  A molten carbonate fuel cell (MCFC) is an electro-chemical energy conversion
technology that runs on natural gas and employs a molten salt electrolyte. In
order to keep the electrolyte in this state, the cell must be kept at a
temperature above 500 C, eliminating the need for precious metals as the
catalyst. There has been only a limited amount of research on modelling the
transport processes inside this device, mainly due to its restricted
applicability for mobile applications.
  In this work, three one-dimensional models of a MCFC cathode are presented
based on different types of diffusion and convection. Comparisons between
models are performed so as to assess their validity. Regarding ion transport,
it is shown that there exists a limiting case for ion migration across the
cathode that depends on the conductivity for the liquid potential. Finally, an
optimization of the diffusivity across the cathode is carried out in an attempt
to increase the cell performance and its longevity.
