithium ion battery

Abstract

The utility model relates to the technical field of lithium ion batteries, in particular to a composite heat dissipation device of a lithium ion battery, which comprises a shell component, a composite heat conduction component, a micro-channel liquid cooling component and an air cooling strengthening component, the shell component is a closed cavity formed by an aluminum alloy base shell and a carbon fiber top cover, and a honeycomb heat dissipation groove is arranged on the bottom surface of the aluminum alloy base shell. The top cover is provided with a vent hole array; the composite heat conduction assembly is embedded in the honeycomb-shaped heat dissipation groove of the aluminum alloy base shell and used for heat conduction of the aluminum alloy base shell. The micro-channel liquid cooling assembly is composed of a liquid cooling copper pipe and a micro circulating pump, and the liquid cooling copper pipe penetrates through the composite heat conduction assembly and forms a distance with the contact surface of the lithium ion battery. According to the utility model, high-efficiency composite heat dissipation is realized, a stable and reliable heat dissipation guarantee is provided for the lithium ion battery, and the strict requirement of the lithium ion battery on heat dissipation during high-power operation is met.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium-ion batteries, in particular to a composite heat dissipation device for lithium-ion batteries. Background Art

[0002] Lithium-ion batteries, with their high energy density and long cycle life, are widely used in a wide range of fields, including electric vehicles and portable electronic devices. However, the charge and discharge process inevitably generates heat, which, if not dissipated effectively and promptly, can lead to a series of problems. With the continuous increase in battery energy density and the increasing complexity of usage scenarios, the problem of battery heat dissipation has become increasingly prominent. Excessive temperatures accelerate chemical reactions within the battery, causing increased capacity degradation and shortening the battery life. Furthermore, localized overheating can trigger thermal runaway, an extremely dangerous condition that can cause the battery to catch fire or explode, posing a serious threat to personal and property safety.

[0003] Traditional heat dissipation methods, such as natural heat dissipation and simple air cooling, have limited heat dissipation efficiency when dealing with high-power, large-capacity lithium-ion battery systems. Therefore, a new design is needed to address the heat dissipation of existing lithium-ion batteries. Utility Model Content

[0004] To solve the above problems, the utility model provides a lithium-ion battery composite heat dissipation device, which realizes efficient composite heat dissipation, provides stable and reliable heat dissipation guarantee for lithium-ion batteries, and meets the strict heat dissipation requirements of lithium-ion batteries when operating at high power.

[0005] The technical solution adopted by the present invention is: a composite heat dissipation device for lithium-ion batteries, comprising a shell component, a composite heat-conducting component, a microchannel liquid cooling component and an air-cooling strengthening component, wherein the shell component is composed of an aluminum alloy base shell and a carbon fiber top cover to form a closed cavity, the bottom surface of the aluminum alloy base shell is provided with a honeycomb heat dissipation groove, and the carbon fiber top cover is provided with an array of ventilation holes; the composite heat-conducting component is embedded in the honeycomb heat dissipation groove of the aluminum alloy base shell to conduct heat from the aluminum alloy base shell; the microchannel liquid cooling component is composed of a liquid-cooling copper tube and a micro-circulation pump, the liquid-cooling copper tube passes through the honeycomb heat dissipation groove and is connected to the composite heat-conducting component; the air-cooling strengthening component comprises an axial fan and a deflector, and the deflector is provided with a conical air flow channel matching the ventilation hole array; wherein the composite heat-conducting component and the microchannel liquid cooling component are arranged orthogonally, and the contact surface between the two is coated with a boron nitride heat-conducting layer; The composite heat-conducting component includes a sealed aluminum box, a graphene sheet is arranged inside the sealed aluminum box, and a dovetail insert is arranged outside the sealed aluminum box, and the dovetail insert is used to match the liquid-cooling copper tube.

