A novel catalyst of titanium boride toward V3+/V2+ redox reaction for vanadium redox flow battery

ABSTRACT Transition metal borides have broad application prospects in the field of electrochemistry due to their excellent physicochemical stability and electrical conductivity. In this study, metal boride (titanium boride, TiB2) was first proposed as a novel catalyst for V3+/V2+ in vanadium redox flow battery. Nano-TiB2 exhibits large specific surface area and great electrical conductivity, and shows excellent catalytic performance in V3+/V2+ redox reaction. The performance of TiB2 as negative catalyst for cell was further investigated. Compared with pristine cell, TiB2 modified cell displays much higher discharge capacity (16.9 mA h) after 50 cycles and the incipient energy efficiency increases by 6.5%. The cell with TiB2 as the negative electrode exhibits excellent rate performance at 50-150 mA cm-2. Voltage efficiency and energy efficiency of modified cell are 8.7% and 7.5% higher than those of pristine cell at 150 mA cm-2, respectively. In conclusion, this work reveals that nano-TiB2 is a promising catalyst for enhancing the electrochemical performance toward V3+/V2+ redox reaction for vanadium redox flow battery.