COMPOSITE CATHODE MATERIAL DOPED WITH NANO-GRAPHITE AND PREPARATION METHOD THEREOF

The invention relates to the technical field of battery material preparation, and in particular to a composite cathode material doped with nano-graphite and a preparation method thereof. The preparation method comprises the following steps: (1) adding nano-graphite into Spartina alterniflora powder, performing primary pyrolysis, cooling and secondary pyrolysis to obtain a mixed carbon material; and (2) treating the mixed carbon material with alkali and acid in turn to obtain the composite cathode material doped with nano-graphite. The preparation method of the invention is simple and convenient, and the nano-graphite doped Spartina alterniflora source hard carbon material (composite cathode material) is prepared by the preparation method of the invention. The hard carbon material has a good first coulombic efficiency, and the battery prepared by using the hard carbon material as the cathode has excellent sodium storage performance.