Preparation research of novel composite phase change materials based on sodium acetate trihydrate

•A novel composite phase change materials based on sodium acetate trihydrate was prepared.•The novel phase change material has lower degree of undercooling and higher thermal conductivity.•The phase change enthalpy of the novel composite material is 247kJ/kg. As phase change thermal storage material, sodium acetate trihydrate (SAT) exhibits certain problems such as large undercooling, stratification in phase change, and small thermal conductivity. To overcome these problems, in this study, a new composite phase change thermal storage material was prepared by adding a certain amount of nucleating agent, thickening agent, and high thermal conductivity medium. The research results showed that addition of an appropriate proportion of nucleating agent disodium phosphate dodecahydrate(DSP) and thickening agent carboxymethyl cellulose(CMC) or gelatin led to a good restrain to the undercooling of SAT, while maintaining the heat storage capacity of sample, and avoiding the phenomenon of phase stratification at room temperature cooling. A certain proportion of expanded graphite could also be used in combination with the thermal storage materials, which resulted in relatively small undercooling of the SAT thermal storage materials and a relatively large thermal conductivity.