CPC H01M 4/525 (2013.01) [H01M 4/366 (2013.01); H01M 4/485 (2013.01); H01M 10/052 (2013.01); H01M 2004/028 (2013.01)] | 11 Claims |
1. A positive electrode active material comprising:
a nickel-based lithium composite metal oxide having a Ni content of 80 atm % or greater among transition metals except lithium, wherein the nickel-based lithium composite metal oxide is in a form of a single particle or pseudo-single particle; and
a coating layer positioned on a surface of the nickel-based lithium composite metal oxide, wherein the coating layer includes cobalt,
wherein the positive electrode active material satisfies Equation 1 below:
![]() wherein, X (mol %) is a number of moles of Co in the coating layer based on 100 moles of the nickel-based lithium composite metal oxide, Y (μm) is an average particle diameter of nodules of the nickel-based lithium composite metal oxide, and Z (μm) is D50 of the positive electrode active material, wherein Z is from 5 μm to 12 μm, and
wherein the nickel-based lithium composite metal oxide is represented by Formula 2 below:
![]() wherein, M1 is Mn, Al, or a combination thereof, M2 is one or more selected from the group consisting of W, Y, Ba, Ca, Ti, Mg, Ta, and Nb, and 0.8≤a≤1.2, 0.8≤b<1, 0<c<0.2, 0<d<0.2, and 0≤e≤0.1.
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