Measurement of Knudsen and Effective Ordinary Diffusion Coefficients in Solid Oxide Fuel Cell Anodes Fabricated by Atmospheric Plasma Spraying Using Powder, Suspension, and Solution Precursor Feedstocks

Abstract

Ni and yttria-stabilized zirconia electrode layers were fabricated by atmospheric plasma spraying using powder, suspension, and solution precursor feedstocks. Permeability measurements were used to evaluate the Knudsen diffusion coefficients for N2. It was demonstrated that the forced flow behavior for a second gas, e.g. Ar, may be determined based on the microstructural parameters obtained using N2. Graham's diffusion cell was used to obtain effective ordinary diffusion coefficients for the H2/N2 system. The values obtained for the three plasma sprayed coatings did not differ significantly. Further work is required to satisfactorily separate the diffusion coefficients for the coatings from the measured results on the support and coating combinations.