Journal
JOURNAL OF SOLID STATE CHEMISTRY
Volume 181, Issue 12, Pages 3303-3307Publisher
ACADEMIC PRESS INC ELSEVIER SCIENCE
DOI: 10.1016/j.jssc.2008.09.002
Keywords
Lithium-ion battery; Positive electrode material; Layered oxide; Li(Ni,Mn,Co)O-2; Fluorine substitution; Coating; X-ray diffraction; NMR spectroscopy
Funding
- Region Aquitaine and Saft
Ask authors/readers for more resources
A series of Li1+z/2(Ni0.425Mn0.425Co0.15)(1-z/2)O2-zFz materials was prepared by a coprecipitation route and their structure was characterized using X-ray diffraction (XRD), as well as Li-7 and F-19 Magic Angle Spinning (MAS) NMR spectroscopy. Two hypotheses were considered: (i) formation of layered oxyfluoride materials and (ii) formation of a mixture between the layered material and LiF. Structural parameters were refined by the Rietveld method, using XRD diffraction data. The refinement results did not allow us to choose between these two hypotheses: no significant change in crystallinity and structural parameters was observed irrespective of the fluorine ratio. Li-7 and F-19 MAS NMR analyses showed signals with isotropic positions characteristic of LiF, but envelopes characteristic of very strong dipolar interactions with the electron spins of the material, demonstrating that LiF was not incorporated into the layered oxide structure but was instead present as a coating. (C) 2008 Elsevier Inc. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available