▎ 摘　　要

NOVELTY - Metal-carbon based composite material comprises a main porous carbon substrate composed of metal-organic framework-derived graphene-based porous carbon and a compound composited with the substrate, where the compound composited with the substrate having a formula (I). USE - The composite material is useful in low-temperature thermal energy storage devices, and solar energy and industrial waste heat treatment fields (claimed). ADVANTAGE - The prepared composite material has excellent energy storage density, which can store efficiently, utilizes low-temperature thermal energy and long-term thermal energy storage across seasons, and can make full use of low-temperature thermal energy e.g. solar thermal energy and industrial waste heat. DETAILED DESCRIPTION - Metal-carbon based composite material comprises a main porous carbon substrate composed of metal-organic framework-derived graphene-based porous carbon and a compound composited with the substrate, where the compound composited with the substrate having a formula MA (I), M = lithium, magnesium, or aluminum; and A = hydroxide, sulfate, or bromide anions. INDEPENDENT CLAIMS are also included for: a method for preparing composite material comprising (1) reacting graphene oxide, polyvinylpyrrolidone, metal salt and organic ligand in a solvent to obtain a mixture,(2) heating the mixture under an inert atmosphere, and then removing the metal salt in an acidic solution to obtain a main porous carbon substrate composed of metal-organic framework-derived graphene-based porous carbon, and (3) mixing the main body porous carbon substrate formed by the graphene-based porous carbon derived from the metal-organic framework and the compound or the hydrate of the compound in water to mixing to obtain metal-carbon based composite material; and a heat storage device comprising composite material.