Journal of Applied Electrochemistry, Vol.35, No.11, 1073-1080, 2005
Synthesis of cathode material LiNi1-yCoyO2 by a simplified combustion method
The optimum conditions for synthesizing LiNi1-y Co (y) O-2 (y=0.1, 0.3 and 0.5) by a simplified combustion method, in which the preheating step is omitted, and the electrochemical properties of these materials were investigated. The optimum condition for synthesizing LiNi0.9Co0.1O2 by the simplified combustion method is calcination at 800 degrees C for 12 h in air in 3.6 mole ratio of urea to nitrate. The LiNi0.9Co0.1O2 synthesized under these conditions shows the smallest R-factor{(I (006)+I (102))/I (101)} and the largest I (003)/I (104), indicating better hexagonal ordering and less cation mixing, respectively. The LiNi0.7Co0.3O2 synthesized at 800 degrees C for 12 h in air in 3.6 mole ratio of urea to nitrate has the largest first discharge capacity 156.2 mA h g(-1) at 0.5C and shows relatively good cycling performance. This sample shows better hexagonal ordering and less cation mixing than the other samples. The particle size of the LiNi0.7Co0.3O2 is relatively small and its particles are spherical with uniform particle size.
Keywords:a simplified combustion method;cation mixing;cycling performance;first discharge capacity;hexagonal ordering;LiNi1-yCoyO2;optimum synthesizing conditions