Low-temperature composite phase change heat storage material and preparation method thereof
By using low vapor pressure ionic liquids, 1,6-hexanediol, carboxylated multi-walled carbon nanotubes and nanoalumina particles in phase change materials, the problems of insufficient thermal conductivity and latent heat of phase change are solved, and efficient thermal management effect is achieved.
Patent Information
- Application Number
- CN202510132869.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-06
- Publication Date
- 2025-06-06
AI Technical Summary
The existing phase change materials have shortcomings in thermal conductivity and latent heat of phase change, resulting in limited application of their applications in thermal management systems.
Low vapor pressure and high thermal stability ionic liquids are used as the core of the phase change material, combined with 1,6-hexanediol, reduced the melting point, and added carboxylated multi-walled carbon nanotubes and nanoalumina particles to improve thermal conductivity and crystallization nucleation stability.
Composite phase change materials with low melting point, large density, high thermal conductivity and high phase change latent heat are realized, suitable for thermal management systems of electronic equipment, and can absorb and store heat more effectively.
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Abstract
Description
Technical Field
[0001] The present application relates to the field of heat storage materials, and in particular to a low-temperature composite phase-change heat storage material and a preparation method thereof. Background Art
[0002] With the development of hybrid and all-electric aircraft, the increasing heat generation of electrical equipment has put forward more stringent requirements on thermal management systems. In order to effectively cope with transient heat loads and take into account the requirements of lightweight design, phase change heat storage technology and cooling technology coupled with phase change materials have been proposed. Phase change materials store excess heat in a specific location container, and then dissipate heat through other cooling methods or thermoelectric power generation to continue to power low-power demand equipment, which is conducive to solving problems such as overheating of some electrical components and power supply of miniaturized devices. However, the optimal operating temperature standard of general electronic components is 20℃-35℃. The important factors that determine the application of phase change heat storage technology are the melting point and latent heat of phase change materials. Therefore, it is necessary to develop a composite phase change material with low melting point and high latent heat of phase change.
[0003] At present, there are some problems with phase change materials, such as high supercooling of hydrated salts and easy phase separation, low thermal conductivity and density of paraffin, corrosiveness of fatty acids, etc. As the core parameter of heat transfer performance, too low thermal conductivity is not conducive to the application of phase change materials. Carbon-based materials are currently widely used to improve thermal conductivity, but this brings problems such as decreased latent heat performance of phase change or increased preparation cost. For example, the thermal conductivity of paraffin is improved by modified low-melting-point metal alloys and expanded graphite, but the latent heat of phase change of composite phase change materials is slightly reduced. Alternatively, polyethylene glycol stearate and palmitic acid are adsorbed by modified expanded graphite to improve the thermal conductivity of phase change materials, but the preparation of composite phase change heat storage materials is relatively complicated, and operations such as crushing, filtration, drying, and tableting are also required, which increases the preparation time and equipment cost. At the same time, the melting temperature is around 55°C, which is not conducive to the application of thermal control of electronic equipment. The present invention is designed for low melting point, high latent heat of phase change and thermal conductivity.
[0004] Ionic liquids have attracted widespread attention due to their high designability, low vapor pressure, good chemical stability without corrosion to metal walls, and excellent thermal stability with high thermal decomposition temperature. The present invention uses ionic liquid as the core of the phase change material, mixes it with 1,6-hexanediol that is easy to form hydrogen bonds to lower the melting point, adds carboxylated multi-walled carbon nanotubes and nano-alumina particles, and concentrates the phase change process time under the combined effect of improving the thermal conductivity of the phase change material and the crystallization nucleation stability, thereby increasing the latent heat of the phase change. Summary of the invention
[0005] In order to solve the problems in the prior art, the present invention provides a low-temperature composite phase change heat storage material and a preparation method thereof, selects an ionic liquid with low vapor pressure and high thermal stability as a phase change material, mixes 1,6-hexanediol to lower the melting point, adds carboxyl multi-walled carbon nanotubes to improve thermal conductivity, and adds nano-alumina particles to optimize the crystallization nucleation performance, finally obtaining a composite phase change material with low melting point, high density, high thermal conductivity and phase change latent heat.
[0006] In order to achieve the above technical objectives, the present invention adopts the following technical means:
[0007] The present application provides a low-temperature composite phase-change heat storage material, characterized in that the material comprises 1-hexadecyl-3-methylimidazolium bromide, 1,6-hexanediol, nano-alumina particles and carboxylated multi-walled carbon nanotubes.
