|Title||Supramolecular Perylene Bisimide-Polysulfide Gel Networks as Nanostructured Redox Mediators in Dissolved Polysulfide Lithium–Sulfur Batteries|
|Publication Type||Journal Article|
|Year of Publication||2015|
|Authors||Peter D Frischmann, Laura CH Gerber, Sean E Doris, Erica Y Tsai, Frank Y Fan, Xiaohui Qu, Anubhav Jain, Kristin A Persson, Yet-Ming Chiang, Brett A Helms|
|Journal||Chemistry of Materials|
|Pagination||6765 - 6770|
Here we report a new redox-active perylene bisimide (PBI)- polysulfide (PS) gel that overcomes electronic charge-transport bottlenecks common to lithium−sulfur (Li−S) 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 π-stacked PBI assemblies were stable even in their reduced state through secondary interactions between PBI nanofibers and Li2Sn, which resulted in a redoxactive, flowable 3-D gel network. The influence of supramolecular charge-transporting PBI-PS gel networks on Li−S 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−2 and energy density of 44 Wh L−1 in the absence of conductive carbon additives.
|Short Title||Chem. Mater.|