High-efficiency heat-dissipation explosion-proof lithium ion battery pack

Abstract

The application discloses a high-efficiency heat-dissipation explosion-proof lithium ion battery pack, which comprises a multifunctional frame body, a heat-dissipation structure and a battery pack; the multifunctional frame body comprises a frame formed by two end plates and two side plates; the heat-dissipation structure comprises a bottom plate arranged at the bottom of the multifunctional frame body and a partition plate arranged along the length direction of the bottom plate; the partition plate comprises a first surface and a second surface arranged oppositely; a plurality of explosion-proof heat-dissipation plates are arranged in parallel and at intervals on the first surface and the second surface respectively; a containing space is formed between two adjacent explosion-proof heat-dissipation plates; the bottom plate, the partition plate and the explosion-proof heat-dissipation plates are respectively provided with liquid cooling flow channels which are communicated with each other; heat-conducting silica gel is arranged on the two side surfaces of the explosion-proof heat-dissipation plates; the battery pack comprises a plurality of battery monomers which are arranged in the containing spaces; and the end plate or the side plate comprises, from outside to inside, an outer protective layer, a heat-absorbing and heat-dissipating layer and a buffer heat-conducting layer which are arranged in sequence. Compared with the prior art, the battery pack has high-efficiency heat-dissipation performance and can effectively prevent battery swelling and explosion.

Description

Technical Field

[0001] This invention relates to the field of lithium-ion battery technology, and more specifically to an explosion-proof lithium-ion battery pack with high heat dissipation. Background Technology

[0002] In the development of modern lithium-ion battery technology, heat dissipation efficiency and safety are two core challenges. Lithium-ion batteries are widely used in various portable electronic devices and electric vehicles due to their high energy density and charge / discharge efficiency. However, during the charging and discharging process, the chemical reactions inside the battery cell generate a significant amount of heat. Especially under high load or fast charging conditions, the internal temperature of the cell can rise rapidly.

[0003] Increased cell temperature not only degrades battery performance but also accelerates battery aging and reduces its overall lifespan. More seriously, excessively high cell temperatures can trigger thermal runaway, one of the most dangerous types of battery safety incidents. Thermal runaway can cause a rapid increase in internal pressure, leading to battery expansion or even explosion, resulting in serious personal injury and property damage.

[0004] Furthermore, battery modules typically consist of multiple cells densely connected by welding or other methods. This dense layout exacerbates heat accumulation and conduction difficulties, and poor heat dissipation in a single cell directly affects the overall heat dissipation performance of the battery module. Existing battery module designs often neglect the management and control of thermal interaction between cells, resulting in low heat dissipation efficiency and increased safety risks when the battery module operates under high loads.

[0005] To address these issues, existing technologies fall short in improving heat dissipation efficiency and preventing battery swelling. Most battery modules lack an effective thermal management system to balance and optimize the temperature of each cell, and also lack safety measures to prevent battery swelling under pressure changes. Therefore, developing a safe lithium-ion battery module with efficient heat dissipation and effective prevention of battery swelling is crucial for improving battery performance and safety. Summary of the Invention

[0006] The main objective of this disclosure is to provide a safe lithium-ion battery pack that has efficient heat dissipation and can effectively prevent battery swelling and explosion.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] An explosion-proof lithium-ion battery pack with high-efficiency heat dissipation includes:

[0009] A multi-functional frame, comprising a frame formed by two end plates and two side plates;

[0010] The heat dissipation structure includes a base plate disposed at the bottom of the multifunctional frame and a partition plate disposed along the length of the base plate. The partition plate includes a first surface and a second surface disposed opposite to each other. The first surface and the second surface are respectively provided with multiple explosion-proof heat dissipation plates arranged side by side and spaced apart. An accommodating space for placing a battery cell is formed between two adjacent explosion-proof heat dissipation plates. The base plate, the partition plate, and the explosion-proof heat dissipation plates are respectively provided with interconnected liquid cooling channels. The two sides of the explosion-proof heat dissipation plates are provided with thermally conductive silicone, and the porosity of the thermally conductive silicone is 65% to 85%.

[0011] A battery pack includes multiple battery cells, each of which is placed within the accommodating space, and the size of the accommodating space is adapted to the size of the battery cells.

[0012] The end plate or side plate includes an outer protective layer, a heat absorption and dissipation layer, and a buffer heat conduction layer stacked sequentially from the outside to the inside. The heat absorption and dissipation layer has multiple heat dissipation grooves arranged side by side at intervals. The inner wall of the heat dissipation groove has a pressure relief port communicating with the outside. The pressure relief port is inclined outward. A spherical airbag is installed inside the heat dissipation groove, and part of the spherical airbag extends outside the heat dissipation groove and is embedded in the buffer heat conduction layer. The spherical airbag is filled with heat-absorbing liquid.

[0013] Preferably, the top of the partition is provided with a cold liquid inlet and a cold liquid outlet that are connected to the liquid cooling channel.

