Positive electrode active material for lithium secondary battery and preparation method thereof

A positive electrode active material for a lithium secondary battery, the positive electrode active material comprising:

• a nickel-based lithium composite metal oxide single particle,
• wherein the single particle includes a plurality of crystal grains, and
• a metal doped in a crystal lattice of the single particle, wherein the metal doped in a crystal lattice of the single particle is one or more metals selected from the group consisting of Al, Ti, Mg, Zr, W, Y, Sr, Co, F, Si, Na, Cu, Fe, Ca, S, and B;
• and a metal compound coated on a surface of the single particle, wherein the metal compound is one or more metals selected from the group consisting of Al, Ti, Mg, Zr, W, Y, Sr, Co, F, Si, Na, Cu, Fe, Ca, S, and B,
• wherein a total content of the metal doped in the crystal lattice of the single particle and the metal in the metal compound coated on the surface thereof is 2500 ppm to 6000 ppm.