JPH0559546B

PURPOSE:To increase the utilization and the productivity of active material by forming a thin layer of beta-cobalt hydroxide on a particle mainly comprising nickel hydroxide having a specific surface area of 60 m /g or more and a cristallinity of 14 or below. CONSTITUTION:A thin layer of beta-cobalt hydroxide is formed on a particle mainly comprising nickel hydroxide having a specific surface area of 60 m /g or more and a cristallinity of 14 or below. By forming a thin layer of beta-cobalt hydroxide on a particle having a suitable range of eutectic structure of nickel hydroxide with cobalt hydroxide and cadmium hydroxide and using as active material of a plate, the expansion of the plate is eliminated and a positive plate having high energy density is formed. By forming solid solution of nickel hydroxide with cobalt and cadmium, the formation of nickel oxyhydroxide (gamma-NiOOH) having low density is prevented, and the expansion of the plate is eliminated.