[0014] Preferably, the thermally conductive silicone is a modified thermally conductive silicone, which can greatly improve the thermal conductivity to 6-10 W / (m·k); effectively balancing thermal conductivity, buffering and bonding performance.

[0015] Preferably, the heat-absorbing and heat-dissipating layer is embedded with a buffer protrusion, and the top end of the buffer protrusion extends outside the heat-absorbing and heat-dissipating layer and is embedded in the buffer heat-conducting layer.

[0016] Preferably, the heat-absorbing and heat-dissipating layer is provided with a liquid guiding channel, the inner cavity of the buffer protrusion is connected to the inner cavity of the spherical airbag through the liquid guiding channel, and the heat-absorbing liquid can flow between the buffer protrusion and the spherical airbag through the liquid guiding channel.

[0017] Preferably, the outer protective layer includes an aluminum substrate and an aluminum silicon carbide layer disposed on the outer surface of the aluminum substrate. The aluminum substrate has a curved liquid cooling channel inside. The thermal conductivity of the aluminum silicon carbide layer is 220-240 W / mK. The Vickers hardness of the aluminum silicon carbide layer is 200-300 HV.

[0018] Preferably, the heat-absorbing and heat-dissipating layer comprises the following components in the indicated weight ratios: 40 parts aluminum nitride powder, 15 parts cubic boron nitride powder, 5 parts graphene nanosheets, 20 parts polyimide resin, 5 parts silane coupling agent, 10 parts nano-sized silver powder, and 5 parts carbon nanotubes.

[0019] Preferably, the buffer thermal conductive layer includes a first aluminum foam, a second aluminum foam, and a third aluminum foam arranged sequentially from the inside out. The densities ρ1 of the first aluminum foam, ρ2 of the second aluminum foam, and ρ3 of the third aluminum foam satisfy the relationship: ρ1 > ρ2 > ρ3. Furthermore, the first aluminum foam, the second aluminum foam, and the third aluminum foam are all provided with staggered pore structures, and the porosities Q1 of the first aluminum foam, Q2 of the second aluminum foam, and Q3 of the third aluminum foam satisfy the relationship: Q1 < Q2 < Q3.

[0020] Preferably, the density ρ1 of the first aluminum foam is 0.8–1.2 g / cm³. 3 The density ρ2 of the second aluminum foam is 0.5–0.8 g / cm³. 3 The density ρ3 of the third aluminum foam is 0.2–0.5 g / cm³. 3 ;

[0021] The porosity Q1 of the first aluminum foam is 45% to 60%; the porosity Q2 of the second aluminum foam is 60% to 75%; and the porosity Q3 of the third aluminum foam is 75% to 90%.

[0022] Preferably, the endothermic liquid is composed of phase change material, sodium chloride, TiO2 particles and water; the mass ratio of the phase change material, sodium chloride, TiO2 particles and water is (15-45):(5-15):(10-30):(40-60).

[0023] Preferably, the phase change material is a mixture of gallium, indium bismuth tin alloy and ortho-decanoic acid, wherein the mass ratio of gallium, indium bismuth tin alloy and ortho-decanoic acid is (1-2):(1-2):(2-4).

[0024] Preferably, the phase change material can be dispersed in the solution in particulate form, with a particle size range of 1 μm to 100 μm; the TiO2 particles have a particle size range of 0.1 μm to 10 μm.

[0025] Compared with the prior art, the present invention has at least the following beneficial effects:

[0026] 1) This invention employs a heat dissipation structure, including a base plate at the bottom of a multi-functional frame and a partition plate along the length of the base plate. The partition plate includes a first surface and a second surface arranged opposite each other, with multiple explosion-proof heat dissipation plates arranged side-by-side and spaced apart on the first and second surfaces. A space for placing battery cells is formed between two adjacent explosion-proof heat dissipation plates. By providing interconnected liquid cooling channels in the base plate, partition plate, and explosion-proof heat dissipation plates, the heat dissipation effect of the battery pack can be effectively improved through liquid cooling. Furthermore, considering that battery cells generate a large amount of heat during charging and discharging, and that this heat can cause the battery casing to expand, thermally conductive silicone is provided on the surface of the explosion-proof heat dissipation plate. The porosity of the thermally conductive silicone is 65% to 85% to ensure that the thermally conductive silicone has good buffering performance. Therefore, this invention utilizes thermally conductive silicone with a specific porosity to both buffer and conduct heat effectively, thus simultaneously solving the problems of battery cell expansion and deformation and thermal conductivity efficiency.

[0027] 2) The present invention uses a multifunctional frame consisting of a rectangular frame formed by special end plates and side plates, which not only provides a robust support structure for the battery pack, but also effectively prevents damage to the battery pack from external impacts. In addition, it has a good heat dissipation effect on the battery pack. This structural design significantly increases the overall stability and durability of the battery pack.

