Phase change energy storage material and preparation method thereof

Abstract

The application belongs to the technical field of energy storage materials, and particularly relates to a phase change energy storage material and a preparation method thereof. The phase change energy storage material is prepared from the following raw materials in parts by weight: 8-12 parts of phase change wax, 10-15 parts of ZnAl-LDH, 6-9 parts of SiC-CuS, and 8 parts of polyethylene glycol dimethyl ether. The application combines bimetallic hydroxide and phase change wax. The interlayer water molecules and ionic bond energy of the bimetallic hydroxide can realize reversible phase change, which can support the phase change wax to reduce high-temperature flow. The phase change wax can compensate for the insufficient latent heat to improve the energy storage capacity. The combination of the two can widen the phase change temperature range and enhance the cycle stability. In addition, the Si-C loaded CuS nanosheet can transfer energy under light or heat to assist storage. The smaller the size of the nanosheet is, the larger the specific surface area is, and the more active sites can be provided to improve the heat conduction efficiency. Through a simple method, the advantages of the material are complementary, and the material has good comprehensive performance.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of energy storage materials, and particularly relates to a phase change energy storage material and a preparation method thereof. BACKGROUND

[0002] The phase change energy storage material is a functional material capable of absorbing or releasing a large amount of latent heat through a phase change process at a specific temperature, thereby realizing energy storage and regulation.

[0003] The phase change energy storage material in the prior art mainly includes organic phase change materials and inorganic phase change materials.

[0004] Therefore, it is important to develop a phase change energy storage material to overcome the problems in the prior art. SUMMARY

[0005] To overcome the defects in the prior art, the phase change energy storage material is prepared by combining double metal hydroxides with phase change waxes.

[0006] To achieve the above object, the technical scheme adopted by the application is a phase change energy storage material prepared from the following raw materials by weight: 8-12 parts of phase change wax, 10-15 parts of ZnAl-LDH, 6-9 parts of SiC-CuS, and 8 parts of polyethylene glycol dimethyl ether.

[0007] Further, the preparation method of the SiC-CuS comprises the following steps:

[0008] (a) 2-4 parts of copper nitrate trihydrate are weighed and added into 30 parts of deionized water, an alkali solution is added to adjust the pH range to 7.5-8.5, the concentration of the alkali solution is 0.5 mol / L, and stirring is performed at a speed of 500 r / min for 30 min to obtain a pre-reaction liquid;

[0009] (b) 4.5-9 parts of thiourea are weighed and added into the pre-reaction liquid obtained in step (a), stirring is performed at a speed of 500 r / min for 30 min, and the mixture is placed in an autoclave for hydrothermal reaction at a temperature of 80-120℃ for 15 h to obtain a precipitate, the precipitate is washed by centrifugation with deionized water and anhydrous ethanol alternately for 3 times, and the mixture is dried in a blast drying oven at a temperature of 65℃ for 24 h to obtain CuS;

[0010] (c) 3-6 parts of SiC are dried and treated, and 10 parts of CuS obtained in step (b) are added and ground to obtain a SiC-CuS precursor;

[0011] (d) the SiC-CuS precursor obtained in step (c) is placed in a tube furnace under the condition of an argon atmosphere with a flow rate of 300 mL / min, the temperature is increased from room temperature to 350-450℃, the temperature is maintained for calcination for 4 h, the heating rate is 5℃ / min, and the mixture is naturally cooled to room temperature to obtain SiC-CuS.

