9. A method for producing a transition metal composite oxide,
the method comprises the following steps:
manufacturing a 1 st metal salt aqueous solution containing nickel, manganese and cobalt;
manufacturing an aqueous solution of a 2 nd metal salt containing nickel, manganese and cobalt;
mixing an alkaline aqueous solution and an aqueous ammonia solution in a reactor, adjusting the concentration of the alkaline aqueous solution according to the nickel concentration of the 1 st metal salt aqueous solution, and adjusting the pH value in the reaction solution to 11.8 to 12.3; and
supplying a 1 st mixed metal salt aqueous solution mixing the 1 st metal salt aqueous solution and the 2 nd metal salt aqueous solution, ammonia, and an alkaline aqueous solution into the reactor,
and a mixing ratio of the 1 st metal salt aqueous solution and the 2 nd metal salt aqueous solution in the 1 st mixed metal salt aqueous solution is 0 v% or more and 100 v% or less.
in the reaction solution
pH
11.8 to 12.3