▎ 摘　　要

NOVELTY - An energy storage material preparation method involves mixing graphite powder and concentrated sulfuric acid, stirring in ice bath, slowly adding potassium permanganate, obtaining mixed solution, placing the mixed solution at 30-40 degrees C, stirring at constant temperature for 0.2-0.6 hours and room temperature for 20-30 hours, heating the mixed solution to 80-90 degrees C, slowly adding water, stirring at constant temperature for 0.4-0.6 hours, filtering the mixed solution for 2-3 times, removing the filtrate, adding water, uniformly stirring, centrifuging for 2-3 times (10-15 minutes each time), obtaining suspension of graphene oxide followed by obtaining graphene oxide substrate, obtaining nickel-cobalt double metal hydroxide grown on graphene oxide substrate and heat-treating. USE - Method for preparing energy storage material that is utilized for preparing electrode material (claimed). ADVANTAGE - The method enables preparing energy storage material in a simple manner by performing hydrothermal and heat treatment steps in a simple manner. The electrode material has improved energy storage performance. DETAILED DESCRIPTION - An energy storage material preparation method involves mixing graphite powder and concentrated sulfuric acid, stirring in ice bath, slowly adding potassium permanganate, obtaining mixed solution, placing the mixed solution at 30-40 degrees C, stirring at constant temperature for 0.2-0.6 hours and room temperature for 20-30 hours, heating the mixed solution to 80-90 degrees C, slowly adding water, stirring at constant temperature for 0.4-0.6 hours, filtering the mixed solution for 2-3 times, removing the filtrate, adding water, uniformly stirring, centrifuging for 2-3 times (10-15 minutes each time), obtaining suspension of graphene oxide, ultrasonically cleaning nickel foam for 20-30 minutes using water, acetone and alcohol, applying suspension of graphene oxide on surface of the nickel foam, obtaining graphene oxide substrate, mixing cobalt(II) nitrate hexahydrate, ammonium fluoride and urea, dissolving in water, stirring for 0.4-0.6 hours, immersing the graphene oxide substrate in the obtained solution for 0.4-0.6 hours, performing hydrothermal reaction, cooling, washing obtained product using water, drying, obtaining nickel-cobalt double metal hydroxide grown on graphene oxide substrate and heat-treating in presence of air and ammonia. An INDEPENDENT CLAIM is also included for an energy storage material prepared by the method.