Inclusion of Gas Phase Diffusion and Electrode Resistance Effects in Models of Molten Carbonate Fuel Cell Electrodes

This work constitutes a relatively compact mathematical scheme for including the effects of restricted gas phase diffusion and finite electronic conductivity of the electrode matrix on porous electrode performance. Preliminary results show physically expected behavior. For fixed electrode thickness at constant current density, total overpotential reaches a minimum at an intermediate value of the electrolyte volume fraction. At lesser volume fractions, ohmic losses increase; at greater volume fractions gas diffusion losses rise. For fixed electrolyte volume fraction at constant current density, similar behavior is observed for variations of the electrode thickness. The model may thus be used to optimize electrode performance as a function of thickness and electrolyte content.