Titre :

A Computational and Spectroscopic Study of the Electronic Structure of V2O5-Based Cathode Materials

Auteur(s) :

Roginskii, E. M. [Auteur]
Smirnov, M. B. [Auteur]
Smirnov, Konstantin [Auteur]
Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement (LASIRE) - UMR 8516
Baddour-Hadjean, Rita [Auteur]
Institut de Chimie et des Matériaux Paris-Est [ICMPE]
Pereira-Ramos, Jean-Pierre [Auteur]
Institut de Chimie et des Matériaux Paris-Est [ICMPE]
Smirnov, A. N. [Auteur]
Davydov, V. Y. [Auteur]

Titre de la revue :

Journal of Physical Chemistry C

Nom court de la revue :

J. Phys. Chem. C

Numéro :

125

Pagination :

-

Date de publication :

2021-04-18

ISSN :

1932-7447

Discipline(s) HAL :

Chimie

Résumé en anglais : [en]

The electronic structure of α-V2O5, γ′-V2O5, and γ-MeV2O5 (Me = Li, Na) bronzes is studied by quantum-chemical calculations completed by spectroscopic experiments. The calculations are performed using the G0W0 method with ...
Lire la suite >The electronic structure of α-V2O5, γ′-V2O5, and γ-MeV2O5 (Me = Li, Na) bronzes is studied by quantum-chemical calculations completed by spectroscopic experiments. The calculations are performed using the G0W0 method with the DFT+U self-consistent wave function as an initial approximation. The electronic band gap Eg = 2.89 eV calculated for α-V2O5 is found to be in fair agreement with available experimental data. The strategy was then applied to studying the electronic structure of the γ′-V2O5 phase and γ-MeV2O5 bronzes for which no experimental band gap data exist in the literature. Computed Eg values are equal to 3.17, 1.21 and 1.18 eV for γ′-V2O5, γ-LiV2O5, and γ-NaV2O5, respectively. The nature of the alkali metal atom is determined to have little influence on the structure and electronic states of the bronzes. Raman spectra recorded with different wavelengths of exciting radiation have allowed the determination of the energy threshold corresponding to the transition from off-resonance to resonance Raman scattering process. In this way, a band gap value in the range 2.54–2.71 eV for α-V2O5 and γ′-V2O5 is obtained in good agreement with the experimental values for the α-phase. Raman spectra of γ-MeV2O5 suggest the band gap smaller than 1.58 eV in these materials, whereas the photoluminescence measurements yield Eg ≈ 0.95 eV for the γ-LiV2O5 bronze. Remarkably, the result of the G0W0 calculations lies in between the experimental estimates. The strong similarity of structures and electronic states of γ-LiV2O5 and γ-NaV2O5 accounts for their the same operating voltage when used as cathodes in Li(Na)-ion batteries.Lire moins >

Langue :

Anglais

Comité de lecture :

Oui

Audience :

Internationale

Vulgarisation :

Non

Établissement(s) :

Université de Lille
CNRS

Collections :

• Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement (LASIRE) - UMR 8516

Date de dépôt :

2024-02-28T23:29:08Z
2024-03-18T13:46:27Z