Abstract: A method for producing a metal composite hydroxide, which includes a first crystallization process of obtaining first metal composite hydroxide particles by supplying a first raw material aqueous solution containing a metal element and an ammonium ion donor to a reaction tank, adjusting a pH of a reaction aqueous solution in the reaction tank, and performing a crystallization reaction and a second crystallization process of forming a tungsten-concentrated layer on a surface of the first metal composite hydroxide particles and obtaining second metal composite hydroxide particles by supplying a second raw material aqueous solution containing a metal element and a more amount of tungsten than the first raw material aqueous solution and an ammonium ion donor to a reaction aqueous solution containing the first metal composite hydroxide particles, adjusting a pH of the reaction aqueous solution, and performing a crystallization reaction, and the like.

Abstract: A transition metal-containing composite hydroxide comprises secondary particles having: a center portion of fine primary particles; and an outer-shell portion having a high-density layer of plate-shaped primary particles formed outside the center portion, a low-density layer of the fine primary particles formed outside the high-density layer, and an outer-shell layer of the plate-shaped primary particles formed outside the low-density layer. The composite hydroxide is obtained by a method comprising a nucleation step in an oxidizing atmosphere and a particle growth step, the particle growth step comprising: a first stage of maintaining the oxidizing atmosphere; a second stage of switching to and maintaining a non-oxidizing atmosphere; a third stage of switching again to and maintaining the oxidizing atmosphere; and a fourth stage of switching again to and maintaining the non-oxidizing atmosphere.

Abstract: A transition metal-containing composite hydroxide comprises secondary particles having: a center portion of fine primary particles; and an outer-shell portion having a high-density layer of plate-shaped primary particles formed outside the center portion, a low-density layer of the fine primary particles formed outside the high-density layer, and an outer-shell layer of the plate-shaped primary particles formed outside the low-density layer. The composite hydroxide is obtained by a method comprising a nucleation step in an oxidizing atmosphere and a particle growth step, the particle growth step comprising: a first stage of maintaining the oxidizing atmosphere; a second stage of switching to and maintaining a non-oxidizing atmosphere; a third stage of switching again to and maintaining the oxidizing atmosphere; and a fourth stage of switching again to and maintaining the non-oxidizing atmosphere.