Graphene-Induced Enhanced Supercapacitor Properties of V2O5-GNPs Nanocomposites for Energy Storage Devices

Abstract

Metal oxides due to high specific capacitances are worthy for electrode material, yielding high energy and power-delivering capacities. Among them, Vanadium pentoxide (V2O5) is a very novel and economical electrode material for supercapacitors using alkaline aqueous electrolytes. In this work, V2O5 and Graphene (GNPs) nanocomposites have been synthesized to improve the conductivity, electrode porosity, and electrode surface area of V2O5. V2O5 nanorods were fabricated using a simple and flexible Sol-gel method, whereas V2O5/Graphene (GNPs) nanocomposites were prepared using an ex-situ approach. Structural analysis of nanocomposites has been performed through XRD, SEM, EDX, EDS, and FTIR. V2O5 nanorods distributed on GNPs substrates showed excellent results as an electrode material. In particular, the nanocomposites (V2O5)0.50 (GNPs)0.50 maintained 96.3% of the initial capacitance over 1350 cycles. High specific capacitance (990 F/g at 5 mV/s from CV, 800 F/g at 2 A/g from GCD), and low ohmic resistance of 0.44 Ω were achieved in 2M NaOH electrolyte. Additionally, these nanocomposites have excellent energy density (27.7 W-hr Kg− 1) at a power density of (1800 W Kg− 1) using a potential window of (0-0.5) V, which is higher than the most previously reported work on V2O5 for supercapacitor.