Thermal conductivity enhancement and shape stabilization of phase change thermal storage material reinforced by combustion synthesized porous Al2O3

Abstract

The utilization of paraffin in latent heat storage system is limited by its leakage and low thermal conductivity. To address such challenges, we prepare composite phase change materials (PCMs) with enhanced thermal conductivity and shape stability. Paraffin is supported by porous Al2O3 which is synthesized by solution combustion synthesis (SCS). The porous structure of Al2O3 is quite influenced by the fuel species in SCS reactions. The glycine-induced Al2O3 shows highly hierarchical porous structure, which can improve the anti-leakage performance of the composites. The thermal conductivity of Al2O3/PW reaches 1.27 W/m•K with an Al2O3 mass ratio of 50 wt%, which is 5 times of pure paraffin. The composite also presents acceptable latent heat capacity of higher than 100 J/g and very good thermal cycling stability. These characteristics assure the promising application of Al2O3/PW composites for thermal energy storage.