Preparation method of core-shell structure Al-Zn@Al2O3 composite phase change heat storage material

Abstract

This invention relates to a method for preparing a core-shell structured Al-Zn@Al2O3 composite phase change thermal storage material, belonging to the technical field of medium- and high-temperature phase change thermal storage materials. This invention involves adding an aluminum powder suspension to an HCl solution and stirring at 45–65°C for 5–10 minutes. Gelatin is then added, and the mixture is reacted at 45–65°C with stirring for 10–20 minutes to obtain solution A. NH4F solution is slowly added to solution A at 40–60°C with stirring, and the reaction continues for 30–60 minutes. A mixture of zinc sulfate solution and ethylenediaminetetraacetic acid is then added, and the mixture is reacted for 3–5 hours. After standing, the solid and liquid are separated. The solid is washed 3–5 times alternately with anhydrous ethanol-water-anhydrous ethanol and dried to obtain solid B. Under a protective atmosphere, solid B is uniformly heated to 600–660°C and calcined at high temperature for 2–4 hours to obtain aluminum-zinc alloy powder. Under an air atmosphere, the aluminum-zinc alloy powder is uniformly heated to ~800°C and calcined at high temperature for 1–4 hours to obtain a core-shell structured Al-Zn@Al2O3 high-temperature phase change heat storage material.

Description

Technical Field

[0001] This invention relates to a method for preparing a core-shell structured Al-Zn@Al2O3 composite phase change thermal storage material, belonging to the technical field of medium- and high-temperature phase change thermal storage materials. Background Technology

[0002] Phase change thermal energy storage technology boasts high heat storage density and rapid response during heat storage and release. The key to this technology lies in phase change materials (PCMs), which possess advantages such as high energy density, high energy conversion efficiency, excellent recyclability, and the ability to store and release large amounts of heat at a constant temperature during phase change. Currently, PCMs are mainly classified into organic PCMs, inorganic molten salt PCMs, and metal-based PCMs. However, organic and inorganic molten salt PCMs suffer from problems such as excessively high supercooling and phase separation during thermal cycling due to their low thermal conductivity. Metal-based PCMs, with their superior thermal conductivity and heat storage density, are particularly important for thermal management and energy regulation. However, the liquid metal after solid-liquid phase change exhibits high chemical corrosion and high thermal stress caused by volume expansion, leading to the development of PCM encapsulation technology. Through continuous research, four relatively successful encapsulation strategies have emerged: metal-metal microcapsules, metal-metal macrocapsules, metal-ceramic microcapsules, and metal-ceramic macrocapsules.

[0003] However, the melting point temperature of commonly used phase change materials is often fixed by the material's inherent properties, and they can only generate enhanced latent heat absorption at specific temperature points. This characteristic limits their application range. Therefore, developing phase change materials with high comprehensive performance is of great significance for future thermal energy storage systems. Summary of the Invention

[0004] This invention addresses the problem that traditional PCMs can only perform phase change heat storage at specific temperatures. It proposes a method for preparing a core-shell structured Al-Zn@Al2O3 composite phase change heat storage material. The method involves adding dilute hydrochloric acid to an ultrasonically treated aluminum powder suspension and using ammonium fluoride solution to remove the alumina film on the aluminum powder surface. Then, a gelatin dispersion system is added, which helps ensure sufficient contact and reaction between the aluminum powder surface and zinc ions. Ethylenediaminetetraacetic acid complexes with the zinc ions, thereby controlling the displacement reaction rate. Calcination under a protective atmosphere allows the zinc coating to dissolve into the aluminum core, forming an aluminum-zinc alloy. Calcination in air allows a stable and dense Al2O3 oxide shell to form on the alloy surface, ultimately forming a core-shell structured Al-Zn@Al2O3 composite phase change heat storage material.

[0005] A method for preparing a core-shell structured Al-Zn@Al2O3 composite phase change thermal storage material, the specific steps of which are as follows:

[0006] (1) Prepare aluminum powder turbid solution, HCl solution, NH4F solution, ZnSO4 solution and ethylenediaminetetraacetic acid mixture respectively with deionized water or ultrapure water;

[0007] (2) Place the aluminum powder turbid liquid in an ultrasonic bath and sonicate for 10-30 minutes to obtain an aluminum powder suspension.

[0008] (3) Add HCl solution to aluminum powder suspension and stir for 5 to 10 minutes at 45 to 65°C. Then add gelatin and react for 10 to 20 minutes at 45 to 65°C with stirring to obtain solution A.

