Catalysis of Dioxovanadium Ion Reduction at Carbonaceous Material with Fe-N4 Site

摘要

Vanadium redox flow batteries (VRFB) have attracted much interest as a promising electrical energy storage system due to their suitability for large-scale energy storage and capability to withstand fluctuating power supplies. Carbon materials, carbon felts in particular, are conventionally used in the VRFB electrodes and the discharge reactions at the positive and negative electrodes are as follows: VO2 ~+ + 2H~+ + e ~- ?VO2~+ (positive electrode). V2~+ ?V~(3+) + e ~- (negative electrode). The slow reaction rates of these reaction is serious problems in VRFB technology, which have to be overcome to improve the efficiency of the VRFB. Several catalysts for the reaction have been proposed, such as dispersed metal particles, metal oxides, N-doped carbon; however, they have problems in the activity, the cost of precursors, and complex production procedures.