Bismuth Trioxide Modified Carbon Nanotubes as Negative Electrode Catalysts for all Vanadium Redox Flow Batteries

Bismuth trioxide modified carbon nanotubes (Bi2O3/CNTs) composite was fabricated by liquid phase deposition-calcinating method and used as electrocatalyst for V3+/V2+ redox couple of all vanadium redox flow batteries (VRFBs). The modification of Bi species at the surface of CNTs can significantly inhibit the hydrogen evolution reaction and enhance the electrochemical activity to the V2+/V3+ redox reaction. The VRFB single cell with Bi2O3/CNTs modified graphite felt as negative electrode exhibits excellent energy storage performances, such as higher charge/discharge capacity and energy efficiency, indicating that the V2+/V3+ redox reaction can be facilitated significantly by Bi2O3/MWCNTs composite.