Diffusion-Dominated Charge Storage in rGO–Ternary Metal Oxide (Mn0.6Zn1.4V2O7-rGO) Nanocomposite: Promising Hybrid Electrodes for High-Capacity and Next-Generation Supercapacitors

In the present study, we have prepared Mn_0.6Zn_1.4V₂O₇ and Mn_0.6Zn_1.4V₂O₇-reduced graphene oxide (rGO) nanocomposite by solution combustion method using sugar as a fuel and investigated its specific capacitance. The composition, morphological, and electrochemical features of ternary metal oxide of manganese, zinc, and vanadium with/without rGO were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and transmission electron microscopy (TEM). The Mn_0.6Zn_1.4V₂O₇-rGO nanocomposite showed good electrochemical properties due to its higher electrical conductivity and larger surface area offered by the folded sheets of rGO besides the synergistic impact induced by each component of the nanocomposite. Electrochemical investigations revealed that the Mn_0.6Zn_1.4V₂O₇-rGO exhibited an enhanced specific capacity of 667.8 mAh/g at a current density of 1 A/g besides long-term cycle stability (4500 cycles) with capacity retention of 95% in 1 M KOH. In view of this, Mn_0.6Zn_1.4V₂O₇-rGO could be used as an effective electrode material for supercapacitor owing to its enhanced electrochemical properties.