Abstract: A substituted lithium cobalt composite oxide for use as a cathode active material in a lithium ion secondary battery, which has the general formula: LixMyCo1−yO2 in which M represents at least one metallic element selected from the group consisting of Ti, Mo and; x is a numeral in the range of 0.8 to 1.2; and y is a numeral in the range of 0.001 to 0.10.

Abstract: A process for producing a lithium manganese oxide with a spinel structure for use as a cathode material of an organic electrolyte lithium ion secondary battery, which comprises: mixing at least one lithium compound selected from the group consisting of lithium hydroxide and lithium carbonate with manganese dioxide in a solvent consisting essentially of water or an aliphatic lower alcohol having from 1 to 3 carbon atoms or a mixture thereof, optionally in the presence of at least one organic acid selected from the group consisting of formic acid and acetic acid; allowing the resultant mixture to form a gel-like mixture; and drying the gel-like mixture as required; and calcining the resulting product.

Abstract: A process for producing a lithium manganese oxide which has a formula of Li.sub.x MnO.sub.2 in which x is between 0.1 and 1 and which is suitable for use as a 3 volt cathode material, which comprises mixing at least one lithium compound with at least one manganese compound at a Li/Mn atomic ratio of 0.1-1 in a solvent selected from an aliphatic lower alcohol having from 1 to 3 carbon atoms, water and a mixture of the alcohol and water, allowing the resultant mixture to form a gel-like mixture, drying the gel-like mixture as required, and calcining the resulting product in an oxidative atmosphere at a temperature of 200-350.degree. C.