Patent ID: 7700238

Claim:
A cathode active material for a lithium secondary battery, comprising a mixture of a lithium/manganese cathode oxide represented by Formula I and a lithium/nickel/cobalt/manganese oxide represented by Formula II: Li 1+x Mn 2−y M y O 4 (I) Li 1+z Ni 0.4 Mn 0.4 CO 0.2 O 2 (II) wherein, M is a metal having an oxidation number of 2 to 3; 0≦x≦0.2; 0<y≦0.2; 0≦z≦0.1; Wherein, the mixture of the lithium/manganese spinel oxide of Formula I and the lithium/nickel/cobalt/manganese composite oxide of Formula II is in the ratio of 30:70 to 70:30 by weight.