Contrasting Correlated Lithium-ion Motions in Crystalline and Amorphous Lithium Thiophosphate Solid-State Electrolytes
발표자
유진아 (서강대학교)
연구책임자
성봉준 (서강대학교)
공동저자
유진아 (서강대학교), 성봉준 (서강대학교)
초록
내용
Lithium thiophosphate (LPS) exists in both crystalline and amorphous phases, and the cooperative motions among neighboring lithium ions has been proposed as a key transport mechanism in both phases. However, this alone cannot explain the higher ionic conductivity of the amorphous despite its similar density to the crystalline phase. To elucidate the origin of this difference, we performed machine-learning molecular dynamics simulations, enabling accurate large-scale analysis. In both phases, lithium ions exhibit high mobility with dynamic heterogeneity, characterized by rattling within polyanion cages and hopping to neighboring sites. Notably, the correlated hopping behavior differs between the two phases: in amorphous LPS, nearest-neighbor lithium ions tend to hop cooperatively following a hop event, whereas in crystalline LPS, neighboring ions remain confined and exhibit localized rattling.