Boosting performance of Ti3C2TX/Bi modified graphite felt electrode for all-vanadium redox flow battery

All-vanadium redox flow battery (VRFB) with high power density is urgent in energy storage area. This study investigated the impact of Ti3C2TX/Bi as catalyst on VRFB performance at high current density. The Ti3C2TX/Bi decorated electrode was prepared based on a facile dropping method. Owing to the synergistic effect between Bi and Ti3C2TX, the hydrogen evolution reaction (HER) is effectively inhibited and the electrochemical activity towards V2+/V3+ redox reaction is enhanced. With the current densities ranging from 100 mA·cm−2 to 220 mA·cm−2, VRFB equipped with Ti3C2TX/Bi modified graphite felt shows the best rate performance. Furthermore, at a current density of 200 mA·cm−2, the battery with Bi and Ti3C2TX modified electrode shows the highest capacity retention rate of 70.3 % after 100 charge-discharge cycles and the highest energy efficiency (EE) of 80.1 %.