Zinc-Iron (Zn-Fe) Redox Flow Battery Single to Stack Cells: A Futuristics Solution for High Energy Storage Off-Grid Applications

Abstract

The decoupling nature of energy and power of redox flow batteries make them an efficient energy storage solution for sustainable off-grid applications. Recently, aqueous zinc-iron redox flow batteries have received great interest due to their eco-friendliness, cost-effectiveness, non-toxicity, and abundance. However, the development of zinc-iron redox flow batteries (RFBs) remains challenging due to severe inherent difficulties such as zinc dendrites, iron (III) hydrolysis, ion-crossover, hydrogen evolution reactions (HER), and expensive membranes which hinder commercialization. Many scientific initiatives have been commenced in the past few years to address these primary difficulties, paving the way for high-performance zinc-iron (Zn-Fe) RFBs. This review collectively provides the various aspects of the Zn-Fe RFB including basic electrochemical cell chemistry of anolyte, catholyte, different approaches made on electrodes, electrolytes, membranes, and other cell components to overcome the above issues. This overview accomplishes with the perceptions into future advances and viewpoints for obtaining the high-performance Zn-Fe RFBs.