Mesoporous 3D graphene@NiCo2O4 arrays on nickel foam as electrodes for high-performance supercapacitors

Abstract

A 3D graphene@NiCo2O4 hierarchitecture was prepared through by chemical vapor deposition and electrochemical deposition. The nickel foam was first coated with a thin graphene layer and then decorated with NiCo2O4 nanosheets, which consisted of many nanoparticles, approximately 4nm. The specific capacitance of the obtained electrode was as high as 1688Fg−1 at a very high current density of 15Ag−1, exceptional rate capability (71.5% capacity retention from 2 to 15Ag−1) and good cycling stability (123% of the initial capacity for 1500 cycles), highlighting its promising applications as a high performance electrode for supercapacitors.