A novel pyridinium-functionalized fluorenone compound for neutral aqueous organic redox flow batteries

Abstract

A novel fluorenone compound, 4-oxo-4,8,9,10-tetrahydro-7a,10a-diazacyclohepta[def]fluorene-7a,10a-diium chloride (OTDFL)Cl₂, was constructed as the organic electroactive material for aqueous organic redox flow batteries (AORFBs). With high solubility in water and highly reversible electrochemical behaviour, (OTDFL)Cl₂ exhibited excellent volumetric capacity and cycling performance, making it a promising candidate electrolyte for AORFBs.