Electrochemical and Structural Investigation on α-V₂O₅ for Energy Storage Applications

Mesoporous -vanadium pentoxide (-V2O5) was prepared by a microwave-assisted method from the solution of ammonium metavanadate (NH4VO3) and urea (NH2CONH2). Structural, and microstructural studies were executed using X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy and field emission scanning electron microscopy. The specific surface area and pore size distribution were calculated by N2 gas adsorption/desorption isotherms. Orthorhombic α-V₂O₅ phase, with crystallite sizes ranging from 23 to 48 nm, and mesoporosity with surface areas between 73.17 to 156.57 m² g⁻¹ were obtained. X-ray photoelectron spectroscopy revealed traces of (V+5/V+4) oxidation states corresponds to V2O5 and VO2, respectively. The electrode prepared with a molar ratio (NH4VO3/NH2CONH2,) of 0.8 shows outstanding performance in a three-electrode setup with a specific capacity (specific capacitance) of 724.8 C/g (1768 F/g) at a current density of 1A/g. Furthermore, the fabricated non-symmetric device shows a specific capacitance of 342.5 F/g at a current density of 1 A/g and shows a notable high energy density of 34 Wh/kg at a power density of 0.889 KW/kg. Additionally, the device sustains 83% of the initial capacitance and around 85% of coulombic efficiency after 5000 continuous charging and discharging cycles with a current density of 1 A/g.