Hybrids of porous NiMoO4@Reduced graphene oxide composites for asymmetric supercapacitor applications

Abstract

A major factor in improving the specific capacitance of supercapacitors is the shape of NiMoO4. In general, it is important to have a morphology with a large surface area and thin electrolytic dielectric characteristic. In this study, a hydrothermal technique was used to create a reduced graphene oxide/nickel molybdate (NiMoO4/rGO) nanocomposite, which was then heated to 450 °C for annealing. Analyses using X-ray diffraction, Raman, and X-ray photoelectron spectroscopy proved that the NiMoO4/rGO nanocomposite was formed. A study using field emission scanning electron microscopy revealed that the rGO surface was embellished with rod-like NiMoO4 nanostructures that ranged in length from 1 to 5 m. The NiMoO4/rGO electrode, when used in the aqueous basic electrolyte, demonstrated remarkable electrochemical properties by obtaining a high capacity of 1516 Fg-1 at current densities of 1 Ag-1 with high degree of rate capability. More intriguingly, during the charge-discharge process, the NiMoO4/rGO electrode showed outstanding cycling stability of 95.8% after 10,000 cycles. In order to create a supercapattery with a large operating potential window of 1.8 V, NiMoO4/rGO is used as a positive electrode and activated carbon (AC) as a negative electrode. at 1 Ag-1 current density, an energy density of 48.2 Whkg-1 and a power density of 878 Wkg-1 were attained, showing tremendous promise for this material's use in supercapacitors.