The present invention provides a nickel hydrogen storage cell including negative electrodes and positive electrodes in which the electrochemically active material containing a majority of nickel hydroxide is deposited electrochemically, and is located in the pores of a three-dimensional porous conductive support, wherein the ratio of the capacity of said positive electrodes over the capacity of said negative electrodes lies in the range 1.02 to 1.10, said active material of said positive electrodes being covered in cobalt hydroxide after impregnation.