Estimates for polarization losses in molten carbonate fuel cell cathodes

This paper compares the polarization losses associated with the various diffusion-reaction-conduction processes in molten carbonate cathodes. The comparisons are made by estimating each type of loss in terms of component electrochemical potentials in joules/mole: this allows diffusive. charge-transfer. and ohmic losses to all be put on equal footing. For characteristic parameter values, diffusion in both the pas and electrolyte phases and conduction in the electrolyte account for similar polarization losses: charge-transfer and conduction in the solid electrode account for significantly smaller losses. These results tend to support and unify the previous work of numerous investigators. Also molecular-channel interactions are found not to contribute significantly to the polarization loss. (C) 2001 The Electrochemical Society.