Progress and prospects of next-generation redox flow batteries

As one of the most promising electrochemical energy storage systems, redox flow batteries (RFBs) have received increasing attention due to their attractive features for large-scale storage applications. However, their practical deployment in commerce and industry is still impeded by their relatively high cost and low energy density. Therefore, developments of the next-generation RFBs should address these challenges by exploring new redoxactive electrolytes and novel membranes with higher ionic selectivity and conductivity, which help to achieve lower cost, longer life and higher energy and power density. In this review, we present a critical overview of the latest progress on the key components of RFBs, including redox species and membranes. Current progress on optimization strategies of the performance of RFB systems, computational modeling, prospects and opportunities in exploration of the advanced RFB systems are also summarized.