[0012] Further, the preparation method of the ZnAl-LDH comprises the following steps:

[0013] (i) 1-1.5 parts of zinc nitrate hexahydrate are weighed and added into 20 parts of deionized water, stirring is performed at a speed of 500 r / min for 30 min to obtain liquid A, and 2.5-4 parts of aluminum nitrate nonahydrate are weighed and added into 20 parts of deionized water, stirring is performed at a speed of 500 r / min for 30 min to obtain liquid B;

[0014] (ii) liquid A obtained in step (i) is added into liquid B obtained in step (i), an alkali solution is added to adjust the pH range to 8-10, the concentration of the alkali solution is 1 mol / L, and stirring is performed at a speed of 500 r / min for 30 min to obtain a mixed liquid I;

[0015] (iii) the mixed liquid I obtained in step (ii) is subjected to hydrothermal reaction at a temperature of 120-150℃ for 24 h, and the mixture is naturally cooled to room temperature to obtain a ZnAl-LDH precursor;

[0016] (vi) The ZnAl-LDH precursor obtained in step (iii) is washed with deionized water and anhydrous ethanol alternately by centrifugation for 3 times, and dried in a blast drying oven at 65℃ for 24h to obtain ZnAl-LDH.

[0017] The application further provides a preparation method of the phase change energy storage material.

[0018] Step one, 10-15 parts of ZnAl-LDH are weighed and added into 25 parts of anhydrous ethanol, and stirred at a rotation speed of 500r / min for 30min to obtain reaction liquid A; 6-9 parts of SiC-CuS are weighed and added into 25 parts of anhydrous ethanol, and stirred at a rotation speed of 500r / min for 30min to obtain reaction liquid B;

[0019] Step two, 8-12 parts of phase change wax and 8 parts of polyethylene glycol dimethyl ether are weighed, the phase change wax is added into the polyethylene glycol dimethyl ether, heated at 70℃ for 40min, and stirred at a rotation speed of 500r / min to obtain mixed liquid I;

[0020] Step three, the reaction liquid A obtained in step one is added into the mixed liquid I obtained in step two, ultrasonic is performed at a power of 0.5KW for 20min, heated at 60℃ and stirred at a rotation speed of 500r / min to obtain mixed liquid II;

[0021] Step four, the reaction liquid B obtained in step one is added into the mixed liquid II obtained in step three, ultrasonic is performed at a power of 0.5KW for 30min, and stirred at a rotation speed of 500r / min, the heating temperature is 75℃ and maintained for 3h, and then naturally cooled to room temperature to obtain the phase change energy storage material.

[0022] The application has the following beneficial effects:

[0023] The phase change energy storage material prepared by this invention combines bimetallic hydroxide and phase change wax for the first time. Bimetallic hydroxide exhibits a reversible phase change process, with water molecules in its interlayers undergoing desorption and adsorption upon temperature changes. Furthermore, as an ionic compound, bimetallic hydroxide's ionic bonds can break and synthesize, enabling a reversible phase change process. Simultaneously, bimetallic hydroxide provides structural support to the phase change wax, reducing its high-temperature flow problem. The phase change wax compensates for any potential deficiency in the latent heat of phase change of bimetallic hydroxide, enhancing the overall energy storage capacity. The combination of these two components flexibly broadens the overall phase change temperature range of the composite phase change material. Moreover, bimetallic hydroxide retains its layered structure after multiple heating-cooling cycles, effectively maintaining the reversible desorption and adsorption processes of water molecules in the interlayers. This provides structural stability to the phase change wax, reducing performance degradation caused by changes in molecular chain structure during repeated cycles. Therefore, the overall cycle stability of the composite phase change energy storage material is improved, extending its service life.

[0024] The phase change energy storage material prepared by this invention, in order to ensure the high efficiency and conversion efficiency of the phase change energy storage material, introduces Si-C supported CuS nanosheets, which can transfer energy to bimetallic hydroxide and phase change wax under light or heat conditions, and realize energy storage through the phase change of the material; at the same time, the smaller the size of the synthesized CuS nanosheets, the larger their specific surface area and the higher the proportion of surface atoms, providing more active sites for Si-C loading and improving the overall thermal conductivity of the material.

