Azepanium-based ionic liquids as green electrolytes for high voltage supercapacitors

Pohlmann S, Olyschläger T, Goodrich P, Vicente JA, Jacquemin J, Balducci A

Abstract

Abstract This work provides a first-time-study of Azepanium-based ionic liquids (ILs) as electrolyte components for electrochemical double layer capacitors (EDLCs). Herein, two Azepanium-based ILs, namely N-methyl, N-butyl-azepanium bis(trifluoromethanesulfonyl)imide (Azp14TFSI) and N-methyl, N-hexyl-azepanium bis(trifluoromethanesulfonyl)imide (Azp16TFSI) were compared with the established \{IL\} N-butyl, N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (Pyr14TFSI) in terms of viscosity, conductivity, thermal stability and electrochemical behavior in \{EDLC\} systems. The ILs' operative potentials were found to be comparable, leading to operative voltages up to 3.5 V without significant electrolyte degradation.