Exploring the Relationship between Composition and Li-Ion Conductivity in the Amorphous Li–La–Zr–O System

Abstract

Amorphous Li–La–Zr–O (a-LLZO), a promising candidate for solid electrolytes in all-solid-state Li batteries, demonstrates exceptional dendrite-inhibiting properties. By adjustment of its elemental composition, the Li-ion conductivity of a-LLZO can be modulated. In this study, we developed an interatomic potential function based on machine learning to describe amorphous LLZO systems with varying compositions. The relationship between element ratios and Li-ion conductivity is investigated by utilizing molecular dynamics simulations covering a wide range of spatial and temporal scales. Our results indicate that the degree of aggregation between La–La atoms is more severe than that between Zr–Zr atoms. Maintaining a constant Li content while increasing the level of Zr and reducing the level of La in the amorphous structure can create additional vacancies and promote Li ion diffusion.