Nickel-containing composite hydroxide and production process therefor, positive-electrode active material for a nonaqueous-electrolyte secondary battery and production process therefor, and nonaqueous-electrolyte secondary battery

Abstract

Provided is a nickel-containing composite hydroxide that is a precursor of a positive-electrode active material with which a nonaqueous-electrolyte secondary battery having a low irreversible capacity and a high energy density can be configured. An aqueous alkaline aqueous solution and a complexing agent are added to an mixed aqueous solution including at least nickel and cobalt to regulate the pH (measured at a reference liquid temperature of 25° C.) of this mixed aqueous solution to 11.0 to 13.0, the ammonium concentration to 4 to 15 g/L, and the reaction temperature to 20° C. to 45° C. Using stirring blades having an inclination angle of 20° to 60° with respect to a horizontal plane, the mixture is stirred to conduct a crystallization reaction under such conditions that when the nickel-containing composite hydroxide to be obtained is roasted in air at 800° C. for 2 hours, the roasted composite hydroxide has a BET value of 12 to 50 m/g. Thus a nickel-containing composite hydroxide expressed by NiCoAlM(OH)(where, 0<x≤0.20, 0<y≤0.15, 0≤t≤0.10, 0≤α 0.50, and M is one or more kind of element selected from among Mg, Ca, Ba, Nb, Mo, V, Ti, Zr and Y), or the general formula: NiCoMnM(OH)(where 0<x≤0.50, 0<z≤0.50, x+z≤0.70, 0≤t≤0.10, 0≤α≤0.50, and M is one or more kind of element selected from among Mg, Ca, Ba, Nb, Mo, V, Ti, Zr and Y) is obtained.