[0008] The present application also provides a method for preparing the low-temperature composite phase-change heat storage material, which is characterized by comprising the following steps:
[0009] Step 1: prepare 1-hexadecyl-3-methylimidazolium bromide, mix hexadecane bromide and N-methylimidazole, add acetonitrile solvent, heat in an oil bath, inject the product into ethyl acetate for decantation to obtain a white solid, wash with ethyl acetate, filter and vacuum dry to obtain 1-hexadecyl-3-methylimidazolium bromide;
[0010] Step 2: preparing a eutectic mixture, mixing the 1-hexadecyl-3-methylimidazolium bromide prepared in step 1 and 1,6-hexanediol, heating in a water bath, adding an activated molecular sieve and drying to obtain a eutectic mixture;
[0011] Step 3: Prepare a low-temperature composite phase change heat storage material. Take the eutectic mixture prepared in step 2, add carboxylated multi-walled carbon nanotubes and nano-alumina particles, heat and then perform ultrasonic treatment to prepare a low-temperature composite phase change heat storage material.
[0012] The present application also provides the use of the low-temperature composite phase-change heat storage material in the preparation of electronic components, wherein the electronic components include electric vehicle or aircraft batteries, camera charge-coupled devices, motors, some low-power chips and low-temperature thermoelectric power generation devices.
[0013] Beneficial Effects
[0014] The present invention discloses a low-temperature composite phase-change heat storage material and a preparation method thereof, which has the following advantages:
[0015] (1) The melting point of the low-temperature composite phase change heat storage material prepared in this application is 32°C-34°C. Compared with the melting point of pure 1-hexadecyl-3-methylimidazolium bromide ionic liquid at 64°C, the addition of 1,6-hexanediol increases the material entropy change and thus reduces the material melting point. At the same time, 1,6-hexanediol itself has a high latent heat of phase change, is easy to form hydrogen bonds, and is easier to mix evenly with ionic liquids. The optimal operating temperature of most electronic components is below 50°C. The thermal management system coupled with the low-temperature composite phase change heat storage material begins to absorb heat when the component temperature is higher than 32°C, which is more conducive to controlling the temperature of electronic equipment at the optimal operating temperature.
[0016] (2) The low-temperature composite phase-change heat storage material prepared in the present application is added with nano-alumina particles that promote nucleation and carboxyl multi-walled carbon nanotubes that enhance thermal conductivity, thereby improving the crystallization nucleation and thermal conductivity properties of the material, thereby increasing the amount of heat absorbed during its melting process. The phase change latent heat of the low-temperature composite phase-change heat storage material is 178J / g-198J / g, and the thermal conductivity is 0.42W / (m·K)-0.49W / (m·K). When the temperature of the electronic components is too high, it is beneficial to absorb more heat faster and maintain continuous operation time.
[0017] (3) The density of the low-temperature composite phase change thermal storage material prepared in this application is 0.95 g / cm 3 -0.98g / cm 3 , higher than the density of traditional paraffin wax (0.88g / cm 3 ), in view of the aviation airborne environment, the space where some electronic components are located is limited. High-density phase change heat storage materials require less space to control the same heat load, which is conducive to the compactness of the design of aviation thermal management devices.
[0018] (4) The low-temperature composite phase change heat storage material prepared in this application has low toxicity and no wall corrosion.
[0019] (5) The low-temperature composite phase change heat storage material prepared in the present application is simple to prepare, does not require pressurization and has a low heating temperature, which reduces the preparation time and economic cost. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 Schematic diagram of the method for preparing low-temperature composite phase change heat storage material according to the present invention.
[0021] Figure 2 The differential scanning calorimetry (DSC) curve of the eutectic mixture prepared for the comparative example of the present invention.
[0022] Figure 3 This is the DSC curve of the low-temperature composite phase change heat storage material prepared in Example 1 of the present invention.
[0023] Figure 4 This is the DSC curve of the low-temperature composite phase change heat storage material prepared in Example 2 of the present invention.
[0024] Figure 5 This is the DSC curve of the low-temperature composite phase-change heat storage material prepared in Example 3 of the present invention.
[0025] Figure 6 The thermal conductivity of Example 1 of the present invention, the comparative example and paraffin at 10°C is compared.