[0028] 3) The end plate and side plate of this invention include an outer protective layer, a heat absorption and dissipation layer, and a buffer heat conduction layer stacked sequentially. The heat absorption and dissipation layer is designed with multiple heat dissipation grooves, which are connected to the outside through pressure relief ports. This improves the air convection and ventilation effect within the multi-functional frame. In conjunction with the spherical airbags installed in the heat dissipation grooves and the heat-absorbing liquid inside them, heat is further absorbed and transferred, thereby improving the overall heat dissipation efficiency and preventing the battery pack from being in a heated state for a long time, effectively protecting the battery pack. In addition, the design of the heat dissipation grooves and pressure relief ports can also effectively disperse the pressure during use and reduce the generation of stress, thereby improving the pressure resistance of the multi-functional frame and reducing the risk of battery damage caused by temperature rise or external impact. Furthermore, part of the spherical surface of the spherical airbags extends outside the heat dissipation grooves and is embedded in the buffer heat conduction layer, which not only helps to further diffuse heat but also enhances the heat exchange efficiency between the heat absorption and dissipation layer and the buffer heat conduction layer. The buffer thermal conductive layer effectively absorbs the energy of external impacts through its highly elastic and compressible material properties. When subjected to drops, collisions, or other physical impacts, the material of the buffer thermal conductive layer deforms, absorbing and dispersing the impact energy and reducing the force directly acting on the battery cells, thus protecting them from damage. Furthermore, during transportation or use, the battery pack may be subjected to various vibrations, which can gradually damage the battery structure and shorten battery life. The buffer thermal conductive layer has excellent vibration isolation performance, effectively isolating or reducing the impact of these vibrations on the battery cells, improving the stability and reliability of the battery pack. The outer protective layer not only provides excellent thermal conductivity but also has strong wear resistance and impact resistance, ensuring the multi-functional frame's resistance to damage from external impacts or pressures, thus making the battery pack safer and more reliable.

[0029] 4) Through the design of the multifunctional frame and heat dissipation structure, this invention enables each surface of the battery cell to conduct heat and dissipate heat simultaneously, which greatly increases the heat dissipation area of ​​the battery pack, effectively improves the heat dissipation efficiency of the battery pack, and effectively prevents the battery from swelling and exploding. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure of an explosion-proof lithium-ion battery pack with high-efficiency heat dissipation in one embodiment of the present invention.

[0031] Figure 2 This is a schematic diagram of the heat dissipation structure in one embodiment of the present invention;

[0032] Figure 3 This is a cross-sectional view of the partition in one embodiment of the present invention.

[0033] Figure 4 This is a cross-sectional view of an explosion-proof heat sink according to an embodiment of the present invention.

[0034] Figure 5This is a schematic diagram of the structure of an end plate or side plate in one embodiment of the present invention;

[0035] Figure 6 This is a cross-sectional view of an end plate or side plate in one embodiment of the present invention;

[0036] Figure 7 for Figure 6 A magnified view of part A in the middle.

[0037] In the diagram: 1. Multifunctional frame; 11. End plate; 111. Outer protective layer; 1111. Aluminum substrate; 1112. Aluminum silicon carbide layer; 112. Heat absorption and dissipation layer; 1121. Heat dissipation groove; 1122. Pressure relief port; 1123. Spherical airbag; 1124. Buffer protrusion; 1125. Liquid guide channel; 113. Buffer thermal conductive layer; 1131. First aluminum foam; 1132. Second aluminum foam; 1133. Third aluminum foam; 12. Side plate; 2. Heat dissipation structure; 21. Base plate; 22. Partition plate; 23. Explosion-proof heat dissipation plate; 231. Thermally conductive silicone; 24. Accommodation space; 25. Cold liquid inlet; 26. Cold liquid outlet; 27. Liquid cooling channel; 3. Battery pack. Detailed Implementation

[0038] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] Please see the appendix Figures 1-7 This embodiment provides an explosion-proof lithium-ion battery pack with high-efficiency heat dissipation, comprising:

[0040] The multifunctional frame 1 includes a rectangular frame formed by two end plates 11 and two side plates 12;

[0041] The heat dissipation structure 2 includes a base plate 21 disposed at the bottom of the multi-functional frame 1 and a partition 22 disposed along the length of the base plate 21. The partition 22 includes a first surface and a second surface disposed opposite to each other. The first surface and the second surface are respectively provided with a plurality of explosion-proof heat dissipation plates 23 arranged side by side and spaced apart. An accommodating space 24 for placing a battery cell is formed between two adjacent explosion-proof heat dissipation plates 23. The base plate 21, the partition 22 and the explosion-proof heat dissipation plates 23 are respectively provided with interconnected liquid cooling channels 27. The two sides of the explosion-proof heat dissipation plate 23 are provided with thermally conductive silicone 231, and the porosity of the thermally conductive silicone 231 is 65% to 85%.

[0042] The battery pack 3 includes multiple battery cells, which are respectively placed in the accommodating space 24, and the size of the accommodating space 24 is adapted to the size of the battery cells.

