Developments of electrodes for vanadium redox flow battery

This paper presented a review on the study of electrode materials for vanadium redox flow battery(VFB), which covered the categories of electrode material, the methods of improving performance in electrode, research progress by modifications, and the aging mechanism of electrode. The methods of electrode modified were presented in detail. The results indicated that improvements of reactivity and active areas of electrode were both effective ways to optimize performance of electrode. Exposure electrodes to acid or heat treatment could increase the reversibility of electrode. Through growing CNTs on the electrode in situ, loading graphene or iridium oxide on surface of electrode, or using porous carbon electrodes prepared from natural waste, the electrodes could exhibit the higher electrochemistry active areas and reversibility at the same time. A practical means to combine bipolar plates with graphite felts as an integrative electrode could obviously reduce the contact resistance, which would benefit for decreasing the polarization voltage. In addition, the aging of electrode could effect on its' service life. The results showed that aging of electrode would have a worse impact on negative electrodes than that on positive electrodes. Finally the present situation and problem for VFB were summarized and the research direction of electrode materials for VFB was prospected.