Effective pseudocapacitive performance of binder free transparent α-V2O5 thin film electrode: Electrochemical and some surface probing

Abstract

Vanadium oxide nanomaterial was successfully prepared on conductive substrate via a simple and facile chemical route with no binder or additive. The film was characterized to investigate its microstructural, optical, electrical and electrochemical properties. The SEM micrographs of the annealed film presented enabling environment that is required for effective photocatalysis. It also demonstrated enhanced interaction between the film and the substrate and adequate pore size distribution that can allow free electrolytic ion intercalation/deintercalation for efficient supercapacitive response. EDX confirmed the elemental composition of the film. XRD and Raman spectroscopy showed substantial characteristic peaks that are attributes of orthorhombic crystal structure of V2O5 powder. Optical studies showed that the film exhibited high visible light transmittance and its energy band gap was found to be 2.77 eV. Pseudocapacitive performance of the V2O5 electrode was investigated via a three-electrode cell configuration. The film electrode exhibited highest areal capacity of 1.18 μAh cm−2, energy density of 0.485 μWhcm−2 at a power density of 107.71 μWcm−2 and current density 0.25 mAcm−2, moderate charge transfer resistance and superior cycling stability. The study demonstrated the viability of V2O5 film as electrode material for the development of high-performance supercapacitors.