Method for producing lithium nickel composite oxide

The purpose of the present invention is to provide a method for producing a lithium-nickel composite oxide with which variation in crystallite size can be suppressed. A method for producing a lithium nickel composite oxide according to one embodiment of the present invention comprises: a filling step for filling a firing container (7) with a Ni-containing metal compound and a Li compound to obtain a filler (5) containing the Ni-containing metal compound and the Li compound; and a firing step in which the filler (5) filled in the firing container (7) is fired, and in which the filler (5) filled in the firing container (7) in the filling step is bisected in the height direction. The molar ratio A of Li in the filler (5a) to a metal other than Li in the upper half region and the molar ratio B of Li in the filler (5b) to a metal other than Li in the lower half region satisfy 1 lt; b/Alt; and 1.15. 本发明的目的在于，提供能够抑制微晶尺寸的偏差的锂镍复合氧化物的制造方法。本发明的一个方式的锂镍复合氧化物的制造方法包括：在烧成容器(7)中填充含Ni金属化合物及Li化合物，得到包含所述含Ni金属化合物及所述Li化合物的填充物(5)的填