Investigation of the Negative Process as the Limiting Factor of Vanadium Flow Battery

Abstract

The electrochemical behavior of the positive and negative electrode reactions for a vanadium flow battery (VFB) on a pyrolytic graphite electrode is investigated. It is found that there is a significant difference in the electrochemical characteristics of the positive and negative electrode reactions, and the negative electrode reaction often exhibits an inferior electrochemical performance. Furthermore, the charge/discharge tests of the VFB with commercial carbon felts as the electrodes are conducted to further make clear the effect of positive and negative electrode processes on the VFB performance. The results indicate that the negative electrode process greatly limits the battery performance of the VFB and enhancement of the battery performance by improving the negative electrode process will be more effective. Therefore, the negative electrode process is the limiting factor of the VFB and more attention should be paid to improving the electrochemical performance of the negative electrode process.