Role of annealing duration on the microstructure and electrochemical performance of β-V₂O₅ thin films

Abstract

Vanadium pentoxide thin films have been prepared by sol–gel spin coating method. The eight-layered films coated on fluorine-doped tin oxide substrate and glass substrate were subjected to different durations of annealing under a constant annealing temperature of 300 °C from 30  to 120 min. The X-ray diffraction spectrum reveals crystallinity along (2 0 0) direction. The SEM images of these films show the variation in the surface morphology with increase in annealing duration. The supercapacitor behaviour has been studied using cyclic voltammetry technique and electrochemical impedance spectroscopy. The film annealed for 60 min exhibits a maximum specific capacitance of 346 F/g at a scan rate of 5 mV/s with a charge transfer resistance of 172 Ω.

Keywords:

• sol–gel
• thin films
• annealing duration
• cyclic voltammetry
• ac impedance