Optimized synthesis of cyclic fluorinated sulfonylimide lithium salts to suppress aluminum corrosion in lithium-ion batteries

LiCTFSI, lithium 4,4,5,5-tetrafluoro-1,3,2-dithiazolidine-1,1,3,3-tetraoxide, is a new promising lithium salt for usage in lithium-ion battery electrolytes, because it doesn't cause corrosion of the aluminum current collector below 5.0 V vs. Li+/Li. LiCTFSI can be synthesized in three steps, in...

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Bibliographic Details
Main Authors: Hori, K. (Author), Ito, M. (Author), Maeda, K. (Author), Matsuoka, N. (Author), Uematsu, N. (Author), Yakigaya, K.-I (Author)
Format: Article
Language:English
Published: Elsevier B.V. 2022
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Online Access:View Fulltext in Publisher
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Summary:LiCTFSI, lithium 4,4,5,5-tetrafluoro-1,3,2-dithiazolidine-1,1,3,3-tetraoxide, is a new promising lithium salt for usage in lithium-ion battery electrolytes, because it doesn't cause corrosion of the aluminum current collector below 5.0 V vs. Li+/Li. LiCTFSI can be synthesized in three steps, including Kolbe electrolysis, using 2,2-difluoro-2-(fluorosulfonyl)acetic acid as raw material. In this study, the synthesis route of LiCTFSI, hereby especially the Kolbe electrolysis, was optimized to achieve high purity (99.9%). Furthermore, performance of 4.2 V batteries using the as-synthesized LiCTFSI as lithium salt in acetonitrile-containing electrolytes showed that LiCTFSI is less corrosive towards aluminum than LiTFSI and reducing the sulfonamide impurity in LiCTFSI synthesis can further reduce aluminum corrosion. © 2022 The Author(s)
ISBN:00221139 (ISSN)
DOI:10.1016/j.jfluchem.2022.109975