LAUSR

Abstract A novel speciation theory solves for the identities and concentrations of all molecular compounds and complexes in an equilibrium state. The speciation range refers to the identity of all molecular compounds, their isomers, and their coordination complexes that co-exist in the mixture. An example equilibrium state is defined as the solution composition that minimizes the Gibbs energy at in a closed, isothermal, isobaric system, and the speciation model uses COSMO-RS to compute species chemical potentials. Measurements of LiPF 6 solubilities in propylene carbonate and methyl-2,2,2 trifluoroethyl carbonate solutions between 12 °C and 50 °C enable the calculation of the Gibbs energy of fusion of LiPF 6 . COSMO-RS illustrates a thermodynamic inconsistency in the speciation models because the computed salt Gibbs energy of fusion is significantly different between solutions of different solvents. The inconsistency requires further study with additional data sets and careful parameterization.