Process for producing lithium-containing composite oxide for positive electrode for lithium secondary battery

Abstract

A process to produce a positive electrode active material for a lithium secondary battery, having a large volume capacity density and high safety, uniform coating properties, charge and discharge cyclic durability and low temperature characteristics even at a high charge voltage is disclosed. The positive electrode active material is a lithium-containing composite oxide represented by the formula LiNMOF, wherein N is at least one element selected from the group consisting of Co, Mn and Ni, M is at least one element selected from the group consisting of Sn, Zn, Al, alkaline earth metal elements, and transition metal elements other than the N element, O.9≦p≦l.1, 0.97≦x≦l.00, 0≦y≦0.03, 1.9≦z≦2.1, x+y=1 and 0≦a≦0.02. The N element source powder having an average particle size of from 2 to 20 μm, is impregnated with the M element salt aqueous solution, and the prepared dry powder comprising the N element, M element, a lithium source and optionally a fluorine source is fired at from 700 to 1 ,050° C. in an oxygen-containing atmosphere.