2017/08/08 by D. Di Stefano, A. Miglio, Di Stefano, D. +27 · 2 citations
Physics and Astronomy · #Classical Physics (physics.class-ph) #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #cond-mat.mtrl-sci #physics.class-ph
paper · pdf · doi:10.48550/arxiv.1708.02997
arxiv created 2019/07/24 · arxiv updated 2019/07/25
Solid-state materials with high ionic conduction are necessary to many technologies including all-solid-state Li-ion batteries. Understanding how crystal structure dictates ionic diffusion is at the root of the development of fast ionic conductors. Here, we show that LiTi2(PS4)3 exhibits a Li-ion diffusion coefficient about an order of magnitude higher than current state-of-the-art lithium superionic conductors. We rationalize this observation by the unusual crystal structure of LiTi2(PS4)3 which offers no regular tetrahedral or octahedral sites for lithium to favorably occupy. This creates a smooth, frustrated energy landscape resembling more the energy landscapes present in liquids than in typical solids. This frustrated energy landscape leads to a high diffusion coefficient combining low activation energy with a high pre-factor.