Structural requirements for fast lithium ion migration in Li10GeP2S12

Abstract

Dynamic lithium distribution, structural stability and ion transport mechanism in the new ultrafast ion conductor Li₁₀GeP₂S₁₂ are clarified with the help of atomistic molecular dynamics simulations, revealing only a weak anisotropy of Li⁺ diffusion, and a coupling of Li⁺ cation diffusion to PS₄³⁻ anion rotational mobility. The role of a previously overlooked Li site and the limited structural stability at elevated temperatures are discussed for the first time.