| abstract |
The present invention relates to a positive electrode active material and to a lithium secondary battery including same. Provided is a positive electrode active material represented by Chemical Formula 1 below, wherein the I003/I104 ratio is at least 1.6, the R-factor value represented by Mathematical Formula 1 is 0.40 to 0.44, and the c-axis lattice constant (c) and a-axis lattice constant (a) satisfy 3(a)+5.555 ≤ (c) ≤ 3(a)+5.580. [Mathematical Formula 1] R-factor = (I102 + I006) / (I101) I003, I006, I101, I102, and I104 are the intensities of the diffraction peaks of the (003), (006), (101), (102), and (104) planes obtained by x-ray diffraction analysis using CuK á radiation; [Chemical Formula 1] Li á [(Ni x Co y ) 1-β A β ]O z (where 0.95 ≤ α ≤ 1.1, 0.75 ≤ x ≤ 0.95, 0.03 ≤ y ≤ 0.25, 0 < β ≤ 0.2, and 1.9 ≤ z ≤ 2.1, A is a dopant metal element, and the average oxidation number N of A satisfies 3.05 ≤ N ≤ 3.35. |