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Muller-Bouvet, D., Emery, N., Tassali, N., Panabiere, E., Bach, S., Crosnier, O., Brousse, T., Cenac-Morthe, C., Michalowicz, A. & Pereira-Ramos, J. P. (2017) Unravelling redox processes of Li7MnN4 upon electrochemical Li extraction-insertion using &IToperando &ITXAS. Physical Chemistry Chemical Physics, 19 27204–27211.
Added by: Richard Baschera (2017-11-10 13:38:16) Last edited by: Richard Baschera (2017-11-10 13:41:30) |
| Type de référence: Article DOI: 10.1039/c7cp05207c Clé BibTeX: MullerBouvet2017 Voir tous les détails bibliographiques  |
Catégories: ST2E Créateurs: Bach, Brousse, Cenac-Morthe, Crosnier, Emery, Michalowicz, Muller-Bouvet, Panabiere, Pereira-Ramos, Tassali Collection: Physical Chemistry Chemical Physics |
Consultations : 1/487
Indice de consultation : 4% Indice de popularité : 1% |
| Résumé |
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A large data set of XAS (X-ray Absorption Spectroscopy) Manganese K-edge spectra has been collected operando and studied upon the electrochemical oxidation of the promising Li-ion battery anode material Li7MnN4. Using chemometric tools such as PCA (Principal Component Analysis) and MCR-ALS (Multivariate Curve resolution - Alternating Least Squares), three independent environment spectra were insulated. Based on the faradaic yield and well-chosen comparison of absorption spectrum energies within the frame of the coordination charge model, these environments were ascribed to unusual oxidation states allowed by nitride chemistry at a low potential (similar to 1.2 V vs. Li+/Li), i.e. Mn5+ (3d(2)), Mn6+ (3d(1)) and Mn-7 (3d). Also, their relative amounts are discussed with regard to the long-range structural variation which can be simply described by two successive biphasic domains followed by a solid-solution behaviour. Gathering this long-range and local structure information provides a complete picture of the redox mechanisms occurring in Li7MnN4.
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