Study of V2O5-GNPs Nanocomposites as a Promising Electrode Material for Supercapacitors Applications

Abstract

Energy storage is an essential for the growth of renewable energy sources, the decentralization of energy production, and demand control due to the erratic nature of energy sources. Supercapacitors and batteries are considered to be the most effective energy storage devices. Recently, research has focused on vanadium pentoxide because of its outstanding electrochemical potential in supercapacitors as electrode material. By lowering the rate of V2O5 agglomeration, its composition has been made with GNPs to improve conductivity, electrode porosity, and electrode surface area. V2O5 NPs have been fabricated using a simple and flexible Sol-gel method, whereas V2O5/GNPs nanocomposites have been synthesized using an ex-situ approach. The structural analysis has been carried out using X-ray diffraction, and FTIR spectroscopy. Different ratios of the GNPs in the V2O5 matrix have tuned its bandgap towards visible range. The electrochemical properties of pristine V2O5, GNPs, and its V2O5-Graphene (GNPs) nanocomposites are examined through different electrochemical technique namely, cyclic voltammetry (CV), Galvano-static charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS), the electrochemical properties of. In particular, the nanocomposites (V2O5)0.50 (GNPs)0.50 maintained 96.3% of the initial capacitance even at 10 Ag 1current density and has a high specific capacitance of 800 Fg-1 at a current density of 2 Ag-1 from Galvanostatic Charge Discharge (GCD), 1193 Fg-1 at a 5mV/s from cyclic voltammetry is obtained. The calculated Ohmic resistance is about 0.44 Ω in a medium of 2M NaOH electrolyte. Supercapacitors made of (V2O5)0.50(GNPs)0.50 electrode materials have higher energy densities of 27.3 WhKg-1 at a power density of 900 WKg-1 in comparison to the majority of previously reported supercapacitors.