Structure of the thio-LISICON, Li4GeS4

Abstract The structure of high lithium ionic conductors, thio-LISICON (LIthium SuperIonic CONductor), Li 4 GeS 4 , was determined by X-ray and neutron Rietveld analysis. Li 4 GeS 4 has orthorhombic space group Pnma with the lattice parameters, a =14.0340(3), b =7.7548(2), c =6.15023(17) A. The structure is related to the γ-Li 3 PO 4 type and is composed of hexagonal close-packed sulfide ion arrays with germanium ions distributed over the tetrahedral sites which form the framework structure. The Li + ions in Li 4 GeS 4 are located in both the octahedral and tetrahedral sites. The LiS 6 octahedra are connected with each other by sharing edges and form (LiS 6 ) ∞ chains along the b -axis. The chain is linked with the adjacent LiS 4 tetrahedra, which might form the lithium conduction pathway.