Research progress of seasonal thermal energy storage technology based on supercooled phase change materials

Seasonal thermal energy storage (STES) is a highly effective energy-use system that uses thermal storage media to store and utilize thermal energy over cycles, which is crucial for accomplishing low and zero carbon emissions. Sensible heat storage, latent heat storage, and thermochemical heat storage are the three most prevalent types of seasonal thermal energy storage. In recent years, latent heat storage based on phase change materials(PCMs) has made great progress in solar energy utilization. However, the inherent defects of phase change materials have become resistant, limiting their further development, including low thermal conductivity, phase separation, and susceptibility to leakage. Supercooling is frequently considered a negative to be avoided in short-term usage. In seasonal thermal energy storage, however, supercooling of PCMs becomes an advantage. The paper begins with a brief overview of existing methods of seasonal thermal energy storage. Afterward, a brief description of the research on PCMs capable of storing seasonal heat is provided. A detailed discussion of the current state of research into supercooled PCMs for seasonal thermal energy storage and systems is presented. Finally, we present a detailed outline of the future directions of seasonal thermal energy storage using PCMs. According to current researches, finding and preparing PCMs with stable supercooling, designing suitable trigger crystallization devices and seasonal thermal energy storage systems with high performance will be the three directions for future research.