钒电池电解液伏安行为研究

Study of Cyclic Voltammetry Behavior of Electrolyte in Vanadium Redox Flow Battery

用电化学法研究了钒离子浓度、支持电解液硫酸浓度、扫描速度以及加入如EDTA等添加剂后在石墨电极上的循环伏安行为,探讨了不同温度热处理石墨电极下的循环伏安行为,以及重铬酸钾活化处理与不进行任何处理的石墨电极的可逆性。结果表明:出现了V(IV)/V(V)电对的氧化和还原峰,而且扫描速度和支持电解液硫酸浓度的增大都使峰值电流增大,但钒离子浓度的增大反而使峰值电流减小,而加入添加剂对峰值几乎没有影响;热处理对石墨电极表面的活性有所提高,活化处理对V(IV)/V(V)电对的氧化和还原可逆性没有明显的提高,但对于V(Ⅲ)/V(Ⅱ)电对的可逆性有显著的增强。

Cyclic voltammetry behaviors on the graphite electrode at different vanadium ion concentration, H2SO4 concentration, scan rate, additives has been studied by electrochemical methods. The conclusion shows that the characteristic peak of V （IV）/V （V） redox couples has appeared. The higher the concentration of the H2SO4 and the scan rate are, the bigger the peak current is. But the increasing of the electrolytic liquid concentration makes the peak current decreased, and there is no influence for adding additives. Cyclic vohammetry behavior on the graphite electrode at different heating temperature, and the reversibility of both activated and non-activated graphite electrode has also been studied. The result indicats that heating treatment could increase activation of the graphite electrode surface, and the activation treatment could not improve reversibility of V （IV）/V （V） redox couples. However, it could enhance the reversibility of V （ Ⅲ）/V （ Ⅱ） redox couples.