Fluorinated Aryl Sulfonimide Tagged (FAST) salts: modular synthesis and structure？property relationships for battery applications
Journal
Energy and Environmental Science
Date
2018.03.21
Abstract
Solid-state electrolytes are attracting great interest for their applications in potentially safe and stable
high-capacity energy storage technologies. Lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) is widely
used as a lithium ion source, especially in solid-state polymer electrolytes, due to its solubility and
excellent chemical and electrochemical stability. Unfortunately, chemically inert LiTFSI cannot be easily
modified to optimize its properties or allow for conjugation to other molecules, polymers, or substrates
to prepare single-ion conducting polymer electrolytes. Chemical modifications of TFSI often erode its
advantageous properties. Herein, we introduce Fluorinated Aryl Sulfonimide Tagged (FAST) salts, which
are derived from successive nucleophilic aromatic substitution (SNAr) reactions. Experimental studies and
density functional theory calculations were used to assess the electrochemical oxidative stabilities,
chemical stabilities, and degrees of ion dissociation of FAST salts as a function of their structures. FAST
salts offer a platform for accessing functional sulfonimides without sacrificing many of the advantageous
properties of TFSI.