For flow batteries (FBs), the current technologies are still expensive and have relatively low energy density, which limits their large-scale applications. Organic FBs (OFBs) which employ organic molecules as redox. Electricity generated from renewable energy sources is one of the critical methods to reduce. In general, several performance metrics including volumetric capacity, energy density, power density, efficiencies (Coulombic efficiency CE, energy efficiency, EE, an. For aqueous OFBs (AOFB), RAMs are always used in pH different environments: acidic, alkaline, and neutral. Different pH will lead to different behaviors of the organic molecule. Organic solvents in non-aqueous organic flow batteries (NOFBs) can break up the limit of the water electrolysis, and the electrochemical window could reach over 5 V. In addition, th. 5.1. MemberanesThe membranes are the key components of FBs which separate the catholytes and anolytes to prevent the crossover of RAMs while conducting.