Review on the thermal property enhancement of inorganic salt hydrate phase change materials

Inorganic salt hydrates in phase change materials (PCM) are important modern materials for latent heat storage at low temperatures (below 120 °C), which is conducive for the efficient use and saving of energy. However, inorganic salt hydrates still have some drawbacks, including high supercooling, phase separation, leakage, low thermal conductivity, and instability. This paper reviews the recent improvements that researchers have made to some classical solutions, such as nucleating agents and thickeners, and proposes some methods, such as eutectic, porous materials, microencapsulation, and multistage encapsulation, to regulate the physical properties of inorganic hydrated salts and prepare PCMs with higher thermal conductivity and better thermal stability. Additionally, this review also introduces the application of inorganic salt hydrates in solar water heating, solar energy building, solar photovoltaic panel heat dissipation, solar photovoltaic-photothermal systems, and other fields, and highlights that future research and development can focus on the research and application of inorganic salts hydrates to address some of the drawbacks of existing organic PCMs.