▎ 摘　　要

NOVELTY - The biomass energy storage material comprises a graphene-like nitrogen-doped carbon material and a lignosulfonate material. The graphene-like nitrogen-doped carbon material is of a lamellar structure. The lignosulfonate material is loaded between graphene-like nitrogen-doped carbon material lamellae. The graphene-like nitrogen-doped carbon material is prepared by mixing melamine, polyvinylpyrrolidone and ammonium chloride, adding a solvent, ball-milling uniformly to obtain slurry, drying the slurry to obtain a solid, and roasting the solid in an air atmosphere. The lignosulfonate is sodium lignosulfonate. USE - Biomass energy storage material. ADVANTAGE - The biomass energy storage material has electrochemical oxidation and reduction characteristics. The graphene-like nitrogen-doped carbon material has high specific surface area and good conductivity, and provides good contact for the lignosulfonate. The nitrogen atoms are doped to provide the conductivity of the graphene-like material and promote electron transmission. The biomass energy storage material obtains high energy storage density and energy storage efficiency due to the synergistic effect of the conductivity of the graphene-like nitrogen-doped carbon and the electrochemical oxidation and reduction of the lignosulfonate. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: (1) a preparation method of the biomass energy storage material; and (2) an energy storage device. DESCRIPTION OF DRAWING(S) - The drawing shows a scanning electron microscope image of the biomass energy storage material.