Kinetics of the charge/discharge characteristics of redox flow battery electrolytes
A comparison of the electrochemical behavior of Ce(IV) and its complexes of ethylenedi-aminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), ethylenedia-minedisuccinic acid (EDDS), and nitrilotriacetic acid (NTA) using cyclic voltammetry (CV) and rotating disc electrode (RDE) on Pt-electrode were carried out. All complexes had an anodic cathodic ratio greater than 1. The Ce(IV)-DTPA had the best properties: highest peak potential, better reversibility, and higher peak current. Potential usage of the Ce(IV)-DTPA in redox flow batteries (RFB) was confirmed by the electrochemical impedance spectroscopy results: lowest electrolyte and charge transfer resistance. The performance evaluation of RFB employing Ce(IV) and Ce(IV) complexes of DTPA and EDTA with constant current charge/discharge analysis proved that CE(IV)-DTPA complex has a potential as an anode in RFB. A maximum potential of 1V and a minimum voltage of 2 V were achieved. Highest energy, voltage, and coulombic efficiencies of 85%, 93%, and 92% were obtained, respectively. © Taylor & Francis Group, LLC.