Impact of Thermal Electrode Activation on Electrocatalyst Performance in KCrPDTA/K₄Fe(CN)₆ Flow Batteries

Abstract Improving electrode performance is crucial for increasing energy efficiency and power density in redox flow batteries. Here, we study the effects of thermal activation of carbon paper electrodes on the performance of bismuth as an electrocatalyst in high‐voltage KCrPDTA/K 4 Fe(CN) 6 flow batteries. While thermal activation improves wettability and surface area, it also leads to the formation of large, agglomerated bismuth deposits that reduce Coulombic efficiency. Although bismuth lowers cell resistance and enhances voltage efficiency, it promotes parasitic hydrogen evolution depending on its morphology, underscoring the need for optimized catalyst deposition techniques.