Organic electrolytes for aqueous organic flow batteries

The increasing energy demand of human society boosts the exploitation of renewable energy, whereas the intermittence and fluctuation of renewable energy necessitate the deployment of high-performance and cost-effective energy storage technology. Aqueous organic flow battery (AOFB) is a novel system with decoupled capacity and power, which stores energy in organic redox-active species and can be easily scaled-up, thereby promising low-cost energy storage solution. Organic electrolytes are composed of earth-abundant molecules, and their electrochemical properties, including potential, water solubility, and chemical stability, could be tuned through function-oriented molecular engineering. Herein, we summarize the developed negolyte molecules and posolyte molecules for AOFBs and the consideration beneath molecular design and modification. We also discuss the calculation methods that might facilitate the development of organic electrolytes. Finally, we make a short conclusion, present the challenges, and suggest future directions for the design of robust organic electrolytes toward advanced AOFBs.