[0025] This invention provides a simple preparation method to obtain a highly efficient and stable phase change energy storage material. Attached Figure Description

[0026] Figure 1 This is a diagram illustrating the preparation method of the phase change energy storage material proposed in this invention;

[0027] Figure 2 The phase spectrum of ZnAl-LDH in the phase change energy storage material prepared in Example 2 of this invention;

[0028] Figure 3 The phase spectrum of CuS in the phase change energy storage material prepared in Example 2 of this invention;

[0029] Figure 4 This is a SEM image of CuS in the phase change energy storage material prepared in Example 2 of the present invention;

[0030] Figure 5 This is a TEM image of SiC-CuS in the phase change energy storage material prepared in Example 2 of the present invention;

[0031] Figure 6This is a high-resolution test image of SiC-CuS in the phase change energy storage material prepared in Example 2 of the present invention;

[0032] Figure 7 This is a test graph showing the light absorption performance of SiC-CuS in the phase change energy storage material prepared in Example 2 of the present invention;

[0033] Figure 8 This is a unidirectional differential scanning calorimetry image of the phase change energy storage material prepared in Example 2 of the present invention.

[0034] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof. Detailed Implementation

[0035] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those familiar to those skilled in the art. Furthermore, any methods and materials similar to or equivalent to those described herein may be applied to this invention. The preferred embodiments and materials described herein are for illustrative purposes only and do not limit the scope of this application.

[0037] The preparation method and test patterns in the following examples are referenced. Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 and Figure 8 Unless otherwise specified, all methods are conventional. Unless otherwise specified, the materials used in the following examples are calculated by mass, and all materials used are new materials purchased from the market. Paraffin wax was selected as the phase change wax.

[0038] Example 1: A phase change energy storage material, prepared from the following raw materials in parts by weight: 8 parts paraffin, 10 parts ZnAl-LDH, 6 parts SiC-CuS, and 8 parts polyethylene glycol dimethyl ether.

[0039] The preparation method of SiC-CuS includes the following steps:

[0040] (a) Weigh 2 parts of copper nitrate trihydrate and add them to 30 parts of deionized water. Add 0.5 mol / L sodium hydroxide solution to adjust the pH to 7.5 and stir for 30 min at a speed of 500 r / min to obtain the solution before reaction.

[0041] (b) Weigh 4.5 parts of thiourea and add them to the pre-reaction liquid obtained in step (a). Stir at 500 r / min for 30 min and place in a hydrothermal reactor. Heat the temperature to 80℃ and carry out hydrothermal reaction for 15 h to obtain a precipitate. Wash the precipitate with deionized water and anhydrous ethanol by centrifugation three times each, and dry it in a forced-air drying oven at 65℃ for 24 h to obtain CuS.

[0042] (c) Weigh 3 parts of SiC and dry them in a forced-air drying oven at 65°C for 12 hours. Add 10 parts of CuS obtained in step (b) and grind and mix them evenly to obtain the SiC-CuS precursor.

[0043] (d) The SiC-CuS precursor obtained in step (c) was placed in a tube furnace with a temperature of 350°C raised from room temperature to 300°C under an argon atmosphere with a flow rate of 300 mL / min. The temperature was maintained for calcination for 4 h at a heating rate of 5°C / min. The precursor was then naturally cooled to room temperature to obtain SiC-CuS.

[0044] The preparation method of ZnAl-LDH includes the following steps:

[0045] (i) Weigh 1 part of zinc nitrate hexahydrate and add it to 20 parts of deionized water. Stir for 30 minutes at a speed of 500 r / min to obtain solution A. Weigh 2.5 parts of aluminum nitrate nonahydrate and add it to 20 parts of deionized water. Stir for 30 minutes at a speed of 500 r / min to obtain solution B.

[0046] (ii) Add solution A obtained in step (i) to solution B obtained in step (i), add 1 mol / L sodium hydroxide solution to adjust the pH to 8, and stir for 30 min at a speed of 500 r / min to obtain mixture I;

[0047] (iii) The mixture I obtained in step (ii) was subjected to a hydrothermal reaction at 120°C for 24 h and then naturally cooled to room temperature to obtain the ZnAl-LDH precursor;

[0048] (vi) The ZnAl-LDH precursor obtained in step (iii) was washed three times each by alternating centrifugation with deionized water and anhydrous ethanol, and then dried in a forced-air drying oven at 65°C for 24 h to obtain ZnAl-LDH.

