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 Co 3 O 4 +graphene@Ni. The hydrothermal method used in this paper is easy to operate, with low-risk factors and environmental protection. The prepared Co 3 O 4 +graphene@Ni electrode exhibits superior electrochemical performance than Co 3 O 4 @Ni electrode. At a current density of 1 A/g, the specific capacitance of the Co 3 O 4 +graphene@Ni electrode calculated by a charge-discharge test is 935 F/g, which is much larger than that of Co 3 O 4 @Ni electrode of 340 F/g.