Active material for positive electrode for alkaline secondary cell and method for producing the same, and alkaline secondary cell using the active material for positive electrode and method for producing the same

Provided is a active material for positive electrode for an alkaline secondary cell, which advantageously exhibits improved overdischarge characteristics, improved utilization of the active material and an improved effect of suppressing the rise in cell internal pressure, a method for producing the same, and an alkaline secondary cell using the above active material for positive electrode, especially a nickel-hydrogen secondary cell. The above active material comprises nickel hydroxide particles each having a surface to which a cobalt oxide sticks, wherein the cobalt oxide contains 20 to 40 % by mole of cobalt(II) oxide, wherein the nickel hydroxide particles form an eutectic together with Co and Zn or/and Y, and the Co content of the eutectic is 2 % by mass or less, and the nickel hydroxide particles have a value of a half width of the peak ascribed to the (101) crystal face diffraction of 0.8°/2theta(Cu-Kalpha) or more as measured by powder X-ray diffractometry.