Highly Stable Asymmetric Viologen As an Anolyte for Aqueous Organic and Halide‐Based Redox Flow Batteries
Energy technology(2022)
摘要
In redox flow batteries (RFBs), energy density mainly depends on the volume and concentration of active species in electrolyte. However, the poor solubility of organic molecules limits the further development of aqueous organic redox flow batteries (AORFBs). Herein, the viologen core structure is modified with asymmetric functional groups such as propyl and triethyl ammonium propyl for enhancing the solubility up to 1.82 m in aqueous medium. Further, the modified viologen structure lowers the redox potential (−0.58 V vs Ag/AgCl) and significantly reduces radical dimerization. Interestingly, synthesized [1‐propyl‐1’‐(3‐triethylammonio)propyl‐4,4’‐bipyridinium tribromide] (PV3+) coupled with bromide/bromine (2Br−/Br2) redox species shows cell voltage (1.66 V). The tested PV3+/PV2+•||2Br−/Br2 RFB having Nafion‐117 membrane exhibits a round‐trip efficiency of 99% over 100 cycles. The self‐discharge behavior of PV3+/PV2+•||2Br−/Br2 RFB system retains 85% of the cell voltage over 20 h, indicating the lowest permeability of bromine in RFB. Thus, the present approach of viologen modification with asymmetric functionalities drastically improves the RFB performance in terms of energy density and cycle life of the system.
更多查看译文
关键词
asymmetric viologens,high cell voltages,low redox potentials,radical dimerization,redox flow batteries
AI 理解论文
溯源树
样例
![](https://originalfileserver.aminer.cn/sys/aminer/pubs/mrt_preview.jpeg)
生成溯源树,研究论文发展脉络
Chat Paper
正在生成论文摘要