Tetragonal Li₁₀GeP₂S₁₂ and Li₇GePS₈ − structure and Li ion dynamics of LGPS Li electrolytes

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 E_A≈0.22eV.