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

Mesoporous α-vanadium pentoxide (α-V 2 O 5 ) was prepared by a microwave-assisted method from the solution of ammonium metavanadate (NH 4 VO 3 ) and urea (NH 2 CONH 2 ). 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 N 2 gas adsorption/desorption isotherms. Orthorhombic α-V 2 O 5 phase, with crystallite sizes ranging from 23 to 48 nm, and mesoporosity with surface areas between 73.17 to 156.57 m 2 g −1 were obtained. X-ray photoelectron spectroscopy revealed traces of (V +5 /V +4 ) oxidation states corresponds to V 2 O 5 and VO 2 , respectively. The electrode prepared with a molar ratio (NH 4 VO 3 /NH 2 CONH 2, ) of 0.8 shows outstanding performance in a three-electrode setup with a specific capacity (specific capacitance) of 724.8 C g −1 (1768 F g −1 ) at a current density of 1 A g −1 . Furthermore, the fabricated non-symmetric device shows a specific capacitance of 342.5 F g −1 at a current density of 1 A g −1 and shows a notable high energy density of 34 Wh kg −1 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 −1 .