4. A process for producing the Li-Ni composite oxide particles as claimed in any one of claims 1 to 3, comprising the steps of:
producing Ni-Co hydroxide particles by mixing an aqueous solution of a sulfuric acid salt of each metal element, an ammonia aqueous solution and a sodium hydroxide aqueous solution such that an ammonia concentration in a reaction vessel is controlled to not more than 1.4 mol/L, and a ratio of the ammonia concentration in the reaction vessel to a surplus hydroxyl group concentration in the reaction vessel is controlled to not less than 6,
mixing lithium compound particles and the Ni-Co hydroxide particles, and
calcining the resulting mixture, the mixing ratio of the particles being controlled such that the molar ratio of Li/(Ni+Co+M1+M2) is 1.00 to 1.10.
ammonia
concentration
1.4 mol/L
mol/L