POROUS-ELECTRODE MODELING OF THE MOLTEN-CARBONATE FUEL-CELL ELECTRODES

Porous-electrode modeling of molten-carbonate fuel-cell (MCFC) electrodes has been critically reviewed. Comparisons of the existing MCFC electrode models indicate that the modeling is still not sufficient to predict electrode performance over the entire range of gas compositions. A complete and accurate set of polarization data has been used to provide a solid basis for critically reconsidering the agglomerate model as applied to MCFC electrodes. The steady-state polarization of the anode can be fitted satisfactorily over the entire range of fuel-gas compositions by the dry-agglomerate model. The steady-state polarization of the cathode cannot be fitted equally well by the film-agglomerate model, which appears to indicate that the reaction mechanisms used are not representative for the entire range of oxidant compositions. Incorporation of the slow homogeneous oxide-CO2 recombination reaction or of various chemical equilibria involving peroxide and superoxide does not improve the fit.