Electrochemical activity of tungsten oxide doped carbon (WO3/C) catalyst for hydroquinone/benzoquinone redox flow battery

Abstract

The research in organic flow batteries is emerging as the cost of the vanadium electrolyte limits the grid-scale application. Tungsten trioxide doped carbon (WO3/C) electrocatalyst is developed to examine its potential in hydroquinone - benzoquinone redox flow battery (HQ/BQ RFB). The catalyst is characterized by a field emission scanning electron microscope (FESEM), X-ray diffraction (XRD), and fourier transform infrared spectroscopy (FTIR) and confirms the formation of active WO3/C electrocatalyst. The electrochemical activity of the synthesized WO3/C electrocatalyst is inspected by cyclic voltammetry (CV). It shows comparatively high anodic and cathodic peak currents, low charge transfer resistance, and relatively high electrokinetic reversibility. The charge–discharge test on single cell HQ/BQ RFB is conducted using pristine carbon paper (CP), and WO3/C coated carbon paper (WO3/C-CP). The columbic efficiency (CE), voltage efficiency (VE), and energy efficiency (EE) of the RFB using WO3/C-CP are around 90%, 75%, and 70%, respectively, which are significantly higher than the CP. The improvement in results demonstrates that the WO3/C electrocatalyst is better at providing active sites and improving the electrochemical reactions kinetics, thus suits the application of HQ/BQ RFB.