BOIVIN, Edouard; CHOTARD, Jean-Noel; BAMINE, Tahya; CARLIER, Dany; SERRAS, Paula; PALOMARES, Verónica; ROJO, Teófilo; IADECOLA, Antonella; DUPONT, Loic; BOURGEOIS, Lydie; FAUTH, François; MASQUELIER, Christian; CROGUENNEC, Laurence

doi:10.1039/C7TA08733K

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BOIVIN, Edouard
Laboratoire réactivité et chimie des solides - UMR CNRS 7314 UPJV [LRCS]
Réseau sur le stockage électrochimique de l'énergie [RS2E]
Institut de Chimie de la Matière Condensée de Bordeaux [ICMCB]

CHOTARD, Jean-Noel
Laboratoire réactivité et chimie des solides - UMR CNRS 7314 UPJV [LRCS]
Réseau sur le stockage électrochimique de l'énergie [RS2E]
Advanced Lithium Energy Storage Systems - ALISTORE-ERI [ALISTORE-ERI]

BAMINE, Tahya
Institut de Chimie de la Matière Condensée de Bordeaux [ICMCB]
Réseau sur le stockage électrochimique de l'énergie [RS2E]

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Article de revue

Ce document a été publié dans

Journal of Materials Chemistry A. 2017, vol. 5, n° 47, p. 25044-25055

Royal Society of Chemistry

Résumé en anglais

Tavorite-type compositions offer rich crystal chemistry for positive electrodes in rechargeable batteries, among which LiVIIIPO4F has the highest theoretical energy density (i.e. 655 Wh kg−1). In this article, we report for the first time the synthesis of the related Na-based phase crystallizing in the Tavorite-like structure. Its in-depth structural and electronic characterization was conducted by a combination of several techniques, spanning electron and X-ray powder diffraction as well as infrared and X-ray absorption spectroscopy. The magnetic susceptibility measurement reveals an average oxidation state for vanadium slightly higher than V3+. This slight oxidation is supported by infrared and X-ray absorption spectroscopies which highlight the presence of V4+[double bond, length as m-dash]O vanadyl-type defects leading to an approximated NaVIII0.85(VIVO)0.15(PO4)F0.85 composition. In this material, the profile of the diffraction lines is governed by a strong strain anisotropic broadening arising from the competitive formation between the ionic V3+–F and the covalent V4+[double bond, length as m-dash]O bonds. This material shows a limited extraction of sodium, close to 15% of the theoretical capacity. Indeed, its electrochemical properties are strongly inhibited by the intrinsic low sodium mobility in the Tavorite framework.< Réduire

DOI

http://dx.doi.org/10.1039/C7TA08733K

Project ANR

Spectromètre EXAFS Rapide pour Cinétiques Chimiques - ANR-10-EQPX-0045
Development of New High Voltage Positive Electrodes for Sustainable Li-Ion Batteries
Laboratory of excellency for electrochemical energy storage

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Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB) - UMR 5026