title: Anionic ordering and thermal properties of FeF3·3H2O.
abstract: Iron fluoride trihydrate 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.
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, CNRS, Laboratoire PHENIX , Case 51, 4 place Jussieu, F-75005 Paris, France.|CNRS, Univ Bordeaux, ICMCB, UPR 9048 , F-33600 Pessac, France.|Réseau sur le Stockage Electrochimique de l'Energie (RS2E), FR CNRS 3459 , 80039 Amiens Cedex, France.
authors.forename: Mario
authors.initials: M
authors.lastname: Burbano
authors.affiliation: CNRS, Univ Bordeaux, ICMCB, UPR 9048 , F-33600 Pessac, France.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Duttine
authors.affiliation: X-ray Science Division, Advanced Photon Source, Argonne National Laboratory , 9700 South Cass Avenue, Argonne, Illinois 60439, United States.
authors.forename: Olaf
authors.initials: O
authors.lastname: Borkiewicz
authors.affiliation: CNRS, Univ Bordeaux, ICMCB, UPR 9048 , F-33600 Pessac, France.
authors.forename: Alain
authors.initials: A
authors.lastname: Wattiaux
authors.affiliation: CNRS, Univ Bordeaux, ICMCB, UPR 9048 , F-33600 Pessac, France.
authors.forename: Alain
authors.initials: A
authors.lastname: Demourgues
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, CNRS, Laboratoire PHENIX , Case 51, 4 place Jussieu, F-75005 Paris, France.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Salanne
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, CNRS, Laboratoire PHENIX , Case 51, 4 place Jussieu, F-75005 Paris, France.
authors.forename: Henri
authors.initials: H
authors.lastname: Groult
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, CNRS, Laboratoire PHENIX , Case 51, 4 place Jussieu, F-75005 Paris, France.
authors.forename: Damien
authors.initials: D
authors.lastname: Dambournet