Some Implications of Porous Electrode Models for Cathode Reaction Mechanisms in Molten Carbonate Fuel Cells

The application of a flooded porous-agglomerate model to in situ oxidized and lithiated NiO cathodes in molten carbonate fuel cells is briefly reviewed. Attention is paid to the effects of various transport phenomena on the observed gas partial pressure dependence of the porous electrode kinetics. A plausible mechanism for the electrode kinetics is proposed which, when used with the porous electrode model, can explain several observed features of porous cathode behavior. This analysis also predicts that the partial pressure dependence of the electrode kinetics on a smooth NiO surface can differ strikingly from that on porous electrodes.