Synthesis and electrochemical performance evaluation of a thermally reduced ZnO@V2O5 binary nanocomposite for supercapacitor applications

Abstract

Developing electrode materials that simultaneously exhibit good electrical conductivity and high electrochemical activity remains a primary concern for high-performance supercapacitors. To address this, we have synthesised a ZnO@V2O5 based binary nanocomposite. The composite was synthesised through a simple solid-state method by thermally reducing the oxides, which enables effective integration of ZnO and V2O5 at the nanoscale level. The morphological study showed a well-built composite structure that helps ions move through short pathways for faster transport, while the structural and phase examination verified the development of crystalline ZnO and V2O5 within the composite. Galvanostatic charge–discharge measurements and cyclic voltammetry were employed to evaluate the electrochemical performance of the synthesised electrode in 2 M KOH electrolyte. The ZnO@ V2O5 electrode was found to exhibit stable charge–discharge characteristics with good rate capabilities at a varying current of 2–10 mA. Also, the cyclic voltammetry measurements revealed an overall specific capacitance of 80 F g−1 at a scan rate of 10 mV s−1, demonstrating effective charge storage behaviour. The current contributions were analysed and found to be predominantly diffusion-controlled, suggesting that Faradaic ion intercalation is the principal and dominating charge storage mechanism in the nanocomposite. Overall, the ZnO@V2O5 nanocomposite is considered a promising electrode material for supercapacitor applications.