Electrolyte thermodynamics provides a foundation for modeling a variety of electrochemical phenomena, processes, and devices. The key applications include corrosion, electrochemical separation technologies and power sources. To gain thermodynamic insights into the behavior of electrochemical systems, thermodynamic models need to accurately predict both speciation and phase equilibria in multicomponent systems ranging from dilute aqueous solutions to very concentrated brines, ionic liquids and electrolytes in nonaqueous solvents. For many applications, thermodynamic models need to be supplemented by transport property models to predict properties such as electrical conductivity, viscosity or diffusivity. Of particular interest are properties such as pH, oxidation-reduction potential and activities of electrochemically active species, which require a realistic and detailed treatment of speciation in reacting systems. Practical requirements will be reviewed including experimental database needs, desired structure of thermophysical models and approaches to model parameterization.
January 27, 2022