skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Electrochemical (de)lithiation of silver ferrite and composites: mechanistic insights from ex situ, in situ, and operando X-ray techniques

Abstract

Here, the structure of pristine AgFeO 2 and phase makeup of Ag 0.2FeO1.6 (a one-pot composite comprised of nanocrystalline stoichiometric AgFeO 2 and amorphous γ-Fe 2O 3 phases) was investigated using synchrotron x-ray diffraction. A new stacking-fault model was proposed for AgFeO2 powder synthesized using the co-precipitation method. The lithiation/de-lithiation mechanisms of silver ferrite, AgFeO 2 and Ag 0.2FeO 1.6 were investigated using ex-situ, in-situ, and operando characterization techniques. An amorphous γ-Fe 2O 3 component in the Ag 0.2FeO 1.6 sample is quantified. Operando XRD of electrochemically reduced AgFeO 2 and Ag 0.2FeO 1.6 composites demonstrated differences in the structural evolution of the nanocrystalline AgFeO 2 component. As complimentary techniques to XRD, ex-situ x-ray Absorption Spectroscopy (XAS) provided insight into the short-range structure of the (de)lithiated nanocrystalline electrodes, and a novel in-situ high energy x-ray fluorescence nanoprobe (HXN) mapping measurement was applied to spatially resolve the progression of discharge. Based on the results, a redox mechanism is proposed where the full reduction of Ag + to Ag0 and partial reduction of Fe 3+ to Fe 2+ occur on reduction to 1.0 V, resulting in a Li 1+yFe IIIFe IIyO 2 phase. The Li 1+yFe IIIFe IIyO 2 phase can thenmore » reversibly cycle between Fe 3+ and Fe 2+ oxidation states, permitting good capacity retention over 50 cycles. In the Ag 0.2FeO 1.6 composite, a substantial amorphous γ-Fe 2O 3 component is observed which discharges to rock salt LiFe 2O 3 and Fe 0 metal phase in the 3.5 – 1.0 V voltage range (in parallel with the AgFeO 2 mechanism), and reversibly reoxidizes to a nanocrystalline iron oxide phase.« less

Authors:
 [1];  [2];  [1];  [3];  [3];  [2];  [4];  [1];  [1];  [4];  [4];  [4]; ORCiD logo [5];  [6]; ORCiD logo [6]
  1. Stony Brook Univ., NY (United States). Dept. of Chemistry
  2. Stony Brook Univ., NY (United States). Dept. of Materials Science and Engineering
  3. Brookhaven National Lab. (BNL), Upton, NY (United States). Energy Sciences Directorate
  4. Brookhaven National Lab. (BNL), Upton, NY (United States). National Synchrotron Light Source II (NSLS-II)
  5. Stony Brook Univ., NY (United States). Dept. of Chemistry; Stony Brook Univ., NY (United States). Dept. of Materials Science and Engineering; Brookhaven National Lab. (BNL), Upton, NY (United States). Energy Sciences Directorate
  6. Stony Brook Univ., NY (United States). Dept. of Chemistry; Stony Brook Univ., NY (United States). Dept. of Materials Science and Engineering
Publication Date:
Research Org.:
Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1376184
Report Number(s):
BNL-114168-2017-JA
Journal ID: ISSN 1463-9076; PPCPFQ
Grant/Contract Number:
SC0012704; AC02-06CH11357
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Physical Chemistry Chemical Physics. PCCP (Print)
Additional Journal Information:
Journal Name: Physical Chemistry Chemical Physics. PCCP (Print); Journal Volume: 19; Journal Issue: 33; Journal ID: ISSN 1463-9076
Publisher:
Royal Society of Chemistry
Country of Publication:
United States
Language:
English
Subject:
25 ENERGY STORAGE