[0043] Each end plate 11 or side plate 12 includes an outer protective layer 111, a heat absorption and dissipation layer 112, and a buffer heat conduction layer 113, which are stacked sequentially from the outside to the inside. The heat absorption and dissipation layer 112 has multiple heat dissipation grooves 1121 arranged side by side at intervals. The inner wall of the heat dissipation groove 1121 has a pressure relief port 1122 communicating with the outside. The pressure relief port 1122 is inclined outward. A spherical airbag 1123 is installed inside the heat dissipation groove 1121, and part of the spherical surface of the spherical airbag 1123 extends outside the heat dissipation groove 1121 and is embedded in the buffer heat conduction layer 113. The spherical airbag 1123 is filled with heat-absorbing liquid. By adopting a multifunctional frame 1 formed by special end plates 11 and side plates 12, not only is an effective support and protection structure provided to ensure the stability of the battery pack 3 in various environments, but the multi-layer design of the end plates 11 and side plates 12 also significantly improves heat dissipation efficiency and energy absorption effect, thereby improving the thermal management performance and shock resistance of the battery pack 3.

[0044] The base plate 21, partition plate 22 and explosion-proof heat dissipation plate 23 of the heat dissipation structure 2 can be made of materials with high thermal conductivity and easy processing, such as aluminum, copper or alloy. The base plate 21, partition plate 22 and explosion-proof heat dissipation plate 23 can be connected by welding or other methods, or they can be formed into an integral structure by integral molding. The end plate 11 and side plate 12 of the multifunctional frame 1 can be formed into an integral sheet structure by hot pressing or spraying processes well known in the art.

[0045] The top of the partition 22 is provided with a coolant inlet 25 and a coolant outlet 26 that are connected to the liquid cooling channel 27. The coolant can be water or a mixed coolant formed by water, ethylene glycol, etc. The coolant enters the liquid cooling channel 27 through the coolant inlet 25 and flows out through the coolant outlet 26 to form a coolant circulation that carries away the heat from the battery pack 3.

[0046] In one embodiment of this application, the thermally conductive silicone 231 is a modified thermally conductive silicone 231, which can greatly improve the thermal conductivity to 6-10 W / (m·k); effectively balancing thermal conductivity, buffering and bonding performance.

[0047] In one embodiment of this application, the method for preparing the modified thermally conductive silicone 231 includes the following steps:

[0048] 1) Boron nitride and KH570 silane coupling agent were dispersed in 100 ml of aqueous solution at a mass ratio of 10:1, with concentrations of 40 mg / ml and 4 mg / ml, respectively. The mixed dispersion was placed in a water bath for sonication at 0°C for 40 min. After centrifugation to remove excess solvent, the mixture was cooled and dried to obtain modified boron nitride powder.

[0049] 2) Modified boron nitride powder and graphene were dispersed in a mixed solvent of alcohol and water at a mass ratio of 1:5, with concentrations of 1.2 mg / ml and 6 mg / ml, respectively. At the same time, 2 mg / ml of carbon nanotubes were added. The mixture was ultrasonically sonicated at 1200W for 10 min using an ultrasonic cell disruptor to obtain graphene slurry.

[0050] 3) Immerse polyurethane foam in 2 mol / L NaOH solution, treat it in 40℃ warm water for 3.5 h, and then soak it in 5 mg / ml aniline methyltriethoxysilane aqueous solution for 24 h to obtain modified polyurethane porous foam.

[0051] 4) The modified polyurethane porous foam structure was impregnated in the uniform graphene slurry prepared above, and ultrasonicated in a water bath at 0°C for 20 min. It was then dried at 60°C, and then heated from 60°C to 200°C at a rate of 15°C per minute, and then heated from 200°C to 380°C at a rate of 3°C per minute for 30 min to remove the porous material, thus obtaining a three-dimensional porous graphene-boron nitride composite material.

[0052] 5) The three-dimensional porous graphene-boron nitride composite material obtained above was immersed in silicone (Wacker SEMICOSIL 9212), the air bubbles were removed by vacuuming, and it was placed in an oven at 125°C and cured for 15 min to obtain modified thermally conductive silicone 231 with an average thermal conductivity of 7.5 W / (m·K).

[0053] In one embodiment of this application, the method for preparing the modified thermally conductive silicone 231 includes the following steps:

[0054] 1) Immerse open-cell polystyrene foam in 20wt% NaOH solution, treat it in 40℃ warm water for 5h, then put it into 2mg / ml polyacrylamide solution for surface modification for 24h, and take it out for use.

[0055] 2) A graphene slurry was prepared by using 40.5 wt% of 120-mesh silicon carbide ceramic powder, 13.5 wt% of graphene, 5 wt% of alumina-yttrium oxide as sintering aid, 30.5 wt% of alcohol-water as solvent, 4 wt% of sodium tetraborate as binder, 4 wt% of kaolin as rheology modifier, 2 wt% of polyethyleneimine as dispersant, and 0.3 wt% of dimethyl silicone oil as defoamer.

