Fabrication of composite material of RuCo2O4 and graphene on nickel foam for supercapacitor electrodes

Abstract

Supercapacitors are energy storage devices with the advantage of rapid charging and discharging, which need a higher specific capacitance and superior cycling stability. Hence, a composite material consisting of RuCo₂O₄ and reduced graphene oxide with a nanowire network structure was synthesized on nickel foam using a one-step hydrothermal method and annealing process. The nanowire network structure consists of nanowires with gaps that provide more active sites for electrochemical reactions and shorten the diffusion path of electrolyte ions. The prepared electrodes exhibit outstanding electrochemical performance with 2283 F g⁻¹ at 1 A g⁻¹. When the current density is 10 A g⁻¹, the specific capacitance of the electrodes is 1850 F g⁻¹, which maintains 81% of the initial specific capacitance. In addition, the prepared electrodes have a long-term cycling life with capacitance retention of 92.60% after 3000 cycles under the current density of 10 A g⁻¹. The composite material is a promising electrode material for high-performance supercapacitors.