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

Highlights: • Determined suitable precursors and growth conditions that will yield binderless nanocrystalline V₂O₅ thin film on conductive ITO glass substrate. • Investigated surface crystalinity, morphology and resistivity of the deposited layer. • Studied optical trasmittance and band structurs of the deposited layer to appraise its optoelectronic properties. • Evaluated the electrochemical performance of the film as stable electrodes for charge storage capability; and. • Examined the charge-discharge potential of the film for energy storage application. 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.