Synthesis of Ni₃V₂O₈-rGO composite nanostructure for high-performance hybrid supercapacitors via hydrothermal method

To address global energy demand, major efforts have been made to develop cutting-edge electrode materials for electrochemical energy storage (EES) devices. The present article discusses the hydrothermal synthesis of bare nickel vanadate and a nickel vanadate/reduced graphene oxide (Ni₃V₂O₈-rGO) composite for supercapacitor applications. The physicochemical properties of pure Ni₃V₂O₈ (NVO) and the Ni₃V₂O₈-rGO (NVO-rGO) composite were investigated using a variety of characterization tools. The electrochemical traits of the NVO-rGO composite outperform bare NVO due to the synergistic effect. At a current density of 1 mAcm⁻², the NVO and NVO-rGO nanostructures exhibit excellent specific capacitances of 85 Fg⁻¹ and 108 Fg⁻¹, respectively. These nanostructures also have energy densities of about 3.82 and 5.02 WhKg⁻¹, with power densities of 141.75 and 151.57 WKg⁻¹ for NVO and NVO-rGO composite, respectively. Electrochemical impedance spectroscopy (EIS) studies revealed a charge resistance of 2.05 Ω. The transfer coefficient and standard rate constant indicate that the charge storage mechanism is based on a quasi-reversible redox process. The present investigation demonstrates that the NVO-rGO composite has exceptional electrochemical performance. The outstanding electrochemical performance of both NVO and NVO-rGO underlines their potential as novel and promising materials for supercapacitor applications, implying significant feasibility for large-scale utilization.