[0006] A further improvement to the above solution is that the depth to width ratio of the honeycomb heat dissipation groove is 1.2:1, and support ribs with a 60° angle are formed between adjacent groove bodies, and the surface of the support ribs is provided with an aluminum hydrophobic coating.

[0007] A further improvement to the above solution is that the ventilation hole array is a gradient ventilation hole array, which includes at least three groups of holes with different apertures, arranged at different densities along the battery arrangement direction, wherein the area with the largest aperture corresponds to the heat accumulation area of the battery module.

[0008] A further improvement to the above solution is that a trapezoidal protrusion is provided on the top of the sealed aluminum box, and the trapezoidal protrusion is used to fit in the honeycomb heat dissipation groove in a wedge shape.

[0009] A further improvement to the above solution is that a plurality of graphene sheets are provided, and the plurality of graphene sheets are arranged at an angle of 45° on the inner wall of the sealed aluminum box.

[0010] A further improvement to the above solution is that the end layer of the graphene sheet extends outside the sealed aluminum box and forms a limiting indentation, and the boron nitride thermal conductive layer is fixed to the limiting indentation by plasma sintering.

[0011] A further improvement to the above solution is that the guide cover is provided with a guide plate, and the guide plate is provided with a texture groove, which extends radially along the guide plate and has a depth dimension with a gradient change of 0.05mm~0.2mm.

[0012] A further improvement to the above solution is that the shell assembly is provided with a heat conductive tape at the carbon fiber top cover, and the heat conductive tape includes a copper foil substrate, a transition layer sprayed on the copper foil substrate, and a contact layer coated on the transition layer.

[0013] A further improvement to the above solution is that the air deflector is provided with a sliding track, the air deflector is connected to the shell assembly through the sliding track, and a locking element is provided on the sliding track to lock and fix the air deflector on the sliding track.

[0014] The beneficial effects of the utility model are:

[0015] Compared with existing battery heat dissipation, the present invention, from the perspective of the shell assembly, is a closed cavity composed of an aluminum alloy base shell and a carbon fiber top cover, which fully combines the good thermal conductivity of aluminum alloy and the lightweight and high strength characteristics of carbon fiber. The honeycomb heat dissipation grooves set on the bottom surface of the aluminum alloy base shell greatly increase the heat dissipation area. According to the principle of heat transfer, the larger heat dissipation area can more efficiently transfer the heat generated by the battery to the external environment. The array of ventilation holes opened on the carbon fiber top cover not only ensures the circulation of internal and external air, creating conditions for air-cooled heat dissipation, but also reduces the weight of the entire device while ensuring structural strength, which helps to improve the portability and overall performance of the battery system. The composite heat-conducting component is embedded in the honeycomb heat dissipation grooves of the aluminum alloy base shell, which can effectively utilize the advantages of the honeycomb structure and further enhance the thermal conductivity of the aluminum alloy base shell. Through the tightly fitting design, the heat generated by the battery is quickly transferred to the entire aluminum alloy base shell, making the heat distribution more uniform and avoiding the occurrence of local overheating, thereby improving the safety and stability of the battery and extending the battery life. The microchannel liquid cooling assembly's copper tubes penetrate the composite thermal conductive component, creating a gap between them and the lithium-ion battery contact surface. This ensures that the coolant circulates within the tubes to remove heat while maintaining a suitable distance from the battery contact surface, preventing potential damage to the battery due to direct contact. A micro-circulation pump ensures continuous and stable coolant circulation within the tubes, achieving efficient liquid cooling and heat dissipation.

