Specifically Designed Ionic Liquids—Formulations, Physicochemical Properties, and Electrochemical Double Layer Storage Behavior

Abstract

Two key features—non-volatility and non-flammability—make ionic liquids (ILs) very attractive for use as electrolyte solvents in advanced energy storage systems, such as supercapacitors and Li-ion batteries. Since most ILs possess high viscosity and are less prone to dissolving common electrolytic salts when compared to traditional electrolytic solvents, they must be formulated with low viscosity thinner solvents to achieve desired ionic conductivity and dissolution of electrolyte salts in excess of 0.5 M concentration. In the past few years, our research group has synthesized several specifically designed ILs (mono-cationic, di-cationic, and zwitterionic) with bis(trifluoromethylsulfonyl)imide (TFSI) and dicyanamide (DCA) as counter anions. This article describes several electrolyte formulations to achieve superior electrolytic properties. The performance of a few representative IL-based electrolytes in supercapacitor coin cells is presented.

Luminescent Poly(vinylidene fluoride)‐Based Inks for Anticounterfeiting Applications

“…ILs are environmentally friendly compounds defined as salts entirely composed of ions with melting points usually below 100 C. [44][45][46] They have drawn significant attention in the last two decades [47,48] owing to their unique physicalchemical properties, including high negligible vapor pressure, thermal, mechanical, chemical, and electrochemical stabilities, and a wide liquid range. [49][50][51][52] Due to their transparency throughout nearly all visible and NIR spectral regions, ILs are particularly useful solvents of optically active compounds. [53,54] The synthesis of the PVDF/[Bmim][Eu(tta) 4 ] and PVDF/ Na[Eu(tta) 4 ] composites was straightforward and fast (Figure 1).…”

“…[ 44–46 ] They have drawn significant attention in the last two decades [ 47,48 ] owing to their unique physical–chemical properties, including high negligible vapor pressure, thermal, mechanical, chemical, and electrochemical stabilities, and a wide liquid range. [ 49–52 ] Due to their transparency throughout nearly all visible and NIR spectral regions, ILs are particularly useful solvents of optically active compounds. [ 53,54 ]…”