Development of phase change materials using hydrolyzed Al-Bi composite powder for solar energy storage

•The composite PCMs were developed using hydrogen generation waste residue stream.•The hydrogen generation yield of Al-Bi powders in 50 min was 537.3 to 565.7 mL/g.•The prepared composite PCMs had good thermal energy storage and reusable properties.•This study achieved the reuse of hydrogen generation waste residue stream.•This study offered a new method for preparing Al-based composite PCMs. The hydrogen generation technology using the hydrolysis of Al-based composite powders has recently gained an increasing attention. However, the emission of hydrogen generation waste residue stream is an urgent problem to be addressed in the actual manufacture. For this purpose, this study reported the development of phase change thermal energy storage materials using hydrogen generation waste residue stream from Al-based composite powder hydrolysis. Specifically, the rapid hydrolysis reaction of Al-Bi composite powders was used to generate hydrogen, and subsequently tetraethoxysilane of different masses was added to the hydrogen generation waste residue stream to prepare Al-Si/Al2O3 composite phase change materials (PCMs) with controllable melting temperature. The results indicated that the hydrogen generation yield of Al-Bi composite powders during the fabrication of composite PCMs was 537.3–565.7 mL/g. Importantly, the prepared composite PCMs, with a controllable melting temperature of 573.2–654.2 °C, thermal energy storage density of 30.9–37.3 J/g, great repeatable utilization performance and structural stability, were potential thermal energy storage materials for concentrated solar power plants. Thus, this study not only achieved the reuse of hydrogen generation waste residue stream but also offered a new method for preparing Al-based composite PCMs.