Process for making a coated oxide material wherein said process comprises the following steps: (a) providing a particulate material selected from lithiated nickel-cobalt aluminum oxides, lithium cobalt oxide, lithiated cobalt-manganese oxides and lithiated layered nickel-cobalt- manganese oxides, (b) treating said particulate material with an aqueous medium, (c) removing said aqueous medium, (d) drying said treated particulate material, (e) treating said particulate material from step (d) with a metal amide or alkyl metal compound, (f) treating the material obtained in step (e) with moisture or an oxidizing agent, and, optionally, repeating the sequence of steps (e) and (f).