Thermodynamics Research Center / ThermoML | Journal of Chemical and Engineering Data

ABSTRACT

Solubilities were measured for five lithium salts (LiF, LiCl, LiBr, LiPF6, and LiTFSI) in 1-butyl-3-methylimidazolium dicyanamide ([BMIM][N(CN)2]) and in 1-butyl-3-methylimidazo- lium tetrafluoroborate ([BMIM][BF4]) from 298.15 to 343.15 K under atmospheric pressure. Measurements were made using inductively-coupled-plasma-optical-emission spectroscopy (ICP-OES). Solubilities increase with rising temperature. Highest solubility is for LiPF6, followed by LiTFSI, LiBr, LiCl, and LiF. In both ionic liquids, LiF is essentially insoluble. Comparing solubilities of the same salts in different [BMIM]-based ILs, the solubility order is [BMIM][OTf] less than [BMIM][BF4] less than [BMIM][N(CN)2]. The new data were correlated by the Margules equation where the standard state for the salt's activity coefficient is the hypothetical pure liquid salt. Estimates are given for total enthalpy, entropy and Gibbs energy of dissolution.