[0049] This embodiment also provides a method for preparing a phase change energy storage material, including the following steps:

[0050] Step 1: Weigh 10 parts of ZnAl-LDH and add them to 25 parts of anhydrous ethanol. Stir at 500 r / min for 30 min to obtain reaction solution A. Weigh 6 parts of SiC-CuS and add them to 25 parts of anhydrous ethanol. Stir at 500 r / min for 30 min to obtain reaction solution B.

[0051] Step 2: Weigh 8 parts of paraffin wax and 8 parts of polyethylene glycol dimethyl ether. Add the paraffin wax to the polyethylene glycol dimethyl ether and heat at 70°C for 40 minutes while stirring at 500 r / min to obtain mixture I.

[0052] Step 3: Add the reaction solution A obtained in Step 1 to the mixture I obtained in Step 2, sonicate for 20 minutes under a power of 0.5KW, heat to 60℃ and stir at a speed of 500r / min to obtain mixture II;

[0053] Step 4: Add the reaction solution B obtained in Step 1 to the mixture II obtained in Step 3, sonicate for 30 minutes under a power of 0.5KW, stir at a speed of 500r / min, heat to 75℃ and maintain for 3 hours, and cool naturally to room temperature to obtain the phase change energy storage material.

[0054] Example 2: A phase change energy storage material, prepared from the following raw materials in parts by weight: 10 parts paraffin, 13 parts ZnAl-LDH, 7.5 parts SiC-CuS, and 8 parts polyethylene glycol dimethyl ether.

[0055] The preparation method of SiC-CuS includes the following steps:

[0056] (a) Weigh 3 parts of copper nitrate trihydrate and add them to 30 parts of deionized water. Add 0.5 mol / L sodium hydroxide solution to adjust the pH to 8 and stir for 30 min at a speed of 500 r / min to obtain the solution before reaction.

[0057] (b) Weigh 6.8 parts of thiourea and add them to the pre-reaction liquid obtained in step (a). Stir for 30 min at a speed of 500 r / min. Place the mixture in a hydrothermal reactor and heat it to 100 °C for hydrothermal reaction for 15 h to obtain a precipitate. Wash the precipitate with deionized water and anhydrous ethanol by centrifugation three times each, and dry it in a forced-air drying oven at 65 °C for 24 h to obtain CuS.

[0058] (c) Weigh 4.5 parts of SiC and dry it in a forced-air drying oven at 65°C for 12 hours. Add 10 parts of CuS obtained in step (b) and grind and mix them evenly to obtain the SiC-CuS precursor.

[0059] (d) The SiC-CuS precursor obtained in step (c) was placed in a tube furnace with a temperature of 400°C raised from room temperature under an argon atmosphere with a flow rate of 300 mL / min. The temperature was maintained for calcination for 4 h at a rate of 5°C / min. The precursor was then naturally cooled to room temperature to obtain SiC-CuS.

[0060] The preparation method of ZnAl-LDH includes the following steps:

[0061] (i) Weigh 1.3 parts of zinc nitrate hexahydrate and add it to 20 parts of deionized water. Stir for 30 minutes at a speed of 500 r / min to obtain solution A. Weigh 3.3 parts of aluminum nitrate nonahydrate and add it to 20 parts of deionized water. Stir for 30 minutes at a speed of 500 r / min to obtain solution B.

[0062] (ii) Add solution A obtained in step (i) to solution B obtained in step (i), add 1 mol / L sodium hydroxide solution to adjust the pH to 9, and stir for 30 min at a speed of 500 r / min to obtain mixture I;

[0063] (iii) The mixture I obtained in step (ii) was subjected to a hydrothermal reaction at 135°C for 24 h and then naturally cooled to room temperature to obtain the ZnAl-LDH precursor;

[0064] (vi) The ZnAl-LDH precursor obtained in step (iii) was washed three times each by alternating centrifugation with deionized water and anhydrous ethanol, and then dried in a forced-air drying oven at 65°C for 24 h to obtain ZnAl-LDH.