[0056] 3) The surface-modified polystyrene foam was immersed in the slurry and ultrasonically treated in a water bath for 20 minutes to ensure the slurry fully penetrated the polystyrene foam. The foam was then dried at 80°C. The product was then subjected to desizing under vacuum. The temperature was set to increase from room temperature to 280°C at a rate of 15°C per minute, then increase from 280°C to 500°C at a rate of 3°C per minute and hold for 30 minutes. Finally, the temperature was rapidly increased to 1700°C at a rate of 20°C per minute and held for 1 hour to obtain a three-dimensional porous graphene-silicon carbide material. The average pore size of the three-dimensional porous graphene-silicon carbide material was measured to be 2–4 mm, and the porosity was 75%.

[0057] 4) A mixture of 35 wt% graphene and 85 wt% silica gel was placed in a degassing machine and stirred for 30 minutes under cooling circulation conditions. The silica gel was type AB, namely Wacker SEMICOSIL 905A / B. After degassing, the mixture was transferred into a mold to obtain a slurry. This slurry was poured into the three-dimensional porous graphene-silicon carbide material prepared above and allowed to stand under vacuum for one hour to fill the pores in the three-dimensional porous graphene-silicon carbide material and eliminate air bubbles. Then, it was cured at 120°C for 30 minutes to obtain modified thermally conductive silica gel 231.

[0058] In one embodiment of this application, the heat-absorbing and heat-dissipating layer 112 is embedded with a buffer protrusion 1124, and the top end of the buffer protrusion 1124 extends outside the heat-absorbing and heat-dissipating layer 112 and is embedded in the buffer heat-conducting layer 113. The buffer protrusion 1124 can be made of a polymer material with good elasticity, such as EVA or polyurethane. The buffer protrusion 1124 further enhances the mechanical strength and buffering capacity of the heat-absorbing and heat-dissipating layer 112, effectively absorbing and dispersing external impact forces.

[0059] In one embodiment of this application, a liquid guiding channel 1125 is provided within the heat-absorbing and heat-dissipating layer 112. The inner cavity of the buffer protrusion 1124 communicates with the inner cavity of the spherical airbag 1123 through the liquid guiding channel 1125, and the heat-absorbing liquid can flow between the buffer protrusion 1124 and the spherical airbag 1123 through the liquid guiding channel 1125. The spherical airbag 1123 can be made of a material with good thermal conductivity and elasticity, such as thermally conductive silicone 231, and is manufactured by injection molding, extrusion molding, or blow molding. The liquid guiding channel 1125 design enables the flow of heat-absorbing liquid between the buffer protrusion 1124 and the spherical airbag 1123, enhancing the efficiency and uniformity of heat dissipation.

[0060] In one embodiment of this application, the outer protective layer 111 includes an aluminum substrate 1111 and an aluminum silicon carbide layer 1112 disposed on the outer surface of the aluminum substrate 1111. A curved liquid cooling channel 27 is disposed inside the aluminum substrate 1111. One end of the liquid cooling channel 27 is connected to a water inlet, and the other end of the liquid cooling channel 27 is connected to a water outlet. The thermal conductivity of the aluminum silicon carbide layer 1112 is 220-240 W / mK, preferably 240 W / mK. The Vickers hardness of the aluminum silicon carbide layer 1112 is 200-300 HV, preferably 300 HV.

[0061] The Vickers hardness of the aluminum substrate 1111 is typically between 30 and 40 HV. Aluminum's relatively low hardness makes it easy to process and shape, facilitating the fabrication of the liquid cooling channel 27, but its wear resistance and impact resistance are insufficient. The Vickers hardness of aluminum silicon carbide is typically between 200 and 300 HV. It is placed on the outside of the aluminum substrate 1111 as an outer protective layer 111 for the end plate 11 or side plate 12, making it more wear-resistant and impact-resistant. Therefore, the outer protective layer 111 combines the aluminum substrate 1111 with the aluminum silicon carbide layer 1112. The aluminum silicon carbide layer 1112 has extremely high thermal conductivity (220-240 W / mK), allowing heat to be rapidly conducted away from the battery cells through the outer protective layer 111. Furthermore, the curved liquid cooling channel 27 inside the aluminum substrate 1111 further enhances heat dissipation efficiency. The circulating coolant effectively removes heat from the battery pack 3, greatly improving the heat dissipation speed and effect. Furthermore, the aluminum silicon carbide layer 1112 of the outer protective layer 111 not only provides excellent thermal conductivity, but also has a Vickers hardness between 200 and 300 HV, ensuring the multifunctional frame 1's resistance to damage when facing external impacts or pressures. This wear-resistant and impact-resistant property makes the battery pack 3 safer and more reliable in daily use.

[0062] In one embodiment of this application, the heat-absorbing and heat-dissipating layer 112 comprises the following components in parts by weight: 40 parts aluminum nitride powder, 15 parts cubic boron nitride powder, 5 parts graphene nanosheets, 20 parts polyimide resin, 5 parts silane coupling agent, 10 parts nanoscale silver powder, and 5 parts carbon nanotubes.

