Metal-based phase change material (PCM) microcapsules/nanocapsules: Fabrication, thermophysical characterization and application

Thermal energy storage by solid-liquid phase change is one of the main energy storage methods, and metal-based phase change material (PCM) have attracted more and more attention in recent years due to their high energy storage density and high thermal conductivity, showing unique advantages in thermal energy storage system and temperature regulation. However, they also have problems such as leakage, corrosion, volume change and so on. Recent studies show that microencapsulation technology is expected to solve the above problems, showing great application prospects. In this paper, firstly, we overview the classification and development process of metal-based PCM microcapsules. Then, three main preparation methods, including facile self-oxidation, sol-gel polymerization and in-situ polymerization are summarized and analyzed. Thermophysical properties such as latent heat, supercooling and cycle stability are compared. Furthermore, the applications in the field of thermal energy storage, heat transfer enhancement and catalysis are introduced in detail. Finally, the existing problems, solutions and future research directions are put forward.