[0065] This embodiment also provides a method for preparing a phase change energy storage material, including the following steps:

[0066] Step 1: Weigh 13 parts of ZnAl-LDH and add them to 25 parts of anhydrous ethanol. Stir at 500 r / min for 30 min to obtain reaction solution A. Weigh 7.5 parts of SiC-CuS and add them to 25 parts of anhydrous ethanol. Stir at 500 r / min for 30 min to obtain reaction solution B.

[0067] Step 2: Weigh 10 parts of paraffin wax and 8 parts of polyethylene glycol dimethyl ether. Add the paraffin wax to the polyethylene glycol dimethyl ether and heat at 70°C for 40 minutes while stirring at 500 r / min to obtain mixture I.

[0068] Step 3: Add the reaction solution A obtained in Step 1 to the mixture I obtained in Step 2, sonicate for 20 minutes under a power of 0.5KW, heat to 60℃ and stir at a speed of 500r / min to obtain mixture II;

[0069] Step 4: Add the reaction solution B obtained in Step 1 to the mixture II obtained in Step 3, sonicate for 30 minutes under a power of 0.5KW, stir at a speed of 500r / min, heat to 75℃ and maintain for 3 hours, and cool naturally to room temperature to obtain the phase change energy storage material.

[0070] Example 3: A phase change energy storage material, prepared from the following raw materials in parts by weight: 12 parts paraffin, 15 parts ZnAl-LDH, 9 parts SiC-CuS, and 8 parts polyethylene glycol dimethyl ether.

[0071] The preparation method of SiC-CuS includes the following steps:

[0072] (a) Weigh 4 parts of copper nitrate trihydrate and add them to 30 parts of deionized water. Add 0.5 mol / L sodium hydroxide solution to adjust the pH to 8.5 and stir for 30 min at a speed of 500 r / min to obtain the solution before reaction.

[0073] (b) Weigh 9 portions of thiourea and add them to the pre-reaction liquid obtained in step (a). Stir at 500 r / min for 30 min and place in a hydrothermal reactor. Heat the temperature to 120℃ and carry out hydrothermal reaction for 15 h to obtain a precipitate. Wash the precipitate with deionized water and anhydrous ethanol by centrifugation 3 times each, and dry it in a forced-air drying oven at 65℃ for 24 h to obtain CuS.

[0074] (c) Weigh 6 parts of SiC and dry them in a forced-air drying oven at 65°C for 12 hours. Add 10 parts of CuS obtained in step (b) and grind and mix them evenly to obtain the SiC-CuS precursor.

[0075] (d) The SiC-CuS precursor obtained in step (c) was placed in a tube furnace with a temperature of 450°C raised from room temperature under an argon atmosphere with a flow rate of 300 mL / min, and calcined for 4 h at a rate of 5°C / min. It was then naturally cooled to room temperature to obtain SiC-CuS.

[0076] The preparation method of ZnAl-LDH includes the following steps:

[0077] (i) Weigh 1.5 parts of zinc nitrate hexahydrate and add it to 20 parts of deionized water. Stir for 30 minutes at a speed of 500 r / min to obtain solution A. Weigh 4 parts of aluminum nitrate nonahydrate and add it to 20 parts of deionized water. Stir for 30 minutes at a speed of 500 r / min to obtain solution B.

[0078] (ii) Add solution A obtained in step (i) to solution B obtained in step (i), add 1 mol / L sodium hydroxide solution to adjust the pH to 10, and stir for 30 min at a speed of 500 r / min to obtain mixture I;

[0079] (iii) The mixture I obtained in step (ii) was subjected to a hydrothermal reaction at 150°C for 24 h and then naturally cooled to room temperature to obtain the ZnAl-LDH precursor;

[0080] (vi) The ZnAl-LDH precursor obtained in step (iii) was washed three times each by alternating centrifugation with deionized water and anhydrous ethanol, and then dried in a forced-air drying oven at 65°C for 24 h to obtain ZnAl-LDH.