[0009] (4) At a temperature of 40-60℃ and under stirring conditions, NH4F solution is slowly added to solution A and the reaction continues for 30-60 min. Then, a mixture of zinc sulfate solution and ethylenediaminetetraacetic acid is added and the reaction continues for 3-5 h. After standing, the solid and liquid are separated. The solid is washed 3-5 times alternately in the order of anhydrous ethanol-water-anhydrous ethanol and dried to obtain solid B.

[0010] (5) Under a protective atmosphere, solid B is heated at a constant rate to a temperature of 600-660℃ and calcined at high temperature for 0.5-4h to obtain aluminum-zinc alloy powder;

[0011] (6) Under air atmosphere, aluminum-zinc alloy powder is heated at a constant rate to a temperature of 750-850℃ and then calcined at high temperature for 1-4 hours to obtain core-shell structured Al-Zn@Al2O3 high-temperature phase change heat storage material.

[0012] Preferably, in step (1), the molar ratio of aluminum powder, hydrochloric acid, NH4F, zinc sulfate, and ethylenediaminetetraacetic acid is 92:(5-20):(15-25):(20-60):(30-70), the concentration of HCl solution is 0.05-0.20 mol / L, the concentration of NH4F solution is 0.15-0.25 mol / L, the concentration of ZnSO4 solution is 0.28-0.56 mol / L, and the concentration of ethylenediaminetetraacetic acid solution is 0.31-0.62 mol / L.

[0013] Preferably, in step (3), the mass ratio of gelatin to aluminum powder in the aluminum powder suspension is 1:(2-50).

[0014] Preferably, the dropping rate of the NH4F solution in step (4) is 2 to 5 mL / min.

[0015] Preferably, the dropping rate of the zinc sulfate solution and ethylenediaminetetraacetic acid mixture in step (4) is 2 to 5 mL / min.

[0016] Preferably, the protective atmosphere in step (5) is N2 atmosphere or inert atmosphere, and the uniform heating rate is 5 to 30 °C / min.

[0017] Preferably, the rate of uniform heating in step (6) is 5 to 30 °C / min.

[0018] This invention controls the amount of zinc plating to form aluminum-zinc alloys with different melting points, thereby achieving regulation of the heat storage temperature range. The heat regulation range is that Al-Zn absorbs heat to undergo a solid-liquid phase transformation, achieving the effect of heat storage and temperature control. When the external temperature decreases, the heat storage core releases the stored heat and undergoes a liquid-solid transformation to slow down the temperature drop of the hot bed. During this process, the oxide shell has high strength and density, which can prevent the liquid alloy from leaking.

[0019] In this invention, gelatin is added to disperse aluminum powder and increase its reaction contact area. Hydrochloric acid and ammonium fluoride solution are added to remove the aluminum oxide film from the aluminum powder. Ethylenediaminetetraacetic acid is added to complex with zinc ions, buffering the reaction between aluminum powder and zinc ions, thus making the replaced zinc coating more uniform and dense, which is beneficial to the formation of the alloy later. Calcination in an inert atmosphere and air is to sequentially generate the alloy and oxide shell, ultimately preparing a core-shell structured Al-Zn@Al2O3 composite phase change thermal energy storage material. The core-shell structured Al-Zn@Al2O3 composite phase change thermal energy storage material can adjust the thermal energy storage temperature range and maintain a high thermal energy storage density while ensuring reliable cycle stability, thus achieving efficient energy utilization.

[0020] The beneficial effects of this invention are:

[0021] (1) In existing heat storage technologies, the heat storage temperature range of heat storage materials is generally affected by the melting point of the phase change core, resulting in a fixed heat storage temperature and lack of universal applicability. However, the core-shell structure Al-Zn@Al2O3 composite phase change heat storage material prepared by the present invention based on micron-sized aluminum powder can adjust the phase change temperature of pure aluminum from 660℃ to the low eutectic point of solid solution aluminum-zinc alloy at 618.5℃. Furthermore, the phase change temperature can be adjusted by adjusting the aluminum-zinc molar ratio in the alloy, thus making it suitable for heat storage needs in different temperature ranges.

[0022] (2) The aluminum-zinc alloy phase change heat storage material prepared by micron-sized aluminum powder in this invention is wrapped in an alumina shell, which is both heat-resistant and enhances mechanical strength. Its microcapsule structure can increase the heat exchange area and the sealing of the wrapping.

