Enhanced Li-Ion Conductivity in Nanosized Li10GeP2S12

Abstract

<div>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</div><div>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.</div>

Ionic Conductivity of Nanocrystalline and Amorphous Li10GeP2S12: The Detrimental Impact of Local Disorder on Ion Transport

“…This behavior does not support the proposed increase in ionic conductivity as suggested by Dawson and Islam. 38 The simulations suggest that diffusion along the ab-plane is facilitated when going from the bulk to nanocrystals with a grain volume of 10 nm 3 . Changes of the local Li + environments are made responsible for this increase observed.…”

“…In that light, it is surprising that till date engineering the conduction properties of Li10GeP2S12 by altering the crystallite size, has not been a substantial matter of experimental study yet. manuscript -2021 -K. Hogrefe Based on their computational results, Dawson and Islam proposed 38 that the already high ionic conductivity of LGPS might be further increased by a factor of 3 when reducing the crystallite size from the conventionally micrometer range down to a grain volume of 10 nm 3 . 38 They explained the slight enhancement seen through changes of the local Li + ion coordination, that is, local disorder.…”

“…manuscript -2021 -K. Hogrefe Based on their computational results, Dawson and Islam proposed 38 that the already high ionic conductivity of LGPS might be further increased by a factor of 3 when reducing the crystallite size from the conventionally micrometer range down to a grain volume of 10 nm 3 . 38 They explained the slight enhancement seen through changes of the local Li + ion coordination, that is, local disorder. These structural changes are assumed to facilitate the slower diffusion process in the abplane of LGPS.…”

Review of the Developments and Difficulties in Inorganic Solid-State Electrolytes

“…Though the conductivity of the film is lower than bulk LGPS due to the film’s stoichiometry deviation and poor crystalline nature, it has a lithium-ion transference number of >0.999, which could be applicable in the thin film all-solid-state lithium-ion batteries [ 152 ]. Dawson et al used nanoscale modeling techniques to simulate nanocrystalline LGPS systems with average grain sizes from 2 to 10 nm and predicted that the ionic conductivity of LGPS can be further improved by nanofication [ 153 ].…”