[0026] Figure 7 a is the low-temperature composite phase-change heat storage material prepared in Example 1 of the present invention, and b is the temperature drift signal of the thermal conductivity test of the eutectic mixture prepared in the comparative example;
[0027] Figure 8 a is the low-temperature composite phase-change heat storage material prepared in Example 1 of the present invention, and b is the transient signal of the thermal conductivity test of the eutectic mixture prepared in the comparative example;
[0028] Fig. 9 Figure a is a graph showing the low-temperature composite phase-change heat storage material prepared in Example 1 of the present invention, and figure b is a graph showing the thermal conductivity test calculation data of a eutectic mixture prepared in a comparative example;
[0029] Fig.10 In the figure, a is the low-temperature composite phase change heat storage material prepared in Example 1 of the present invention, and b is the residual signal of the thermal conductivity test of the eutectic mixture prepared in the comparative example. DETAILED DESCRIPTION
[0030] The preferred embodiments of the present invention will be described in detail below in conjunction with examples. It should be understood that the following examples are provided only for the purpose of illustration and are not intended to limit the scope of the present invention. Those skilled in the art may make various modifications and substitutions to the present invention without departing from the purpose and spirit of the present invention.
[0031] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.
[0032] Unless otherwise specified, the materials and reagents used in the following examples can be obtained from commercial sources.
[0033] An embodiment of the present application provides a low-temperature composite phase-change heat storage material, characterized in that the material comprises 1-hexadecyl-3-methylimidazolium bromide, 1,6-hexanediol, nano-alumina particles and carboxylated multi-walled carbon nanotubes.
[0034] In one embodiment of the present application, 1-hexadecyl-3-methylimidazolium bromide is used as the core component of the ionic liquid, mixed with 1,6-hexanediol to form a eutectic mixture to lower the melting point, nano-alumina particles are added to improve its phase transformation to nucleation crystallization process, and carboxylated multi-walled carbon nanotubes are added to improve the thermal conductivity.
[0035] In one embodiment, the mass ratio of 1-hexadecyl-3-methylimidazolium bromide to 1,6-hexanediol is 4:6 to 6:4, the mass fraction of nano-alumina particles is 2.0% of the total mass of the 1-hexadecyl-3-methylimidazolium bromide and 1,6-hexanediol, and the mass fraction of carboxylated multi-walled carbon nanotubes is 0.2% of the total mass of the 1-hexadecyl-3-methylimidazolium bromide and 1,6-hexanediol.
[0036] An embodiment of the present application provides a method for preparing the low-temperature composite phase-change heat storage material, comprising the following steps:
[0037] Step 1: prepare 1-hexadecyl-3-methylimidazolium bromide, mix hexadecane bromide and N-methylimidazole, add acetonitrile solvent, heat in an oil bath, inject the product into ethyl acetate for decantation to obtain a white solid, wash with ethyl acetate, filter and vacuum dry to obtain 1-hexadecyl-3-methylimidazolium bromide;
[0038] Step 2: preparing a eutectic mixture, mixing the 1-hexadecyl-3-methylimidazolium bromide prepared in step 1 and 1,6-hexanediol, heating in a water bath, adding an activated molecular sieve and drying to obtain a eutectic mixture;
[0039] Step 3: Prepare a low-temperature composite phase change heat storage material. Take the eutectic mixture prepared in step 2, add carboxylated multi-walled carbon nanotubes and nano-alumina particles, heat and then perform ultrasonic treatment to prepare a low-temperature composite phase change heat storage material.
[0040] In one embodiment, in step 1, the molar ratio of hexadecane bromide to N-methylimidazole is 1-1.05:11.
[0041] In one embodiment, in step 1, the oil bath heating is 75°C-85°C oil bath treatment for 45h-55h, and the pouring into ethyl acetate for decantation is pouring into ethyl acetate at -5°C-5°C for decantation.
[0042] In one embodiment, in step 1, vacuum drying is performed at 60° C.-80° C. for 20 h-30 h.
[0043] In one embodiment, in step 2, water bath heating is stirring at 70° C.-90° C. for 2 h-4 h.
[0044] In one embodiment, in step 2, the activated molecular sieve is a molecular sieve activated at 280° C.-380° C. for 6 h-12 h.
[0045] In one embodiment, in step 3, the ultrasonic treatment after heating is heating to 40° C.-60° C. and ultrasonic treatment for 20 min-60 min.
