Assembling and properties characterization of boron nitride-chitosan porous structure embedded low supercooling and shape stable sodium acetate trihydrate based phase change materials

Super cooling and phase separation seriously abate the safety level of hydrated salt for applying in thermal management of electrical power industry. A novel composite phase change material (PCMs) was prepared based on assembling boron nitride-chitosan (BNCA) porous structure with Lyophilization and embedded sodium acetate trihydrate (SAT). Disodium hydrogen phosphate dodecahydrate (DHPD) and Gum arabic powder (GA) were applied as nucleating agent and thickener, respectively. Furthermore, FTIR, XRD, TGA, Hot Disk, DSC, T-history method were used to character the samples and 100 times thermal cycles were introduced to assess the shape stability. The results showed that BNCA/SDG composite PCMs has been prepared successfully. The supercooling of samples was adjusted by adding DHPD. And it can drop to minimum (1.17 °C), when 4% DHPD was added in SAT. As for melting enthalpy, can be adjusted by adding GA in SAT. And when GA was 5%, the melting enthalpy was 253.43 J/g and supercooling drop to 4.95 °C. Adopting BNCA as SAT carrier can further suppress the supercooling (Tsc = 2.54 °C) and improved the thermal conductivity (1.00 W/(m·K)) of composite PCMs. After 100 freezing-melting cycles test, the thermal properties of BNCA/SDG composite PCMs nearly didn't change, the latent heat reduced from 193.17 to 191.23 J/g. The modified SAT adsorbed by BNCA, showing stable chemical, crystalline, and microstructure which provided guarantee for long-term operation of heat storage materials. The BNCA/SDG composite PCMs with high thermal conductivity and thermal storage density have a great potential application in electrical power systems. •SAT was chosen as inorganic PCMs and the influence of DHPD and GA were studied to resolve supercooling and phase separation.•BNCA was used for loading the SAT-based composite PCMs to solve the shape stability and thermal conductivity.•The mass fraction of PCMs can be controlled, without leakage.•Good thermal conductivity and thermal reliability of BNCA/SDG composite PCMs.•After 100 thermal cycles, the thermal properties and shape stability of the composite remain good.