Gabriel Sikukuu Nambafu, Aaron Hollas, Guosheng Li
Integrating large-scale energy storage technologies is crucial for enhancing grid stability and reliability in an evolving market and energy demand mix. Among various storage systems, redox flow batteries (RFBs) have emerged as a promising solution to independently manage energy capacity and power density, which are particularly suitable for meeting variable-duration storage applications. This review focuses on iron-based redox flow batteries (Fe-RFBs), which leverage the natural abundance, nontoxicity, and cost-effectiveness of iron as an active material. This account details recent progress in Fe-RFBs, examining their history, challenges, degradation mechanisms, and future research directions. It also discusses design considerations for suitable Fe electrolytes with the aim of accelerating the development of high-performance Fe-RFBs for large-scale applications. Overall, this review seeks to illuminate pathways for advancing Fe-RFBs as viable solutions to meet growing energy demands in a sustainable, reliable, and cost-effective way.