[0046] An embodiment of the present application provides an application of the low-temperature composite phase change heat storage material in the preparation of electronic components, wherein the electronic components include electric vehicle or aircraft batteries, camera charge-coupled devices, motors, some low-power chips and low-temperature thermoelectric power generation devices.
[0047] Embodiment 1:
[0048] Preparation of 1-hexadecyl-3-methylimidazolium bromide: 11.630 g of hexadecane bromide and 3.127 g of N-methylimidazole were mixed, acetonitrile solvent was added, and the mixture was heated in an oil bath at 75° C. for 45 h. The product was poured into ethyl acetate and decanted to obtain a white solid. The solid was washed with ethyl acetate, filtered, and dried in a vacuum at 60° C. for 20 h to obtain 1-hexadecyl-3-methylimidazolium bromide.
[0049] Weigh 6.192 g of 1-hexadecyl 3-methylimidazolium bromide and 4.859 g of 1,6-hexanediol, place in a 100 ml volumetric flask, seal with sealing film and plastic wrap, heat in an 80°C water bath, and stir magnetically at 400 rpm for 3 h. After taking out, add two 3A and two 4A molecular sieves activated at 320°C for 8 h to obtain a eutectic mixture for use.
[0050] A eutectic mixture with a mass of 10.231 g was weighed, 0.20462 g of nano-alumina particles and 0.205 g of carboxylated multi-walled carbon nanotubes were added, and after melting in an oven at 40° C., an ultrasonic treatment at 40 kHz was performed for 40 min to obtain a low-temperature composite phase change thermal storage material.
[0051] Embodiment 2:
[0052] Preparation of 1-hexadecyl-3-methylimidazolium bromide: 11.946 g of hexadecane bromide and 3.211 g of N-methylimidazole were mixed, acetonitrile solvent was added, and the mixture was heated in an oil bath at 80° C. for 50 h. The product was poured into ethyl acetate and decanted to obtain a white solid. The solid was washed with ethyl acetate, filtered, and dried in a vacuum at 70° C. for 25 h to obtain 1-hexadecyl-3-methylimidazolium bromide.
[0053] Weigh 5.387 g of 1-hexadecyl 3-methylimidazolium bromide and 6.642 g of 1,6-hexanediol, place in a 100 ml volumetric flask, seal with sealing film and plastic wrap, heat in a 70° C. water bath, and stir magnetically at 400 rpm for 3 h. Take out and add two 3A and two 4A molecular sieves activated at 280° C. for 8 h to obtain a eutectic mixture for use.
[0054] A eutectic mixture with a mass of 10.106 g was weighed, to which 0.202 g of nano-alumina particles and 0.020 g of carboxylated multi-walled carbon nanotubes were added. After being melted in an oven at 50° C., an ultrasonic treatment at 40 kHz was performed for 20 min to obtain a low-temperature composite phase change heat storage material.
[0055] Embodiment 3:
[0056] To prepare 1-hexadecyl-3-methylimidazolium bromide, 11.537 g of hexadecane bromide and 3.102 g of N-methylimidazole were mixed, acetonitrile solvent was added, and the mixture was heated in an oil bath at 85° C. for 55 h. The product was poured into ethyl acetate and decanted to obtain a white solid. The solid was washed with ethyl acetate, filtered, and dried in a vacuum at 80° C. for 30 h to obtain 1-hexadecyl-3-methylimidazolium bromide.
[0057] Weigh 7.465 g of 1-hexadecyl 3-methylimidazolium bromide and 3.978 g of 1,6-hexanediol, place in a 100 ml volumetric flask, seal with sealing film and plastic wrap, heat in a 90° C. water bath, and stir magnetically at 400 rpm for 3 h. Take out and add two 3A and two 4A molecular sieves activated at 380° C. for 8 h to obtain a eutectic mixture for use.
[0058] The eutectic mixture with a mass of 10.003 was weighed, the mass of the nano-alumina particles was 0.200 g, and the mass of the carboxylated multi-walled carbon nanotubes was 0.020 g. After being melted in an oven at 60° C., an ultrasonic treatment at 40 kHz was performed for 60 minutes to obtain a low-temperature composite phase change heat storage material.
[0059] Comparative Example:
[0060] The mass of 1-hexadecyl 3-methylimidazolium bromide is 5.603 g, the mass fraction of 1,6-hexanediol is 4.402 g, no nanoparticles are added, and other operations are the same as the preparation process of Example 1.
