Cathode active material for non-aqueous electrolyte secondary battery and its production method

Abstract

Provided are a cathode active material with high safety, with high discharge capacity even at high operating voltage, and with excellent cyclic charge and discharge properties, its production method and a non-aqueous electrolyte secondary battery containing the cathode active material. The cathode active material for a non-aqueous electrolyte secondary battery comprises a surface-modified lithium-containing composite oxide particle, wherein the particle is a lithium-containing composite oxide particle represented by the general formula LiNO(wherein N═NiML, M contains at least one element selected from Co and Mn, L is an element selected from alkaline earth metal elements, aluminum and transition metal elements other than Ni, Co and Mn, 0.9≦p≦1.1, 0.9≦x<1.1, 0.2≦y≦0.9, and 0≦z≦0.3), and a surface layer of the particle contains aluminum, said surface layer within 5 nm having an aluminum content of at least 0.8 as an atomic ratio to a total of Ni and the element M.