| abstract |
(57) Abstract: A composite particle is formed by forming a cobalt hydroxide layer on the surface of nickel hydroxide particles containing manganese as a solid solution element, and then oxidizing the cobalt hydroxide layer. Then, the composite particles are mixed with an aqueous alkaline solution containing hypochlorite or hypobromite so as to be converted to the cobalt oxyhydroxide layer. According to the method of the present invention, it is possible to produce a positive electrode active material having extremely good conductivity on the particle surface. Further, by using the positive electrode active material produced by the method of the present invention, a paste-type nickel electrode having an extremely high active material utilization rate can be produced. Further, by using the positive electrode active material produced by the method of the present invention as a positive electrode active material of a sealed nickel-zinc storage battery having a zinc electrode as a negative electrode, A highly reliable sealed battery with little generation of hydrogen gas at the negative electrode can be manufactured. |