Atomistic Assessments of Lithium-Ion Conduction Behavior in Glass–Ceramic Lithium Thiophosphates

We determined the interatomic potentials of the Li-[PS43–] building block in (Li2S)0.75(P2S5)0.25 (LPS) and predicted the Li-ion conductivity (σLi) of glass–ceramic LPS from molecular dynamics. The Li-ion conduction characteristics in the crystalline/interfacial/glassy structure were decomposed by considering the structural ordering differences. The superior σLi of the glassy LPS could be attributed to the fact that ∼40% of its structure consists of the short-ranged cubic S-sublattice instead of the hexagonally close-packed γ-phase. This glassy LPS has a σLi of 4.08 × 10–1 mS cm–1, an improvement of ∼100 times relative to that of the γ-phase, which is in agreement with the experiments.