[0081] This embodiment also provides a method for preparing a phase change energy storage material, including the following steps:

[0082] Step 1: Weigh 15 parts of ZnAl-LDH and add them to 25 parts of anhydrous ethanol. Stir at 500 r / min for 30 min to obtain reaction solution A. Weigh 9 parts of SiC-CuS and add them to 25 parts of anhydrous ethanol. Stir at 500 r / min for 30 min to obtain reaction solution B.

[0083] Step 2: Weigh 12 parts of paraffin wax and 8 parts of polyethylene glycol dimethyl ether. Add the paraffin wax to the polyethylene glycol dimethyl ether and heat at 70°C for 40 minutes while stirring at 500 r / min to obtain mixture I.

[0084] Step 3: Add the reaction solution A obtained in Step 1 to the mixture I obtained in Step 2, sonicate for 20 minutes under a power of 0.5KW, heat to 60℃ and stir at a speed of 500r / min to obtain mixture II;

[0085] Step 4: Add the reaction solution B obtained in Step 1 to the mixture II obtained in Step 3, sonicate for 30 minutes under a power of 0.5KW, stir at a speed of 500r / min, heat to 75℃ and maintain for 3 hours, and cool naturally to room temperature to obtain the phase change energy storage material.

[0086] The difference between Example 4 and Example 2 is that the sodium hydroxide solution is replaced with potassium hydroxide solution, and the rest is the same as Example 2.

[0087] Comparative example:

[0088] The difference between Comparative Example 1 and Example 2 is that ZnAl-LDH was not added; the rest is the same as Example 2.

[0089] The difference between Comparative Example 2 and Example 2 is that SiC-CuS was not added; the rest is the same as Example 2.

[0090] The difference between Comparative Example 3 and Example 2 is that ZnAl-LDH and SiC-CuS were not added; the rest of the parts are the same as Example 2.

[0091] The specific performance analysis of the prepared phase change energy storage material is as follows:

[0092] in Figure 2 The phase spectrum of ZnAl-LDH is obtained by... Figure 2 It can be seen that the diffraction peaks of ZnAl-LDH at 2θ of 11.64°, 23.39°, 34.56°, 39.15°, and 46.64° correspond to ZnAl-LDH-JCPDS, respectively. # The 003, 006, 012, 015 and 018 crystal planes of 38-0486 indicate that ZnAl-LDH was successfully prepared; Figure 3 The phase spectrum of CuS is obtained by... Figure 3 It can be seen that the diffraction peaks of CuS at 2θ of 29.27°, 31.78°, 32.85° and 47.94° correspond to CuS-JCPDS, respectively. # The 102, 103, 006, and 110 crystal planes of 06-0464 indicate that CuS was successfully prepared; the phase spectra of the above materials do not show any other impurity peaks, indicating that the prepared materials have high purity. Figure 4 The CuS SEM image shows a uniform nanosheet structure, which provides more active sites for SiC loading. Figure 5 The TEM image of SiC-CuS shows that the two materials are closely bonded, indicating that SiC was successfully loaded onto the CuS surface. Figure 6 The image shows a high-resolution test pattern of SiC-CuS, where D=0.282nm corresponds to the 103 crystal plane of CuS, further indicating that SiC-CuS was successfully prepared. Figure 7 The graph shows the light absorption performance of SiC-CuS. It can be seen that the loading of SiC causes a blue shift in the light absorption performance of CuS, which improves the light absorption of CuS in the visible light range. Figure 8 The one-way differential scanning calorimetry (DSC) curve for preparing phase change energy storage materials shows that the phase change temperature of the phase change energy storage material prepared in Example 2 is 84.23℃, the phase change enthalpy is 261 J / g, and the thermal conductivity is 7.81 W / (m·K).

[0093] Table 1 shows the performance data of the phase change energy storage materials prepared in the examples and comparative examples:

[0094]

[0095] The data comparison in Table 1 shows that the phase change energy storage material prepared in the example has a higher phase change temperature than the comparative example, and also has a higher phase change enthalpy and thermal conductivity, indicating that the prepared phase change energy storage material has a better energy storage effect.

