Thermodynamic assessment of the Ga-Li-Sn system and its binary subsystems

The Ga–Li–Sn system, relevant for self-healing Ga–Sn-based anodes in lithium-ion batteries, has been thermodynamically assessed using the CALPHAD approach. The binary subsystems Ga–Sn, Ga–Li, and Li–Sn were first re-evaluated based on recent experimental data, with particular attention to phase equilibria and thermodynamic properties. Building on experimental investigations, the first thermodynamic description of the ternary system focussing on the experimental work on the βLiGa-Sn quasi-binary section is developed. The liquid phase was modelled using an associate solution model including a Li 3.5 Sn species, while the solubilities in βSn (Sn_BCT_A5), βLiGa and Li 7 Sn 2 were described using appropriate multi-sublattice models. Several ternary stoichiometric compounds were incorporated into the thermodynamic database. The resulting description reproduces phase equilibria, mixing enthalpies, and component activities in both the binary subsystems and the ternary system in good agreement with the available experimental data.