Investigations on new Fe-Mn redox couple based aqueous redox flow battery

A new class of redox flow batteries involving Fe3+/Fe2+ and Mn3+/Mn2+ redox couples in the anolyte and catholyte, respectively being investigated. The proposed novel design of Fe-Mn redox flow battery exhibits significant Coulombic efficiency of around 96%, at a current density of 7 mA cm(-2). The Fe-Mn cell shows good capacity retention even after 100 cycles with the coulombic efficiency retaining at similar to 95%. Further, high concentration anolyte and catholyte was used which helps to improve the practical energy density of the system (>40 Wh L-1). The overall cost of the system is expected to be significantly lower than the existing redox flow battery systems. Thus, the low-cost and eco-friendly nature of these active species make this flow battery to be a potential candidate for large scale electricity storage applications which further facilitates the full utilisation of the intermittent renewable energy resources. (C) 2020 Published by Elsevier Ltd.