Abstract
Nanosized electrodes for Li-ion batteries typically display improved electrochemical properties, which are generally attributed to the reduced dimensionality for lithiation. However, the intriguing roles of surface defects and disorder associated with the nanosized materials are often overlooked. Here, combining atomically resolved structural analysis with density functional theory calculations, we reveal that the formation of intrinsic oxygen vacancies near surface in silver hollandite nanorods modifies the local atomic structure and valence state. These surface reconstructions resulted from oxygen vacancies can significantly affect the diffusion pathways in what are otherwise one-dimensional (1D) tunneled structures. On the basis of energy barrier calculations, we demonstrate that the oxygen vacancies boost ionic transport through the edge sharing MnO6 polyhedra in the a-b plane. Thus, within a single rod different from the inherent 1D tunnel diffusion in the interior, the ionic transport at oxygen vacancy decorated surfaces likely adopts a three-dimensional diffusion pathway including both tunnel and planar diffusion.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 6124-6133 |
| Number of pages | 10 |
| Journal | Chemistry of Materials |
| Volume | 30 |
| Issue number | 17 |
| DOIs | |
| State | Published - Sep 11 2018 |
Funding
Structural characterizations using electron microscopy were supported by the U.S. Department of Energy, Basic Energy Sciences (DOE-BES), Materials Science and Engineering Division, under Contract #DE-SC0012704. Materials synthesis, electrochemistry and theory, and the TEM data collected by X.H. were supported by the Center for Mesoscale Transport Properties, an Energy Frontier Research Center supported by the DOE-BES, under award #DE-SC0012673. Theory and computational research was done in part at the Center for Functional Nanomaterials, which is a U.S. DOE Office of Science Facility, and the Scientific Data and Computing Center, a component of the Computational Science Initiative, at Brookhaven National Laboratory under Contract #DE-SC0012704. Part of the calculations were performed using the high-performance LI-red and Handy computing systems at the Institute of Advanced Computational Sciences (IACS) and the SeaWulf cluster at Stony Brook University. The X-ray absorption spectroscopy measurements were performed at Beamline 12BM-B of the Advanced Photon Source, a U.S. DOE Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract DE-AC02-06CH11357. Structural characterizations using electron microscopy were supported by the U.S. Department of Energy, Basic Energy Sciences (DOE-BES), Materials Science and Engineering Division, under Contract #DE-SC0012704. Materials synthesis, electrochemistry and theory, and the TEM data collected by X.H. were supported by the Center for Mesoscale Transport Properties, an Energy Frontier Research Center supported by the DOE-BES, under award #DE-SC0012673. Theory and computational research was done in part at the Center for Functional Nanomaterials which is a U.S. DOE Office of Science Facility, and the Scientific Data and Computing Center, a component of the Computational Science Initiative, at Brookhaven National Laboratory under Contract #DE-SC0012704. Part of the calculations were performed using the high-performance LI-red and Handy computing systems at the Institute of Advanced Computational Sciences (IACS) and the SeaWulf cluster at Stony Brook University. The X-ray absorption spectroscopy measurements were performed at Beamline 12BM-B of the Advanced Photon Source, a U.S. DOE Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract DE-AC02-06CH11357.
ASJC Scopus subject areas
- General Chemistry
- General Chemical Engineering
- Materials Chemistry