Alkaline storage battery

A process for preparing nickel oxide powder for use in an alkaline storage battery which comprises a positive electrode comprising said nickel oxide powder as the main active material, a negative electrode, a separator and an alkaline electrolyte,

• wherein the nickel oxide powder is prepared by a process comprising:
• (a) first synthesizing active material particles comprising a nickel oxide powder containing at least one element selected from the group consisting of manganese, aluminum, and chromium as a solid solution, and thereafter
• (b) coating a high-conductivity cobalt oxyhydroxide on the surface of the synthesized active material particles by a method comprising the steps of
• (i) applying a positive electrode additive comprising mainly divalent cobalt oxide to the surface and/or the vicinity of the surface of the active material particles by means of mechanical kneading or reaction-deposition,
• (ii) further adding a powder or an aqueous solution of at least one compound selected from the hydroxides of sodium, potassium and lithium to the particles resulting from step (i), and
• (iii) subjecting the resulting active material particles to an oxidation treatment in an oxidizing atmosphere at a temperature not lower than 80° C. and not higher than 120° C.