Abstract
The B-site cation-excess K2NiF4-type structure oxide, Pr2Ni0.75Cu0.25Ga0.05O4+delta (PNCG) is investigated as a cathode for intermediate-temperature solid oxide fuel cells (IT-SOFCs). XRD result shows that PNCG cathode is chemically compatible with the electrolyte Gd0.1Ce0.9O2-delta (GDC) at 900 degrees C for 5 h. The PNCG material exhibits a semiconductor to metal transition around 425 degrees C. The thermal expansion coefficient (TEC) of the PNCG sample is 12.72 x 10(-6) K-1 between 30 and 850 degrees C in air. The polarization resistance (R-p) of PNCG cathode on GDC electrolyte is 0.105, 0.197 and 0.300 Omega cm(2) at 800, 750, 700 degrees C, respectively. A maximum power density of 371 mW cm(-2) is obtained at 800 degrees C for single-cell with 300 mu m thick GDC electrolyte and PNCG cathode. The results of this study demonstrate that PNCG can be a promising cathode material for IT-SOFCs. (C) 2015 Elsevier Ltd and Techna Group S.r.l. All rights reserved.