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Dupre, N., Martin, J.-F., Oliveri, J., Soudan, P., Yamada, A., Kanno, R. & Guyomard, D. (2011) Relationship between surface chemistry and electrochemical behavior of LiNi1/2Mn1/2O2 positive electrode in a lithium-ion battery. J. Power Sources, 196 4791–4800.
Added by: Laurent Cournède (2016-03-10 21:32:20) |
| Type de référence: Article DOI: 10.1016/j.jpowsour.2010.07.049 Numéro d'identification (ISBN etc.): 0378-7753 Clé BibTeX: Dupre2011 Voir tous les détails bibliographiques  |
Catégories: ST2E Mots-clés: Cathode material, Interface, layered lini1/2mn1/2o2, LiFePO4, Lithium batteries, MAS NMR, NMR, oxide electrodes, Positive electrode, Sol-gel, thin-films, ultrahigh-vacuum, x-ray-diffraction, xps analysis Créateurs: Dupre, Guyomard, Kanno, Martin, Oliveri, Soudan, Yamada Collection: J. Power Sources |
Consultations : 1/591
Indice de consultation : 4% Indice de popularité : 1% |
| Résumé |
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The formation and the evolution of lithium-containing species on the surface of grains of a layered 4V material such as LiNi1/2Mn1/2O2 along the electrochemical cycling have been followed using Li-7 MAS NMR, electrochemical impedance spectroscopy (EIS) and XPS. Materials displaying different specific surface areas and stored in different atmospheres have been investigated in order to study the influence of the surface/volume ratio and the influence of the initial surface state, respectively. It is shown that the presence of an initial interphase of Li2CO3 influences the electrochemical behavior of the electrode, emphasizing the importance of the history of the electrode prior cycling. Li-7 MAS NMR experiments performed upon cycling indicate the formation of interphase species in reduction and their partial removal in oxidation, indicating the dynamic character of the interphase upon cycling. Combined NMR, EIS and XPS experiments show the strong influence of the electrode/electrolyte interphase evolution on the electrochemical performance. Such results lead us to draw conclusions on the optimal storage conditions of layered 4V materials for Li-ion batteries such as LiNi1/2Mn1/2O2. (C) 2010 Elsevier B.V. All rights reserved.
Added by: Laurent Cournède |