LiCoO2 cathode materials with uniform grain size were prepared using fine grained Co3O4 particles. The effects of the molar ratio of Li/Co and the sintering temperature on the microstructure and the electric properties were studied. The grain size of LiCoO2 increases with an increase in the Li/Co molar ratio and with the sintering temperature. The grain size distribution also depended on both the Li/Co molar ratio and the sintering temperature. The electrical conductivity took a maximum at a certain value of the Li/Co molar ratio, and this variation was related to the presence of the secondary phase at the grain boundary. In addition, the effect of the preparation conditions on the reversible Li-intercalation/deintercalation reaction was also briefly examined. The maximum value in the reversible capacity, 130 mAh/g, was obtained, using the optimum preparation condition (Li/Co molar ratio of 1.03 and sintering temperature of 850 degrees C).