Thermal Hysteresis Mitigation in Advanced Al–Cu–Si Phase Change Materials Developed via Dry Synthesis Approach for Effective Thermal Energy Storage and Industrial Thermal Regulations

Metals and their alloy-based phase change materials (PCMs) are fascinating for thermal energy storage (TES) and thermal management (TM) because of their high heat storage density, wide range of temperature selection, and high thermal conductivity, calling for new materials’ development and enhancements for effective utilization in TES or TM systems. In this report, we present an advancement in the synthesis and enhancement of the thermal and structural properties of ternary eutectic Al–Cu–Si microencapsulated PCMs (MEPCMs) via high-speed impact blending, an approach to adhere TiO2 nanoadditive to PCMs, and heat oxidation treatment. Consequently, Ti doping led to formation of CuTi2 and TiSi intermetallic compounds, resulting in enhanced structural and thermal properties: highly thermally stable MEPCMs with enhanced crystallization attributed to heterogeneous nucleation of TiSi, evident in the outstanding suppression of their inherent phase change hysteresis (PCH). The degrees of PCH are 24.08 °C for Al–Cu–Si@Al2O3 MEPCMs without TiO2 and 13.70, 11.07, and 6.32 °C for 1, 3, and 5 wt % additions with respective reduction rates of 43.11%, 54.03%, and 73.75%, demonstrating remarkable improved thermal features. This study underscores the complex interplay of heterogeneous nucleation agents in ternary eutectic Al–Cu–Si@Al2O3 MEPCMs, their mechanisms for enhanced nucleation, and consequent PCH suppression. The advanced Al–Cu–Si–Ti@Al2O3 MEPCMs exhibit efficient and quicker release of the stored energy, providing a solution to the bottleneck of increased energy consumption with the promise to contribute to the overall efficiency of the TES system in real-life applications, laying the foundation for the fabrication of advanced and multifunctional MEPCMs for a broad range of practical applications. Our developed Ti-doped MEPCMs have great potential for integration into high-temperature latent heat TES systems and thermal regulation technologies.