Flexible cooling thermal insulation material as well as preparation method and application thereof

Abstract

The invention discloses a flexible cooling thermal insulation material and a preparation method and application thereof, and belongs to the field of new energy safety. The flexible cooling thermal insulation material comprises a phase change heat absorption material, a flexible supporting material, a modified additive, an expansion auxiliary agent and a coating material, the cooling effect is achieved through the phase change heat absorption material with the excellent heat absorption capacity, certain flexibility is achieved by combining the phase change heat absorption material with the flexible supporting material, and the heating expansion function is achieved by adding the expansion auxiliary agent; the heat insulation effect is achieved. The flexible cooling thermal insulation material and the preparation method can be used for lithium battery fire prevention and control, and the problem of lithium battery fire spreading and diffusion is solved.

Description

Technical Field

[0001] The present invention relates to the field of new energy safety technology, and more particularly to a flexible cooling and heat-insulating material and a preparation method and application thereof. Background Art

[0002] With the widespread use of lithium batteries in electric vehicles, energy storage power stations and other fields, fire accidents caused by lithium batteries have occurred frequently. Efficient fire prevention and control technology is one of the key means to ensure the safe application of lithium batteries. Existing battery fire extinguishing media mainly include: water, foam, inert gas, chemical gas and dry powder, etc., but they all require storage devices, driving gas, pipelines, valves, nozzles, fire detectors and other additional devices, so they have high weight and large volume, which limits their application in electric vehicles and other fields. Adding thermal insulation materials (such as thermal insulation aerogel, etc.) between batteries in the battery module can minimize the changes in weight and volume caused by fire prevention and control technology. However, simple thermal insulation materials do not have the heat absorption and cooling effect and fire extinguishing effect. It is difficult to effectively achieve battery fire safety prevention and control in actual applications.

[0003] Invention patent CN202410428128.1 discloses a fire-extinguishing cooling block for battery fires. Its application in battery packs is effective in suppressing the spread of lithium battery fires. However, the cooling block produced by this method is rigid and cannot meet the deformation requirements of lithium battery packs during charging and discharging. Therefore, it is necessary to develop flexible cooling and thermal insulation materials tailored to the actual application characteristics and fire prevention requirements of lithium batteries during use. Summary of the Invention

[0004] To address these issues, the present invention provides a flexible cooling and thermal insulation material. This material utilizes a phase-change endothermic material with excellent heat absorption as the cooling material. This material is combined with a flexible support material to achieve a certain degree of flexibility. The addition of an expansion aid allows the material to expand upon heating, providing a thermal insulation effect.

[0005] In order to achieve the above objectives, the first objective of the present invention is to provide a flexible cooling and heat-insulating material, which adopts the following technical solutions:

[0006] A flexible cooling and heat-insulating material, comprising a phase-change heat-absorbing material, a flexible supporting material, a modifying additive, an expansion aid, and a coating material;

[0007] Wherein, the mass ratio of the phase change heat absorbing material, the flexible supporting material, the modifying additive and the expansion aid is (50-90):(5-35):(5-15):(1-5).

[0008] Further, the phase change endothermic material is selected from at least one of dipotassium hydrogen phosphate hexahydrate, ferric bromide hexahydrate, calcium chloride dodecahydrate, potassium ferric sulfate dodecahydrate, calcium bromide hexahydrate, ferric chloride hexahydrate, magnesium iodide octahydrate, calcium iodide hexahydrate, manganese chloride tetrahydrate, sodium sulfate decahydrate, sodium carbonate decahydrate, disodium hydrogen phosphate dodecahydrate, sodium metasilicate nonahydrate, dipotassium hydrogen phosphate heptahydrate, sodium metasilicate tetrahydrate, sodium metasilicate pentahydrate, magnesium ammonium phosphate hexahydrate, magnesium sulfate heptahydrate, sodium oxalate trihydrate, magnesium chloride tetrahydrate, magnesium iodide octahydrate, calcium iodide hexahydrate, trisodium phosphate dodecahydrate, sodium borate decahydrate, potassium aluminum sulfate dodecahydrate, sodium aluminum sulfate decahydrate, barium hydroxide octahydrate, magnesium chloride hexahydrate, ammonium aluminum sulfate dodecahydrate and hydrated alumina.