Citation Formats

Durham, Jessica L., Brady, Alexander B., Cama, Christina A., Bock, David C., Pelliccione, Christopher J., Zhang, Qing, Ge, Mingyuan, Li, Yue Ru, Zhang, Yiman, Yan, Hanfei, Huang, Xiaojing, Chu, Yong, Takeuchi, Esther S., Takeuchi, Kenneth J., and Marschilok, Amy C. Electrochemical (de)lithiation of silver ferrite and composites: mechanistic insights from ex situ, in situ, and operando X-ray techniques. United States: N. p., 2017. Web. doi:10.1039/C7CP04012A.
Durham, Jessica L., Brady, Alexander B., Cama, Christina A., Bock, David C., Pelliccione, Christopher J., Zhang, Qing, Ge, Mingyuan, Li, Yue Ru, Zhang, Yiman, Yan, Hanfei, Huang, Xiaojing, Chu, Yong, Takeuchi, Esther S., Takeuchi, Kenneth J., & Marschilok, Amy C. Electrochemical (de)lithiation of silver ferrite and composites: mechanistic insights from ex situ, in situ, and operando X-ray techniques. United States. doi:10.1039/C7CP04012A.
Durham, Jessica L., Brady, Alexander B., Cama, Christina A., Bock, David C., Pelliccione, Christopher J., Zhang, Qing, Ge, Mingyuan, Li, Yue Ru, Zhang, Yiman, Yan, Hanfei, Huang, Xiaojing, Chu, Yong, Takeuchi, Esther S., Takeuchi, Kenneth J., and Marschilok, Amy C. Wed . "Electrochemical (de)lithiation of silver ferrite and composites: mechanistic insights from ex situ, in situ, and operando X-ray techniques". United States. doi:10.1039/C7CP04012A.
@article{osti_1376184,
title = {Electrochemical (de)lithiation of silver ferrite and composites: mechanistic insights from ex situ, in situ, and operando X-ray techniques},
author = {Durham, Jessica L. and Brady, Alexander B. and Cama, Christina A. and Bock, David C. and Pelliccione, Christopher J. and Zhang, Qing and Ge, Mingyuan and Li, Yue Ru and Zhang, Yiman and Yan, Hanfei and Huang, Xiaojing and Chu, Yong and Takeuchi, Esther S. and Takeuchi, Kenneth J. and Marschilok, Amy C.},
abstractNote = {Here, the structure of pristine AgFeO2 and phase makeup of Ag0.2FeO1.6 (a one-pot composite comprised of nanocrystalline stoichiometric AgFeO2 and amorphous γ-Fe2O3 phases) was investigated using synchrotron x-ray diffraction. A new stacking-fault model was proposed for AgFeO2 powder synthesized using the co-precipitation method. The lithiation/de-lithiation mechanisms of silver ferrite, AgFeO2 and Ag0.2FeO1.6 were investigated using ex-situ, in-situ, and operando characterization techniques. An amorphous γ-Fe2O3 component in the Ag0.2FeO1.6 sample is quantified. Operando XRD of electrochemically reduced AgFeO2 and Ag0.2FeO1.6 composites demonstrated differences in the structural evolution of the nanocrystalline AgFeO2 component. As complimentary techniques to XRD, ex-situ x-ray Absorption Spectroscopy (XAS) provided insight into the short-range structure of the (de)lithiated nanocrystalline electrodes, and a novel in-situ high energy x-ray fluorescence nanoprobe (HXN) mapping measurement was applied to spatially resolve the progression of discharge. Based on the results, a redox mechanism is proposed where the full reduction of Ag+ to Ag0 and partial reduction of Fe3+ to Fe2+ occur on reduction to 1.0 V, resulting in a Li1+yFeIIIFeIIyO2 phase. The Li1+yFeIIIFeIIyO2 phase can then reversibly cycle between Fe3+ and Fe2+ oxidation states, permitting good capacity retention over 50 cycles. In the Ag0.2FeO1.6 composite, a substantial amorphous γ-Fe2O3 component is observed which discharges to rock salt LiFe2O3 and Fe0 metal phase in the 3.5 – 1.0 V voltage range (in parallel with the AgFeO2 mechanism), and reversibly reoxidizes to a nanocrystalline iron oxide phase.},
doi = {10.1039/C7CP04012A},
journal = {Physical Chemistry Chemical Physics. PCCP (Print)},
number = 33,
volume = 19,
place = {United States},
year = {Wed Aug 02 00:00:00 EDT 2017},
month = {Wed Aug 02 00:00:00 EDT 2017}
}

Journal Article:
Free Publicly Available Full Text
This content will become publicly available on August 2, 2018
Publisher's Version of Record

Save / Share: