Analysis of the solid electrolyte interphase formed with an ionic liquid electrolyte for lithium-sulfur batteries
Journal article, 2014

We have investigated the formation of the solid electrolyte interphase (SEI) on lithium electrodes in the presence of an ionic liquid electrolyte with a particular focus on the influence of polysulfides present in the electrolyte on the SEI. The electrochemical performance of symmetric cells with lithium electrodes and electrolytes composed of N-Methyl-(n-butyl)pyrrolidinium bis(trifluoromethanesulfonyl)imide (PYR14-TFSI) and LiTFSI, with and without the addition of polysulfides, were analyzed as well as the chemical composition of the SEI, before and after cycling. The cycling behavior of the symmetrical cells shows that the SEI films are relatively stable in the ionic liquid electrolyte, also in the presence of polysulfides. However, the presence of polysulfides results in a higher SEI layer resistance (R-SEI) and a higher activation energy. From X-ray photoelectron spectroscopy spectra (XPS), with argon-ion sputtering for depth profiling, we find that the SEI is formed by decomposition products from both cations and anions of the electrolyte. The XPS spectra show that the presence of polysulfides alters the decomposition process of the electrolyte, resulting in a SEI film with different chemical composition and structure, in line with the results from the electrochemical performance.


Solid electrolyte interphase

Lithium-sulfur batteries

Ionic liquid

X-ray photoelectron spectroscopy


Shizhao Xiong

Chalmers, Applied Physics, Condensed Matter Physics

K Xie

National University of Defense Technology

Erik Blomberg

Chalmers, Earth and Space Sciences, Radar Remote Sensing

Per Jacobsson

Chalmers, Applied Physics, Condensed Matter Physics

Aleksandar Matic

Chalmers, Applied Physics, Condensed Matter Physics

Journal of Power Sources

0378-7753 (ISSN)

Vol. 252 150-155

Subject Categories

Inorganic Chemistry

Other Engineering and Technologies



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