[0023] (3) The aluminum-zinc alloy phase change heat storage material prepared by micron-sized aluminum powder in this invention has a high phase change enthalpy and thermal conductivity. Compared with traditional non-metallic heat storage materials, it has a higher heat storage density and thermal conductivity, which is beneficial to improving heat transfer efficiency.

[0024] (4) The present invention employs calcination under an inert atmosphere to prevent metal oxidation and to homogenize the composition of the generated aluminum-zinc alloy, which is beneficial to the formation of the oxide shell Al2O3 during the subsequent oxidation calcination process, ensuring that it has good uniformity and density.

[0025] (5) The phase change temperature range of the aluminum-zinc alloy core of the core-shell structure Al-Zn@Al2O3 composite phase change heat storage material of the present invention is 618.5~646.9℃. The alumina of the coating layer has good high temperature resistance and high strength and density, and can be used in medium and high temperature environments, making it easier to meet industrial needs.

[0026] (6) The raw materials of this invention are cheap and readily available. Compared with the chemical zinc plating method, this process is simpler and has higher controllability, and can achieve large-scale production.

[0027] (7) The core-shell structure composite phase change heat storage material powder of the present invention can be processed into blocks or components of various shapes, which is convenient for construction when used in fields such as solar collectors and waste heat recovery devices, and is suitable for different application scenarios. Attached Figure Description

[0028] Figure 1 SEM images of the original aluminum powder and the Al@Zn prepared in Examples 1-3;

[0029] Figure 2 The images show SEM images and partial cross-sectional EDS images of the core-shell structured Al-Zn@Al2O3 composite phase change thermal energy storage material prepared in Example 1 after oxidation calcination at 800℃.

[0030] Figure 3 The following are DSC heat absorption and release characteristics of the core-shell structured Al-Zn@Al2O3 composite phase change heat storage materials prepared in Examples 1 to 3. (a) is the DSC heat absorption curve of Al-Zn@Al2O3 after calcination at 800℃ with Al-Zn alloys of different zinc concentrations, and (b) is its heat release curve.

[0031] Figure 4 The images show the XRD patterns of Al@Zn and aluminum-zinc alloy powder prepared in Examples 1-3, where (a) is Al@Zn and (b) is aluminum-zinc alloy powder. Detailed Implementation

[0032] The present invention will be further described in detail below with reference to specific embodiments, but the scope of protection of the present invention is not limited to the content described.

[0033] Example 1: A method for preparing a core-shell structured Al-Zn@Al2O3 composite phase change thermal storage material, the specific steps of which are as follows:

[0034] (1) Aluminum powder, hydrochloric acid, NH4F, zinc sulfate, and ethylenediaminetetraacetic acid were added to deionized water to prepare aluminum powder turbid solution, HCl solution, NH4F solution, ZnSO4 solution, and ethylenediaminetetraacetic acid solution, respectively; wherein the molar ratio of aluminum powder, hydrochloric acid, NH4F, zinc sulfate, and ethylenediaminetetraacetic acid was 92:20:20:28:31, the concentration of HCl in hydrochloric acid was 0.2 mol / L, the concentration of NH4F solution was 0.2 mol / L, the concentration of ZnSO4 solution was 0.28 mol / L, and the concentration of ethylenediaminetetraacetic acid solution was 0.31 mol / L;

[0035] (2) The aluminum powder turbid liquid was placed in an ultrasonic wave for 20 minutes to obtain an aluminum powder suspension; the ultrasonic power was 80W.

[0036] (3) Add HCl solution to aluminum powder suspension, stir for 5 min at 50℃, then add gelatin and react for 15 min at 50℃ with stirring to obtain solution A;

[0037] (4) At a temperature of 50℃ and under stirring conditions, NH4F solution was slowly added to solution A at a dropping rate of 2 mL / min and the reaction was continued for 30 min. Then, zinc sulfate solution and ethylenediaminetetraacetic acid solution were added at a dropping rate of 2 mL / min and the reaction was continued for 3 h. After standing for 80 min, the solid and liquid were separated. The solid was washed three times alternately in the order of anhydrous ethanol-water-anhydrous ethanol and then vacuum dried at 70℃ to obtain solid B.

[0038] (5) Under a protective atmosphere (nitrogen), solid B is heated at a constant rate of 20℃ / min to a temperature of 650℃ and then calcined at high temperature for 30 min to obtain aluminum-zinc alloy powder.

