Nickel composite hydroxide and process for producing same

Abstract

A nickel composite hydroxide containing reduced amounts of sulfate radicals and chlorine as impurities. The nickel composite hydroxide is represented by Ni1-x-yCoxAly(OH)2+α(0.05≤x≤0.01≤y≤0.2, x+y<0.4, and 0≤α<0.5), and includes spherical secondary particles formed by aggregation of plurality of plate-shaped primary particles, secondary particles have an average particle diameter of 3-20 μm, sulfate radical content of 1.0 mass % or less, chlorine content of 0.5 mass % or less, and carbonate radical content of 1.0-2.5 mass %. The nickel composite hydroxide is obtained by a process including a crystallization step in which crystallization is performed in reaction solution obtained by adding alkali solution to aqueous solution containing mixed aqueous solution containing nickel and cobalt, ammonium ion supplier, and aluminum source. The alkali solution is mixed aqueous solution of alkali metal hydroxide and carbonate, and ratio of carbonate to alkali metal hydroxide in mixed aqueous solution represented by [C032−]/[OH−]=0.002 or more but 0.050 or less.

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