Abstract
The impact of the electrolyte solvation structure on the performance of Li-S battery was investigated using an electrolyte system containing various solvent ratios of DOL and a nonafluorinated ether: 1,1,2,2-tetrafluoroethyl-2,2,3,3,3-pentafluoropropyl ether (TPE). The cell testing results indicate that increasing the TPE ratio led to both a higher discharge capacity and a higher Coulombic efficiency. The Li electrodes from the Li/Li symmetric cells showed that the one in higher TPE-content electrolyte has a smoother and more continuous SEI layer. AIMD simulation revealed the solvation structure of DOL/TPE – lithium polysulfide changes when the TPE concentration increases, which dictates the lithium polysulfide solubility in such electrolyte. These results shed light on the underpinned mechanism of the improved Coulombic efficiency and cycling performance of the Li-S cell.
| Original language | English |
|---|---|
| Pages (from-to) | A3653-A3659 |
| Journal | Journal of the Electrochemical Society |
| Volume | 166 |
| Issue number | 15 |
| DOIs | |
| State | Published - 2019 |
| Externally published | Yes |
Funding
This research is supported by Daimler AG/Mercedes-Benz Research & Development North America, Inc. Argonne, a U.S. Department of Energy laboratory, is operated by UChicago Argonne, LLC under contract DE-AC02-06CH11357. We gratefully acknowledge the computing resources provided on Bebop, a high-performance computing cluster operated by the Laboratory Computing Resource Center at Argonne National Laboratory.