[0063] This material combines aluminum nitride, cubic boron nitride, graphene nanosheets, nanoscale silver powder, and carbon nanotubes to achieve a balance of high thermal conductivity, high-temperature resistance, and mechanical strength. Aluminum nitride and cubic boron nitride, with their high thermal conductivity, enhance heat dissipation efficiency, while graphene nanosheets and carbon nanotubes further improve thermal conductivity. Polyimide resin is used as a high-temperature resistant matrix material, working in conjunction with the high thermal conductivity filler to provide excellent heat dissipation and high-temperature resistance. A silane coupling agent is used to modify the surface of the filler, improving the interfacial adhesion between the filler and the matrix and enhancing the overall performance of the material. Furthermore, the synergistic effect of the components forms a highly efficient thermally conductive network, further improving the material's thermal conductivity and heat dissipation performance.

[0064] The method for preparing the heat absorption and dissipation layer 112 is as follows:

[0065] Step 1: Pre-processing

[0066] Materials preparation:

[0067] Weigh aluminum nitride powder, cubic boron nitride powder, graphene nanosheets, nanoscale silver powder, and carbon nanotubes according to the specified proportions and set aside.

[0068] Prepare the polyimide resin and silane coupling agent.

[0069] Surface modification:

[0070] The fillers (aluminum nitride, cubic boron nitride, graphene nanosheets, nanoscale silver powder and carbon nanotubes) were mixed with silane coupling agents in anhydrous ethanol and stirred for 2 hours to perform surface modification.

[0071] The modified filler was dried at 80°C to remove residual ethanol.

[0072] Step 2: Mixing and Dispersing

[0073] Mixed packing:

[0074] Mix the modified fillers using a high-speed mixer or ball mill to ensure uniform dispersion; control the mixing time to more than 2 hours to ensure that all components are fully mixed.

[0075] Add matrix material:

[0076] The polyimide resin was dissolved in N-methylpyrrolidone (NMP) to form a homogeneous solution;

[0077] The mixed filler is gradually added to the polyimide solution, and stirring is continued until a uniform slurry is formed.

[0078] Step 3: Molding and Curing

[0079] The uniformly mixed slurry is evenly coated onto the aluminum substrate 1111;

[0080] The coated aluminum substrate 1111 was dried at 80°C for 2 hours to allow the NMP solvent to evaporate completely.

[0081] Then, the aluminum substrate 1111 is placed in an oven and cured at 300°C for 2 hours to allow the polyimide resin to fully crosslink and cure, thus obtaining the heat-absorbing and heat-dissipating layer 112.

[0082] In one embodiment of this application, the heat-absorbing and heat-dissipating layer 112 may also be made of metal or alloy materials with high temperature resistance and thermal conductivity, such as aluminum, copper and their alloys.

[0083] In one embodiment of this application, the buffer thermal conductive layer 113 includes a first aluminum foam 1131, a second aluminum foam 1132, and a third aluminum foam 1133 arranged sequentially from the inside out. The densities ρ1 of the first aluminum foam 1131, ρ2 of the second aluminum foam 1132, and ρ3 of the third aluminum foam 1133 satisfy the relationship: ρ1 > ρ2 > ρ3. Furthermore, the first aluminum foam 1131, the second aluminum foam 1132, and the third aluminum foam 1133 are all provided with staggered pore structures. The porosity Q1 of the first aluminum foam 1131, the porosity Q2 of the second aluminum foam 1132, and the porosity Q3 of the third aluminum foam 1133 satisfy the relationship: Q1 < Q2 < Q3.

[0084] The three-layer aluminum foam structure with gradient density and porosity effectively absorbs and disperses impact energy, and has good thermal conductivity and heat dissipation, thus providing excellent buffer protection and thermal conductivity and heat dissipation performance. Specifically, the high-density, low-porosity first aluminum foam 1131 initially receives and disperses external impact energy, reducing the direct transmission of impact force to the interior; the medium-density, high-porosity second aluminum foam 1132 further absorbs and disperses the remaining impact energy. The low-density, high-porosity third aluminum foam 1133 has extremely high energy absorption capacity, ultimately absorbing and dispersing the remaining impact energy, protecting the battery pack 3. This application, through an innovative combination design of the porosity and density of each layer, achieves the effect of layer-by-layer absorption and dispersion of impact energy, thereby significantly improving the buffer protection performance of the lithium-ion battery pack 3. This gradient parameter design can provide comprehensive protection under different mechanical environments, ensuring the safety and reliability of the battery module.

