Influence of Some Inorganic Impurities on the Electrochemical Properties and Microstructure of Ni-CGO Anode in Artificial Woodgas Atmosphere

Abstract

The influence of inorganic impurities on the SOFC anode behavior is one of the key issues that have to be solved for developing a SOFC system fuelled with gasified biomass. In this paper the results of initial electrochemical tests of Ni-CGO anodes under load in N2/H2/H2O gas mixtures and in the presence of KCl salt as an inorganic impurity are presented. The Ni-CGO anodes were studied in different conditions: in low concentration potassium chloride vapors (approx. 6 ppm) similar to potassium concentrations in woodgas, very high concentration KCl vapors (approx. 3500 ppm) and after impregnation with KCl solution. Significant dependence of the anode electrochemical behavior on the salt concentration in the fuel stream was observed. Condensation of salt droplets on the anode surface and inside the porous anode takes place.