Bidirectionally Enhanced Reaction Kinetics in Vanadium Redox Flow Battery via Regulating Mixed-Valence States in Perovskite Electrodes

Abstract Various metal oxide catalysts have been utilized to enhance the electrode reaction kinetics in vanadium redox flow battery (VRFB). However, the determining factor governing their catalysis is still insufficiently understood. Herein, selectively doping of Sr and Ce at La site of LaMnO 3 perovskite (LSMO and LCMO) was used to modulate chemical environments of Mn ion activity donors, thereby boosting vanadium redox reaction processes. Sr doping increases the valence state of Mn ions, making it easier for Mn ions to take an electron from the electrode and transfer it to V 3+ ions, which lowers the reaction energy barrier of V 3+ /V 2+ redox processes. Conversely, Ce doping decreases the Mn valence and…