[0016] The axial fan and shroud in the enhanced air cooling assembly work together to further enhance heat dissipation efficiency. The airflow generated by the axial fan passes through tapered air channels on the shroud, which match the vent array, creating a directed and concentrated airflow that quickly removes internal heat from the device. The tapered air channel design optimizes the airflow path, reduces resistance and turbulence, and enhances the air cooling effect. The composite thermal conductive assembly and microchannel liquid cooling assembly are arranged orthogonally, and the contact surface is coated with a boron nitride thermal conductive layer, enhancing the synergy between the two heat dissipation methods. This orthogonal arrangement allows heat to be transferred and dissipated more efficiently in different directions, preventing heat accumulation in a single area. The boron nitride thermal conductive layer has an extremely high thermal conductivity, further improving the thermal conductivity between the two components and ensuring rapid heat transfer between the composite thermal conductive assembly and the microchannel liquid cooling assembly, thereby achieving efficient combined heat dissipation. This provides stable and reliable heat dissipation for lithium-ion batteries, meeting the stringent heat dissipation requirements of lithium-ion batteries during high-power operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of an explosion of the lithium-ion battery composite heat dissipation device of the utility model;

[0018] Figure 2 for Figure 1 Explosion diagram of the composite heat dissipation device for lithium-ion batteries from another perspective;

[0019] Figure 3 for Figure 1 Explosion diagram of the composite heat dissipation device for lithium-ion batteries from another perspective;

[0020] Figure 4 for Figure 3 A is an enlarged schematic diagram;

[0021] Figure 5 for Figure 1 Schematic diagram of the structure of the thermal conductive belt of the composite heat dissipation device for lithium-ion batteries.

[0022] Explanation of the reference numerals: shell assembly 1, aluminum alloy base shell 11, carbon fiber top cover 12, enclosed cavity 13, honeycomb heat dissipation groove 14, support ribs 141, ventilation hole array 15, thermal conductive belt 16, copper foil substrate 161, transition layer 162, contact layer 163, composite thermal conductive component 2, sealed aluminum box 21, dovetail insert 211, trapezoidal protrusion 212, graphene sheet 22, microchannel liquid cooling component 3, liquid cooling copper tube 31, micro circulation pump 32, air cooling enhancement component 4, axial flow fan 41, air guide cover 42, air guide plate 421, textured groove 422, sliding rail 423, locking element 424, conical air flow channel 43. DETAILED DESCRIPTION

[0023] To facilitate understanding of the present invention, a more comprehensive description of the present invention will be provided below with reference to the accompanying drawings. The drawings illustrate preferred embodiments of the present invention. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to facilitate a more thorough and comprehensive understanding of the disclosure of the present invention.

[0024] 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 referred to as being “connected to” another element, it may be directly connected to the other element or there may be an intermediate element.

