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Title: Impact of Fluorination on Phase Stability, Crystal Chemistry, and Capacity of LiCoMnO 4 High Voltage Spinels

Abstract

In this paper, fluorinated LiCoMnO 4–yF y (y = 0, 0.05, 0.1) spinel electrodes, electrochemically active at 5–5.3 V versus Li/Li +, show enhanced phase purity and enhanced capacity with increasing y. We disclose the impact of fluorination on the phase purity and reversible capacity of LiCoMnO 4 via joint Rietveld refinement of neutron and synchrotron powder diffraction data, combined with micro-Raman spectroscopy. It is found that fluorination stabilizes the spinel phase and hinders precipitation of Li 2MnO 3 as a secondary phase, which controls the cation distribution on tetrahedral and octahedral sites in spinel. That is to say, for higher fluorine content the cobalt occupancy at the tetrahedral site in spinel decreases, and the lithium occupancy increases. Accordingly, the number of lithium sites that are available for electrochemical extraction and insertion of lithium ions is raised so that the capacity is increased. Further investigation of the lithium ion diffusion by means of cyclic voltammetry at different scan rates and the application of the Randles–Sevcik equation were carried out to investigate the extent of capacity enhancement due to faster lithium ion diffusion in the high voltage region.

Authors:
ORCiD logo [1]; ORCiD logo [2]; ORCiD logo [1];  [1]; ORCiD logo [1]; ORCiD logo [2]; ORCiD logo [1]; ORCiD logo [1];  [1]
  1. Forschungszentrum Julich GmbH, Julich (Germany); Julich Aachen Research Alliance: JARA-Energy, Julich (Germany)
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1494020
Grant/Contract Number:  
AC05-00OR22725
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
ACS Applied Energy Materials
Additional Journal Information:
Journal Volume: 1; Journal Issue: 2; Journal ID: ISSN 2574-0962
Publisher:
American Chemical Society (ACS)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; high voltage spinel; lithium battery; neutron diffraction; Raman spectroscopy; synchrotron diffraction

Citation Formats

Windmüller, Anna, Bridges, Craig A., Tsai, Chih -Long, Lobe, Sandra, Dellen, Christian, Veith, Gabriel M., Finsterbusch, Martin, Uhlenbruck, Sven, and Guillon, Olivier. Impact of Fluorination on Phase Stability, Crystal Chemistry, and Capacity of LiCoMnO4 High Voltage Spinels. United States: N. p., 2018. Web. doi:10.1021/acsaem.7b00186.
Windmüller, Anna, Bridges, Craig A., Tsai, Chih -Long, Lobe, Sandra, Dellen, Christian, Veith, Gabriel M., Finsterbusch, Martin, Uhlenbruck, Sven, & Guillon, Olivier. Impact of Fluorination on Phase Stability, Crystal Chemistry, and Capacity of LiCoMnO4 High Voltage Spinels. United States. doi:10.1021/acsaem.7b00186.
Windmüller, Anna, Bridges, Craig A., Tsai, Chih -Long, Lobe, Sandra, Dellen, Christian, Veith, Gabriel M., Finsterbusch, Martin, Uhlenbruck, Sven, and Guillon, Olivier. Tue . "Impact of Fluorination on Phase Stability, Crystal Chemistry, and Capacity of LiCoMnO4 High Voltage Spinels". United States. doi:10.1021/acsaem.7b00186. https://www.osti.gov/servlets/purl/1494020.
@article{osti_1494020,
title = {Impact of Fluorination on Phase Stability, Crystal Chemistry, and Capacity of LiCoMnO4 High Voltage Spinels},
author = {Windmüller, Anna and Bridges, Craig A. and Tsai, Chih -Long and Lobe, Sandra and Dellen, Christian and Veith, Gabriel M. and Finsterbusch, Martin and Uhlenbruck, Sven and Guillon, Olivier},
abstractNote = {In this paper, fluorinated LiCoMnO4–yFy (y = 0, 0.05, 0.1) spinel electrodes, electrochemically active at 5–5.3 V versus Li/Li+, show enhanced phase purity and enhanced capacity with increasing y. We disclose the impact of fluorination on the phase purity and reversible capacity of LiCoMnO4 via joint Rietveld refinement of neutron and synchrotron powder diffraction data, combined with micro-Raman spectroscopy. It is found that fluorination stabilizes the spinel phase and hinders precipitation of Li2MnO3 as a secondary phase, which controls the cation distribution on tetrahedral and octahedral sites in spinel. That is to say, for higher fluorine content the cobalt occupancy at the tetrahedral site in spinel decreases, and the lithium occupancy increases. Accordingly, the number of lithium sites that are available for electrochemical extraction and insertion of lithium ions is raised so that the capacity is increased. Further investigation of the lithium ion diffusion by means of cyclic voltammetry at different scan rates and the application of the Randles–Sevcik equation were carried out to investigate the extent of capacity enhancement due to faster lithium ion diffusion in the high voltage region.},
doi = {10.1021/acsaem.7b00186},
journal = {ACS Applied Energy Materials},
issn = {2574-0962},
number = 2,
volume = 1,
place = {United States},
year = {2018},
month = {1}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Figures / Tables:

Figure 1 Figure 1: Combined Rietveld refinement of LCMOFoo a) neutron diffraction (excerpt from 1 - 10.3 Å-1, actual fitting range from 1 - 15 Å-1), b) synchrotron diffraction, full Q-range, c) Visualization of spinel Fd-3m structure and cation distributions, d) cation distributions of spinel phase and phase content of Li2MnO3 (C2/m)more » as a function of fluorine content - error bars are not displayed in Figure 1d, since they are smaller than the symbols.« less

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Figures/Tables have been extracted from DOE-funded journal article accepted manuscripts.