Positive electrode active material for lithium secondary battery and lithium secondary battery comprising same

Embodiments of the present disclosure provide a positive electrode active material for a lithium secondary battery. A positive electrode active material for a lithium secondary battery according to an exemplary embodiment includes lithium metal phosphorus oxide particles having a grain size in a (020) plane direction of 150 nm to 450 nm as measured by X-ray diffraction (XRD) analysis. 本公开的实施例提供一种锂二次电池用正极活性物质。根据示例性实施例的锂二次电池用正极活性物质包括：锂金属磷氧化物颗粒，其通过X射线衍射(X-ray diffraction，XRD)分析测量的向(020)面方向的晶粒尺寸为150nm至450nm。