The use of ionic liquids as solvent-free green electrolytes for hybrid supercapacitors

The aim of this paper is to demonstrate that the use of ionic liquids (ILs) in activated carbon (AC)//poly(3-methyl-thiophene) (pMeT) hybrid supercapacitors is a very promising strategy to develop high voltage supercapacitors operating above room temperature with solvent-free green electrolytes. The ILs used were 1-butyl-3-methyl-imidazolium tetrafluoroborate, 1-butyl-3-methyl-imidazolium hexafluorophosphate, N-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide. We report and discuss the performance of AC and pMeT electrodes in such ILs compared to that in propylene carbonate-based electrolytes, in order to give indications for further research effort in IL-based hybrid supercapacitors.