Investigation of quality and performance of Cu impregnated NiO-GDC as anode for IT-SOFCs

Abstract

Ni-based cermet as solid oxide fuel cell (SOFC) anodes suffers from redox instability issues when operated with hydrocarbon as fuel. This paper investigates the Cu impregnated NiO-GDC as anode electrode for intermediate temperature (IT-) SOFCs using structural and morphological characterizations along with the dc conductivity measurement in hydrogen and biogas. The bulk of Cu impregnated NiO-GDC composite and its reduced (heat-treated in H2 at 850 °C for 3 h) counterpart samples were analyzed after exposing different layers within the bulk of samples to different characterization tools. Cu particles are observed at all three layers investigated, suggesting the distribution of Cu in the bulk of composite anode samples. Also, the porous morphology of fabricated samples was decreased with increased depth into the sample. The BSE and EDS characterization show that Cu and Ni particles are distributed within the bulk of the reduced composite anode sample while the Cu particles are largely located in the middle layer. Relatively higher (lower) dc conductivity (activation energy) was observed for the reduced composite anode sample in biogas than that of hydrogen and were 9.9 × 10−3 (0.81 eV) and 4.5 × 10−3 S/cm (0.88 eV), respectively.