title: Ionic liquid based lithium battery electrolytes: fundamental benefits of utilising both TFSI and FSI anions?
abstract: Several IL based electrolytes with an imidazolium cation (EMI) have been investigated trying to elucidate a possible beneficial effect of mixing FSI and TFSI anions in terms of physico-chemical properties and especially Li(+) solvation. All electrolytes were evaluated in terms of phase transitions, densities and viscosities, thermal stabilities, ionic conductivities and local structure, i.e. charge carriers. The electrolytes with up to 20% of Li-salts showed to be promising for high temperature lithium ion battery application (ca. 100 °C) and a synergetic effect of having mixed anions is discernible with the LiTFSI0.2EMIFSI0.8 electrolyte giving the best overall performance. The determination of the charge carriers revealed the SN to be ca. 2 for all analysed electrolytes, and proved the analysis of the mixed anion electrolytes to be challenging and inherently leads to an ambiguous picture of the Li(+) solvation.
authors.affiliation: Department of Applied Physics, Chalmers University of Technology, SE-41296 Gothenburg, Sweden. manfred.kerner@chalmers.se.
authors.forename: M
authors.initials: M
authors.lastname: Kerner
authors.forename: N
authors.initials: N
authors.lastname: Plylahan
authors.forename: J
authors.initials: J
authors.lastname: Scheers
authors.forename: P
authors.initials: P
authors.lastname: Johansson