[0096] Obviously, the above comparative examples and embodiments are only a part of the comparative examples and embodiments of the present invention, and they, along with the comparative examples and embodiments referenced based on such examples, are all within the scope of protection of this invention.

[0097] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

[0098] The present invention and its embodiments have been described above. This description is not restrictive, and the accompanying drawings are only one embodiment of the present invention. The actual application is not limited to this. In conclusion, if those skilled in the art are inspired by this description and design similar methods and embodiments without departing from the spirit of the present invention, they should all fall within the protection scope of the present invention.

Claims

1. A phase change energy storage material, characterized in that, It is prepared from the following raw materials in parts by weight: 8-12 parts phase change wax, 10-15 parts ZnAl-LDH, 6-9 parts SiC-CuS, and 8 parts polyethylene glycol dimethyl ether; The raw materials for preparing ZnAl-LDH include zinc nitrate hexahydrate and aluminum nitrate nonahydrate, wherein the mass ratio of zinc nitrate hexahydrate to aluminum nitrate nonahydrate is 1-1.5:2.5-4. The raw materials for preparing SiC-CuS include copper nitrate trihydrate, thiourea and SiC, wherein the mass ratio of copper nitrate trihydrate to thiourea is 2-4:4.5-9. The preparation method of SiC-CuS includes the following steps: (a) Weigh out copper nitrate trihydrate and add it to deionized water. Add alkali solution to adjust the pH and stir to obtain the solution before reaction. (b) Weigh thiourea and add it to the pre-reaction liquid obtained in step (a) and stir. Perform hydrothermal reaction to obtain a precipitate. Wash and dry the precipitate to obtain CuS. (c) Weigh and dry SiC, add CuS obtained in step (b) and grind and mix to obtain SiC-CuS precursor; (d) The SiC-CuS precursor obtained in step (c) is calcined and cooled to obtain SiC-CuS; The preparation method of ZnAl-LDH includes the following steps: (i) Weigh zinc nitrate hexahydrate and add it to deionized water and stir to obtain solution A. Weigh aluminum nitrate nonahydrate and add it to deionized water and stir to obtain solution B. (ii) Add solution A obtained in step (i) to solution B obtained in step (i), add alkali solution to adjust pH and stir to obtain mixture I; (iii) The mixture I obtained in step (ii) is subjected to a hydrothermal reaction and cooled to obtain the ZnAl-LDH precursor; (vi) Wash and dry the ZnAl-LDH precursor obtained in step (iii) to obtain ZnAl-LDH.

2. The phase change energy storage material according to claim 1, characterized in that, The alkaline solution mentioned in step (a) is a sodium hydroxide solution or a potassium hydroxide solution, the concentration of the alkaline solution is 0.5 mol / L, the pH range is 7.5-8.5, and the mass ratio of SiC to CuS mentioned in step (c) is 3-6:

10.

3. The phase change energy storage material according to claim 1, characterized in that, The alkaline solution mentioned in step (ii) is a sodium hydroxide solution or a potassium hydroxide solution, the concentration of the alkaline solution is 1 mol / L, and the pH range is 8-10.

4. A method for preparing a phase change energy storage material according to any one of claims 1-3, characterized in that, Includes the following steps: Step 1: Weigh ZnAl-LDH and add it to anhydrous ethanol, stir to obtain reaction solution A; weigh SiC-CuS and add it to anhydrous ethanol, stir to obtain reaction solution B. Step 2: Weigh out the phase change wax and polyethylene glycol dimethyl ether, add the phase change wax to the polyethylene glycol dimethyl ether, heat and stir to obtain mixture I; Step 3: Add the reaction solution A obtained in Step 1 to the mixture I obtained in Step 2, sonicate, heat and stir to obtain mixture II; Step 4: Add the reaction solution B obtained in Step 1 to the mixture II obtained in Step 3, sonicate and stir, heat, and cool to obtain the phase change energy storage material.

Images