skip to main content


Title: Anionic ordering and thermal properties of FeF 3·3H 2O

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-FeF 3·3H 2O is first performed by means of DFT calculations and Mössbauer spectroscopy. The structure of this compound consists of infinite chains of [FeF 6]n and [FeF 2(H2O) 4] n. The decomposition of FeF 3·3H 2O induces a collapse and condensation of these chains, which lead to the stabilization, under specific conditions, of a hydroxyfluoride network FeF 3-x(OH) x with the HTB structure. The release of H 2O and HF was monitored by thermal analysis and physical characterizations during the decomposition of FeF 3·3H 2O. An average distribution of FeF 4(OH) 2 distorted octahedra in HTB-FeF 3-x(OH) x was obtained subsequent to the thermal hydrolysis/olation of equatorial anionic positions involving F- and H 2O. This study provides a clear understanding of the structure and thermal properties of FeF 3·3H 2O, 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:
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
OSTI Identifier: