LAUSR

Abstract Combining cold energy storage using phase change materials (PCMs) with cooling system used in air conditioner can make notable improvement in energy conservation. In this research, 40% tetra-n-butyl ammonium bromide (TBAB) solution as cold energy medium was preferred due to its appropriate phase change temperature (11.81 °C) and high latent heat (211.9 J g−1). Additionally, Na2HPO4·12H2O as nucleating agent could minimize its supercooling degree, with the enhanced crystallization behavior confirmed by optical microscope. A form-stable TBAB hydrate/fumed silica (SiO2) composite PCM was prepared and characterized. The results indicated that the composite PCM containing 30% SiO2 possessed large latent heat (134.0 J g−1), low supercooling degree (2.01 °C) and excellent form-stable performance without any liquid leakage above melting temperature (8.33 °C). Besides, the composite PCM exhibited an outstanding chemical compatibility, thermal reliability and thermal insulation performance. Considering its desirable properties, TBAB hydrate/SiO2 composite PCM has great potential for cold energy storage.