Progress in Profitable Fe-Based Flow Batteries for Broad-Scale Energy Storage

The development of an affordable, environmentally acceptable alternative energy storage devices are required to address the present energy problem and offer a viable solution for renewable energy sources with intermittency. As a broad-scale energy storage technology, redox flow battery (RFB) has broad application prospects. However, commercializing mainstream all-vanadium RFBs is slow due to the high cost. Owing to the environmental friendliness and affordable iron-based raw materials the interest on iron-based RFBs are increasing. The aim of the perspective is to offer a quick overview on research progress of iron-based RFBs, including their research status, history, and development of essential components. Influencing factors such as conductivity, solubility, hydrogen evolution, reaction kinetics, etc. are summarized comprehensively. Further research was identified on reducing the hydrogen evolution on the electrodes, exploring economical and easy-to-recycle solutions for active materials, improving the stability of electrodes, and developing new electrode structures.