[0039] (6) Under air atmosphere, aluminum-zinc alloy powder is heated to 800℃ at a heating rate of 10℃ / min and then calcined at high temperature for 2h to obtain core-shell structured Al-Zn@Al2O3 high temperature phase change heat storage material.

[0040] The aluminum-zinc alloy powder, an intermediate product of the core-shell structured Al-Zn@Al2O3 composite phase change thermal storage material prepared in this embodiment, is shown in the SEM image. Figure 1 As shown, from Figure 1 It can be seen that the zinc plating effect of aluminum powder is significant. The zinc is basically wrapped around the surface of the aluminum powder to form a spherical shape, and there is no agglomeration. This is conducive to a more uniform distribution of the aluminum-zinc alloy and a tighter coating of the aluminum-zinc composite oxide shell in the later stage.

[0041] The SEM and EDS images of the core-shell structured Al-Zn@Al2O3 aluminum-zinc alloy phase change thermal storage material in this embodiment are shown below. Figure 2 As shown, from Figure 2It can be seen that the core-shell structure Al-Zn@Al2O3 aluminum-zinc alloy phase change heat storage material has a thick and dense surface shell, uniform coverage, and good encapsulation.

[0042] The DSC heat absorption and release characteristics of the core-shell structured Al-Zn@Al2O3 aluminum-zinc alloy phase change thermal storage material prepared in this embodiment are shown in the figure below. Figure 3 As shown, (a) is the DSC endothermic curve of Al-Zn@Al2O3 alloys with different zinc concentrations after calcination at 800℃, and (b) is its exothermic curve; from Figure 3 As shown in curve O-1, the endothermic peak is at 646.9℃ and the exothermic peak is at 610.1℃, indicating that the storage and release temperature range of the material is located near this range. The single phase change peak shows that the material prepared at this zinc sulfate solution concentration can almost completely form a solid solution aluminum-zinc alloy. The fusion heat and solidification heat of MEPCMs are both very large, and the difference between the fusion heat and solidification heat is very small, indicating that the material has excellent heat storage density and low supercooling, which is beneficial to ensuring high energy storage density and improving heat transfer efficiency.

[0043] Example 2: A method for preparing a core-shell structured Al-Zn@Al2O3 composite phase change thermal storage material, the specific steps of which are as follows:

[0044] (1) Aluminum powder, hydrochloric acid, NH4F, zinc sulfate, and ethylenediaminetetraacetic acid were added to deionized water to prepare aluminum powder turbid solution, HCl solution, NH4F solution, ZnSO4 solution, and ethylenediaminetetraacetic acid solution, respectively; wherein the molar ratio of aluminum powder, hydrochloric acid, NH4F, zinc sulfate, and ethylenediaminetetraacetic acid was 92:20:20:42:46, the concentration of HCl in hydrochloric acid was 0.2 mol / L, the concentration of NH4F solution was 0.2 mol / L, the concentration of ZnSO4 solution was 0.42 mol / L, and the concentration of ethylenediaminetetraacetic acid solution was 0.46 mol / L;

[0045] (2) The aluminum powder turbid liquid was placed in an ultrasonic wave and ultrasonically treated for 10 minutes to obtain an aluminum powder suspension; wherein the ultrasonic power was 100W.

[0046] (3) Add HCl solution to aluminum powder suspension, stir at 45℃ for 20 min, then add gelatin and react at 45℃ for 20 min with stirring to obtain solution A;

[0047] (4) At a temperature of 40℃ and under stirring conditions, NH4F solution was slowly added to solution A at a dropping rate of 3 mL / min and the reaction was continued for 40 min. Then, zinc sulfate solution and ethylenediaminetetraacetic acid solution were added at a dropping rate of 4 mL / min and the reaction was continued for 4 h. After standing for 50 min, the solid and liquid were separated. The solid was washed three times in the order of anhydrous ethanol-water-anhydrous ethanol and then dried under vacuum at 60℃ to obtain solid B.

[0048] (5) Under a protective atmosphere (argon), solid B is heated at a constant rate of 25℃ / min to a temperature of 600℃ and then calcined at high temperature for 3.5h to obtain aluminum-zinc alloy powder.

[0049] (6) Under air atmosphere, aluminum-zinc alloy powder is heated at a constant rate of 15℃ / min to a temperature of 750℃ and then calcined at high temperature for 4h to obtain core-shell structured Al-Zn@Al2O3 high temperature phase change heat storage material.

