Structural, Microstructural and Electrochemical Characterization of Ni-YSZ Anodes Fabricated from Pechini-Derived Composite Powders

Abstract

The most widely used solid oxide fuel cell (SOFC) anodes, nickel-yttria stabilized zirconia (NiO-YSZ) composites, are generally fabricated by co-sintering of NiO and YSZ powders. In this study, to achieve a longer triple phase boundary length, these composites were fabricated from powders synthesized via an ethylene glycol-based Pechini method. Polymeric precursors of NiO and YSZ were prepared separately and then mixed, dried and calcined 600, 700 and 800°C for 4 hours, in air. NiO and YSZ crystals with average sizes of 26 and 7 nm, respectively were achieved upon calcination at 600 °C. With increasing heat treatment temperature, both the crystal and agglomerate sizes increased, which, in turn, an increased the anode polarization resistances. Electrochemical activities comparable to or higher than anode prepared by co-sintering of powder mixtures were achieved in the anodes prepared by sintering of the composite powders.