Mono-sized Al–Si alloy particles with identical thermal history for energy storage application fabricated via the pulsated orifice ejection method

Metallic phase-change materials (PCMs) offer significant benefits, including a latent heat of phase change and dense heat storage capacity, and have broad application prospects in recovery and utilization of various high-temperature industrial waste heats. However, the application of metallic PCMs is considerably restricted due to leakage and corrosion issues during high-temperature phase transition. In this study, high-quality mono-sized Al–Si particles with excellent spherical shapes and narrow size distributions were prepared by pulsated orifice ejection method (POEM) in different cooling gas atmospheres. After high-temperature thermal oxidation, an Al₂O₃ shell layer formed around the particles, enabling the self-encapsulation of the metallic core. The results showed that the particles prepared in argon and helium gas exhibited thermal energy storage densities of 403.81 J/g and 429.02 J/g, respectively, while their thermal energy release densities were 408.57 J/g and 428.19 J/g. After 100 thermal cycles, the Al₂O₃ shell proved effective in preserving the core-shell structure, demonstrating excellent thermal stability and oxidation resistance throughout the thermal cycling process.