Ionic conductivity and viscosity of solvate ionic liquids composed of glymes and excess lithium bis(trifluoromethylsulfonyl)amide

Abstract

Ionic conductivity and viscosity of lithium bis(trifluoromethylsulfonyl)amide (LiTFSA)-glyme solvate ionic liquids with the mole fraction of LiTFSA from 50.0 to 54.5mol% were investigated at 298-323 K. The ionic conductivity of the solvate ionic liquids was found to be inversely proportional to the viscosity, as expected from Walden's rule. The ionic conductivity of the solvate ionic liquid decreased with increasing the mole fraction of LiTFSA, probably due to formation of a bulky lithium species, [Li(TFSA)2]?, which forms at the compositions of more than 50mol% of LiTFSA.