▎ 摘　　要

NOVELTY - Preparing ultra thin bimetallic organic framework/carbon composite material, comprises (1) adding soluble salts of metal M, soluble salts of iron (III), organic ligands and carbon dots into the mixed solvent and mixing to obtain a mixed solution, (2) adding a second solvent to the mixed solution, and stirring at room temperature to react to obtain a suspension, (3) separating the suspension from solid to liquid, washing and drying to obtain an ultrathin bimetallic organic framework/carbon composite; where the mixed solvent is a mixed solvent of the first solvent, water and ethanol; the first solvent is dimethylformamide, dimethylacetamide, and/or N-Methyl-2-pyrrolidone; and the second solvent is aqueous ammonia, triethylamine, ethylenediamine, and/or n-butylamine. USE - The composite material is useful as cathode active material of lithium ion battery of electrochemical energy storage device (all claimed). ADVANTAGE - The method is simple, and the obtained bimetallic organic framework/carbon composite is in the form of a single layer nanosheet and as cathode active material exhibits better electrochemical performance. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: ultra thin bimetallic organic framework/carbon composite material, obtained by the method as mentioned above, and the thickness is 1-10 nm; and cathode active material of lithium ion battery.