Patent ID: 7192672

Claim:
A process for producing a lithium-cobalt composite oxide for a positive electrode of a lithium secondary battery, said lithium-cobalt composite oxide being represented by the formula Li p Co x M y O z F a (wherein M is a transition metal element other than Co, or an alkaline earth metal element, 0.9≦p≦1.1, 0.980≦x≦1.000, 0≦y≦0.02, 1.9≦z≦2.1, x+y=1, and 0≦a≦0.02), which comprises firing a mixture comprising a cobalt source and a lithium source in an oxygen-containing atmosphere, characterized in that as the cobalt source, a mixture is used which comprises cobalt hydroxide in the form of substantially spherical secondary particles with an average particle size of from 8 to 20 μm formed by agglomeration of primary particles and tricobalt tetroxide in the form of secondary particles with an average particle size of from 2 to 10 μm formed by agglomeration of primary particles, in a cobalt atomic ratio of from 5:1 to 1:5, and the firing is carried out at from 700 to 1,050° C.