Positive electrode active material for secondary battery, and secondary battery including the same

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

• a core comprising a lithium composite metal oxide of Formula 1 below;
• a first surface-treated layer positioned on a surface of the core, and including a lithium oxide of Formula 2 below;
• and
• a second surface-treated layer positioned on the core or the first surface-treated layer, and including a lithium compound of Formula 3 below,
• LiaNi1-x-yCoxM1yM3zM2wO2 [Formula 1]
• (in Formula 1, M1 is at least any one selected from the group consisting of Al and Mn, M2 is any one or at least two elements selected from the group consisting of Zr, Ti, Mg, Ta and Nb, and M3 is any one or at least two elements selected from consisting of W, Mo, and Cr, and 1.0≤a≤1.5, 0<x≤0.5, 0<y≤0.5, 0.002≤z≤0.03, 0≤w≤0.02, 0<x+y≤0.7),
• LimM4O(m+n)/2 [Formula 2]
• (in Formula 2, M4 is any one or at least two elements selected from the group consisting of W, Mo, and Cr, and 2≤m≤6, and n is an oxidation number of M4),
• LipM5qAr [Formula 3]
• (in Formula 3, M5 is any one or at least two elements selected from the group consisting of elements in Group 13 to Group 15, A is any one selected from the group consisting of O, OH, CO3, PO4, F, and SO4, and 1≤p≤10, 1≤q≤10, r=(p+s)/t where s is the absolute value of an oxidation number of M5 and t is the absolute value of an oxidation number of A).