Electrochemical investigation of ZnO effect of amorphous V2O5–P2O5 glassy electrodes

Abstract

Using amorphous structures in the electrochemical environment is of great interest due to the excellent properties of the materials. In this work, electrochemical and surface properties of ZnO effect on Li-ion storage mechanism of amorphous V2O5–P2O5 glassy electrodes have been investigated. Cyclic voltammetry results were shown a large potential range application for the electrodes. Analysis was demonstrated a reverse relationship between charge accumulation and scan rate for both electrodes. The specific capacitance of the electrodes was highly changed. The electrochemical impedance spectroscopy analyses were shown lower internal resistance, higher Warburg diffusion constant, higher ionic conductivity, and lower Li-ion diffusion coefficient for the V2O5–P2O5 glassy electrode in the liquid LiClO4 electrolyte. This improvement was proved the negative influence of ZnO upon the host architecture and hindered Li-ion storage in the electrode. According to the repeating chronoamperometry results, V2O5–P2O5–ZnO electrode is more stable in electrochemical test cycles. V2O5–P2O5 electrode performance are increasing by test cycle. Surface properties of conductive layer for V2O5–P2O5–ZnO electrode was not damaged during the test. Lithium-ion diffusion coefficient of the V2O5–P2O5 and V2O5–P2O5–ZnO was also calculated as 1 × 10–11 and 2.1 × 10–11 cm2 s−1, respectively. Evaluate the results, ZnO doping decreased the current density and also increased the charge transfer time drastically. V2O5–P2O5–ZnO electrode showed the best performance and it is a promising material for the battery storage, electrochromic windows, super capacitor and sensor applications.