▎ 摘　　要

NOVELTY - A cathode material comprises 60-95 wt.% iron-based compound modified three-dimensional porous nitrogen-doped graphene composite material, 2-30 wt.% conductive agent and 3-10 wt.% polyvinylidene fluoride binder. The iron-based compound modified three-dimensional porous nitrogen-doped graphene composite material comprises iron carbide nanoparticles modified three-dimensional porous nitrogen-doped graphene composite material, ferric oxide nanoparticles modified three-dimensional porous nitrogen-doped graphene composite material and iron disulfide nanoparticles. USE - The cathode material is useful for lithium ion battery. ADVANTAGE - The cathode material is economical and prepared by simple method, and has large specific surface area and excellent stability and electrochemical property. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) preparation method of cathode material, which involves dissolving ferric nitrate nonahydrate and polyvinylpyrrolidone in deionized water, stirring and uniformly mixing, then drying and grinding into powder, heating the mixture in an inert protective gas to obtain iron carbide nanoparticles modified three-dimensional porous nitrogen-doped graphene composite material, heat-treating the product in an air atmosphere to obtain ferric oxide nanoparticles modified three-dimensional porous nitrogen-doped graphene composite material, vulcanizing product by chemical vapor deposition to obtain iron disulfide nanoparticles modified three-dimensional porous nitrogen-doped graphene composite material, mixing conductive agent and binder polyvinylidene fluoride, then adding N-methyl-2-pyrrolidone to prepare uniform slurry, coating the uniform slurry on copper foil and drying; and (2) electrolyte, which comprises 10-40 %mass potassium salt and 60-90 %mass solvent comprising carbonate-based solvent and ether-based solvent.