Film Thickness and Distribution of Electrolyte in Porous Fuel Cell Components

The DLVO theory of liquid film stability is used to estimate the thickness of electrolyte films that may be present in molten carbonate fuel cell cathodes. Our result is ≈ 30Å, which is 2 orders of magnitude thinner than the values postulated in thin film models of cathode performance. We also examine carefully the thermodynamic basis of an equation governing the equilibrium of electrolyte among the different porous components of the fuel cell. We show that the validity of this equation is more general than previously recognized in that its derivation does not depend on the assumption of cylindrical or spherical pore geometry.