title: The mechanism of NaFePO₄ (de)sodiation determined by in situ X-ray diffraction.
abstract: The reaction mechanism occurring during the (de)intercalation of sodium into the host olivine FePO4 structure is thoroughly analysed through a combination of structural and electrochemical methods. In situ XRD experiments have confirmed that the charge and discharge reaction mechanisms are different and have revealed the existence of a solid solution domain from 1 < x < 2/3 in Na(x)FePO4 upon charge. The second part of the charge proceeds through a 2-phase reaction between Na(2/3)FePO4 and FePO4 with strongly varying solubility limits. The strong cell mismatch between Na(2/3)FePO4 and FePO4 enhances the effects of the diffuse interface and therefore varying solubility limits are first observed here in micrometric materials.
authors.affiliation: CIC ENERGIGUNE, Parque Tecnológico de Álava, Albert Einstein 48, ED.CIC, 01510, Miñano, Spain. mcasas@cicenergigune.com.
authors.forename: Montserrat
authors.initials: M
authors.lastname: Galceran
authors.forename: Damien
authors.initials: D
authors.lastname: Saurel
authors.forename: Begoña
authors.initials: B
authors.lastname: Acebedo
authors.forename: Vladimir V
authors.initials: VV
authors.lastname: Roddatis
authors.forename: Egoitz
authors.initials: E
authors.lastname: Martin
authors.forename: Teófilo
authors.initials: T
authors.lastname: Rojo
authors.forename: Montse
authors.initials: M
authors.lastname: Casas-Cabanas