Preparation of graphene oxide coated tetradecanol/expanded graphite composite phase change material for thermal energy storage

•Graphene oxide coated tetradecanol/expanded graphite composite phase change material (TD/EG-GO) was prepared.•Porous carrier adsorption and microencapsulation technologies were combined.•TD/EG-GO showed good phase change and thermal properties due to the closed honeycomb structure. In this work, the form-stable phase change material (PCM) was prepared by absorbing tetradecanol (TD) into expanded graphite (EG). Then, the obtained TD/EG was coated with graphene oxide (GO) through electrostatic self-assembly to prepare a novel composite PCM (TD/EG-GO). The morphology, phase change and thermal properties of TD/EG-GO were fully discussed. The DSC analysis shows that the TD/EG-GO composite melts at 35.2 °C with latent heat value of 189.5 J/g and freezes at 34.9 °C with latent heat value of 187.9 J/g. The thermal cycling test results reveal that the latent heat of TD/EG-GO composite decrease by less than 1% after 500 thermal cycles, indicating that the structure of GO-coated EG efficiently prevents the leakage of TD. The thermal stability and thermal conductivity of TD/EG-GO composite are also improved compared with that of uncoated TD/EG, demonstrating the multiple benefits of surface coating of GO.