A Benchmarking Approach for Routine Determination of Flow Battery Kinetics

This work focusses on improved precision and reproducibility in the study of redox flow battery (RFB) kinetics. We measured the electron-transfer reaction rates of the Fe(III/II) redox couple at polycrystalline Pt and Au electrodes in aqueous HCl supporting electrolyte using rotating disk electrode voltammetry. We made considerable effort to implement a systematic electrode preparation protocol, which was necessary for reproducibility. We found the reaction to be quasi-reversible at both electrodes and Pt to be a slightly more effective catalyst than Au. We further discuss some of the benefits and challenges of applying classical electroanalysis to RFB device design.