[0061] DSC Testing
[0062] After the prepared low-temperature composite phase change heat storage material is naturally cooled and solidified, 5 mg of sample is scraped from the cross section with a small steel spatula and placed in a pure aluminum crucible. Under a nitrogen atmosphere, the initial equilibrium temperature is -60°C. After keeping at -60°C for 10 minutes, the temperature is raised to 80°C at a rate of 5°C / min for DSC testing.
[0063] Table 1.DSC test data
[0064] Melting point(℃) Latent heat of phase change (J / g) Phase change temperature range(℃) Example 1 32.79 192.71 6.01 Example 2 34.31 183.12 5.07 Example 3 34.95 182.12 8.63 Comparative Example 33.05 179.89 9.18
[0065] Example 1 Thermal properties See attached Figure 2 The melting point is 32.79°C and the latent heat of phase change is 192.71 J / g.
[0066] The low-temperature composite phase-change heat storage material prepared in Example 2 was subjected to DSC test, and the thermal properties were shown in Figure 3 The melting point is 34.31°C and the latent heat of phase change is 183.12 J / g, which is lower than that of Example 1.
[0067] Example 3 Preparation of low-temperature composite phase change heat storage material for DSC test, thermal properties are shown in Figure 4 The melting point is 34.95°C and the latent heat of phase change is 182.12 J / g, which is lower than that of Example 1.
[0068] The mixture prepared by the comparative example was subjected to DSC test, and the thermal properties are shown in the attached Figure 5 , its melting point is 33.05℃ and its latent heat of phase change is 179.89J / g.
[0069] Density test
[0070] Take the prepared low-temperature composite phase change heat storage material and completely melt it in a 40°C oven. Use a 1000μL pipette with a maximum range of 1000μL to draw 1000μL, transfer it to a peeled beaker and weigh it. Read the reading after it stabilizes. Repeat this three times and calculate the average.
[0071] Example 1 Density is 0.967 g / cm 3 .
[0072] Example 2 Density is 0.971 g / cm 3 .
[0073] Example 3 Density is 0.965 g / cm 3 .
[0074] The density of the comparative example is 0.962 g / cm 3 .
[0075] The density of the low-temperature composite phase change heat storage material prepared in this application is measured to be 0.96 g / cm at 40°C. 3 -0.97g / cm 3 -High-density phase-change thermal storage materials require less space to control the same heat load, which is conducive to the compactness of thermal management device design.
[0076] Thermal conductivity test
[0077] The samples prepared in Example 1 and the comparative example were sent to a thermal conductivity meter to test the thermal conductivity of the prepared samples. The test results are shown in Figure 6-Figure 10 .
[0078] Test item: Thermal conductivity
[0079] Instrument model: Swedish thermal constant analyzer Hotdisk Tps 2500
[0080] Test steps and conditions:
[0081] Two approximately rectangular block samples with one side flat were prepared, with a side length greater than 2 cm and a thickness greater than 200 μm.
[0082] The test result diagram of Example 1 is shown in Figure 7-Figure 10 ,in, Figure 7 a is the temperature drift signal of the thermal conductivity test of the low-temperature composite phase-change heat storage material prepared in Example 1 of the present invention; Figure 8 a is a transient signal of thermal conductivity test of the low-temperature composite phase-change heat storage material prepared in Example 1 of the present invention; Fig. 9 a is a graph showing the thermal conductivity test calculation data of the low-temperature composite phase-change heat storage material prepared in Example 1 of the present invention; Fig.10 Figure a is the residual signal of the thermal conductivity test of the low-temperature composite phase change heat storage material prepared in Example 1 of the present invention.
[0083] For the test results of the comparative example, see Figure 7-Figure 10 ,in, Figure 7 b is the temperature drift signal of the thermal conductivity test of the eutectic mixture prepared in the comparative example of the present invention; Figure 8 b is a transient signal of thermal conductivity test of the eutectic mixture prepared in the comparative example of the present invention; Fig. 9 b is a graph showing the calculation data of the thermal conductivity test of the eutectic mixture prepared in the comparative example of the present invention; Fig.10 Figure b is the residual signal of the thermal conductivity test of the eutectic mixture prepared in the comparative example of the present invention.
[0084] Figure 6 It is a thermal conductivity diagram of Example 1, Comparative Example and paraffin.
