The Chemistry of Redox-Flow Batteries

The development of various redox‐flow batteries for the storage of fluctuating renewable energy has intensified in recent years because of their peculiar ability to be scaled separately in terms of energy and power, and therefore potentially to reduce the costs of energy storage. This has resulted in a considerable increase in the number of publications on redox‐flow batteries. This was a motivation to present a comprehensive and critical overview of the features of this type of batteries, focusing mainly on the chemistry of electrolytes and introducing a thorough systematic classification to reveal their potential for future development. Energy storage and electrolyte solutions: After a short technical introduction, this Review describes a systematic classification of different electrolyte systems of redox‐flow batteries. The chemical properties of true redox‐flow batteries as well as different hybrid systems are discussed from the standpoint of the current literature, and their development potential noted.