Supercapacitor Performance of Vanadium Oxide Nanostructures Synthesized by Spray Pyrolysis Technique
Abstract
Vanadium oxide (V2O5) is a potential material for energy storage devices due to its good redox characteristics and high specific capacitance. In the present manuscript, the authors applied a simple and inexpensive spray pyrolysis method to prepare vanadium oxide electrodes for supercapacitor applications. Vanadium oxide samples were prepared by spray pyrolysis method using aqueous vanadyl sulphate solution on glass and nickel foam (substrate) at different substrates temperatures, 350 oC to 550 oC in the interval of 100 oC. With the increase in substrate temperature, changes in phase formation of vanadium oxide are observed, as well as the band gap energy of prepared vanadium oxide sample from 2.36 eV, 2.57 eV, and 2.66 eV with an increase in temperature. Scanning electron micrographs revealed that no specific morphology or crystallites were observed at low temperatures, whereas with increasing temperature flakes-like morphology was observed. From electrochemical characterizations, at a current density of 0.2 mA cm-2, the sample prepared at 450 oC achieved a specific capacitance of 374 Fg-1. The high specific capacitance attained in this work can be due to the V2O5 nanoparticle's distinctive shape and crystallinity, which were aided by the controlled pyrolysis process.