2020年6月18日
Impact of Anion Asymmetry on Local Structure and Supercooling Behavior of Water-in-Salt Electrolytes
The Journal of Physical Chemistry Letters
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- 巻
- 11
- 号
- 12
- 開始ページ
- 4720
- 終了ページ
- 4725
- 記述言語
- 英語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1021/acs.jpclett.0c00806
- 出版者・発行元
- American Chemical Society (ACS)
Salts with asymmetric (fluorosulfonyl)(trifluoromethanesulfonyl)imide (FTFSI) anions have recently been shown to suppress crystallization of water-in-salt electrolytes, enabling low-temperature operation of high-voltage aqueous rechargeable batteries. To clarify the underlying mechanism for the kinetic suppression of crystallization, we investigate the local solution structures and dynamic behaviors of water-in-salt electrolytes based on the asymmetric FTFSI anion and its symmetric anion analogues by Raman spectroscopy and molecular dynamics simulations. We find that monodentate coordination of FTFSI to cations leads to high rotational mobility of the uncoordinated SO2CF3 group. We conclude that the peculiar, coordination-dependent, local dynamics in the asymmetric FTFSI anion, manifested by enhanced intramolecular bond rotation, enables the strong supercooling behavior.
- リンク情報
- ID情報
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- DOI : 10.1021/acs.jpclett.0c00806
- ISSN : 1948-7185
- eISSN : 1948-7185
- Web of Science ID : WOS:000548027700027