Electrochemical Performance of Nanocrystalline Vanadium Pentoxide Thin Films Grown by RF Magnetron Sputtering

Abstract

Nanocrystalline V2O5 thin films were prepared by radio frequency (RF) magnetron sputtering and explored as potential electrodes for Li-ion microbatteries and supercapacitors based on microstructure and electrochemical properties. All the films grown in the substrate temperature (Ts) range 250–350°C exhibited predominant (001) orientation corresponding to the orthorhombic V2O5 layered structure. However, notable changes were observed in the surface morphology and crystallite size of the grown films by varying the substrate temperature. The films deposited at Ts of 250°C showed uniformly distributed spherical grain morphology and demonstrated pseudocapacitive behavior with a specific capacitance of 960 mF cm−2 at current density of 1 mA cm−2 with good cycle stability. The films deposited at Ts of 350°C showed needle like nanorod structure with an average crystallite size of 36 nm. These films exhibited sharp oxidation and reduction peaks, exhibiting cathodic behavior with a discharge capacity of 62.6 μAh cm−2 μm−1 at a current rate of 50 μA.