Preparation of a new capsule phase change material for high temperature thermal energy storage

Phase change materials (PCMs) have the function of the high temperature thermal energy storage through the phase transition of Al alloys. The liquid alloys have certain liquidity and strong corrosivity. Therefore, general metals and alloys as container would hardly assure the long-term stability in high temperature. Therefore, the encapsulation of melt under the condition of high temperature is a necessary way to fabricate the practical materials. The study seeks to a new method to enhance the stability, high-temperature re-sistance, high-strength shell and leakage prevention by copper plating on the Al/Al2O3 composite surface. Firstly, the Al microspheres (20-40 mu m) are treated by boiling treatment in water forms the AlOOH shell. The AlOOH shell was transformed into Al2O3 shell through heating at 550 degrees C. And then, the electroless copper plating is implemented to become the multilayered micro-encapsulated phase change material (MEPCM). The thermal durability, cross-sectional structure, surface morphology, and stability of the MEPCM are investigated. The latent heat of Al/Al2O3@Cu MEPCM reaches 223.4 J/g. The shell surface of Al/Al2O3@Cu particles are smooth and dense, after 10 melting-solidification cycles. Moreover, the MEPCM particles maintain their integrity to prevent the leakage of liquid which can be used for high-temperature thermal energy storage such as industrial waste heat recovery. The research also provides a method for the preparation of other heat storage materials, especially for the low-temperature metal-based PCMs. (C) 2021 Elsevier B.V. All rights reserved.