▎ 摘　　要

NOVELTY - Cobalt oxide-graphene electrode material as working electrode, platinum electrode as counter electrode, saturated calomel electrode as reference electrode are immersed in the electrolyte solution containing cobalt nitrate and nickel nitrate, deposition process is performed, working electrode is removed and washed with deionized water and dried, to obtain cobalt oxide-graphene-nickel hydroxide-cobalt hydroxide composite material having three dimensional network structure. USE - Preparation of cobalt oxide-graphene-nickel hydroxide-cobalt hydroxide composite material used as electrode active material for supercapacitor (claimed). ADVANTAGE - The method provides cobalt oxide-graphene-nickel hydroxide-cobalt hydroxide composite material having excellent electron transmission and ion-diffusion capacity, and high purity and uniformity, by simple process. The supercapacitor provided with cobalt oxide-graphene-nickel hydroxide-cobalt hydroxide composite material has excellent rate performance and cycle stability. DETAILED DESCRIPTION - A foam nickel electrode substrate is immersed in 0.1 mol/L dilute sulfuric acid, ultrasonically pretreated, the electrode is removed, washed with deionized water and dried, to obtain pretreated foam nickel electrode substrate. 0.2-1 g Cobalt nitrate hexahydrate and 0.2-1 g urea are dissolved and 70 ml deionized water is added and stirred uniformly, to form clear solution. The obtained clear solution and pretreated foam nickel electrode substrate are placed into a reactor, reacted, the pretreated foam nickel electrode substrate is discharged, cooled to room temperature, dried, and sintered in air and argon gas atmosphere, to obtain cobalt oxide electrode material. Cobalt oxide electrode material as working electrode, platinum electrode as counter electrode and saturated calomel electrode as reference electrode are immersed in 100 ml electrolyte solution containing 30 ml graphene and 3.58 g disodium hydrogen phosphate, deposition process is carried out, working electrode is removed and washed with deionized water, to obtain cobalt oxide-graphene electrode material. The obtained cobalt oxide-graphene electrode material as working electrode, platinum electrode as counter electrode, saturated calomel electrode as reference electrode are immersed in the electrolyte solution containing cobalt nitrate and nickel nitrate, deposition process is performed, working electrode is removed and washed with deionized water and dried, to obtain cobalt oxide-graphene-nickel hydroxide-cobalt hydroxide composite material having three dimensional network structure.