| abstract |
(57) [Abstract] [Purpose] Provided are a lithium composite oxide which, when used as a positive electrode active material of a lithium secondary battery, provides high energy density with excellent discharge capacity and discharge retention rate, a method for producing the same, and a lithium secondary battery. To do. [Structure] General formula (I): Li x Ni 1-y Me y O 2 (I) (Me is a transition metal element other than Ni, 0 <x <1.1, 0 In the lithium composite oxide represented by ≦ y <0.6, the hexagonal layered compound having a lithium content of 90% or more in 3a sites by Rietveld analysis by X-ray diffraction (space group R- 3m), the lithium composite oxide having a purity of 90% or more, and a method for producing the same. A lithium secondary battery containing a lithium composite oxide A lithium secondary battery using a positive electrode plate using a positive electrode active material. |