Redox targeting-based flow batteries

The redox flow battery (RFB) is an electrochemical device for large-scale energy storage. The most attractive merit of the RFB is the decoupling of energy storage and power generation. It is one of the most promising energy storage technologies for renewable energy, such as solar and wind, and grid energy storage due to its flexible design, high storage capacity, long cycle life, and safety. The development of the different RFB systems is holistically reviewed here, classified by the redox couples and supporting electrolytes. Particularly, based on the redox targeting concept, redox targeting-based flow batteries are extensively discussed as a novel flow battery technology for high-density energy storage. The working principles, key materials, and some typical redox targeting-based flow battery chemistries are highlighted.