Effects of organic additives containing NH₂ and SO₃H on electrochemical properties of vanadium redox flow battery

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• 作者：Zhangxing He ; Jianlei Liu ; Huiguo Han ; Yong Chen ; Zhi Zhou ; Shijie Zheng ; Wei Lu ; Suqin Liu ; Zhen He
• 关键词：Vanadium redox flow battery ; Additives ; Aminomethyl sulfonic acid ; Thermal stability ; Electrochemical activity
• 刊名：Electrochimica Acta
• 出版年：2013
• 出版时间：1 September, 2013
• 年：2013
• 卷：106
• 期：Complete
• 页码：556-562
• 全文大小：2018 K

文摘

Effects of methanesulfonic acid (MSA) and aminomethylsulfonic acid (AMSA) as additives for positive electrolyte on thermal stability and electrochemical performance are investigated. Both additives can improve the thermal stability of V(V) electrolyte, and AMSA has better effect, especially. The electrochemical results show that V(IV)/V(V) exhibits superior electrochemical activity and reversibility with additives, and the diffusion coefficient of V(IV) species, exchange current density and reaction rate constant become larger with additives in positive electrolyte. Among the two additives, AMSA has better effect for improvement of electrochemical activity and kinetics. The cell using positive electrolyte with additive of AMSA was assembled and the charge-discharge performance was evaluated. The assembled cell using AMSA as positive electrolyte additive shows good cycling performance, with higher energy efficiency (81.5 % ) and larger discharge capacity retention (40 cycles: 82.7 % ). The improved electrochemical performance may be ascribed to more active sites provided by NH₂ group and the enhanced hydrophilicity of the electrode provided by NH₂ and SO₃H groups.