An investigation of lithium solid electrolyte materials with first principles calculations.

摘要

Inorganic solid electrolyte materials have recently become the focus of considerable interest due to the discovery of novel compounds with high ionic conductivities (> 1e-4 S/cm ). Sulfur based solid electrolytes are particularly notable in this regard, as well as for their compatibility for Li-S electrode systems. This work applies compu- tational methods based on density functional theory to the problem of identifying and characterizing novel electrolyte materials, with an emphasis on the Li2S-P2S5 system. In addition to a broad overview of likely materials, two compounds are studied in depth, Li7P3S11 and Li3PS4 . For Li7P3 S11 the results show excellent agreement with respect to migration energetics, and good agreement with the experimentally described structure and observed stability. For Li3PS4 , in addition to structure, stability, and migration energetics, the properties of the interface between the electrolyte and vacuum and the electrolyte and lithium metal are considered.