[0085] In one embodiment according to this application, the density ρ1 of the first aluminum foam 1131 is 0.8–1.2 g / cm³. 3 The preferred value is 0.95 g / cm³. 3 The density ρ2 of the second aluminum foam 1132 is 0.5–0.8 g / cm³. 3 The preferred value is 0.65 g / cm³. 3 The density ρ3 of the third aluminum foam 1133 is 0.2–0.5 g / cm³. 3 The preferred value is 0.35 g / cm³. 3 ;

[0086] The porosity Q1 of the first aluminum foam 1131 is 45% to 60%, preferably 55%; the porosity Q2 of the second aluminum foam 1132 is 60% to 75%, preferably 70%; and the porosity Q3 of the third aluminum foam 1133 is 75% to 90%, preferably 85%.

[0087] In one embodiment of this application, the endothermic liquid is composed of a phase change material, sodium chloride, TiO2 particles, and water; the mass ratio of the phase change material, sodium chloride, TiO2 particles, and water is (15-45):(5-15):(10-30):(40-60); preferably 30:10:20:40. The endothermic liquid formulation contains a phase change material, which absorbs heat and undergoes a phase change at a specific temperature, effectively reducing the battery temperature. The addition of sodium chloride and TiO2 particles further enhances the heat absorption capacity and stability of the endothermic liquid.

[0088] In one embodiment of this application, the phase change material is a mixture of gallium, indium bismuth tin alloy, and ortho-capric acid, wherein the mass ratio of gallium, indium bismuth tin alloy, and ortho-capric acid is (1-2):(1-2):(2-4); preferably 1:1:3. The phase change material possesses excellent thermal absorption and conductivity properties, and the specific mass ratio ensures the stability and high efficiency of the endothermic liquid.

[0089] In one embodiment of this application, the phase change material can be dispersed in the solution in particulate form, with a particle size ranging from 1 μm to 100 μm; the TiO2 particles have a particle size ranging from 0.1 μm to 10 μm. Controlling the particle size ensures the uniformity of the endothermic liquid dispersion, further improving the efficiency and stability of thermal management.

[0090] In one embodiment of this application, the phase change material includes sodium sulfate decahydrate, multi-walled carbon nanotubes, sodium carboxymethyl cellulose, and polyvinyl alcohol, wherein the mass percentages of sodium sulfate decahydrate, multi-walled carbon nanotubes, sodium carboxymethyl cellulose, and polyvinyl alcohol are 80-85%:5-10%:5-10%:5-10%, preferably 85%:5%:5%:5%. Sodium sulfate decahydrate, as the main phase change material, has a moderate phase change temperature and a high latent heat of phase change, enabling it to significantly absorb heat and thus reduce the temperature of the battery pack 3. Multi-walled carbon nanotubes improve the thermal conductivity of the phase change material, ensuring rapid heat diffusion within the material, making the phase change process more uniform and efficient. Sodium carboxymethyl cellulose, as a stabilizer, prevents crystallization deformation and phase separation during repeated use of the phase change material, improving the material's mechanical strength and stability. Polyvinyl alcohol, as a dispersant, ensures uniform dispersion of multi-walled carbon nanotubes and other additives in the phase change material, preventing aggregation and sedimentation, and improving the overall performance of the material.

[0091] In one embodiment of this application, the endothermic liquid comprises the following components by weight percentage: 20% paraffin wax, 5% sodium chloride, 10% hexagonal boron nitride nanosheets, 2% polyvinyl alcohol, and the balance being water. Paraffin wax, as a phase change material, can absorb a large amount of heat, improving the overall heat dissipation effect; sodium chloride enhances the overall thermal conductivity and lowers the freezing point of water, preventing the solution from freezing in low-temperature environments; hexagonal boron nitride nanosheets significantly improve the thermal conductivity of the endothermic liquid, ensuring rapid heat dispersion within the solution and preventing localized overheating; polyvinyl alcohol ensures uniform dispersion of the hexagonal boron nitride nanosheets in the solution, preventing aggregation and sedimentation, and improving the overall performance and stability of the solution; water, as the matrix solution, provides good fluidity and thermal conductivity, ensuring uniform dispersion of other components.

[0092] In one embodiment of this application, the end plate 11 and the side plate 12 are fixed by protective fasteners. A hook groove is formed on the outer surface of the end of the side plate 12. The protective fasteners include armored strips and hook blocks disposed at both ends of the armored strips, with the hook blocks engaging within the hook grooves. The end plate 11 and the side plate are connected by a convex-concave fit. To further improve the stability of the connection between the end plate 11 and the side plate 12, protective fasteners are provided, connecting the end plate 11 and the side plate 12 via the armored strips and hook blocks, providing additional mechanical strength and stability, and ensuring the reliability and stability of the multi-functional frame 1 under extreme conditions.

