▎ 摘　　要

NOVELTY - Composition phase change thermal storage material comprises polybasic nitrate/graphene/nanoparticle stereo complex material, which includes calcium nitrate, sodium nitrate and/or potassium nitrate. The graphene is modified reticular expanded graphite, and nano-particles are nano-silica or titania, where the modified reticulated and expanded graphene coated and adsorbed polybasic nitrate and nano-particles in a three-dimensional network-type pore structure. USE - Used as composition phase change thermal storage material. ADVANTAGE - The storage material has large unit energy storage density, stable chemical property, has high strength; and is economical. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for preparing thermal storage comprising (i) adding worm-shaped expanded graphite in to a volume ratio of 1:8-9 sulfuric acid and phosphoric acid mixed solution, stirring at low temperature, adding oxidant oxidation, washing, centrifuging, drying, carrying out hydrazine hydrate reduction, to obtain modified mesh expanded graphite; (iii) mixing the nitrate mixture with the modified reticulated expanded graphene prepared in step (i), adding water and stirring, to form a suspension, evaporating and drying, placing in a muffle furnace for pre-sintering, and cooling to room temperature to obtain a granular nitrate-loaded graphene composition material; and (iii) preparing the granular nitrate-loaded graphene composition material and performing nano-ball milling treatment, mold pressing, demolding, placing in a muffle furnace and sintering, and cooling to room temperature.