On the LixCo1-yMgyO2 system upon deintercalation: electrochemical, electronic properties and 7Li MAS NMR studies
Language
en
Article de revue
This item was published in
Journal of Power Sources. 2002, vol. 112, n° 2, p. 419-427
Elsevier
English Abstract
A detailed characterization of the structural modifications and redox processes occurring upon lithium deintercalation from the Lix0Co1−yMgyO2 materials (x0=1.0 and 1.10; y=0.0, 0.03, 0.05 and 0.06) was performed in order ...Read more >
A detailed characterization of the structural modifications and redox processes occurring upon lithium deintercalation from the Lix0Co1−yMgyO2 materials (x0=1.0 and 1.10; y=0.0, 0.03, 0.05 and 0.06) was performed in order to determine the effect of Mg doping on the cycling properties. Using electrochemical tests, X-ray diffraction (XRD), 7Li MAS NMR and electrical properties measurements, we show that the LixCo1−yMgyO2 system exhibits a solid solution existing in the whole deintercalation range studied (0.30≤×≤1.0). These phases exhibit reversible capacities equivalent to that of LiCoO2 upon cycling with a good structural stability. Moreover, the 7Li MAS NMR study shows that the structural defects (O vacancies and intermediate spin Co3+ ions) which are present in the starting Mg-doped phases govern the electronic properties upon lithium deintercalation. Indeed, regardless of the presence of Mg ions in the structure, a behavior similar to that of the LixCoO2 (1Read less <
English Keywords
LiCoO2
Layered oxide
NMR
Lithium battery
Electrical properties
Magnesium substitution
Origin
Hal imported