Iron-Doped Sodium-Vanadium Fluorophosphates: Na3V2-yO2-yFe y (PO4)2F1+y (y < 0.3)

Palomares, V; Iturrondobeitia, A; Sanchez-Fontecoba, P; Goonetilleke, D; Sharma, N; Lezama, L; Rojo, T

HERO ID

6308317

Reference Type

Journal Article

Year

2020

Language

English

PMID

31840984

HERO ID 6308317
In Press No
Year 2020
Title Iron-Doped Sodium-Vanadium Fluorophosphates: Na3V2-yO2-yFe y (PO4)2F1+y (y < 0.3)
Authors Palomares, V; Iturrondobeitia, A; Sanchez-Fontecoba, P; Goonetilleke, D; Sharma, N; Lezama, L; Rojo, T
Journal Inorganic Chemistry
Volume 59
Issue 1
Page Numbers 854-862
Abstract The sodium-vanadium fluorophosphate family has been actively investigated recently, but few examples tackle chemical doping or the substitution of vanadium. This work presents a series of iron-doped compounds Na3V2-yO2-yFe y (PO4)2F1+y (y ≤ 0.3) prepared by hydrothermal synthesis with low iron content. The amount of iron in the structure is confirmed by X-ray and neutron powder diffraction, electronic paramagnetic resonance, magnetic susceptibility measurements, and solid-state nuclear magnetic resonance (ssNMR). The degree of vanadium substitution, together with the solubility limit for iron in sodium-vanadium fluorophosphates, has been calculated by ssNMR and magnetic susceptibility measurements to be y = 0.3 based on the synthetic route used here. The introduction of small amounts of Fe3+ to the structure leads to the reduction of a fraction of V4+ to V3+, and the voltage profiles do not change with the introduction of iron to the structure. In situ synchrotron X-ray diffraction demonstrates that the electrochemical-structural changes during charge and discharge are very similar to those observed in the V3+/V4+ mixed-valent Na3V2O1.6(PO4)2F1.4, which could be related to the existence of both iron dopant and V3+ in the phase.
Doi 10.1021/acs.inorgchem.9b03111
Pmid 31840984
Wosid WOS:000506719300089
Is Certified Translation No
Dupe Override No
Is Public Yes
Language Text English