Anodic stability of aluminum current collectors in an ionic liquid based on the (fluorosulfonyl)(trifluoromethanesulfonyl)imide anion and its implication on high voltage supercapacitors

Kühnel R-S, Reiter J, Jeong S, Passerini S, Balducci A

Abstract

In this work, the characterization regarding the stability of aluminum current collectors in the ionic liquid (IL) N-butyl-N-methylpyrrolidinium (fluorosulfonyl)(trifluoromethanesulfonyl)imide (PYR14FTFSI) by cyclic voltammetry (CV), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) is reported. ILs based on this anion are of great interest because they usually show a good combination of properties when compared with those ILs based on other bis[(perfluoroalkyl)sulfonyl]imide anions. In particular, ILs based on FTFSI- show higher conductivities and lower viscosities than those based on the well-known bis(trifluoromethanesulfonyl)imide (FTFSI-) anion. Furthermore, PYR14FTFSI was tested as electrolyte for high voltage double layer capacitors via constant voltage (float) tests. © 2013 Elsevier B.V. All rights reserved.