Electrochemical performance of Ni3V2O8/rGO composites for supercapacitor applications

Abstract

Hydrothermally synthesized Ni3V2O8 (NV) and Ni3V2O8–reduced graphene oxide (NV–R) nanocomposites offer promising electrode materials for high-performance supercapacitors. The crystal structure and the phase purity of the composites were confirmed by X-ray diffraction (XRD). Fourier transform infrared (FTIR) spectroscopy was confirmed the characteristic of M–O (M = Ni, V) vibrations. Field-emission scanning electron microscopy (FE-SEM) and high-resolution transmission electron microscopy (HR-TEM) images confirmed that well-integrated Ni3V2O8 nanoparticles were uniformly distributed on the rGO nanosheets. Cyclic voltammetry (CV), galvanostatic charge/discharge (GCD) and electrochemical impedance spectroscopy (EIS) were used to assess the electrochemical performance. The intimate contact between rGO and Ni3V2O8 is consistent with rapid electron transport, good electrical conductivity, and a large electrochemically active surface area. Therefore, at a current density of 1 A g−1, the NV–R electrode achieved a high specific capacitance of 494 F g−1, which is larger than that of the NV electrode (264 F g−1). In addition, the assembled asymmetric supercapacitor device exhibited a specific capacitance of 81 F g−1, a specific energy density of 22.05 Wh kg−1, and a power density of 4177 W kg−1, maintaining 86.76% of the initial capacitance after 5000 charge–discharge cycles. The findings show that the NV–R/NF electrode, which is grown in situ, exhibits electrochemical performance and could be one of the ideal candidates for next-generation high-performance applications in supercapacitors.