A method for making an electrode for lithium secondary cells. Lithium and cobalt ions are co-precipitated in an alkaline solution in such a way that the ratio of the former to the latter is 1.05:1 or more and then, are thermally treated to give LiCoO2 powder. This ternary system compound is combined with a current collector and a binder. The electrode has an initial discharge capacity of 160 mAh/g and retains 90% of the initial capacity even after 400 times of charge/discharge cycle.