[0093] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0094] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A high-efficiency heat dissipation explosion-proof lithium-ion battery pack, characterized in that, include: A multi-functional frame, comprising a frame formed by two end plates and two side plates; The heat dissipation structure includes a base plate disposed at the bottom of the multifunctional frame and a partition plate disposed along the length of the base plate. The partition plate includes a first surface and a second surface disposed opposite to each other. The first surface and the second surface are respectively provided with multiple explosion-proof heat dissipation plates arranged side by side and spaced apart. An accommodating space for placing a battery cell is formed between two adjacent explosion-proof heat dissipation plates. The base plate, the partition plate, and the explosion-proof heat dissipation plates are respectively provided with interconnected liquid cooling channels. The two sides of the explosion-proof heat dissipation plates are provided with thermally conductive silicone, and the porosity of the thermally conductive silicone is 65% to 85%. A battery pack includes multiple battery cells, each of which is placed within the accommodating space, and the size of the accommodating space is adapted to the size of the battery cells. The end plate or side plate includes an outer protective layer, a heat absorption and dissipation layer, and a buffer heat conduction layer stacked sequentially from the outside to the inside. The heat absorption and dissipation layer has multiple heat dissipation grooves arranged side by side at intervals. The inner wall of the heat dissipation groove has a pressure relief port communicating with the outside. The pressure relief port is inclined outward. A spherical airbag is installed inside the heat dissipation groove, and part of the spherical airbag extends outside the heat dissipation groove and is embedded in the buffer heat conduction layer. The spherical airbag is filled with heat-absorbing liquid.

2. The explosion-proof lithium-ion battery pack with high-efficiency heat dissipation according to claim 1, characterized in that: The top of the partition is provided with a cold liquid inlet and a cold liquid outlet that are connected to the liquid cooling channel.

3. The explosion-proof lithium-ion battery pack with high-efficiency heat dissipation according to claim 1, characterized in that: The heat-absorbing and heat-dissipating layer is embedded with a buffer protrusion, and the top of the buffer protrusion extends outside the heat-absorbing and heat-dissipating layer and is embedded in the buffer heat-conducting layer.

4. The explosion-proof lithium-ion battery pack with high-efficiency heat dissipation according to claim 3, characterized in that: The heat-absorbing and heat-dissipating layer is provided with a liquid guiding channel. The inner cavity of the buffer protrusion is connected to the inner cavity of the spherical airbag through the liquid guiding channel, and the heat-absorbing liquid can flow between the buffer protrusion and the spherical airbag through the liquid guiding channel.

5. The explosion-proof lithium-ion battery pack with high-efficiency heat dissipation according to claim 1, characterized in that: The outer protective layer includes an aluminum substrate and an aluminum silicon carbide layer disposed on the outer surface of the aluminum substrate. The aluminum substrate has a curved liquid cooling channel inside. The thermal conductivity of the aluminum silicon carbide layer is 220-240 W / mK. The Vickers hardness of the aluminum silicon carbide layer is 200-300 HV.

6. The explosion-proof lithium-ion battery pack with high-efficiency heat dissipation according to claim 1, characterized in that: The heat absorption and heat dissipation layer comprises the following components in the indicated weight ratios: 40 parts aluminum nitride powder, 15 parts cubic boron nitride powder, 5 parts graphene nanosheets, 20 parts polyimide resin, 5 parts silane coupling agent, 10 parts nano-sized silver powder, and 5 parts carbon nanotubes.

7. The explosion-proof lithium-ion battery pack with high-efficiency heat dissipation according to claim 1, characterized in that: The buffer thermal conductive layer includes a first aluminum foam, a second aluminum foam, and a third aluminum foam arranged sequentially from the inside out. The densities ρ1 of the first aluminum foam, ρ2 of the second aluminum foam, and ρ3 of the third aluminum foam satisfy the relationship: ρ1 > ρ2 > ρ3. Furthermore, the first aluminum foam, the second aluminum foam, and the third aluminum foam are all provided with staggered pore structures. The porosities Q1 of the first aluminum foam, Q2 of the second aluminum foam, and Q3 of the third aluminum foam satisfy the relationship: Q1 < Q2 < Q3.

8. The explosion-proof lithium-ion battery pack with high-efficiency heat dissipation according to claim 7, characterized in that: The density ρ1 of the first aluminum foam is 0.8–1.2 g / cm³. 3 The density ρ2 of the second aluminum foam is 0.5–0.8 g / cm³. 3 The density ρ3 of the third aluminum foam is 0.2–0.5 g / cm³. 3 ; The porosity Q1 of the first aluminum foam is 45% to 60%; the porosity Q2 of the second aluminum foam is 60% to 75%; and the porosity Q3 of the third aluminum foam is 75% to 90%.

9. The explosion-proof lithium-ion battery pack with high-efficiency heat dissipation according to claim 1, characterized in that: The endothermic liquid is composed of phase change material, sodium chloride, TiO2 particles and water; the mass ratio of the phase change material, sodium chloride, TiO2 particles and water is (15-45):(5-15):(10-30):(40-60).

10. The explosion-proof lithium-ion battery pack with high-efficiency heat dissipation according to claim 9, characterized in that: The phase change material is a mixture of gallium, indium bismuth tin alloy and ortho-capric acid, wherein the mass ratio of gallium, indium bismuth tin alloy and ortho-capric acid is (1-2):(1-2):(2-4).

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