Enhanced Catalysis of P-doped SnO2 for the V2+/V3+ Redox Reaction in Vanadium Redox Flow Battery

In this work, nanosized P-doped SnO 2 (SnO 2 -P) was prepared by a sol–gel method as a catalyst for the V 3+ /V 2+ redox reaction in vanadium redox flow battery. Compared with SnO 2 , the electrochemical performance of SnO 2 -P is significantly improved. This is because P doping provides more active sites and shows greatly improved electrical conductivity, thereby increasing the electron transfer rate. As a result, SnO 2 -P shows better catalytic performance than SnO 2 . The SnO 2 -P modified cell is designed, and it exhibits an increase of 47.2 mA h in discharge capacity and 8.7% in energy efficiency compared with the pristine cell at 150 mA cm −2 . These increases indicate that the modified cell has a higher electrolyte utilization rate. This study shows that SnO 2 -P is a new and efficient catalyst for vanadium redox flow battery.