Lithium composite metal oxide and nonaqueous electrolyte secondary battery

A lithium composite metal oxide comprising Li, Ni and M (where, M represents one or more kinds of transition metal elements selected from the group consisting of Mn, Co and Fe), having a diffraction peak (diffraction peak A) at an angle 2θ in a range from 20° to 23° in a powder X-ray diffraction pattern of a lithium composite metal oxide which is obtained by powder X-ray diffraction measurement made in the condition that CuKα is used as a radiation source and the measurement range of the diffraction angle 20θ is in a range from 10° to 90°,

• wherein the amount (mol) of Li is 1.4 or more and 1.7 or less based on the total amount (mol) of the transition metal elements, at least one lithium composite metal oxide particle constituting the lithium composite metal oxide has both hexagonal and monoclinic crystal structures, the monoclinic crystal structure is a crystal structure belonging to the space group C2/m, and the hexagonal crystal structure is a crystal structure belonging to the space group R-3m.