The thermal phase behavior and ionic conductivity of mixtures of N-alkyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide ionic liquids (PY1RTFSI where R = 4 or 5 for butyl or pentyl) with LiTFSI have been examined as model systems for ionic liquid-based lithium battery electrolytes. Several mixed salt crystalline phases form. The ionic conductivity variability of the mixtures correlates well with the reported phase behavior. The crystal structures for the (1-x) PY1RTFSI-(x) LiTFSI (x = 0.67) (or 1/2 PY1RTFSI/LiTFSI with R = 4 or 5) phases have been determined. These phases are isostructural, consisting of ionic planar layers formed by Li +•••TFSI- linkages in which the uncoordinated PY1R+ cations reside in cavities within the layers. These structures have been used to aid in correlating Raman data with cation-anion coordination in the IL-LiTFSI binary salt mixtures. © 2011 American Chemical Society.
All Science Journal Classification (ASJC) codes
- Materials Chemistry
- Chemical Engineering(all)
Zhou, Q., Boyle, P. D., Malpezzi, L., Mele, A., Shin, J-H., Passerini, S., & Henderson, W. A. (2011). Phase behavior of ionic liquid-LiX mixtures: Pyrrolidinium cations and TFSI- anions - Linking structure to transport properties. Chemistry of Materials, 23(19), 4331 - 4337. https://doi.org/10.1021/cm201427k