Thermal energy storage is an essential technology for improving the utilization rate of solar energy and the energy efficiency of industrial processes. Heat storage and release by the dehydration and rehydration of Ca(OH)2 are hot topics in thermochemical heat storage. Previous studies have described different methods for improving the thermodynamic, kinetic, and structural stability of Ca(OH)2 to improve energy storage density, energy storage rate, and cycle stability, respectively. Here, the mechanisms and effects of different techniques on the performance improvement of Ca(OH)2 and some common problems were reviewed. Specific problems were also clarified based on the characteristics of different technologies. Finally, suggestions for the future development of Ca(OH)2 heat storage materials were provided.
