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Title: Quantification of Honeycomb Number-Type Stacking Faults: Application to Na 3Ni 2BiO 6 Cathodes for Na-Ion Batteries

Here, ordered and disordered samples of honeycomb-lattice Na 3Ni 2BiO 6 were investigated as cathodes for Na-ion batteries, and it was determined that the ordered sample exhibits better electrochemical performance, with a specific capacity of 104 mA h/g delivered at plateaus of 3.5 and 3.2 V (vs Na +/Na) with minimal capacity fade during extended cycling. Advanced imaging and diffraction investigations showed that the primary difference between the ordered and disordered samples is the amount of number-type stacking faults associated with the three possible centering choices for each honeycomb layer. A labeling scheme for assigning the number position of honeycomb layers is described, and it is shown that the translational shift vectors between layers provide the simplest method for classifying different repeat patterns. We demonstrate that the number position of honeycomb layers can be directly determined in high-angle annular dark-field scanning transmission electron microscopy (STEM-HAADF) imaging studies. By the use of fault models derived from STEM studies, it is shown that both the sharp, symmetric subcell peaks and the broad, asymmetric superstructure peaks in powder diffraction patterns can be quantitatively modeled. About 20% of the layers in the ordered monoclinic sample are faulted in a nonrandom manner, while the disorderedmore » sample stacking is not fully random but instead contains about 4% monoclinic order. Furthermore, it is shown that the ordered sample has a series of higher-order superstructure peaks associated with 6-, 9-, 12-, and 15-layer periods whose existence is transiently driven by the presence of long-range strain that is an inherent consequence of the synthesis mechanism revealed through the present diffraction and imaging studies. This strain is closely associated with a monoclinic shear that can be directly calculated from cell lattice parameters and is strongly correlated with the degree of ordering in the samples. The present results are broadly applicable to other honeycomb-lattice systems, including Li 2MnO 3 and related Li-excess cathode compositions.« less
Authors:
 [1] ;  [2] ;  [3] ;  [4] ;  [5] ;  [5] ;  [3] ;  [5] ;  [1]
  1. Stony Brook Univ., NY (United States). Dept. of Chemistry; Brookhaven National Lab. (BNL), Upton, NY (United States). Dept. of Chemistry
  2. Stony Brook Univ., NY (United States). Dept. of Chemistry
  3. Brookhaven National Lab. (BNL), Upton, NY (United States). Condensed Matter Physics and Materials Science Dept.
  4. Brookhaven National Lab. (BNL), Upton, NY (United States). Photon Science Division
  5. Brookhaven National Lab. (BNL), Upton, NY (United States). Dept. of Chemistry
Publication Date:
Report Number(s):
BNL-113232-2016-JA
Journal ID: ISSN 0020-1669; VT1201000
Grant/Contract Number:
SC0012704; SC0012583; AC02-76SF00515; DMR-0955646
Type:
Accepted Manuscript
Journal Name:
Inorganic Chemistry
Additional Journal Information:
Journal Volume: 55; Journal Issue: 17; Journal ID: ISSN 0020-1669
Publisher:
American Chemical Society (ACS)
Research Org:
Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); USDOE Office of Energy Efficiency and Renewable Energy (EERE); National Science Foundation (NSF)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; 25 ENERGY STORAGE; honeycomb lattice; sodium ion batteries; Na3Ni2BiO6; Li2MnO3; stacking faults
OSTI Identifier:
1336212