화학공학소재연구정보센터
Journal of Materials Science, Vol.37, No.11, 2367-2375, 2002
Layered LiNi1-yCoyO2 compounds synthesized by a glycine-assisted combustion method for lithium batteries
The lithiated nickel-cobalt oxide cathode materials were prepared at low temperature using the aqueous glycine-nitrate combustion method. Physicochemical and electrochemical properties of LiNi1-yCoyO2 (0.3 less than or equal to y less than or equal to 0.7) calcined at 400-600degreesC were extensively investigated. It has been found that powders of submicron-sized particles with a layered structure (R (3) over barm space group) were obtained at temperatures below 400degreesC by the acidification reaction of the aqueous nitrate solution. The method involves the mixing of nitrates of Li, Ni and Co, with a combustion agent, glycine in an aqueous medium. Glycine functioned such as a fuel, decomposed the homogeneous precipitate of metal complexes at low temperature, and yielded the free impurity LiNi1-yCoyO2 compounds. The synthesized products were characterized by structural (XRD, SEM), spectroscopic (FTIR) and thermal (DTA/TG) analyses. The electrochemical properties of the synthesized products in rechargeable Li cells were evaluated using a non-aqueous organic electrolyte mixture of 1M LiPF6 in EC + DMC. The electrodes fired at low temperature exhibed a good cycling behavior.