  The predictive electrolyte model COSMO-RS-ES is refined to improve the
description of systems at 25{\deg}C in which strong ion pairing is expected due
to a low static permittivity of the liquid phase. Furthermore, the short-range
ion energy interaction equations have been modified to better describe the
misfit and energy interaction terms between ions and solvent molecules. In
addition, the salt solubility database is extended with additional non-aqueous
systems containing solvents that have a low (\epsilon_s<15) dielectric constant
and promote near to full ion association. Throughout this work it is
demonstrated that liquid-liquid equilibrium calculations and solid-liquid
equilibrium predictions for electrolyte systems can be markedly improved with
the inclusion of Bjerrum treatment based phenomenological considerations while
introducing only one general additional parameter. Our modified approach
reinforces the capabilities of COSMO-RS ES as a powerful predictive tool for
the calculation of phase equilibria in systems with scarce experimental data.
