A new redox flow battery using Fe2+/Fe3+ and V2+/V3+ redox couples in chloride-supporting electrolyte was proposed and investigated for potential stationary energy storage applications. The Fe/V redox flow cell using mixed reactant solutions operated within a voltage window of 0.5–1.35 V with a nearly 100% utilization ratio and demonstrated stable cycling with energy efficiency around 80% at room temperature. Stable performance was also achieved in the temperature range between 0 °C and 50 °C. The improved stability and electrochemical activity over a broader temperature range over the current technologies (such as Fe/Cr redox chemistry) potentially eliminate the necessity of external heat management and use of catalysts, making the Fe/V redox flow battery a promising option as a stationary energy storage device to enable renewable integration and stabilization of the electrical grid.
