An Imidazolium based ionic liquid electrolyte for lithium batteries
Journal article, 2010

An electrolyte for lithium batteries based on the ionic liquid 3-methy-1-propylimidazolium bis(trifluoromethysulfony)imide (PMIMTFSI) complexed with lithium bis(trifluoromethysulfony)imide (LiTFSI) at a molar ratio of 1:1 has been investigated. The electrolyte shows a high ionic conductivity (1.2 × 10−3 S cm−1) at room temperature. Over the whole investigated temperature range the ionic conductivity is more than one order of magnitude higher than for an analogue electrolyte based on N-butyl-N-methyl-pyrrolidinium bis(trifluoromethanesulfonyl)imide (Py14TFSI) complexed with LiTFSI and used here as a benchmark. Raman results indicate furthermore that the degree of lithium coordinated TFSI is slightly lower in the electrolyte based on PMIMTFSI and thus that the Li+ charge carriers should be higher than in electrolytes based on Py14TFSI. An ionic liquid gel electrolyte membrane was obtained by soaking a fibrous fully interconnected membrane, made of electrospun P(VdF-HFP), in the electrolyte. The gel electrolyte was cycled in Li/ionic liquid polymer electrolyte/Li cells over 15 days and in Li/LiFePO4 cells demonstrating good interfacial stability and highly stable discharge capacities with a retention of >96% after 50 cycles (146 mAh g−1).

Ionic liquid electrolyte

Ionic conductivity


Ion–ion interaction

Lithium batteries


Jae-Kwang Kim

Chalmers, Applied Physics, Condensed Matter Physics

Aleksandar Matic

Chalmers, Applied Physics, Condensed Matter Physics

J. H. Ahn

Gyeongsang National University

Per Jacobsson

Chalmers, Applied Physics, Condensed Matter Physics

Journal of Power Sources

0378-7753 (ISSN)

Vol. 195 22 7639-7643

Areas of Advance


Materials Science

Subject Categories

Other Materials Engineering



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