New Zinc–Vanadium (Zn–V) Hybrid Redox\nFlow Battery: High-Voltage and Energy-Efficient Advanced Energy Storage\nSystem

Abstract

Herein for the first\ntime, we have reported the performance and\ncharacteristics of new high-voltage zinc–vanadium (Zn–V)\nmetal hybrid redox flow battery using a zinc bromide (ZnBr₂)-based electrolyte. The Zn–V system showed an open-circuit\nvoltage of 1.85 V, which is very close to that of zinc–bromine\nflow cell. The obtained results exhibited a voltaic, Coulombic, and\nenergy efficiencies of 88, 82, and 72% at 20 mA.cm^–2, respectively, in which low-cost microporous membrane was used as\na separator. However, the cell tested using Nafion-117 membrane showed\nvoltaic, Coulombic, and energy efficiencies of 84, 83, and 71%, respectively\nat a current density of 20 mA.cm^–2. Furthermore,\nthe Zn–V cell performance is also compared with the Zn–Br₂ flow system to highlight the advancement of the new Zn–V\nsystem. The cell also showed stable performance up to 50 cycles at\na current density of 20 mA.cm^-2.