Synthesis And Characteristics Of Lini0.85co0.15o2 Cathode Materials By Particulate Sol-Gel Method For Lithium Ion Batteries

A particulate sol-gel (PSG) method has been successfully used to prepare LiNi0.85CO0.15O2 cathode materials, utilizing the reaction of LiOH-H2O with Ni(CH3COO)(2)-4H(2)O and Co(CH3COO)(2)-4H(2)O in water-ethanol system. The thermal history of the as-prepared xerogel was established by differential thermal analysis and thermogravimetric analysis. Powder X-ray diffraction confirmed the formation of layered alpha-NaFeO2 structure at temperature of 700 degrees C under flowing oxygen. Scanning electron microscope exhibited that the crystalline powder prepared by PSG method had relatively smaller particle size with narrow distribution than the one prepared by solid state reaction. The first discharge capacity of the material by PSG method was 196.4 mAh/g, and the 10th discharge capacity was 189.1 mAh/g at the current density of 18 mA/g between 3.0 and 4.3 V. Its cycling reversibility was observed to be much better than that by solid state reaction, which had 187.3 mAh/g of the first discharge capacity and 167.1 mAh/g of the 10th discharge capacity.