Electrochemical active material for electrode

Active electrochemical material, consists of monophase particles of hydroxide with alpha crystallographic structure containing mainly nickel. Apparent volume mass of hydroxide ≥ 1.75 g/cm. By preference nickel hydroxide contains at least one syncrystalline element chosen from cobalt and manganese and also at least one syncrystalline element chosen from aluminum, iron, yttrium, manganese and chromium. Independent claims are also included for the following: (a) a positive electrode for a secondary alkaline electrolyte battery containing such an active electrochemical material; (b) a method for the fabrication of such active electrochemical material by precipitation of a nickel salt in an alkaline and/or ammoniac solution.