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Title: Unraveling the Complex Delithiation Mechanisms of Olivine-Type Cathode Materials, LiFe x Co 1–x PO 4

Authors:
; ; ; ; ; ; ;
Publication Date:
Research Org.:
Energy Frontier Research Centers (EFRC) (United States). Northeastern Center for Chemical Energy Storage (NECCES)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1371400
DOE Contract Number:
SC0001294
Resource Type:
Journal Article
Resource Relation:
Journal Name: Chemistry of Materials; Journal Volume: 28; Journal Issue: 11; Related Information: NECCES partners with Stony Brook University (lead); Argonne National Laboratory; Binghamton University; Brookhaven National University; University of California, San Diego; University of Cambridge, UK; Lawrence Berkeley National Laboratory; Massachusetts Institute of Technology; University of Michigan; Rutgers University
Country of Publication:
United States
Language:
English
Subject:
energy storage (including batteries and capacitors), defects, charge transport, materials and chemistry by design, synthesis (novel materials)

Citation Formats

Strobridge, Fiona C., Liu, Hao, Leskes, Michal, Borkiewicz, Olaf J., Wiaderek, Kamila M., Chupas, Peter J., Chapman, Karena W., and Grey, Clare P. Unraveling the Complex Delithiation Mechanisms of Olivine-Type Cathode Materials, LiFe x Co 1–x PO 4. United States: N. p., 2016. Web. doi:10.1021/acs.chemmater.6b00319.
Strobridge, Fiona C., Liu, Hao, Leskes, Michal, Borkiewicz, Olaf J., Wiaderek, Kamila M., Chupas, Peter J., Chapman, Karena W., & Grey, Clare P. Unraveling the Complex Delithiation Mechanisms of Olivine-Type Cathode Materials, LiFe x Co 1–x PO 4. United States. doi:10.1021/acs.chemmater.6b00319.
Strobridge, Fiona C., Liu, Hao, Leskes, Michal, Borkiewicz, Olaf J., Wiaderek, Kamila M., Chupas, Peter J., Chapman, Karena W., and Grey, Clare P. 2016. "Unraveling the Complex Delithiation Mechanisms of Olivine-Type Cathode Materials, LiFe x Co 1–x PO 4". United States. doi:10.1021/acs.chemmater.6b00319.
@article{osti_1371400,
title = {Unraveling the Complex Delithiation Mechanisms of Olivine-Type Cathode Materials, LiFe x Co 1–x PO 4},
author = {Strobridge, Fiona C. and Liu, Hao and Leskes, Michal and Borkiewicz, Olaf J. and Wiaderek, Kamila M. and Chupas, Peter J. and Chapman, Karena W. and Grey, Clare P.},
abstractNote = {},
doi = {10.1021/acs.chemmater.6b00319},
journal = {Chemistry of Materials},
number = 11,
volume = 28,
place = {United States},
year = 2016,
month = 6
}
  • The delithiation mechanisms occurring within the olivine-type class of cathode materials for Li-ion batteries have received considerable attention owing to the good capacity retention at high rates for LiFePO4. A comprehensive mechanistic study of the (de)lithiation reactions that occur when the substituted olivine-type cathode materials LiFexCo1-xPO4 (x = 0, 0.05, 0.125, 0.25, 0.5, 0.75, 0.875, 0.95 and 1) are electrochemically cycled is reported here, using in situ X-ray diffraction (XRD) data. On the first charge, two intermediate phases are observed and identified: Li1-x(Fe3+)x(Co2+)1- xPO4 for 0 < x < 1 (i.e. after oxidation of Fe2+ => Fe3+) and Li2/3FexCo1-xPO4 formore » 0 ≤ x ≤ 0.5 (i.e. the Co-majority materials). For the Fe-rich materials, we study how nonequilibrium, single-phase mechanisms that occur discretely in single particles, as observed for LiFePO4 at high rates, is affected by Co substitution. In the Co-majority materials, a two-phase mechanism with a coherent interface is observed, as was seen in LiCoPO4, and we discuss how it is manifested in the XRD patterns. We then compare the nonequilibrium, single-phase mechanism with the bulk single-phase and the coherent interface two-phase mechanisms. Despite the apparent differences between these mechanisms, we discuss how they are related and interconverted as a function of Fe/Co substitution and the potential implications for the electrochemistry of this system.« less
  • V 6O 13 is a promising Li-ion battery cathode material for use in the high temperature oil field environment. The material exhibits a high capacity, and the voltage profile contains several plateaus associated with a series of complex structural transformations, which are not fully understood. The underlying mechanisms are central to understanding and improving the performance of V 6O 13-based rechargeable batteries. In this study, we present in situ X-ray diffraction data that highlight an asymmetric six-step discharge and five step charge process, due to a phase that is only formed on discharge. The LixV 6O 13 unit cell expandsmore » sequentially in c, b, and a directions during discharge and reversibly contracts back during charge. The process is associated with change of Li ion positions as well as charge ordering in LixV 6O 13. Density functional theory calculations give further insight into the electronic structures and preferred Li positions in the different structures formed upon cycling, particularly at high lithium contents, where no prior structural data are available. Lastly, the results shed light into the high specific capacity of V 6O 13 and are likely to aid in the development of this material for use as a cathode for secondary lithium batteries.« less