Simulation of the surface structure of lithium manganese oxide spinel.
Abstract
Simulations of the surface structure of low-index surfaces of LiMn{sub 2}O{sub 4} (LMO), a candidate Li-ion battery electrode material, have been performed within the GGA+U approximation, using the VASP code. Surfaces of (001), (110), and (111) orientation were considered, with at least two terminations treated in each case. A slab geometry was employed, with termination-layer vacancies introduced to remove the bulk dipole moment while maintaining ideal stoichiometry. To complement static-structure relaxation calculations, molecular-dynamics simulations were performed to explore the phase space of possible surface reconstructions. A reconstruction is predicted for the Mn-terminated (111) surface, in which the top layers mix in stoichiometric proportions to form an LMO termination layer with square-planar-coordinated Mn. Average surface Mn oxidation states are reduced, relative to the bulk, for all surfaces considered, as a consequence of the lower-energy cost of Jahn-Teller distortion at the surface. Threefold-coordinated surface Mn, found for two terminations, is divalent, which may enhance its vulnerability to dissolution. The Li-terminated (001) surface is lowest in energy, consistent with previous classical-potential simulations for MgAl{sub 2}O{sub 4} that showed the Mg-terminated (001) surface to be lowest in energy.
- Authors:
-
- Chemical Sciences and Engineering Division
- Publication Date:
- Research Org.:
- Argonne National Lab. (ANL), Argonne, IL (United States)
- Sponsoring Org.:
- EE
- OSTI Identifier:
- 1018504
- Report Number(s):
- ANL/CSE/JA-69811
Journal ID: 1098-0121; TRN: US201114%%35
- DOE Contract Number:
- DE-AC02-06CH11357
- Resource Type:
- Journal Article
- Journal Name:
- Phys. Rev. B
- Additional Journal Information:
- Journal Volume: 83; Journal Issue: 19 ; May 31, 2011
- Country of Publication:
- United States
- Language:
- ENGLISH
- Subject:
- 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; DIPOLE MOMENTS; DISSOLUTION; ELECTRODES; GEOMETRY; LITHIUM; MANGANESE OXIDES; ORIENTATION; PHASE SPACE; RELAXATION; SIMULATION; STOICHIOMETRY; VACANCIES; VALENCE; VULNERABILITY
Citation Formats
Benedek, R, and Thackeray, M M. Simulation of the surface structure of lithium manganese oxide spinel.. United States: N. p., 2011.
Web. doi:10.1103/PhysRevB.83.195439.
Benedek, R, & Thackeray, M M. Simulation of the surface structure of lithium manganese oxide spinel.. United States. https://doi.org/10.1103/PhysRevB.83.195439
Benedek, R, and Thackeray, M M. 2011.
"Simulation of the surface structure of lithium manganese oxide spinel.". United States. https://doi.org/10.1103/PhysRevB.83.195439.
@article{osti_1018504,
title = {Simulation of the surface structure of lithium manganese oxide spinel.},
author = {Benedek, R and Thackeray, M M},
abstractNote = {Simulations of the surface structure of low-index surfaces of LiMn{sub 2}O{sub 4} (LMO), a candidate Li-ion battery electrode material, have been performed within the GGA+U approximation, using the VASP code. Surfaces of (001), (110), and (111) orientation were considered, with at least two terminations treated in each case. A slab geometry was employed, with termination-layer vacancies introduced to remove the bulk dipole moment while maintaining ideal stoichiometry. To complement static-structure relaxation calculations, molecular-dynamics simulations were performed to explore the phase space of possible surface reconstructions. A reconstruction is predicted for the Mn-terminated (111) surface, in which the top layers mix in stoichiometric proportions to form an LMO termination layer with square-planar-coordinated Mn. Average surface Mn oxidation states are reduced, relative to the bulk, for all surfaces considered, as a consequence of the lower-energy cost of Jahn-Teller distortion at the surface. Threefold-coordinated surface Mn, found for two terminations, is divalent, which may enhance its vulnerability to dissolution. The Li-terminated (001) surface is lowest in energy, consistent with previous classical-potential simulations for MgAl{sub 2}O{sub 4} that showed the Mg-terminated (001) surface to be lowest in energy.},
doi = {10.1103/PhysRevB.83.195439},
url = {https://www.osti.gov/biblio/1018504},
journal = {Phys. Rev. B},
number = 19 ; May 31, 2011,
volume = 83,
place = {United States},
year = {Tue May 31 00:00:00 EDT 2011},
month = {Tue May 31 00:00:00 EDT 2011}
}