[0009] Furthermore, the modifying additive is selected from at least one of graphite, activated carbon, carbon nanotubes, Ketjen black, acetylene black, alumina powder, zinc oxide powder, silicon nitride powder, boron nitride powder, aluminum powder, copper powder, silver powder, silicon carbide powder, silicon dioxide powder, aluminum nitride powder, floating bead powder, hollow glass microbead powder, mica powder, and talc powder;

[0010] The particle size of the modifying additive is ≤300 microns.

[0011] It is worth noting that the thermal conductivity of the flexible cooling and thermal insulation material can be adjusted according to functional needs through modified additives. At the same time, the bonding effect between the phase change heat absorption material and the flexible support material can be improved, making the final flexible cooling and thermal insulation material easier to form.

[0012] Furthermore, the flexible supporting material is selected from at least one of polydimethylsiloxane, addition silicone rubber, condensation silicone rubber, room temperature vulcanized silicone rubber, polyurethane adhesive, and borosilicate rubber.

[0013] It is worth noting that the flexible supporting material can not only provide flexibility for the flexible cooling and heat-insulating material, but also interact with the phase-change heat-absorbing material and the expansion aid after being heated to a certain temperature to achieve an expansion and heat-insulating effect.

[0014] Furthermore, the expansion aid is selected from at least one of azo compounds, sulfonylhydrazide compounds, and sulfonylsemicarbazide compounds.

[0015] It is worth noting that the expansion aid can generate a large amount of inert gas after being heated to a certain temperature. The inert gas can not only extinguish the fire, but also interact with the flexible support material and the phase change heat absorption material to achieve an expansion and heat insulation effect.

[0016] Furthermore, the coating material is selected from at least one of polytetrafluoroethylene, polyethylene terephthalate, polyimide, polyphenylene sulfide, and polyaryletherketone;

[0017] The coating material has a thickness of 0.01-0.8 mm.

[0018] Furthermore, the outer layer of the phase change heat-absorbing material is wrapped by a hydrophobic anti-corrosion material, and the wrapping material is selected from at least one of thiol-olefin functionalized polysiloxane, styrene polysiloxane, vinyl ether functionalized polysiloxane, epoxy functionalized polysiloxane, acrylated polysiloxane, and vinyl silicone oil.

[0019] It is worth noting that the phase change endothermic material has poor compatibility with the flexible support material, and the phase change endothermic material is easily affected by the environment and becomes powdery and deliquescent during long-term storage. By wrapping the hydrophobic anti-corrosion material on the outer layer of the phase change endothermic material, the compatibility between the phase change endothermic material and the flexible support material and the long-term storage performance of the phase change endothermic material can be improved.

[0020] Another object of the present invention is to provide a method for preparing the above-mentioned flexible temperature-reducing and heat-insulating material, comprising the following steps:

[0021] 1) First, the phase change heat absorbing material is subjected to a hydrophobic anti-corrosion treatment;

[0022] 2) then uniformly mixing the treated phase change endothermic material with the modified additive and the expansion aid according to a certain proportion;

[0023] 3) The above materials are then mixed evenly with the synthetic raw materials of the flexible support material, and then prepared into profiles of different shapes and subjected to vulcanization polymerization reaction;

[0024] 4) Finally, the above materials are coated with a coating material;

[0025] Among them, the hydrophobic anti-corrosion treatment method of the phase change endothermic material includes: crushing and refining the phase change endothermic material, mixing the refined powder with light-curing silicone in a mass ratio of (90-99): (1-10), and then curing it with ultraviolet light. After curing, it is crushed again to form a hydrated salt powder with hydrophobic anti-corrosion function.

[0026] Another object of the present invention is to provide application of the above-mentioned flexible temperature-reducing and heat-insulating material in the field of new energy safety.

