Abstract: Molten carbonate fuel cells having anodes, cathodes, and matrices of specific characteristics result in improved cell performance as electrolyte is lost due to evaporation, reaction, etc. The anode has a mean pore diameter less than that of the cathode, a porosity sufficient to contain enough electrolyte to provide for the electrolyte lost, and a ratio of maximum pore diameter at 90% electrolyte fill to maximum pore diameter at 10% electrolyte fill of less than about three. The cathode has a larger mean pore size than that of the anode, a thickness greater than about 0.050 cm, a porosity greater than about 78%, and pore-size distribution such that, when the anode electrolyte content changes from 90% to 10% fill, the cathode electrolyte content changes from about 40% to about 25% fill. In addition, the cathode has about 20% of its pore volumes in pores less than about 0.5.mu. resulting in a surface area of the cathode above about 1 m.sup.2 /g.