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

Title: Controlled Formation of Mixed Nanoscale Domains of High Capacity Fe2O3–FeF3 Conversion Compounds by Direct Fluorination

Abstract

In this paper, we report a direct fluorination method under fluorine gas atmosphere using a fluidized bed reactor for converting nanophase iron oxide (n-Fe2O3) to an electrochemically stable and higher energy density iron oxyfluoride/fluoride phase. Interestingly, no noticeable bulk iron oxyfluoride phase (FeOF) phase was observed even at fluorination temperature close to 300 °C. Instead, at fluorination temperatures below 250 °C, scanning transmission electron microscopy coupled with electron energy loss spectroscopy (STEM-EELS) and X-ray photoelectron spectroscopy (XPS) analysis showed surface fluorination with nominal composition, Fe2O3-xF2x (x < 1). At fluorination temperatures of 275 °C, STEM-EELS results showed porous interconnected nanodomains of FeF3 and Fe2O3 coexisting within the same particle, and overall the particles become less dense after fluorination. We performed potentiometric intermittent titration and electrochemical impedance spectroscopy studies to understand the lithium diffusion (or apparent diffusion) in both the oxyfluoride and mixed phase FeF3 + Fe2O3 composition, and correlate the results to their electrochemical performance. Finally and further, we analyze from a thermodynamical perspective, the observed formation of the majority fluoride phase (77% FeF3) and the absence of the expected oxyfluoride phase based on the relative formation energies of oxide, fluoride, and oxyfluorides.

Authors:
 [1];  [1];  [2];  [1];  [3];  [4]
  1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division
  2. Univ. of Tennessee, Knoxville, TN (United States). Dept. of Chemistry
  3. Univ. of Tennessee, Knoxville, TN (United States). Dept. of Chemistry; Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Chemical Sciences Division
  4. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division; Univ. of Tennessee, Knoxville, TN (United States). Bredesen Centre for Interdisciplinary Science and Graduate Education. Dept. of Chemical and Biomolecular Engineering
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)
OSTI Identifier:
1286723
Grant/Contract Number:  
AC05-00OR22725
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
ACS Nano
Additional Journal Information:
Journal Volume: 9; Journal Issue: 3; Journal ID: ISSN 1936-0851
Publisher:
American Chemical Society (ACS)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; conversion electrode; fluoride; fluorination; nano-Fe2O3

Citation Formats

Zhou, Hui, Ruther, Rose E., Adcock, Jamie, Zhou, Wu, Dai, Sheng, and Nanda, Jagjit. Controlled Formation of Mixed Nanoscale Domains of High Capacity Fe2O3–FeF3 Conversion Compounds by Direct Fluorination. United States: N. p., 2015. Web. doi:10.1021/acsnano.5b00191.
Zhou, Hui, Ruther, Rose E., Adcock, Jamie, Zhou, Wu, Dai, Sheng, & Nanda, Jagjit. Controlled Formation of Mixed Nanoscale Domains of High Capacity Fe2O3–FeF3 Conversion Compounds by Direct Fluorination. United States. https://doi.org/10.1021/acsnano.5b00191
Zhou, Hui, Ruther, Rose E., Adcock, Jamie, Zhou, Wu, Dai, Sheng, and Nanda, Jagjit. 2015. "Controlled Formation of Mixed Nanoscale Domains of High Capacity Fe2O3–FeF3 Conversion Compounds by Direct Fluorination". United States. https://doi.org/10.1021/acsnano.5b00191. https://www.osti.gov/servlets/purl/1286723.
@article{osti_1286723,
title = {Controlled Formation of Mixed Nanoscale Domains of High Capacity Fe2O3–FeF3 Conversion Compounds by Direct Fluorination},
author = {Zhou, Hui and Ruther, Rose E. and Adcock, Jamie and Zhou, Wu and Dai, Sheng and Nanda, Jagjit},
abstractNote = {In this paper, we report a direct fluorination method under fluorine gas atmosphere using a fluidized bed reactor for converting nanophase iron oxide (n-Fe2O3) to an electrochemically stable and higher energy density iron oxyfluoride/fluoride phase. Interestingly, no noticeable bulk iron oxyfluoride phase (FeOF) phase was observed even at fluorination temperature close to 300 °C. Instead, at fluorination temperatures below 250 °C, scanning transmission electron microscopy coupled with electron energy loss spectroscopy (STEM-EELS) and X-ray photoelectron spectroscopy (XPS) analysis showed surface fluorination with nominal composition, Fe2O3-xF2x (x < 1). At fluorination temperatures of 275 °C, STEM-EELS results showed porous interconnected nanodomains of FeF3 and Fe2O3 coexisting within the same particle, and overall the particles become less dense after fluorination. We performed potentiometric intermittent titration and electrochemical impedance spectroscopy studies to understand the lithium diffusion (or apparent diffusion) in both the oxyfluoride and mixed phase FeF3 + Fe2O3 composition, and correlate the results to their electrochemical performance. Finally and further, we analyze from a thermodynamical perspective, the observed formation of the majority fluoride phase (77% FeF3) and the absence of the expected oxyfluoride phase based on the relative formation energies of oxide, fluoride, and oxyfluorides.},
doi = {10.1021/acsnano.5b00191},
url = {https://www.osti.gov/biblio/1286723}, journal = {ACS Nano},
issn = {1936-0851},
number = 3,
volume = 9,
place = {United States},
year = {Sun Feb 22 00:00:00 EST 2015},
month = {Sun Feb 22 00:00:00 EST 2015}
}

