ChemRxiv
These are preliminary reports that have not been peer-reviewed. They should not be regarded as conclusive, guide clinical practice/health-related behavior, or be reported in news media as established information. For more information, please see our FAQs.
chemrxiv-lgps.pdf (2.4 MB)
0/0

Defect Chemistry of Disordered Solid-State Electrolyte Li10GeP2S12

preprint
submitted on 05.10.2019 and posted on 08.10.2019 by Prashun Gorai, Hai Long, Eric Jones, Shriram Santhanagopalan, Vladan Stevanovic
Several classes of materials, including thiophosphates, garnets, argyrodites, and anti-perovskites, have been considered as electrolytes for all-solid-state batteries. Native point defects and dopants play a critical role in impeding or facilitating fast ion conduction in these solid electrolytes. Despite its significance, comprehensive studies of the native defect chemistry of well-known solid electrolytes is currently lacking, in part due their compositional and structural complexity. Most of these solid-state electrolytes exhibit significant structural disorder, which requires careful consideration when modeling the point defect energetics. In this work, we model the native defect chemistry of a disordered solid electrolyte, Li10GeP2S12 (LGPS), by uniquely combining ensemble statistics, accurate electronic structure, and modern first-principles defect calculations. We find that VLi, Lii, and PGe are the dominant defects. From these calculations, we determine the statistics of defect energetics; formation energies of the dominant defects vary over ~140 meV. Combined with ab initio molecular dynamics simulations, we find that anti-sites PGe promote Li ion conductivity, suggesting LGPS growth under P-rich/Ge-poor conditions will enhance ion conductivity. To this end, we offer practical experimental guides to enhance ion conductivity.

History

Email Address of Submitting Author

prashun.iitm4@gmail.com

Institution

Colorado School of Mines

Country

USA

ORCID For Submitting Author

0000-0001-7866-0672

Declaration of Conflict of Interest

No conflict of interest

Exports