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0026] like Figures 1 to 5As shown, in one embodiment of the present invention, a composite heat dissipation device for lithium-ion batteries is provided, comprising a housing assembly 1, a composite heat-conducting assembly 2, a microchannel liquid cooling assembly 3, and an air-cooling strengthening assembly 4. The housing assembly 1 is composed of an aluminum alloy base shell 11 and a carbon fiber top cover 12 to form a closed cavity 13. The bottom surface of the aluminum alloy base shell 11 is provided with a honeycomb heat dissipation groove 14, and the carbon fiber top cover 12 is provided with a ventilation hole array 15; the composite heat-conducting assembly 2 is embedded in the honeycomb heat dissipation groove 14 of the aluminum alloy base shell 11. 4, for heat conduction from the aluminum alloy base shell 11; the microchannel liquid cooling assembly 3 is composed of a liquid cooling copper tube 31 and a micro-circulation pump 32. The liquid cooling copper tube 31 extends through the honeycomb heat dissipation grooves 14 and connects to the composite heat conduction assembly 2; the air cooling enhancement assembly 4 includes an axial fan 41 and a shroud 42, the shroud 42 having a tapered air flow channel 43 that matches the vent array 15; the composite heat conduction assembly 2 and the microchannel liquid cooling assembly 3 are arranged orthogonally, and the contact surface between them is coated with a boron nitride thermal conductive layer. In this embodiment, the housing assembly 1, through a sealed cavity 13 formed by the aluminum alloy base shell 11 and the carbon fiber top cover 12, fully combines the excellent thermal conductivity of aluminum alloy with the lightweight and high strength of carbon fiber. The honeycomb heat dissipation grooves 14 provided on the bottom surface of the aluminum alloy base shell 11 greatly increase the heat dissipation area. According to the principle of heat transfer, the larger heat dissipation area can more efficiently transfer the heat generated by the battery to the external environment. The array of ventilation holes 15 formed in the carbon fiber top cover 12 not only ensures internal and external air circulation, creating conditions for air cooling and heat dissipation, but also reduces the weight of the entire device while maintaining structural strength, helping to improve the portability and overall performance of the battery system. The composite thermal conductive component 2 is embedded in the honeycomb-shaped heat dissipation grooves 14 of the aluminum alloy base shell 11, effectively leveraging the advantages of the honeycomb structure and further enhancing the thermal conductivity of the aluminum alloy base shell 11. Through its tightly fitting design, heat generated by the battery is quickly transferred to the entire aluminum alloy base shell 11, making the heat distribution more uniform and avoiding local overheating, thereby improving the safety and stability of the battery and extending its service life. The liquid cooling copper tube 31 of the microchannel liquid cooling assembly 3 passes through the composite thermal conductive component 2 and forms a gap between the contact surface of the lithium-ion battery. This layout ensures that the coolant circulates within the liquid cooling copper tube 31 to remove heat, while also maintaining an appropriate distance from the battery contact surface to avoid damage to the battery due to direct contact. The provision of the micro-circulation pump 32 ensures that the coolant can circulate continuously and stably in the liquid-cooling copper tube 31 , thereby achieving an efficient liquid-cooling heat dissipation effect.

[0027] In this embodiment, the axial flow fan 41 and the air guide cover 42 in the air cooling enhancement component 4 work together to further improve the heat dissipation efficiency. The airflow generated by the axial flow fan 41 passes through the conical airflow channel 43 on the air guide cover 42 that matches the ventilation hole array 15, forming a directional and concentrated airflow, which can quickly bring the internal heat out of the device. The design of the conical airflow channel 43 optimizes the flow path of the airflow, reduces the resistance and turbulence of the airflow, and makes the air cooling effect more significant. The composite thermal conductive component 2 and the microchannel liquid cooling component 3 are arranged orthogonally and the contact surface is coated with a boron nitride thermal conductive layer, which enhances the synergy between the two heat dissipation methods. The orthogonal arrangement enables heat to be more effectively transferred and dissipated in different directions, avoiding heat accumulation in a certain area. The boron nitride thermal conductive layer has an extremely high thermal conductivity coefficient, which can further improve the heat conduction efficiency between the two components, ensuring that heat can be quickly transferred between the composite thermal conductive component 2 and the microchannel liquid cooling component 3, thereby achieving efficient composite heat dissipation, providing stable and reliable heat dissipation guarantee for lithium-ion batteries, and meeting the strict heat dissipation requirements of lithium-ion batteries when operating at high power.

[0028] In the above embodiment, the composite structure of the aluminum alloy base shell 11 and the carbon fiber top cover 12 reduces the device's weight while improving overall structural strength. Combined with the three-dimensionally expanded surface of the honeycomb-shaped heat dissipation grooves 14, the effective heat dissipation area reaches 2.8 times that of a conventional flat-plate structure. The orthogonal arrangement of the composite heat-conducting assembly 2 and the microchannel liquid cooling assembly 3 creates a multi-dimensional heat conduction path. The boron nitride heat-conducting layer reduces the interfacial thermal resistance to 18% of that of conventional silicone grease materials. The tapered airflow channels 43 of the air-cooling assembly improve convective heat transfer efficiency by 40%.

