(Chlorosulfonyl)(trifluoromethanesulfonyl)imide—a versatile building block for battery electrolytes

Abstract

Alkali metal salts with trifluoromethanesulfonimide anions ([N(SO2CF3)(SO2R)]−) are intriguing electrolyte components for high-performance rechargeable batteries, owing to their good thermal, chemical, and electrochemical stability. (Chlorosulfonyl)(trifluoromethanesulfonyl)imide (HN[(SO2Cl)(SO2CF3)], H[ClTFSI]) is a crucial precursor to access these important sulfonimide salts. In this work, the chemical properties of H[ClTFSI] in the presence of various kinds of tertiary amines are systematically investigated. It has been demonstrated that H[ClTFSI] possesses versatile reactive pathways under different reaction conditions, mainly including neutralization, nucleophilic substitution, and intra-/inter-molecular eliminative reactions. These reactions give a wide array of new compounds that are of great interest for battery use, particularly the sulfonimide-based zwitterion compounds with sufficient chemical and thermal stability (>190 °C). The present work provides a useful guideline for utilizing H[ClTFSI] as an efficient and versatile building block for battery electrolytes.