[0027] When used, the flexible cooling and heat insulating material is placed between, around or inside the battery pack.

[0028] It is worth noting that, to fully realize the present invention, a method for preparing and applying the flexible cooling and thermal insulation material is disclosed. However, it should be understood that all methods for preparing and applying the flexible cooling and thermal insulation material of the present invention, which are based on existing technologies and do not involve inventive steps, are also applicable to the multifunctional material disclosed herein.

[0029] It can be seen from the above technical solutions that, compared with the prior art, the present invention has the following technical effects:

[0030] (1) The flexible cooling and heat-insulating material prepared by the present invention can realize the functions of flexibility, heat conduction, cooling, and heat insulation, and can meet the fire prevention and control needs of power battery packs such as electric vehicles and electric aircraft.

[0031] (2) The flexible cooling and heat-insulating material prepared by the present invention can achieve regulation of the thermal conductivity of the flexible cooling and heat-insulating material by adjusting different types of modifying additives.

[0032] (3) The flexible cooling and heat-insulating material prepared by the present invention can achieve an expansion and heat-insulating effect through the interaction of the flexible supporting material, the expansion aid and the phase-change heat-absorbing material under heating conditions. DETAILED DESCRIPTION

[0033] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0034] Example 1

[0035] First, trisodium phosphate dodecahydrate powder and styrene-based polysiloxane are evenly mixed in a mass ratio of 95:5, and then a UV curing lamp (500W) is used to irradiate and cure for 30 minutes for hydrophobic anti-corrosion coating. After crushing, the mixture is evenly mixed with graphite and azodicarbonamide in a mass ratio of 80:15:1; the above-mentioned mixed material is evenly mixed with addition-type silicone rubber raw materials (95wt% ethylene silicone oil, 4wt% hydrogenated silicone oil, 0.5wt% platinum catalyst, 0.5wt% 1-ethynyl-1-cyclohexanol) in a mass ratio of 96:15 and pressed into a sheet profile with a thickness of 2 mm; the sheet profile is heated to 60°C for vulcanization polymerization, and then coated with a tetrafluoroethylene film with a thickness of 0.01 mm.

[0036] Example 2

[0037] First, ammonium aluminum sulfate dodecahydrate powder and epoxy-functionalized polysiloxane are evenly mixed in a mass ratio of 98:2, and then a UV curing lamp (500W) is used to cure for 30 minutes for hydrophobic anti-corrosion coating. After crushing, the mixture is evenly mixed with alumina powder and p-toluenesulfonyl hydrazide in a mass ratio of 86:10:1; the above-mentioned mixed material is evenly mixed with room temperature vulcanized silicone rubber raw materials (95wt% hydroxyl-terminated polydimethylsiloxane, 4wt% methyltrimethoxysilane, 1wt% dibutyltin dilaurate) in a mass ratio of 97:35 and pressed into a sheet profile with a thickness of 2 mm; the sheet profile is heated to 60°C for vulcanization polymerization, and then coated with a polyimide film with a thickness of 0.05 mm.

[0038] Example 3

[0039] First, sodium metasilicate nonahydrate powder and styrene-based polysiloxane are evenly mixed in a mass ratio of 97:3, and then a UV curing lamp (500W) is used to cure for 30 minutes for hydrophobic anti-corrosion coating. After crushing, the mixture is evenly mixed with silica powder and p-toluenesulfonylamino urea in a mass ratio of 60:15:5; the above-mentioned mixed material and polyurethane adhesive raw materials (45wt% polyether polyol, 54.9wt% diphenylmethane diisocyanate, 0.1wt% triethylenediamine) are evenly mixed in a mass ratio of 80:20 and pressed into a sheet profile with a thickness of 2 mm; the sheet profile is heated to 60°C for vulcanization polymerization, and then coated with polyaryletherketone with a thickness of 0.1 mm.

[0040] Comparative Example 1

[0041] On the basis of Example 1, the phase change heat absorption material is not coated with a hydrophobic anti-corrosion layer, and the effect of the hydrophobic anti-corrosion layer on the performance of the flexible cooling and heat insulating material is compared.