[0085] According to the test results, it can be concluded that compared with the comparative example, the thermal conductivity of the low-temperature phase change heat storage material prepared in the present application is increased from 0.4086 W / (m·K) to 0.4511 W / (m·K) after using the additive.
[0086] The start and end temperature range of the phase change is shortened, the extrapolated temperature difference is reduced from 9.18°C to 6.01°C, the melting point is reduced from 33.05°C to 32.79°C, the latent heat of phase change is increased from 179.89 J / g to 192.71 J / g, and the thermal performance is significantly improved.
[0087] The low-temperature composite phase-change heat storage materials prepared in Examples 1 to 3 have higher density and thermal conductivity than paraffin wax, and have a clearer and faster heat release process than the mixture without adding nanoparticles in the control example. The present invention provides the low-temperature composite phase-change heat storage material and a preparation method thereof, selecting an ionic liquid with low vapor pressure and high thermal stability as a phase change material, mixing 1,6-hexanediol to lower the melting point, adding carboxyl multi-walled carbon nanotubes to improve thermal conductivity, and adding nano-alumina particles to optimize crystallization nucleation performance, and finally obtaining a composite phase change material with low melting point, high density, high thermal conductivity and phase change latent heat.
[0088] The above are only preferred embodiments of the present invention. It should be pointed out that ordinary technicians in this technical field can make improvements and modifications without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.
Claims
1. A low-temperature composite phase change heat storage material, characterized in that: The material comprises 1-hexadecyl-3-methylimidazolium bromide, 1,6-hexanediol, nano-alumina particles and carboxylated multi-walled carbon nanotubes.
2. The low-temperature composite phase change heat storage material according to claim 1, characterized in that: The mass ratio of 1-hexadecyl-3-methylimidazolium bromide to 1,6-hexanediol is 4:6 to 6:4, the mass fraction of nano-alumina particles is 2.0% of the total mass of 1-hexadecyl-3-methylimidazolium bromide and 1,6-hexanediol, and the mass fraction of carboxylated multi-walled carbon nanotubes is 0.2% of the total mass of 1-hexadecyl-3-methylimidazolium bromide and 1,6-hexanediol.
3. The method for preparing the low-temperature composite phase-change heat storage material according to claim 1, characterized in that: The following steps are involved: Step 1: prepare 1-hexadecyl-3-methylimidazolium bromide, mix hexadecane bromide and N-methylimidazole, add acetonitrile solvent, heat in an oil bath, inject the product into ethyl acetate for decantation to obtain a white solid, wash with ethyl acetate, filter and vacuum dry to obtain 1-hexadecyl-3-methylimidazolium bromide; Step 2: Prepare a eutectic mixture by taking the 1-hexadecyl-3-methylimidazolium bromide and 1,6- Hexanediol is mixed, heated in a water bath, activated molecular sieves are added and dried to obtain a eutectic mixture; Step 3: Prepare a low-temperature composite phase change heat storage material. Take the eutectic mixture prepared in step 2, add carboxylated multi-walled carbon nanotubes and nano-alumina particles, heat and then perform ultrasonic treatment to prepare a low-temperature composite phase change heat storage material.
4. The preparation method according to claim 3, characterized in that: In step 1, the molar ratio of hexadecane bromide to N-methylimidazole is 1-1.05:
11.
5. The preparation method according to claim 3, characterized in that: In step 1, the oil bath heating is 75° C.-85° C. oil bath treatment for 45 h-55 h, and the pouring into ethyl acetate for decantation is pouring into ethyl acetate at -5° C.-5° C. for decantation.
6. The preparation method according to claim 3, characterized in that: In step 1, vacuum drying is performed at 60° C.-80° C. for 20 h-30 h.
7. The preparation method according to claim 3, characterized in that: In step 2, the water bath heating is performed by stirring at 70° C.-90° C. for 2 h-4 h.
8. The preparation method according to claim 3, characterized in that: In step 2, the activated molecular sieve is a molecular sieve activated at 280° C.-380° C. for 6 h-12 h.
9. The preparation method according to claim 3, characterized in that: In step 3, the ultrasonic treatment after heating is heating to 20° C.-60° C. and ultrasonic treatment for 20 min-60 min.
10. Use of the low-temperature composite phase-change heat storage material according to claim 1 in the preparation of electronic components, wherein the electronic components include electric vehicle or aircraft batteries, camera charge-coupled devices, motors, some low-power chips and low-temperature thermoelectric power generation devices.