[0029] See Figures 2 to 4 As shown, the honeycomb heat dissipation grooves 14 have a depth-to-width ratio of 1.2:1, and adjacent groove bodies form support ribs 141 at a 60° angle. The surface of the support ribs 141 is provided with an aluminum hydrophobic coating. In this embodiment, the triangular stabilization structure of the 60° support ribs 141 improves the bending strength of the shell. The proportional design of the honeycomb groove depth and width maximizes the heat dissipation surface area while maintaining structural rigidity. The super-hydrophobic properties of the aluminum hydrophobic coating shorten the contact time of water droplets on the surface, extending the service life of the device.

[0030] The ventilation hole array 15 is a gradient ventilation hole array 15, which includes at least three groups of holes with different apertures, arranged at different densities along the battery arrangement direction, wherein the area with the largest aperture corresponds to the heat accumulation area of the battery module. In this embodiment, the three-stage aperture design of the gradient ventilation holes increases the airflow velocity in the high-heat area and maintains a balanced flow velocity of 6m / s in the low-heat area. The staggered arrangement of the hole groups effectively suppresses the generation of vortices and reduces the airflow pressure loss. Combined with the flow field reconstruction technology of the internal guide boss, the temperature uniformity index of the battery pack is improved and the area of the temperature peak area is reduced.

[0031] The composite thermally conductive component 2 comprises a sealed aluminum box 21, within which a graphene sheet 22 is positioned. A dovetail insert 211 is positioned on the outside of the sealed aluminum box 21, which is adapted to mate with a liquid-cooled copper tube 31. In this embodiment, the mechanical interlocking structure of the dovetail insert 211 stabilizes the contact pressure between the liquid-cooled copper tube 31 and the composite thermally conductive component 2 within a certain range, reducing fluctuations in the contact thermal resistance. The three-dimensional network of graphene sheets 22 enhances the thermal conductivity of the phase change material and accelerates the release of latent heat.

[0032] The top of the sealed aluminum box 21 is provided with a trapezoidal protrusion 212, which is designed to wedge into the honeycomb-shaped heat dissipation groove 14. In this embodiment, the wedge-shaped fit of the trapezoidal protrusion 212 creates assembly preload, eliminating microscopic gaps on the contact surface. The internal reinforcement ribs of the trapezoidal protrusion 212 enhance shear strength, keeping displacement within ±0.05mm during vibration testing. The titanium nitride coating on the mating surface reduces the coefficient of friction, maintaining over 90% thermal conductivity after 500 assembly and disassembly cycles.

[0033] A plurality of graphene sheets 22 are provided, and the plurality of graphene sheets 22 are arranged at a 45° angle on the inner wall of the sealed aluminum box 21. Specifically, the end layer of the graphene sheet 22 extends outside the sealed aluminum box 21 and forms a limiting indentation, and the boron nitride thermal conductive layer is fixed to the limiting indentation by plasma sintering. In this embodiment, the bionic fishbone structure formed by the 45° inclination of the graphene sheets 22 increases the axial heat flow conduction speed and enhances the lateral heat diffusion capacity. The limiting indentation design limits the graphene displacement to within ±0.03mm.

[0034] The deflector 42 is provided with a deflector plate 421, which is provided with a textured groove 422. The textured groove 422 extends radially along the deflector plate 421 and has a gradient depth of 0.05 mm to 0.2 mm. In this embodiment, the optimized flow-guiding design of the gradient-depth textured groove 422 reduces the thickness of the airflow boundary layer and lowers surface friction resistance.

[0035] See Figure 5 As shown, the housing assembly 1 is provided with a heat conductive tape 16 located on the carbon fiber top cover 12. The heat conductive tape 16 comprises a copper foil substrate 161, a transition layer 162 sprayed onto the copper foil substrate 161, and a contact layer 163 coated onto the transition layer 162. In this embodiment, the aluminum nitride transition layer 162 reduces the electrochemical corrosion rate and, combined with the flexible support structure of the copper foil substrate 161, maintains a complete heat conduction path under a certain degree of thermal expansion and deformation. The contact layer 163 is used to contact the carbon fiber top cover 12.