[0042] First, trisodium phosphate dodecahydrate powder is evenly mixed with graphite and azodicarbonamide in a mass ratio of 80:15:1; the above mixed material is evenly mixed with addition-type silicone rubber raw materials (95wt% ethylene silicone oil, 4wt% hydrogenated silicone oil, 0.5wt% platinum catalyst, 0.5wt% 1-ethynyl-1-cyclohexanol) in a mass ratio of 96:15 and pressed into a sheet profile with a thickness of 2 mm; the sheet profile is heated to 60°C for vulcanization polymerization, and then coated with a tetrafluoroethylene film with a thickness of 0.01 mm.

[0043] Comparative Example 2

[0044] On the basis of Example 1, no flexible supporting material was added to compare the effects of the flexible supporting material on the performance of the flexible cooling and heat insulating material.

[0045] First, trisodium phosphate dodecahydrate powder and styrene-based polysiloxane are evenly mixed in a mass ratio of 95:5, and then a UV curing lamp (500W) is used to cure for 30 minutes for hydrophobic anti-corrosion coating. After crushing, the mixture is evenly mixed with graphite and azodicarbonamide in a mass ratio of 80:15:1; the above-mentioned mixed material is pressed into a sheet profile with a thickness of 2 mm; and it is coated with a tetrafluoroethylene film with a thickness of 0.01 mm.

[0046] Comparative Example 3

[0047] On the basis of Example 1, no modifying additives were added to compare the effects of the modifying additives on the performance of the flexible cooling and thermal insulation material.

[0048] First, trisodium phosphate dodecahydrate powder and styrene-based polysiloxane are evenly mixed in a mass ratio of 95:5, and then a UV curing lamp (500W) is used to irradiate and cure for 30 minutes for hydrophobic anti-corrosion coating. After crushing, the mixture is evenly mixed with azodicarbonamide in a mass ratio of 80:1; the above-mentioned mixed material and addition-type silicone rubber raw materials (95wt% ethylene silicone oil, 4wt% hydrogenated silicone oil, 0.5wt% platinum catalyst, 0.5wt% 1-ethynyl-1-cyclohexanol) are evenly mixed in a mass ratio of 96:15 and pressed into a sheet profile with a thickness of 2 mm; the sheet profile is heated to 60°C for vulcanization polymerization, and then coated with a tetrafluoroethylene film with a thickness of 0.01 mm.

[0049] Comparative Example 4

[0050] On the basis of Example 1, no expansion aid was added to compare the effects of the expansion aid on the performance of the flexible cooling and heat insulating material.

[0051] First, trisodium phosphate dodecahydrate powder and styrene-based polysiloxane are evenly mixed in a mass ratio of 95:5, and then a UV curing lamp (500W) is used to irradiate and cure for 30 minutes for hydrophobic anti-corrosion coating. After crushing, the mixture is evenly mixed with graphite in a mass ratio of 80:15; the above-mentioned mixed material is evenly mixed with addition-type silicone rubber raw materials (95wt% ethylene silicone oil, 4wt% hydrogenated silicone oil, 0.5wt% platinum catalyst, 0.5wt% 1-ethynyl-1-cyclohexanol) in a mass ratio of 95:15 and pressed into a sheet profile with a thickness of 2 mm; the sheet profile is heated to 60°C for vulcanization polymerization, and then coated with a tetrafluoroethylene film with a thickness of 0.01 mm.

[0052] Comparative Example 5

[0053] On the basis of Example 1, no coating material was added to compare the effects of the coating material on the performance of the flexible cooling and heat insulating material.

