The electrochemical hydrogen discharge characteristics of pure Pd and Pd-Ni-Rh alloy hydride electrodes, activated by a superimposed electrodeposited film of Pd/Pt-black, were investigated as a negative electrode for nickel oxide-metal hydride battery. The Pd/Pt-black superposed catalysts brought about high discharge rate characteristics of the electrodes. The best discharge characteristics were obtained for Pd-7.5 at % Ph and/or Pd-2.5 at % Ni-7.5 at % Ph alloy hydrides, the electrode surfaces of which were activated first with about 1-2mgcm(-2) of Pd-black and then almost the same amount of Pt-black.