Preparation and characterization of LiMn(1.8)Co(0.2)O(3.95)F(0.05) by the combustion-assisted soft route

LiMn(1.8)Co(0.2)O(3.95)F(0.05) powder was prepared by heating the ignited LiMn(1.8)Co(0.2)O(3.95)F(0.05) precursor gel using lithium acetate, magnesium acetate, cobalt acetate, lithium fluoride, citric acid and glycol as raw materials. The influence of the calcination temperature on the structural and electrochemical properties of LiMn(1.8)Co(0.2)O(3.95)F(0.05) was investigated by X-ray diffraction, scanning electron microscopy, and galvanostatic charge-discharge experiments. The powders prepared under different conditions are of good crystallinity. The discharge capacity of LiMn(1.8)Co(0.2)O(3.95)F(0.05) powder increased from 92 mAh/g to 105 mAh/g as the calcination temperature increased from 750 deg C to 850 deg C. The capacity of LiMn(1.8)Co(0.2)O(3.95)F(0.05) heated at 750 deg C, 800 deg C, 850 deg C for 4 hours remained at 95.2%, 97%, 94.2%, respectively, after being cycled 20 times, suggesting that the multiple substitution of Co and F for Mn and 0 results in a good cycling behavior.