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.