Process of producing lithium metal composite oxide particles

A process of producing lithium metal composite oxide particles which electrochemically intercalate and deintercalate lithium ions, the lithium metal composite oxide particles comprising a plurality of secondary particles in an elongated shape each comprised of a plurality of primary particles with an average particle size of 0.1 μm to 1 μm so aggregated as to form voids therebetween, wherein the plurality of secondary particles have an average size in a long length direction of 5 μm to 15 μm, and wherein each of the plurality of secondary particles has a columnar shape or a planar shape, said process comprising:

• (1) mixing a cobalt-salt containing aqueous solution, a surfactant and unsubstituted or substituted urea to prepare a mixed solution;
• (2) heating the mixed solution or adding an alkali component to the mixed solution to raise the pH value of the mixed solution, thereby depositing a cobalt-containing compound;
• (3) mixing a lithium-containing material with the deposited cobalt-containing compound or a cobalt-containing oxide obtained by heat-treating the deposited cobalt-containing compound to prepare a mixture;
• and
• (4) calcining the mixture in air or oxygen.