Evaluation of N-ethyl-N-methyl-morpholinium bromide and N-ethyl-N-methyl-pyrrolidinium bromide as bromine complexing agents in vanadium bromide redox flow batteries

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• 作者：Grace Poon ; Aishwarya Parasuraman ; Tuti Mariana Lim ; Maria Skyllas-Kazacos
• 关键词：Vanadium bromide batteries ; Bromine evolution ; Bromine complexing agents ; Quaternary ammonium bromides ; Cell performance
• 刊名：Electrochimica Acta
• 出版年：2013
• 出版时间：30 September, 2013
• 年：2013
• 卷：107
• 期：Complete
• 页码：388-396
• 全文大小：2046 K

文摘

Evolution of bromine gas in the positive half cell of the Generation 2 (G2) vanadium bromide (V/Br) battery during charging is a concern which can be resolved by the use of bromine complexing agents. In this paper, for the first time, we report the effect of the addition of two quaternary ammonium bromides; N-ethyl-N-methyl-morpholinium bromide (MEM) and N-ethyl-N-methyl-pyrrolidinium bromide (MEP) to the positive and negative half cell electrolytes of the V/Br. Cyclic voltammetry (CV), linear sweep voltammetry and electrochemical impedance spectroscopy (EIS) studies showed that the addition of MEM-MEP effectively reduce Br₂ vapours. Although the presence of MEM and MEP did not affect the mechanism of the electrode reactions, performance tests conducted in lab scale V/Br cells employing the VF11 cation exchange membrane resulted in lower average cell efficiencies possibly due to the increase in membrane resistance caused by membrane fouling.