Spongy Raney Nickel Hydrogen Electrodes for Alkaline Fuel Cells

Spongy Raney nickel catalysts for use as hydrogen electrodes of fuel cells were prepared by a new method. In this method molten a luminum was sprayed on both sides of a spongy plate of nickel as substrate with an acetylene-oxygen flame gun. Then, the spongy nickel electrodes were activated by alloying at a given temperature of from 550 ~ to 750 ~ and leaching the a luminum from the alloy in alkaline solution. This type of catalyst showed good thermal and electrical con-ductivity and also mechanical strength by itself. Its polarization resistance was very low, and the characteristics of the electrodes improved with increase in the temperature of heat-treatment for alloying. The finding that activity depended on the alloying temperature was consistent with observations by scanning electron microscope on the surface textures of cat-a]ysts alloyed at different emperatures. Raney nickel catalyst is said to be suitable for hydrogen electrodes of alkaline H2-O2 fuel cells because of its low cost and high activity. The characteristics of polarization for electrodes of Raney nickel electrocatalyst depend mainly on the structure of the electrodes. For this reason, many electrodes have been designed to obtain high per