Redox-targeted catalysis for vanadium redox-flow batteries

This work reports an unprecedented method based on the redox targeting concept to facilitate the interfacial charge transfer of the vanadium species and concomitantly inhibit the hydrogen and oxygen evolutions. Prussian blue (PB) and a Prussian blue analogues (PBA) with identical redox potentials to VO2+/VO2+ and V2+/V3+ are grafted on cathode and anode, respectively. It improves the selectivity of the redox reactions and considerably enhances the round-trip energy efficiency and cycling performance of VRB in a wide range of current densities. We anticipate the redox catalysis approach demonstrated here would generically provide a paradigm for improving the sluggish kinetic processes in a variety of electrochemical devices.234