Super-Ionic Conduction in Solid-State Li 7 P 3 S 11 -Type Sulfide Electrolytes

Here, we examine the intrinsic ion conduction properties of Li 7 P 3 S 11 -type materials, one of the important solid electrolytes for lithium batteries, through a comprehensive computational investigation on the interplay among the crystal structure, defects, and diffusion mechanism. Our extensive ab initio molecular dynamics calculations suggest that the Li 7 P 3 S 11 crystal frame is inherently flexible with readily-fluctuating P 2 S 7 polyhedra and possesses high density of interstitial sites, which flatten the overall energy landscape for ion migration and provide higher degrees of freedom for ion movement. Statistical analysis also presents that ionic conduction in Li 7 P 3 S 11 is negligibly influenced by the presence of defects and the change of charge carrier concentrations. It implies that the intrinsic high ionic conductivity of Li 7 P 3 S 11 can be easily preserved in various…