[0050] The DSC heat absorption and release characteristics of the core-shell structured Al-Zn@Al2O3 composite phase change thermal storage material prepared in this embodiment are shown in the figure below. Figure 3 As shown, from Figure 3 Curve O-2 shows that the endothermic peak is 630.5℃ and the exothermic peak is 613.9℃, indicating that the material's heat storage and release temperature range is near this range. The single phase change peak indicates that the material prepared at this zinc sulfate solution concentration can almost completely form a solid solution aluminum-zinc alloy. MEPCMs exhibit high values ​​for both fusion and solidification heats, with a small difference between them, indicating excellent heat storage density and low supercooling, which is beneficial for ensuring high energy storage density and improving heat transfer efficiency. This means the material's heat storage and release temperature range is within the desired temperature range and achieves the expected heat storage temperature regulation effect. Furthermore, the core-shell structure Al-Zn@Al2O3 aluminum-zinc alloy phase change heat storage material maintains its original high values ​​for fusion and solidification heats, with a small difference between them, indicating excellent heat storage density and low supercooling, which is beneficial for improving heat storage and heat transfer efficiency.

[0051] Example 3: A method for preparing a core-shell structured Al-Zn@Al2O3 composite phase change thermal storage material, the specific steps of which are as follows:

[0052] (1) Aluminum powder, hydrochloric acid, NH4F, zinc sulfate, and ethylenediaminetetraacetic acid were added to deionized water to prepare aluminum powder turbid solution, HCl solution, NH4F solution, ZnSO4 solution, and ethylenediaminetetraacetic acid solution, respectively; wherein the molar ratio of aluminum powder, hydrochloric acid, NH4F, zinc sulfate, and ethylenediaminetetraacetic acid was 92:20:20:56:62, the concentration of HCl in hydrochloric acid was 0.2 mol / L, the concentration of NH4F solution was 0.2 mol / L, the concentration of ZnSO4 solution was 0.56 mol / L, and the concentration of ethylenediaminetetraacetic acid solution was 0.62 mol / L;

[0053] (2) The aluminum powder turbid liquid was placed in an ultrasonic wave for 30 minutes to obtain an aluminum powder suspension; the ultrasonic power was 70W.

[0054] (3) Add HCl solution to aluminum powder suspension, stir for 5 min at 65℃, then add gelatin and react for 10 min at 65℃ with stirring to obtain solution A;

[0055] (4) At a temperature of 60℃ and under stirring conditions, NH4F solution was slowly added to solution A at a dropping rate of 5 mL / min and the reaction was continued for 50 min. Then, zinc sulfate solution and ethylenediaminetetraacetic acid solution were added at a dropping rate of 4 mL / min and the reaction was continued for 5 h. After standing for 40 min, the solid and liquid were separated. The solid was washed three times in the order of anhydrous ethanol-water-anhydrous ethanol and then vacuum dried at 60℃ to obtain solid B.

[0056] (5) Under a protective atmosphere (argon), solid B is heated at a constant rate of 15℃ / min to a temperature of 650℃ and then calcined at high temperature for 2h to obtain aluminum-zinc alloy powder.

[0057] (6) Under air atmosphere, aluminum-zinc alloy powder is heated to 850℃ at a heating rate of 12℃ / min and then calcined at high temperature for 1.5h to obtain core-shell structured Al-Zn@Al2O3 high temperature phase change heat storage material.

[0058] The DSC heat absorption and release characteristics of the core-shell structured Al-Zn@Al2O3 composite phase change thermal storage material prepared in this embodiment are shown in the figure below. Figure 3 As shown, from Figure 3 Curve O-3 shows that the endothermic peak is at 618.5℃ and the main exothermic peak is at 593℃, indicating that the heat storage and release temperature range of this material is located near this range. At this zinc plating amount, the aluminum-zinc alloy formed on the surface of the single endothermic / exothermic peak is almost entirely composed of a single phase of zinc fused to aluminum solid solution. This indicates that by further increasing the zinc plating amount, the phase change temperature can be adjusted to 618.5℃. Therefore, the MEPCMs prepared in this study have excellent applicability and controllability in medium- and high-temperature heat storage. Furthermore, the fusion heat and solidification heat values ​​of the core-shell structure Al-Zn@Al2O3 aluminum-zinc alloy phase change heat storage material remain at their original high values, and the difference between the fusion heat and solidification heat is very small, indicating that the material has excellent heat storage density and low supercooling, which is beneficial for improving energy storage and conduction efficiency.

