Estimates for polarization losses in molten carbonate fuel cell cathodes

This paper compares the polarization losses associated with the various dif fusion-reaction-conduction processes in molten carbonate cathodes. The comp arisons are made by estimating each type of loss in terms of component elec trochemical potentials in joules/mole: this allows diffusive. charge-transf er. and ohmic losses to all be put on equal footing. For characteristic par ameter values, diffusion in both the pas and electrolyte phases and conduct ion in the electrolyte account for similar polarization losses: charge-tran sfer and conduction in the solid electrode account for significantly smalle r losses. These results tend to support and unify the previous work of nume rous investigators. Also molecular-channel interactions are found not to co ntribute significantly to the polarization loss. (C) 2001 The Electrochemic al Society.