Electrochemical applications of electrolytes based on ionic liquids

Abstract

The potential utility of room temperature ionic liquids as electrolytes in current electrochemical applications has been explored. Hence, the electrochemical behavior of [Ni(tmc)]Br2 complex at a glassy carbon electrode in the absence or in the presence of unsaturated halides in the ionic liquids, 1-ethyl-3- methylimidazolium ethylsulfate, [C2mim][C2SO4] and N,N,Ntrimethyl- N-(2-hydroxyethyl) ammonium bis(trifluoromethylsulfonyl)imide, [N1 1 1 2(OH)][NTf2], has been examined by cyclic voltammetry. It was observed that [Ni(tmc)]2+ complex is reduced in a reversible one-electron step and the electrogenerated [Ni(tmc)]+ complex catalytically reduces the carbon-halogen bond of unsaturated halides. The potencial use of natural ionic conducting polymer matrixes was also investigated. Samples of natural macromolecules-based electrolytes with the ionic liquid 1-ethyl- 3-methylimidazolium ethylsulfate, [C2mim][C2SO4], were prepared and characterized. The preliminary studies carried out with electrochromic devices (ECDs) incorporating optimized compositions have confirmed that these materials may perform as satisfactory multifunctional component layers in the field of ECD-based devices.