Eutectic Electrolytes for High-Energy-Density Redox Flow Batteries

Redox flow batteries (RFBs) have attracted immense research interests as one of the most promising energy storage devices for grid-scale energy storage. However, designing cost-effective systems with high energy and power density as well as long cycle life is still a big challenge for the development of RFBs. Eutectic electrolytes as a novel class of electrolytes have been recently explored to enhance the energy density of RFBs as they offer advantageous features such as low cost, ease of preparation, and tunable high concentration of active materials. In this Perspective, we present an overview of recent progress of eutectic electrolyte-based RFBs and highlight the development of understanding the working mechanism and related coordination chemistry. The challenges and potential research opportunities of eutectic electrolytes for RFBs are also discussed.