Mono-and di-cationic Ionic Liquids: Synthesis, Characterization and Applications in Batteries

In this paper, a mono-cationic ionic liquid (MIL) ([BMIM] [NTF2 ]) and two di-cationic ionic liquids (DILs) ([C5 (MIM)2 ][NTF2 ]2 and [C6 (MIM)2 ][NTF2 ]2 ) were synthesized by two-step method, and the conductivity, viscosity and electrochemical stability of the three ionic liquids were systematically studied and analyzed. The results show that the conductivity of MIL is better than that of DILs, while the viscosity and the electrochemical stability of DILs are higher than those of MIL. The viscosity of the DILs decreases with the increasing length of the group within the DILs. Finally, the application of MIL as the electrolyte in the lithium-oxygen battery was studied.