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

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 0 K 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.