Patent ID: 8496855

Claim:
A cathode active material comprising a spinel lithium manganese composite oxide represented by Formula 1 below: Li x Mn 2-y-z Ni y M z O 4-n X n , <Formula 1> wherein: 0.025≦x≦1.1, 0.3≦y<0.5, 0<z≦0.15, 0<n<1, M is a metal selected from the group consisting of gallium (Ga), zirconium (Zr), niobium (Nb), molybdenum (Mo), tungsten (W), barium (Ba), strontium (Sr), lanthanum (La), cerium (Ce), silver (Ag), tantalum (Ta), hafnium (Hf), ruthenium (Ru), bismuth (Bi), antimony (Sb), tin (Sn), and arsenic (As), and X is a halogen element selected from the group consisting of fluorine (F), chloride (Cl), bromine (Br), and iodine (I).