Ni-Al alloy as alternative cathode for molten carbonate fuel cells

The in situ oxidation of Ni-5at.%Al and Ni-15at.%Al alloys in Li+K carbonat e melt were investigated by measuring open-circuit potential and electroche mical impedance spectroscopy under an O-2 + CO2 gas mixture in the ratio 90 :10 at a total pressure of 1 atm at 650 degreesC. In situ oxidation process es of Ni-Al alloys demonstrate three stages. The period of the oxidation pr ocess depends on the aluminum content in the alloy. The final product has p robably a multilayer structure. Where the inner part is compact (probably a lso multilayer in nature) and the outer part (solution side) is porous. Ni- 5at.% Al electrode exhibited excellent stability during one-week; immersion in the carbonate melt. Extension of cathode lifetime in molten carbonate f uel cells (MCFC) appears possible if the Ni cathode is modified by the addi tion of small concentration of aluminum. (C) 2001 Elsevier Science B.V. All rights reserved.