Patent ID: 8840815

Claim:
A composite cathode active material comprising: a layered lithium manganese oxide represented by Chemical Formula 1 shown below; and a lithium-containing metal oxide represented by Chemical Formula 3 shown below, a [Li 2 MnO 3 ].(1 −a )[LiM 1 O 2 ] Chemical Formula 1 wherein, 0<a<1 and M 1 is one or more metals selected from the group consisting of manganese (Mn), nickel (Ni), cobalt (Co), iron (Fe), chromium (Cr), vanadium (V), copper (Cu), zinc (Zn), titanium (Ti), aluminum (Al), magnesium (Mg), and boron (B); and Li(Ni x Co y Al z )O 2 Chemical Formula 3 wherein, x, y, and z are each independently selected from a range of 0<x, y, z<1, and x+y+z=1.