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Title: Anionic ordering and thermal properties of FeF3·3H2O

In this study, iron fluoride tri-hydrate can be used to prepare iron hydroxyfluoride with the Hexagonal-Tungsten-Bronze (HTB) type structure, a potential cathode material for batteries. To understand this phase transformation, a structural description of β-FeF3·3H2O is first performed by means of DFT calculations and Mössbauer spectroscopy. The structure of this compound consists of infinite chains of [FeF6]n and [FeF2(H2O)4]n. The decomposition of FeF3·3H2O induces a collapse and condensation of these chains, which lead to the stabilization, under specific conditions, of a hydroxyfluoride network FeF3-x(OH)x with the HTB structure. The release of H2O and HF was monitored by thermal analysis and physical characterizations during the decomposition of FeF3·3H2O. An average distribution of FeF4(OH)2 distorted octahedra in HTB-FeF3-x(OH)x was obtained subsequent to the thermal hydrolysis/olation of equatorial anionic positions involving F- and H2O. This study provides a clear understanding of the structure and thermal properties of FeF3·3H2O, a material that can potentially bridge the recycling of pickling sludge from the steel industry by preparing battery electrodes.
 [1] ;  [2] ;  [3] ;  [2] ;  [2] ;  [4] ;  [4] ;  [4]
  1. Sorbonne Univ., UPMC Univ. Paris, CNRS, Lab. PHENIX, Paris (France); CNRS, Univ. Bordeaux, Pessac (France); Reseau sur le Stockage Electrochimique de l'Energie, Amiens Cedex (France)
  2. CNRS, Univ. Bordeaux, Pessac (France)
  3. Argonne National Lab. (ANL), Argonne, IL (United States)
  4. Sorbonne Univ., UPMC Univ. Paris, CNRS, Lab. PHENIX, Paris (France)
Publication Date:
OSTI Identifier:
Grant/Contract Number:
AC02-06CH11357; 321879
Accepted Manuscript
Journal Name:
Inorganic Chemistry
Additional Journal Information:
Journal Volume: 54; Journal Issue: 19; Journal ID: ISSN 0020-1669
American Chemical Society (ACS)
Research Org:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org:
European Commission - Community Research and Development Information Service (CORDIS) - Seventh Framework Programme (FP7); USDOE Office of Science (SC)
Country of Publication:
United States
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; 25 ENERGY STORAGE; HTB; anionic ordering; cathode; metal fluoride hydrate; thermal analysis