Positive active material for non-aqueous electrolyte secondary battery and non-aqueous electroyte secondary battery comprising same

摘要

A positive active material for the non-aqueous electrolyte secondary battery comprising a lithium-nickel composite oxide represented by the compositional formula LiaNi1-b-cCobMncO2 (a ≤ 1.09, 0.05 ≤ b ≤ 0.35, 0.15 ≤ c ≤ 0.35, and 0.25 ≤ b+c ≤ 0.55). BY the X-ray diffractometry with the CuK alpha ray, the lithium-nickel composite oxide exhibits an intensity ratio R ((I012 + I006)/I101) of not greater 0.50, wherein R is the ratio of the sum of the diffraction peak intensity I012 on the 012 plane and the diffraction peak intensity I006 on the 006 plane to the diffraction peak intensity I101 on the 101 plane. The crystallinity of the positive active material of the compositional formula LiaNi1-b-cCobMncO2 can be kept high and it is possible to secure the good capacity density and cycle life performance.