Supramolecular Perylene Bisimide-Polysulfide Gel Networks as Nanostructured Redox Mediators in Dissolved Polysulfide Lithium鈥揝ulfur Batteries

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• 作者：Peter D. Frischmann ; Laura C. H. Gerber ; Sean E. Doris ; Erica Y. Tsai ; Frank Y. Fan ; Xiaohui Qu ; Anubhav Jain ; Kristin A. Persson ; Yet-Ming Chiang ; Brett A. Helms
• 刊名：Chemistry of Materials
• 出版年：2015
• 出版时间：October 13, 2015
• 年：2015
• 卷：27
• 期：19
• 页码：6765-6770
• 全文大小：379K
• ISSN：1520-5002

文摘

Here we report a new redox-active perylene bisimide (PBI)-polysulfide (PS) gel that overcomes electronic charge-transport bottlenecks common to lithium鈥搒ulfur (Li鈥揝) hybrid redox flow batteries designed for long-duration grid-scale energy storage applications. PBI was identified as a supramolecular redox mediator for soluble lithium polysulfides from a library of 85 polycyclic aromatic hydrocarbons by using a high-throughput computational platform; furthermore, these theoretical predictions were validated electrochemically. Challenging conventional wisdom, we found that 蟺-stacked PBI assemblies were stable even in their reduced state through secondary interactions between PBI nanofibers and Li₂S_n, which resulted in a redox-active, flowable 3-D gel network. The influence of supramolecular charge-transporting PBI-PS gel networks on Li鈥揝 battery performance was investigated in depth and revealed enhanced sulfur utilization and rate performance (C/4 and C/8) at a sulfur loading of 4 mg cm^鈥? and energy density of 44 Wh L^鈥? in the absence of conductive carbon additives.