[0054] First, trisodium phosphate dodecahydrate powder and styrene-based polysiloxane are evenly mixed in a mass ratio of 95:5, and then a UV curing lamp (500W) is used to cure for 30 minutes for hydrophobic anti-corrosion coating. After crushing, the mixture is evenly mixed with graphite and azodicarbonamide in a mass ratio of 80:15:1; the above-mentioned mixed material is evenly mixed with addition-type silicone rubber raw materials (95wt% ethylene silicone oil, 4wt% hydrogenated silicone oil, 0.5wt% platinum catalyst, 0.5wt% 1-ethynyl-1-cyclohexanol) in a mass ratio of 96:15 and pressed into a sheet profile with a thickness of 2 mm; the sheet profile is heated to 60°C for vulcanization polymerization.

[0055] Material performance test:

[0056] The sheet profiles prepared in Examples 1 to 3 and Comparative Examples 1 to 5 were tested for heat absorption from room temperature to 500° C. using differential scanning calorimetry, for thermal expansion when heated to 500° C. using an imaging sintering point tester, for thermal conductivity in a normal state and after expansion at 500° C. using ASTM D5470-06, for 3 kN compression set using an electronic universal testing machine, and for storage stability over a period of 6 months using a 40° C. hot box aging test. The specific test results are shown in Table 1.

[0057] Table 1

[0058]

[0059] The test results of Examples 1 to 3 and Comparative Example 1 show that if the phase change heat-absorbing material is not subjected to hydrophobic anti-corrosion treatment, the sample will soften and powder after long-term storage; the test results of Examples 1 to 3 and Comparative Example 2 show that the flexibility of the sample without adding flexible support material is poor; the test results of Examples 1 to 3 and Comparative Example 3 show that the thermal conductivity, flexibility and expansion effect of the sample without adding modifying additives deteriorate; the test results of Examples 1 to 3 and Comparative Example 4 show that the expansion effect of the sample without adding expansion aid is poor, and the thermal insulation effect after expansion is poor; the test results of Examples 1 to 3 and Comparative Example 5 show that the surface of the sample without adding coating material is prone to powdering. In addition, it can be seen from Examples 1 to 3 that when the phase change endothermic material, the flexible support material and the expansion aid are present at the same time, the thermal conductivity of the sample decreases significantly after expansion. It can be seen from Comparative Examples 2 and 4 that without using flexible support materials or expansion aids, the expansion effect is not significant, and the decrease in thermal conductivity after expansion is not significant enough. Therefore, it is shown that the phase change endothermic material, the flexible support material and the expansion aid in the patented technical solution can interact with each other when used in combination, showing significant expansion effect and thermal insulation effect.

[0060] Application Example 1:

[0061] The sheet-like profiles prepared in Examples 1 to 3 and Comparative Examples 1 to 4 were placed between 10 square ternary lithium batteries arranged together (the battery positive electrode material was NCM523, and the single battery capacity was 100 Ah) to form a battery module, which was then subjected to a fire spread prevention and control test.

[0062] The test method is: place the battery module in an explosion-proof box, heat the first battery until it experiences thermal runaway and catches fire, and observe whether the thermal runaway of the first battery can trigger thermal runaway of other batteries, as well as the temperatures of the first and second batteries.

[0063] The test results are shown in Table 2:

[0064] Table 2

[0065]

[0066] The test results of Examples 1-3 demonstrate that sheets made from multifunctional materials can effectively suppress the propagation of thermal runaway in batteries. Comparative Example 2, which lacks a flexible support material, and Comparative Example 4, which lacks an expansion aid, fail to effectively suppress the propagation of thermal runaway in lithium batteries. These results demonstrate the significant technical effectiveness of the patented technical solution in the field of new energy safety.

[0067] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Reference can be made to the common and similar parts between the various embodiments. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method description.

[0068] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A flexible cooling and heat-insulating material, characterized in that: The flexible cooling and heat-insulating material comprises a phase-change heat-absorbing material, a flexible supporting material, a modifying additive, an expansion aid and a coating material; Wherein, the mass ratio of the phase change heat absorbing material, the flexible supporting material, the modifying additive and the expansion aid is (50-90):(5-35):(5-15):(1-5).

