Thermodynamic optimizations on the binary Li–Sn system and ternary Mg–Sn–Li system

Abstract

The critical re-optimization of the Li–Sn binary system and optimization of Mg–Sn–Li ternary system in the Mg-rich portion have been conducted using a coupled first-principles calculations and CALPHAD method. The enthalpies of formation of LiSn, Li7Sn3, Li5Sn2, Li13Sn5, Li7Sn2, Li2Sn5, Li17Sn4 and Li2MgSn phases at 0K were obtained by first-principles calculations. Based on the experimental data and the results from first-principles calculations, thermodynamic model parameters for all solid and liquid phases for binary Li–Sn and ternary Mg–Li–Sn were optimized. In particular, the strong ordered binary liquid Li–Sn solution and ternary liquid Mg–Li–Sn solution were well described by the Modified Quasichemical Model (MQM) taking into account the short range ordering of atoms with the pair approximation.