Organic superbase derived ionic liquids based on the TFSI anion: synthesis, characterization, and electrochemical properties

A series of hydrophobic room temperature ionic liquids (RTILs) composed of organic superbase-derived cations and the TFSI anion (bis(trifluromethylsulfonyl)imide) were designed and synthesized. The structures of these new RTILs were determined using 1H-NMR, 13C-NMR, IR, and elemental analysis. Their physicochemical properties, including thermal properties, density, viscosity, and electrochemical properties, were investigated. Thermogravimetric analysis (TGA) revealed that these superbase-derived RTILs have high decomposition temperatures of up to 450 °C. Studies on their electrochemical properties demonstrated that these RTILs have relatively wide electrochemical windows of up to 4.6 V and good ionic conductivities at room temperature. Their application potential as novel electrolytes in supercapacitors was also evaluated.