POSITIVE ELECTRODE ACTIVE MATERIAL COMPRISING LITHIUM-RICH LITHIUM MANGANESE OXIDE HAVING FORMED THEREON COATING LAYER COMPRISING LITHIUM-DEFICIENT TRANSITION METAL OXIDE, AND LITHIUM SECONDARY BATTERY COMPRISING SAME

摘要

The present invention provides a positive electrode active material comprising a lithium-rich lithium manganese-based oxide,wherein the lithium-rich lithium manganese-based oxide is represented by the following chemical formula (1),        Lisub1+a/subNisubx/subCosuby/subMnsubz/subMsubv/subOsub2-b/subAsubb/sub     (1)wherein, 0a≤0.2, 0x≤0.4, 0y≤0.4, 0.5≤z≤0.9, 0≤v≤0.2, a+x+y+z+v=1, and 0≤b≤0.5;M is one or more elements selected from the group consisting of Al, Zr, Zn, Ti, Mg, Ga, In, Ru, Nb, and Sn; andA is one or more elements selected from the group consisting of P, N, F, S and Cl;wherein a coating layer containing a lithium-deficient transition metal oxide in a lithium-deficient state having a molar ratio of lithium to transition metal of less than 1 is formed on the surface of the lithium-rich lithium manganese-based oxide, andwherein the content of the coating layer is 1% to 10% by weight based on the total weight of the positive electrode active material, and a method for producing the same.