METHOD FOR PRODUCING LITHIUM TRANSITION METAL OXIDE

摘要

Disclosed is a novel method for producing a lithium transition metal oxide, which is capable of increasing the crystallite size, while suppressing oxygen defects. Specifically disclosed is a method for producing a lithium transition metal oxide, which comprises a step of mixing starting materials, a firing step, and a heat treatment step, and which is characterized in that the starting materials are fired in an atmosphere having an oxygen partial pressure of from 0.015 MPa to 0.15 MPa at a temperature not less than 850°C, and then the resulting material is heat-treated in an atmosphere having an oxygen partial pressure of not less than 0.03 MPa at a temperature that is the primary oxygen release temperature ± 50°C. Since the method is capable of suppressing oxygen defects while increasing the crystallite size, the strain is reduced and the lithium transition metal oxide has a strong skeleton. Consequently, when the lithium transition metal oxide is used as a positive electrode active material for a lithium secondary battery, the lithium secondary battery is able to have adequate output characteristics and adequate high-temperature cycle life characteristics at the same time.