Enhanced Li-Ion Transport in Nanosized Li10GeP2S12

Abstract

The discovery of the lithium superionic conductor Li10GeP2S12 (LGPS) has led to significant research activity on solid electrolytes for high-performance and safe solid-state batteries. LGPS exhibits a remarkably high room-temperature Li-ion conductivity of 12 mS/cm, comparable to that of the liquid electrolytes used in current Li-ion batteries. Here, we predict that nanosizing of LGPS can be used to further enhance its already outstanding Li-ion conductivity. By utilizing state-of-the-art nanoscale molecular dynamics techniques, we are able to simulate the Li-ion conductivities of nanocrystalline LGPS systems with average grain sizes from 10 to 2 nm. Our results reveal that the Li-ion conductivity of LGPS increases with decreasing grain volume. For the smallest nanometric grain size, the Li-ion conductivity at room temperature is three times higher that of the bulk system. These findings reveal that nanosizing LGPS and related solid electrolytes could be an effective approach for enhancing their Li-ion conductivity.