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Reversible Sodium Metal Electrodes: Is Fluorine an Essential Interphasial Component?
Author(s) -
Doi Kyosuke,
Yamada Yuki,
Okoshi Masaki,
Ono Junichi,
Chou ChienPin,
Nakai Hiromi,
Yamada Atsuo
Publication year - 2019
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201901573
Subject(s) - fluorine , electrolyte , inorganic chemistry , chemistry , electrode , faraday efficiency , sodium , stripping (fiber) , metal , sodium tetraphenylborate , lithium (medication) , materials science , organic chemistry , medicine , composite material , endocrinology
Alkaline metals are an ideal negative electrode for rechargeable batteries. Forming a fluorine‐rich interphase by a fluorinated electrolyte is recognized as key to utilizing lithium metal electrodes, and the same strategy is being applied to sodium metal electrodes. However, their reversible plating/stripping reactions have yet to be achieved. Herein, we report a contrary concept of fluorine‐free electrolytes for sodium metal batteries. A sodium tetraphenylborate/monoglyme electrolyte enables reversible sodium plating/stripping at an average Coulombic efficiency of 99.85 % over 300 cycles. Importantly, the interphase is composed mainly of carbon, oxygen, and sodium elements with a negligible presence of fluorine, but it has both high stability and extremely low resistance. This work suggests a new direction for stabilizing sodium metal electrodes via fluorine‐free interphases.