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

Abstract

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 (sigma(Li)) 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 sigma(Li) of the glassy LPS could be attributed to the fact that similar to 40% of its structure consists of the short-ranged cubic S-sublattice instead of the hexagonally close-packed gamma-phase. This glassy LPS has a sigma(Li) of 4.08 X 10(-1) mS cm(-1), an improvement of similar to 100 times relative to that of the gamma-phase, which is in agreement with the experiments.