Multielectron Organic Redoxmers for Energy-Dense Redox Flow Batteries

Redox flow battery is a highly promising stationary energy storage method, but the limited energy density and high chemical cost are among the main barriers for commercialization. Multielectron organic redoxmers represent a family of structurally tailorable candidates that can achieve multiplied energy density with decreased materials consumption, potentially resulting in a viable solution to address these challenges. Here, the recent development of organic molecules with reversible multiredox activities in both aqueous and nonaqueous electrolytes is reviewed. The major focus is on the fundamental correlation between the chemical structures and the functional properties of reported multielectron organic molecules. Valuable insights are offered on rational structural design strategies for improving the relevant physicochemical and electrochemical properties. Finally, the current challenges are discussed to suggest future research needs along the avenue of using the multielectron approach to achieve energy-dense, stable, cost-effective redox flow batteries.