Preparation and performance of modified calcium chloride hexahydrate composite phase change material for air-conditioning cold storage

Cold energy storage technology with phase change materials (PCMs) has been receiving increasing attention due to the ability to effectively alleviate the electricity load. The modified CaCl2·6H2O composite PCM for cold energy storage was prepared using urea and ethanol as thermoregulation additives, strontium chloride hexahydrate (SrCl2·6H2O) and methyl cellulose (MC) as nucleating agent and thickening agent respectively. The results manifested that CaCl2·6H2O composite PCM containing 15 wt% urea and 5.0 wt% ethanol had a promising potential in air-conditioning application with phase change temperature of 11.62°C and phase change enthalpy of 127.2 J/g. Fourier transform infrared spectroscopy (FT-IR) verified the composition of the composite PCM. With the addition of 2.0 wt% SrCl2·6H2O, the degree of supercooling of CaCl2·6H2O composite PCM could be reduced to 0.95°C, and its enhanced crystallization behavior was confirmed by optical microscope. The modified composite PCM also showed an excellent thermal reliability after 50 heating-cooling cycles.