Effect of temperature on the electrochemical performance of silver oxide thin films supercapacitor

Abstract

The effect of temperature change on the electrochemical performance of silver oxide thin films supercapacitor in an aqueous electrolyte (saline solution), is presented in this paper. Scanning electron microscopy and energy-dispersive X-ray spectroscopy (EDX) were used to probe the morphology and the elemental constituent of the prepared silver oxide thin films. The stoichiometry along with oxide phases of the films were observed with X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The effect of temperature in the range 35 °C to 75 °C, on the electrochemical performance of the films were evaluated by applying electrochemical impedance spectroscopy (EIS), charge-discharge and cyclic voltammetry (CV). The EIS and CV results indicate improved electrochemical performance as operating temperature increases, with an increase in capacitance and reduction in resistance observed. The enhanced electrochemical capacity of the silver oxide thin films with temperature can be attributed to higher ionic conductivity, reduced resistance and faster ion adsorption/desorption at higher temperatures. • XRD reveal that the primary phase is Ag2O • Nyquist plot confirms enhanced mobility of ions at higher temperature • Redox peaks both on the anodic and cathodic sides, are due to Faradaic reactions