Electrochemical Performance of a New Triazole Functionalized Ferrocene in Aqueous Redox Flow Batteries

ABSTRACT A new 1,2,3‐triazole functionalized ferrocene (1,2,3‐TAFc) produced by Cu(I)‐catalyzed click reaction was investigated as positive electrolyte for aqueous organic flow batteries (AOFBs). The molecule is highly soluble in 1 M hydrochloric acid and displays high electrochemical reversibility. 1,2,3‐TAFc demonstrated good stability during cycling with a low capacity decay (0.011%/cyc, 3.0%/day) and high Coulombic efficiency (99.4%) over 280 cycles when tested in a flow battery at low concentration. This low capacity decay was attributed to the instability of ferrocene. These findings indicate that a stable and water‐soluble catholyte for AOFBs can be obtained with structural modifications of 1,2,3‐TAFc.