Journal
JOURNAL OF SOLID STATE CHEMISTRY
Volume 316, Issue -, Pages -Publisher
ACADEMIC PRESS INC ELSEVIER SCIENCE
DOI: 10.1016/j.jssc.2022.123643
Keywords
-
Funding
- National Natural Science Foundation of China [11674145]
- Natural Science Foundation of Shandong Province [ZR2019PA006]
- Conversion of New and Old Kinetic Energy Projects [2021LHX111]
Ask authors/readers for more resources
This study investigates the properties and ion migration mechanism of sodium-rich anti-perovskite Na(3)SA materials using first-principles calculations. The results show that substituting cluster ions at the anion position can improve the band gap and sodium ion conductivity. The research provides a reference for the design of solid-state electrolyte materials and the mechanism of sodium ion transport.
The next-generation solid-state batteries need safe and efficient solid-state electrolytes. However, the conventional solid-state electrolytes materials often suffer from low ionic conductivity. The emerging anti-perovskites are potential solid electrolytes materials for their rich cations and tunable crystal structure. Here, the first -principles density functional theory (DFT) calculations are employed to investigate the stability, electronic properties, elastic constants and the ions migration of sodium-rich anti-perovskite Na(3)SA (A = AlF4, ClO4, ICl4, IO4). Calculations show that the clusters substitution at anion position A of Na(3)SA displays larger band gap and faster Na ion transport than that of halogen anions (e.g., Cl, Br, I). Among them, the band gaps of Na3SAlF4 and Na3SClO4 exceed 3.5 eV, which indicates their excellent electrochemical stability. The AlF4 cluster exhibits high sodium ion conductivity (6.55 x 10-2 S cm(-1)), low activation energy (0.19 eV) and small migration barrier (0.46 eV) according to the ab initio molecular dynamics (AIMD) simulations and transition states study. Molecular dynamics simulations suggest that the enhanced ionic conductivity is due to the rotation of cluster ions which promotes the migration of sodium ions; moreover, the large volume created by anion clusters leads to larger lattices which is also benefit for fast ion transport. Therefore, this work designs Na-rich anti-perovskite with high ionic conductivity by substitution of anion clusters and also provides the Na ion transport mechanism for reference in solid-state electrolytes.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available