title: Solvate structures and spectroscopic characterization of LiTFSI electrolytes.
abstract: A Raman spectroscopic evaluation of numerous crystalline solvates with lithium bis(trifluoromethanesulfonyl)imide (LiTFSI or LiN(SO2CF3)2) has been conducted over a wide temperature range. Four new crystalline solvate structures-(PHEN)3:LiTFSI, (2,9-DMPHEN)2:LiTFSI, (G3)1:LiTFSI and (2,6-DMPy)1/2:LiTFSI with phenanthroline, 2,9-dimethyl[1,10]phenanthroline, triglyme, and 2,6-dimethylpyridine, respectively-have been determined to aid in this study. The spectroscopic data have been correlated with varying modes of TFSI(-)···Li(+) cation coordination within the solvate structures to create an electrolyte characterization tool to facilitate the Raman band deconvolution assignments for the determination of ionic association interactions within electrolytes containing LiTFSI. It is found, however, that significant difficulties may be encountered when identifying the distributions of specific forms of TFSI(-) anion coordination present in liquid electrolyte mixtures due to the wide range of TFSI(-)···Li(+) cation interactions possible and the overlap of the corresponding spectroscopic data signatures.
authors.affiliation: Ionic Liquids & Electrolytes for Energy Technologies (ILEET) Laboratory, Department of Chemical & Biomolecular Engineering, North Carolina State University , Raleigh, North Carolina 27695, United States.
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Seo
authors.forename: Paul D
authors.initials: PD
authors.lastname: Boyle
authors.forename: Roger D
authors.initials: RD
authors.lastname: Sommer
authors.forename: James S
authors.initials: JS
authors.lastname: Daubert
authors.forename: Oleg
authors.initials: O
authors.lastname: Borodin
authors.forename: Wesley A
authors.initials: WA
authors.lastname: Henderson