POSITIVE ACTIVE MATERIAL FOR LITHIUM SECONDARY, METHOD FOR PREPARING THEREOF, AND LITHIUM SECONDARY BATTERY CONTAINING THE SAME

摘要

PURPOSE: A positive electrode active material for a lithium secondary battery is provided to improve stability and capacity of a lithium secondary battery by consisting of a nickel-based composite oxide. CONSTITUTION: A positive electrode active material for a lithium secondary battery contains a core part including a nickel-based composite oxide represented by chemical formula 1: Li_a[Ni_xCo_yMn_z]O_2, and a shell part. The nickel content of the core part is higher than the nickel content of the shell part. The core part is a needle-shape particle. In chemical formula 1, 0.8<=a<=1.2, 0.05<=x<=0.9, 0.1<=y<=0.8, 0.1<=z<=0.8, and x+y+z=1. The core part or the precursor thereof has pores and a surface-bent structure.