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J. Fleig, J. Maier:
"The polarization of mixed conducting SOFC cathodes: Effects of surface reaction coefficient, ionic conductivity and geometry";
Journal of the European Ceramic Society, 24 (2004), 1343 - 1347.

Multi-dimensional finite element simulations of current distributions in mixed ionic and electronic conducting cathodes (MIEC) are presented for the case that the cathodic oxygen incorporation into an electrolyte takes place through the bulk of the electrode. The effects of the ionic conductivity and the surface reaction coefficient on the overall process are analyzed. Depending on these material parameters different parts of the cathode are involved in the oxide ion transport to the electrolyte (from a very small region close to the three phase boundary for a fast surface reaction up to the entire cathode for a very slow surface reaction). The calculations also reveal which combinations of ionic conductivity and surface reaction coefficient are appropriate to achieve acceptable polarization resistances. The influence of the particle size is discussed and interpolation formulae are given to estimate the cathodic polarization in porous MIECs.

http://dx.doi.org/10.1016/S0955-2219(03)00561-2