Preparation and capacitance properties of Ni foam@graphene@Co3O4 composite electrode materials

Graphene under high temperature was prepared and loaded on Ni foam. Then, cobalt tetroxide precursor was grown on Ni foam in situ by the hydrothermal method. Finally, the sample was burned at high temperature to obtain Co3O4+graphene@Ni. The hydrothermal method used in this paper is easy to operate, with low-risk factors and environmental protection. The prepared Co3O4+graphene@Ni electrode exhibits superior electrochemical performance than Co3O4@Ni electrode. At a current density of 1 A/g, the specific capacitance of the Co3O4+graphene@Ni electrode calculated by a charge-discharge test is 935 F/g, which is much larger than that of Co3O4@Ni electrode of 340 F/g.