Preparation and Application of Co3O4/Reduced Graphene Oxide/Ni Foam as High-Performance Asymmetric Supercapacitor Electrodes

Co3O4 nanorods and hybrid reduced graphene oxide (Co3O4/rGO) were synthesized on a Ni foam substrate using affordable and simple hydrothermal synthesis. Then, the structural and morphological investigations of nanoparticles were carried out using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS) mapping, Raman spectroscopy, and Brunauer-Emmett-Teller (BET) analysis. It was found that rGO increased the surface and short channels for the transfer of ions and electrons. The maximum capacitance of Co3O4/rGO was found to be 2870 F/g, while Co3O4/rGO/NF was observed to have the largest capacitance in the literature. Furthermore, rGO decreased resistance arising from charge and ion transfer by creating shorter channels. Therefore, the superior Co3O4/rGO/NF electrode in the tow-electrode system was investigated for asymmetric supercapacitor purposes. The rGO electrode served as the negative electrode, while the Co3O4/rGO/NF was assumed to be the positive electrode. A discharge time of 144 s led to a capacitance of 148 F/g, a power density of 486 W/kg, and an energy density of 20 Wh/kg.