2. The flexible cooling and heat-insulating material according to claim 1, characterized in that: The phase-change endothermic material is selected from at least one of dipotassium hydrogen phosphate hexahydrate, ferric bromide hexahydrate, calcium chloride dodecahydrate, potassium ferric sulfate dodecahydrate, calcium bromide hexahydrate, ferric chloride hexahydrate, magnesium iodide octahydrate, calcium iodide hexahydrate, manganese chloride tetrahydrate, sodium sulfate decahydrate, sodium carbonate decahydrate, disodium hydrogen phosphate dodecahydrate, sodium metasilicate nonahydrate, dipotassium hydrogen phosphate heptahydrate, sodium metasilicate tetrahydrate, sodium metasilicate pentahydrate, magnesium ammonium phosphate hexahydrate, magnesium sulfate heptahydrate, sodium oxalate trihydrate, magnesium chloride tetrahydrate, magnesium iodide octahydrate, calcium iodide hexahydrate, trisodium phosphate dodecahydrate, sodium borate decahydrate, potassium aluminum sulfate dodecahydrate, sodium aluminum sulfate decahydrate, barium hydroxide octahydrate, magnesium chloride hexahydrate, ammonium aluminum sulfate dodecahydrate, and hydrated alumina.

3. The flexible cooling and heat-insulating material according to claim 1, characterized in that: The modifying additive is selected from at least one of graphite, activated carbon, carbon nanotubes, Ketjen black, acetylene black, alumina powder, zinc oxide powder, silicon nitride powder, boron nitride powder, aluminum powder, copper powder, silver powder, silicon carbide powder, silicon dioxide powder, aluminum nitride powder, floating bead powder, hollow glass microbead powder, mica powder, and talc powder; The particle size of the modifying additive is ≤300 microns.

4. The flexible cooling and heat-insulating material according to claim 1, characterized in that: The flexible supporting material is selected from at least one of polydimethylsiloxane, addition silicone rubber, condensation silicone rubber, room temperature vulcanized silicone rubber, polyurethane adhesive, and borosilicate rubber.

5. The flexible cooling and heat-insulating material according to claim 1, characterized in that: The expansion aid is selected from at least one of azo compounds, sulfonylhydrazide compounds, and sulfonylsemicarbazide compounds.

6. The flexible cooling and heat-insulating material according to claim 1, characterized in that: The coating material is selected from at least one of polytetrafluoroethylene, polyethylene terephthalate, polyimide, polyphenylene sulfide, and polyaryletherketone; The coating material has a thickness of 0.01-0.8 mm.

7. The flexible cooling and heat-insulating material according to claim 1, characterized in that: The outer layer of the phase change heat-absorbing material is wrapped by a hydrophobic anti-corrosion material, and the wrapping material is selected from at least one of thiol-olefin functionalized polysiloxane, styrene-based polysiloxane, vinyl ether functionalized polysiloxane, epoxy-functionalized polysiloxane, acrylated polysiloxane, and vinyl silicone oil.

8. A method for preparing the flexible cooling and heat-insulating material according to any one of claims 1 to 7, characterized in that: The following steps are involved: 1) First, the phase change heat absorbing material is subjected to a hydrophobic anti-corrosion treatment; 2) then uniformly mixing the treated phase change endothermic material with the modified additive and the expansion aid according to a certain proportion; 3) The above materials are then mixed evenly with the synthetic raw materials of the flexible support material, and then prepared into profiles of different shapes and subjected to vulcanization polymerization reaction; 4) Finally, the above materials are coated with a coating material; Among them, the hydrophobic anti-corrosion treatment method of the phase change endothermic material includes: crushing and refining the phase change endothermic material, mixing the refined powder with light-curing silicone in a mass ratio of (90-99): (1-10), and then curing it with ultraviolet light. After curing, it is crushed again to form a hydrated salt powder with hydrophobic anti-corrosion function.

9. Application of the flexible cooling and heat-insulating material according to claims 1 to 8 in the field of new energy safety.

10. The use according to claim 9, characterized in that The flexible temperature-reducing and heat-insulating material is placed between, around or inside the battery pack.

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