Density, Viscosity, and Vapor Pressure Measurements of Water + Lithium Bis(trifluoromethylsulfonyl)imide Solutions

The solubility, density (ρ), viscosity (η), and vapor pressure (P) of lithium bis(trifluoromethylsulfonyl)imide (LiTf2N) in water are evaluated. The maximum salt solublity for LiTf2N in water was determined to be between mass fractions (ws) of 0.8065 and 0.8217 at 295.15 K. The density (ρ) and viscosity (η) were evaluated at temperatures ranging from 298.15 to 373.15 K and mass fractions of up to 0.8024. Least-squares regression is used to correlate the viscosity and density data over the entire range of temperatures and concentrations. The vapor pressure of LiTf2N in water is determined for temperatures of 274.15 to 471.15 K and mass fractions of up to 0.8065. In addition, this work describes the solvent activity (as), osmotic coefficient (Φ), molal activity (γ±), and enthalpy of vaporization (ΔHv). The osmotic coefficients were calculated using the second virial coefficient of water, and Pitzer–Mayorga and Clausius–Clapeyron models are used to evaluate the vapor pressure data.