Microencapsulation of ethanol-soluble inorganic salts for high temperature thermal energy storage

Abstract Inorganic salts are typically used phase change materials for high temperature thermal energy storage. Leakage and corrosion of phase change materials can be addressed by microencapsulation methods. However, microencapsulation of ethanol-soluble inorganic salts has not been reported. In this study, lithium nitrate (LiNO3) as a model ethanol-soluble inorganic salt was microencapsulated in silica (SiO2) by a novel method. Experimental results show that LiNO3 was physically encapsulated by SiO2, confirming the formation of the microcomposites. The crystal structure of LiNO3 was not changed during the microencapsulation process. The onset melting temperature and the melting enthalpy of the microcomposites stabilized at 250.9 °C and 265.2 kJ/kg after thermal cycles, demonstrating the effectiveness of the proposed method.