Article ID Journal Published Year Pages File Type
1627260 Journal of Alloys and Compounds 2006 8 Pages PDF
Abstract
Particulate sol-gel LiNi0.8Co0.2O2 has been synthesized by a maleic-acid-assisted process using de-ionized water or ethanol as the solvent. A comparison of the effect on these two different solvents was made on the basis of thermal studies, Fourier transform infrared spectroscopy, X-ray diffraction analysis, chemical diffusion coefficients measurement, and electrochemical cyclability tests. An esterification reaction occurred on the xerogel prepared with ethanol as solvent, reducing Ni and Co from their nitrate salts. LiNi0.8Co0.2O2 grew at the expense of Li2CO3, NiO, and CoO during calcination. Better results of capacity and cyclability were obtained in a DI-water-solvent sample associated with a larger interslab thickness between OLiO and lower Ni occupancy on the Li site. The activation energy for the calcinations of DI-water-solvent sample is one-half of that of the ethanol-solvent one, which could be the reason for its better properties. Chemical diffusion coefficients of Li+ ion are of the same order 10−10 cm2/s, is not affected by the solvents used and/or the temperature raise to 55 °C.
Related Topics
Physical Sciences and Engineering Materials Science Metals and Alloys
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