Bismuth-lead oxides co-modified graphite felt as efficient catalyst for the Cr3+/Cr2+ redox reaction

Iron-chromium flow battery is considered one of the preferred technologies for large-scale energy storage facilities due to its advantages of low pollutability, less cost and high safety. However, the poor reversibility of the Cr 3+ /Cr 2+ redox reaction at the anode of iron-chromium flow batteries, the low activity and the susceptibility to hydrogen evolution reaction are the primary problems that restrict the development and application of this battery. On the basis of graphite felt electrodes, we prepared bismuth-lead oxides co-modified graphite felt electrodes via acid etching and electrodeposition method to improve the electrochemical performance in the reaction kinetics. The structural and catalytic properties of the materials were characterized and evaluated by scanning electron microscopy, X-ray photoelectron spectroscopy, X‐ray diffraction spectroscopy and electrochemical methods, respectively. The results show that with the help of the interaction between Bi and Pb elements, the successfully prepared modified electrode not only improves the reversibility and reaction rate of the electrochemical redox reaction of Cr 3+ /Cr 2+ but also effectively inhibits the occurrence of hydrogen evolution reaction.