Patent ID: 7601462

Claim:
A cathode active material for a lithium rechargeable battery containing a cathode, an anode, and an electrolytic solution, wherein the cathode active material comprises 0.5% by weight or less of carbonate ion (CO 3 2− ) plus bicarbonate ion (HCO 3 − ) and 0.1% by weight or less of hydroxyl ion (OH − ), wherein the cathode active material is a compound selected from the group consisting of Li x Mn 1−y M′ y A 2 , Li x Mn 2 O 4−z X z , Li x Mn 2−y M′ y A 4 , Li x Co 1−y M′ y A 2 , Li x Co 1−y M′ y O 2−z X z , Li x Ni 1−y−z Co y M′ z O 2−α X α , and Li x Ni 1−y−z Mn y M′ z O 2−α X α , where 0.95≦x≦1.1, 0≦y≦0.5, 0≦z≦0.5, 0<α≦2, M′ is at least one element selected from the group consisting of Al, Mn, Cr, Fe, Mg, Sr, V, and a rare earth element, A is selected from the group consisting of O, F, S and P, and X is selected from the group consisting of F, S and P.