Patent ID: 7510805

Claim:
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 Î¼m to 1 Î¼m so aggregated as to form voids therebetween, wherein the sizes of the plurality of secondary particles in a long length direction are 5 Î¼m to 14 Î¼m, wherein the plurality of secondary particles comprises columnar secondary particles and planar secondary particles, wherein the sizes of the columnar secondary particles in a short length direction are 1 Î¼m to 4 Î¼m, and the thicknesses of the planar secondary particles are 0.1 Î¼m to 0.3 Î¼m, and wherein the lithium metal composite oxide particles have an elemental composition represented by the general formula: Li x CoO 2 (0<xâ‰¦1.2) or Li x Co 1-y M y O 2 (0<xâ‰¦1.2, 0<yâ‰¦0.2), where M is an element selected from the group consisting of Ni, Mn, Ti, Fe, Al, Si, Y, Zr, Nb, and Mo.