[0036] The air deflector 42 is provided with a sliding track 423, which connects the air deflector 42 to the housing assembly 1. The sliding track 423 is provided with a locking element 424 to lock the air deflector 42 to the sliding track 423. In this embodiment, the precise guide structure of the sliding track 423 enables stepless position adjustment of the air deflector 42. The locking element 424 secures the air deflector 42, making adjustment convenient and the structure stable.

[0037] The above embodiments merely illustrate several implementations of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the concept of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A composite heat dissipation device for lithium-ion batteries, characterized in that: include: A housing assembly, wherein the housing assembly comprises an aluminum alloy base shell and a carbon fiber top cover forming a sealed cavity, wherein the bottom surface of the aluminum alloy base shell is provided with honeycomb-shaped heat dissipation grooves, and the carbon fiber top cover is provided with an array of ventilation holes; A composite heat-conducting component, wherein the composite heat-conducting component is embedded in the honeycomb heat dissipation groove of the aluminum alloy base shell to conduct heat to the aluminum alloy base shell; A microchannel liquid cooling assembly, the microchannel liquid cooling assembly consisting of a liquid cooling copper tube and a micro circulation pump, the liquid cooling copper tube passing through the honeycomb heat dissipation groove and connected to the composite heat conduction assembly; and An air-cooling enhancement component, the air-cooling enhancement component comprising an axial flow fan and a shroud, the shroud being provided with a tapered air flow channel matching the vent array; Among them, the composite thermal conductive component and the microchannel liquid cooling component are arranged orthogonally, and the contact surfaces of the two are coated with a boron nitride thermal conductive layer; the composite thermal conductive component includes a sealed aluminum box, a graphene sheet is arranged inside the sealed aluminum box, and a dovetail insert is arranged outside the sealed aluminum box, and the dovetail insert is used to match the liquid cooling copper tube.

2. The lithium-ion battery composite heat dissipation device according to claim 1, characterized in that: The depth-to-width ratio of the honeycomb heat dissipation grooves is 1.2:1, and support ribs with a 60° angle are formed between adjacent groove bodies. The surface of the support ribs is provided with an aluminum hydrophobic coating.

3. The lithium-ion battery composite heat dissipation device according to claim 1, characterized in that: The ventilation hole array is a gradient ventilation hole array, which includes at least three groups of holes with different apertures, arranged with different densities along the battery arrangement direction, wherein the area with the largest aperture corresponds to the heat accumulation area of the battery module.

4. The lithium-ion battery composite heat dissipation device according to claim 1, characterized in that: A trapezoidal convex block is provided on the top of the sealed aluminum box, and the trapezoidal convex block is used to fit in the honeycomb heat dissipation groove.

5. The lithium-ion battery composite heat dissipation device according to claim 4, characterized in that: The graphene sheets are provided in plurality, and the graphene sheets are arranged at an angle of 45° on the inner wall of the sealed aluminum box.

6. The lithium-ion battery composite heat dissipation device according to claim 5, characterized in that: The end layer of the graphene sheet extends outside the sealed aluminum box and forms a limiting indentation.

7. The lithium-ion battery composite heat dissipation device according to claim 1, characterized in that: The deflector cover is provided with a deflector plate, and the deflector plate is provided with a texture groove. The texture groove extends along the radial direction of the deflector plate, and the depth dimension changes gradually from 0.05 mm to 0.2 mm.

8. The lithium-ion battery composite heat dissipation device according to claim 1, characterized in that: The shell component is provided with a heat conducting belt at the carbon fiber top cover. The heat conducting belt includes a copper foil substrate, a transition layer sprayed on the copper foil substrate, and a contact layer coated on the transition layer.

9. The lithium-ion battery composite heat dissipation device according to claim 1, characterized in that: The air deflector is provided with a sliding track, and the air deflector is connected to the housing assembly through the sliding track. A locking element is provided on the sliding track to lock and fix the air deflector on the sliding track.

Images