▎ 摘　　要

NOVELTY - Preparing graphene composite phase change materials comprises (1) performing first contact reaction with hydroxylated iron oxide nanoparticles and silane coupling agent in the presence of aqueous ethanol to obtain aminated ferric oxide, where the average particle diameter of the hydroxylated iron oxide nanoparticles is 30-50 nm, (2) performing the second contact reaction with graphene oxide, L-ascorbic acid and the aminated ferric oxide in the presence of water to obtain graphene hydrogel, (3) freeze-drying the graphene hydrogel to obtain graphene foam, and (4) performing the third contact reaction with the paraffin wax in the molten state and the graphene foam to obtain the graphene composite phase change material. USE - The material is useful in energy storage and/or heat preservation (claimed). ADVANTAGE - The material has stable three-dimensional structure, characteristics of large specific surface area and high phase change enthalpy. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for graphene composite phase-change material prepared by the above-mentioned method, where the specific surface area of the graphene composite phase change material is 550-570 m2/g, and the phase change enthalpy is 170-200 kJ/kg.