Thermodynamic analysis of the Li–Si phase equilibria from 0 K to liquidus temperatures

Thermodynamic and constitutional data of the Li–Si system were critically reviewed and the importance of using original experimental data is highlighted, as opposed to a previous thermodynamic modeling of this system. The Cp-functions of all Li–Si compounds were experimentally determined for 2–900 K and those for pure solid Li and Si from 0 to 298 K from experimental literature data. The reliability of solubility data for the dilute solution of Si in liquid Li was assessed by thermodynamic considerations. A consistent thermodynamic description of all solid phases in the Li–Si system from 0 K to high temperature is developed, jointly with that for the liquid phase, using the Calphad method. The first calculated and validated Li–Si phase diagram from 0 K to liquidus temperatures is presented. Experimental liquidus data are found to be inconsistent with well established experimental thermodynamic data and further research is required.