Investigations of High Voltage Vanadium-Metal Hydride Flow Battery toward kWh Scale Storage with 100 cm2 Electrodes

Recently reported vanadium-metal hydride redox couple exploits the pH difference between the negative and positive electrodes to obtain a high cell voltage of 2.0 V in aqueous environment. The metal hydride replaces the negative electrode of an all vanadium redox flow battery and eliminates limitations arise from the V2+/V3+ redox species. We report further improvements of this new redox couple with achievements of increased current density, operation of larger 100 cm(2) electrodes, and the operation of 10 large cells in series. Preliminary data using a fluctuating simulated power input tested the viability toward kWh scale storage. (C) 2015 The Electrochemical Society. All rights reserved.