POSITIVE ACTIVE MATERIAL FOR RECHARGEABLE LITHIUM BATTERY METHOD OF PREPARING THE SAME AND RECHARGEABLE LITHIUM BATTERY INCLUDING THE SAME

The present invention relates to a positive electrode active material for a lithium secondary battery, comprising nickel-based transition metal oxide secondary particles composed of inside and outside, wherein the inside has a dense structure with higher density than the outside, the nickel-based transition metal oxide secondary particles include a plurality of protrusion units on surfaces, and the area ratio of the protrusion units calculated by equation 1, [A_t-A_i]/A_t, based on the cross-section of the nickel-based transition metal oxide secondary particles is 25 to 30% and, more specifically, to a positive electrode active material for a lithium secondary battery with high lithium ion permeability into the particles. 내부와 외부로 구성된 니켈계 전이금속 산화물 2차 입자를 포함하고, 상기 내부는 외부보다 밀도가 높은 치밀 구조를 가지고, 상기 니켈계 전이금속 산화물 2차 입자는 표면에 다수의 돌출부를 포함하고, 상기 니켈계 전이금속 산화물 2차 입자의 단면 기준으로, 수학식 1로 계산되는 상기 돌출부가 차지하는 면적비가 25% 내지 30%인, 리튬 이차 전지용 양극 활물질을 제공한다.