Tetragonal Li10GeP2S12 and Li7GePS8 − structure and Li ion dynamics of LGPS Li electrolytes
A. Kuhn, V. Duppel, J. Köhler, and B.V. Lotsch
We present an in-depth study on the structure and Li ion dynamics of tetragonal Li10GeP2S12 (LGPS), which is the fastest solid lithium electrolyte reported to date. Two different LGPS samples, Li10GeP2S12 and Li7GePS8, were comprehensively characterized using a multitude of techniques, including X-ray and electron diffraction, EDX, 31P MAS NMR, impedance spectroscopy, 7Li PFG NMR and relaxometry. The exceptionally high ionic conductivity of tetragonal LGPS of 10−2Scm−1 is traced back to nearly isotropic Li hopping processes in the bulk lattice of LGPS with EA≈0.22eV.