Abstract
Fundamental understanding of ionic transport plays a pivotal role in designing and optimizing fast ionic conductors. Here, through a systematic neutron scattering and theoretical investigation, we discovered new insights about how anion sublattice affects Li+ distribution and transport in Li-argyrodite. We found that the promotion of Li+ conductivities is strongly correlated with a previously overlooked Li+ interstitial site (16e), which is critical for realizing intercage Li+ migration. More isotropic Li+ migration pathways with higher Li+ occupancies on the interstitial 16e site are found to be the underlying reason for the much higher Li+ conductivity in Li6PS5Cl relative to the Br- and I-based analogues. We further confirm that they are also the universal driving force for the ultrahigh Li+ conductivities in both anion-substituted Li-poor (Li6-aPS5-aXa, X = Cl and Br) and cation-substituted Li-rich argyrodite (e.g., Li6+aGeaP1-aS5I and Li6+aSiaSb1-aS5I). It is expected this strategy can be generally adopted to improve the ionic conductivity of the broad family of Li-rich argyrodite and beyond.
| Original language | English |
|---|---|
| Pages (from-to) | 382-393 |
| Number of pages | 12 |
| Journal | Chemistry of Materials |
| Volume | 36 |
| Issue number | 1 |
| DOIs | |
| State | Published - Jan 9 2024 |
Funding
Part of this work was conducted at the NOMAD beamline at ORNL’s Spallation Neutron Source, which is sponsored by the Scientific User Facilities Division, Office of Basic Sciences, U.S. Department of Energy. J.L. would like to thank partial financial support from ORNL LDRD #10761. X.F. and D.M. acknowledge the financial support from the Energy Storage Program, Office of Electricity (Grant Numbers: DE-AC0500OR22725). B.O. acknowledge the supported by the Assistant Secretary of Energy Efficiency and Renewable Energy, Vehicle Technologies Office of the US Department of Energy (DOE) under contract no. DE-AC02-05CH11231 under the Advanced Battery Materials Research (BMR) Program. X.F. and L.D. acknowledge the Fundamental Research Funds for the Central Universities (JZ2022HGTB0251). The computational analysis was performed using computational resources sponsored by the Department of Energy’s Office of Energy Efficiency and Renewable Energy at the National Renewable Energy Laboratory. Computational resources were also provided by the Extreme Science and Engineering Discovery Environment (XSEDE), which is supported by the National Science Foundation grant number ACI1053575 and the National Energy Research Scientific Computing Center (NERSC), a DOE Office of Science User Facility supported by the Office of Science and the U.S. Department of Energy under contract no. DE-AC02-05CH11231.
| Funders | Funder number |
|---|---|
| Assistant Secretary of Energy Efficiency and Renewable Energy, Vehicle Technologies Office of the US Department of Energy | DE-AC02-05CH11231 |
| ORNL LDRD | 10761 |
| Office of Basic Sciences | |
| Scientific User Facilities Division | |
| National Science Foundation | ACI1053575 |
| U.S. Department of Energy | |
| Office of Science | |
| Office of Energy Efficiency and Renewable Energy | |
| National Renewable Energy Laboratory | |
| Office of Electricity | DE-AC0500OR22725 |
| Fundamental Research Funds for the Central Universities | JZ2022HGTB0251 |
