Solid-liquid equilibria and thermo-physical properties of liquid electrolyte systems for lithium ion batteries

Alkyl carbonate and γ-butyrolactone (GBL) are attractive organic electrolyte materials that are stable over a wide range of operating voltages and ethylene sulfite (ES) is used as a supplementary film-forming electrolyte additive for lithium ion batteries (LIBs). This paper reports the solid-liquid phase equilibrium (SLE) data and the thermo-physical mixture properties such as the density, refractive index, excess and deviation properties for organic liquid electrolyte solutions of carbonate-based or GBL electrolytes containing ES. The SLE data were correlated with two activity coefficient models: NRTL and UNIQUAC. In addition, the extent to which the excess volume (VE) and molar refraction deviation (ΔR) of each of the binary systems correlated with the values calculated using the Redlich-Kister polynomial equations was determined.