In:
Pure and Applied Chemistry, Walter de Gruyter GmbH, Vol. 80, No. 11 ( 2008-01-01), p. 2521-2536
Abstract:
An inverse spinel LiCoVO 4 cathode material was synthesized by a citric acid-urea polymeric method, calcined at 773 K for 5 h. The synthesized LiCoVO 4 sample was surface-modified with La 2 O 3 and/or malonic acid. The composite materials were comprehensively characterized with the aid of various spectroscopic and analytical techniques. X-ray diffraction (XRD) patterns revealed that single-phase crystallinity occurred when they were heated at 773 K for 5 h in air. For the La 2 O 3 -coated samples, there was no evident signal corresponding to secondary-phase peaks. Fourier transform infrared (FTIR) spectra showed the complete elimination of organic residues, nitrates, and the formation of pure LiCoVO 4 at 773 K. The two strong peaks due to sp 2 and sp 3 carbon bonding in the Raman spectra clearly confirm the presence of carbon coating at the surface of LiCoVO 4 particles. Transmission electron microscopy (TEM) images showed that the 0.5 wt % La 2 O 3 -coated LiCoVO 4 material calcined with 60 wt % malonic acid was compact with an average thickness of about 15 nm. This composite cathode material also demonstrated the best cell performance with an initial capacity of 71 mAhg -1 and better thermal stability with lower heat evolution of 35 Jg -1 , and a higher onset temperature of thermal decomposition at 475 K, vs. 176 Jg -1 and 452 K for the bare LiCoVO 4 sample.
Type of Medium:
Online Resource
ISSN:
1365-3075
,
0033-4545
DOI:
10.1351/pac200880112521
Language:
English
Publisher:
Walter de Gruyter GmbH
Publication Date:
2008
detail.hit.zdb_id:
2022101-0
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