[0059] The XRD patterns of the Al@Zn and aluminum-zinc alloy powders prepared in Examples 1-3 are shown below. Figure 4 Figure (a) shows Al@Zn. After zinc plating, all samples simultaneously exhibited both Al phase (JCPDS No. 04-0787) and Zn phase (JCPDS No. 04-0831). As the zinc sulfate content required for the reaction increased (sample spectra from bottom to top), the zinc plating amount on the sample surface increased after reduction. As can be observed in Figure (a), the peak intensity corresponding to zinc increased accordingly, and the analytical results are consistent with reality. Figure (b) shows aluminum-zinc alloy powder. Figure 4 It can be seen that the peaks of Al and the corresponding peaks of Al-Zn that are shifted from the Al peak were detected in all samples. It can also be observed that the characteristic peaks of Al in the alloy decrease with the increase of the molar fraction of zinc in the alloy, and the melting point of the alloy decreases with the increase of zinc concentration.

[0060] The specific embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A method for preparing a core-shell structured Al-Zn@Al2O3 composite phase change thermal storage material, characterized in that, The specific steps are as follows: (1) Prepare aluminum powder turbid solution, HCl solution, NH4F solution, ZnSO4 solution and ethylenediaminetetraacetic acid mixture respectively with deionized water or ultrapure water; (2) Place the turbid aluminum powder liquid in an ultrasonic bath and sonicate for 10-30 minutes to obtain an aluminum powder suspension; (3) Add HCl solution to aluminum powder suspension and stir for 5 to 10 minutes at 45 to 65°C. Then add gelatin and react for 10 to 20 minutes at 45 to 65°C with stirring to obtain solution A. (4) At a temperature of 40~60℃ and under stirring conditions, NH4F solution is slowly added to solution A and the reaction continues for 30~60 min. Then, ZnSO4 solution and ethylenediaminetetraacetic acid mixture are added and the reaction continues for 3~5 h. After standing, the solid and liquid are separated. The solid is washed 3~5 times in the order of anhydrous ethanol-water-anhydrous ethanol and dried to obtain solid B. (5) Under a protective atmosphere, solid B is heated at a constant rate to a temperature of 600~660℃ and calcined at high temperature for 0.5~4h to obtain aluminum-zinc alloy powder; (6) Under air atmosphere, aluminum-zinc alloy powder is heated at a constant rate to a temperature of 750~850℃ and then calcined at high temperature for 1~4h to obtain core-shell structured Al-Zn@Al2O3 high temperature phase change heat storage material.

2. The preparation method of the core-shell structured Al-Zn@Al2O3 composite phase change thermal storage material according to claim 1, characterized in that: Step (1) The molar ratio of aluminum powder, HCl in HCl solution, NH4F in NH4F solution, ZnSO4 in ZnSO4 solution, and ethylenediaminetetraacetic acid in the ethylenediaminetetraacetic acid mixture is 92:(5~20):(15~25):(20~60):(30~70), the concentration of HCl solution is 0.05~0.20mol / L, the concentration of NH4F solution is 0.15~0.25mol / L, the concentration of ZnSO4 solution is 0.28~0.56mol / L, and the concentration of the ethylenediaminetetraacetic acid mixture is 0.31~0.62mol / L.

3. The preparation method of the core-shell structured Al-Zn@Al2O3 composite phase change thermal storage material according to claim 1, characterized in that: Step (3) The mass ratio of gelatin to aluminum powder in the aluminum powder suspension is 1:(2~50).

4. The preparation method of the core-shell structured Al-Zn@Al2O3 composite phase change thermal storage material according to claim 1, characterized in that: In step (4), the dropping rate of the NH4F solution is 2~5 mL / min.

5. The preparation method of the core-shell structured Al-Zn@Al2O3 composite phase change thermal storage material according to claim 1, characterized in that: In step (4), the dropping rate of the zinc sulfate solution and the ethylenediaminetetraacetic acid mixture is 2~5 mL / min.

6. The preparation method of the core-shell structured Al-Zn@Al2O3 composite phase change thermal storage material according to claim 1, characterized in that: Step (5) The protective atmosphere is an inert atmosphere, and the heating rate is 5~30℃ / min.

7. The preparation method of the core-shell structured Al-Zn@Al2O3 composite phase change thermal storage material according to claim 1, characterized in that: Step (6) involves a uniform heating rate of 5~30℃ / min.

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