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

Citation Metrics:
Cited by: 44 works
Citation information provided by
Web of Science

Save / Share:

Works referenced in this record:

Nanostructured Fe3O4/SWNT Electrode: Binder-Free and High-Rate Li-Ion Anode
journal, May 2010


Formation of Fe 2 O 3 Microboxes with Hierarchical Shell Structures from Metal–Organic Frameworks and Their Lithium Storage Properties
journal, October 2012


?-Fe2O3 Nanotubes in Gas Sensor and Lithium-Ion Battery Applications
journal, March 2005


Hollow Iron Oxide Nanoparticles for Application in Lithium Ion Batteries
journal, April 2012


Mesoporous Co 3 O 4 Nanowire Arrays for Lithium Ion Batteries with High Capacity and Rate Capability
journal, January 2008


Interface electrochemistry in conversion materials for Li-ion batteries
journal, January 2011


Conversion mechanism of nickel fluoride and NiO-doped nickel fluoride in Li ion batteries
journal, January 2012


Metal hydrides for lithium-ion batteries
journal, October 2008


Carbon Metal Fluoride Nanocomposites: High-Capacity Reversible Metal Fluoride Conversion Materials as Rechargeable Positive Electrodes for Li Batteries
journal, January 2003


Transition-metal chlorides as conversion cathode materials for Li-ion batteries
journal, April 2012


Assembling carbon-coated α-Fe 2 O 3 hollow nanohorns on the CNT backbone for superior lithium storage capability
journal, January 2012


α-Fe2O3 Nanoflakes as an Anode Material for Li-Ion Batteries
journal, October 2007


Spindle-like Mesoporous α-Fe 2 O 3 Anode Material Prepared from MOF Template for High-Rate Lithium Batteries
journal, January 2012


Carbon-Metal Fluoride Nanocomposites: Structure and Electrochemistry of FeF3 : C
journal, January 2003


Li-Storage via Heterogeneous Reaction in Selected Binary Metal Fluorides and Oxides
journal, January 2004


Structure and Electrochemistry of Carbon-Metal Fluoride Nanocomposites Fabricated by Solid-State Redox Conversion Reaction
journal, January 2005


Fluoride based electrode materials for advanced energy storage devices
journal, April 2007


Iron Oxyfluorides as High Capacity Cathode Materials for Lithium Batteries
journal, January 2009


First-principles study of iron oxyfluorides and lithiation of FeOF
journal, March 2013


An Electron Diffraction and Crystal Chemical Investigation of Oxygen/Fluorine Ordering in Rutile-Type Iron Oxyfluoride, FeOF
journal, December 2000


Formation of Iron Oxyfluoride Phase on the Surface of Nano-Fe 3 O 4 Conversion Compound for Electrochemical Energy Storage
journal, October 2013


X-ray photoelectron study of the valence state of iron in iron-containing single-crystal (BiFeO3, PbFe1/2Nb1/2O3), and ceramic (BaFe1/2Nb1/2O3) multiferroics
journal, February 2011


Analysis of XPS spectra of Fe2+ and Fe3+ ions in oxide materials
journal, February 2008


The Dirac Vector Model in Complex Spectra
journal, March 1934


Synthesis and characterization of in situ Fe2O3-coated FeF3 cathode materials for rechargeable lithium batteries
journal, January 2012


Structural characterization of the lithiated iron oxides LixFe3O4 and LixFe2O3 (0<x<2)
journal, June 1982


Iron Oxide Nanosheets and Nanoparticles Synthesized by a Facile Single-Step Coprecipitation Method for Lithium-Ion Batteries
journal, January 2011


Transport, Phase Reactions, and Hysteresis of Iron Fluoride and Oxyfluoride Conversion Electrode Materials for Lithium Batteries
journal, April 2014


Low-Temperature Fluorination of Soft-Templated Mesoporous Carbons for a High-Power Lithium/Carbon Fluoride Battery
journal, October 2011


EXPGUI , a graphical user interface for GSAS
journal, April 2001


Dedicated STEM for 200 to 40 keV operation
journal, June 2011


Works referencing / citing this record:

Fluorination of MXene by Elemental F 2 as Electrode Material for Lithium‐Ion Batteries
journal, March 2019


In situ surface protection for enhancing stability and performance of conversion-type cathodes
journal, January 2017


Fluoride doped γ-Fe 2 O 3 nanoparticles with increased MRI relaxivity
journal, January 2018


Improved Performance in FeF 2 Conversion Cathodes through Use of a Conductive 3D Scaffold and Al 2 O 3 ALD Coating
journal, July 2017


Electrochemically driven conversion reaction in fluoride electrodes for energy storage devices
journal, April 2018


Toward Low-Cost, High-Energy Density, and High-Power Density Lithium-Ion Batteries
journal, June 2017


FeO x @carbon yolk/shell nanowires with tailored void spaces as stable and high-capacity anodes for lithium ion batteries
journal, January 2016


3D Honeycomb Architecture Enables a High‐Rate and Long‐Life Iron (III) Fluoride–Lithium Battery
journal, September 2019


Defect-enriched iron fluoride-oxide nanoporous thin films bifunctional catalyst for water splitting
journal, May 2018


Fluorination of MXene by Elemental F 2 as Electrode Material for Lithium‐Ion Batteries
journal, April 2019


Fluorination of MXene by Elemental F 2 as Electrode Material for Lithium‐Ion Batteries
journal, March 2019