Analysis of macro segregation in twin-roll cast aluminium strips via solidification curves

A porous NiO/yttria-stabilized zirconia (YSZ) anode substrate for zirconia-based tubular solid oxide fuel cells (SOFCs) was prepared by the gelcasting. The effect of the impregnation of SDC in the substrate was studied. Electrochemical impedance spectroscopy and I–V and I–P curves of the cells were measured. Scanning electron microscopy (SEM) was used to observe the microstructures. The results indicate that the performance of the cell can be significantly improved by incorporating the nano-structured SDC particles in the substrate. The peak power density of the cell is increased by about 60% and the area specific resistance (ASR) decreased by about 47% at 700 °C, compared with the unmodified cells. It is explained as the extended triple-phase boundary (TPB) in the anode substrate and the excellent electrocatalytic property of SDC. It is also found that the nano-scale SDC particles change a lot during the reduction of the anode substrate, and the morphology of the resultant SDC particles on the metal Ni is significantly different from that on the YSZ. After the long-term operation, the morphology of the SDC particles on the Ni changes again, but that on the YSZ keeps almost unchanged.