Ionic liquid based electrolytes for sodium-ion batteries: Na+ solvation and ionic conductivity
Journal article, 2014

Ionic liquid (IL) based sodium-ion (Na+) battery electrolytes obtained by mixing imidazolium-TFSI ILs (EMIm-TFSI and BMIm-TFSI) with the corresponding sodium salt (NaTFSI) have been investigated using a wide range of characterization techniques: dielectric spectroscopy, differential scanning calorimetry, densitometry, viscometry, and Raman spectroscopy. The sodium ion conducting electrolytes exhibit excellent ionic conductivities, up to 5.5 mS cm(-1) at room temperature, and a useful thermal window of -86 degrees C to 150 degrees C. In more detail, Raman data analysis supported by DFT calculations on Na+-TFSI complexes, allow us to determine the sodium ion solvation and charge carrier nature as a function of salt concentration. The results are compared to data for the corresponding Li systems and while such electrolytes essentially form [Li(TFSI)(2)](-) as the main Li+ carrier, the sodium systems seem to dominantly form [Na(TFSI)(3)](2-) complexes. The effects on conductivity and viscosity and the consequences for sodium-ion battery implementation are discussed. (C) 2013 Elsevier B.V. All rights reserved.



Ionic liquid

Raman spectroscopy


Sodium-ion battery


Damien Monti

Chalmers, Applied Physics, Condensed Matter Physics

Erlendur Jonsson

Chalmers, Applied Physics, Condensed Matter Physics

M. R. Palacin

Alistore - European Research Institute

Institute of Material Science of Barcelona (ICMAB)

Patrik Johansson

Chalmers, Applied Physics, Condensed Matter Physics

Journal of Power Sources

0378-7753 (ISSN)

Vol. 245 630-636

Subject Categories

Inorganic Chemistry

Areas of Advance



Materials Science



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