Effect of reduction temperature on the electrochemical properties of a Ni/YSZ anode-supported solid oxide fuel cell

The influence of reduction temperature on the anodic microstructure and electrochemical properties of a typical nickel/yttria-stabilized zirconia anode-supported solid oxide fuel cell (SOFC) has been investigated in a range of temperatures from 550 degrees C to 750 degrees C. The cell reduced at 650 degrees C yields the largest power output (P-max = 0.56 W cm(-2) at 850 degrees C) and the lowest area specific resistance (ASR = 0.5 Omega cm(2) at 850 degrees C). Electrochemical impedance spectrum (EIS) analysis shows that the cell reduced at 650 degrees C exhibits the lowest polarization resistance (R-p) of 0.72 Omega cm2, which is in good agreement with the results from i-V curves. Nickel agglomeration is observed in the anode for the cells reduced at 550 degrees C and 750 degrees C while a homogeneous anodic microstructure is inspected for the cell reduced at 650 degrees C, suggesting reduction process has a vital effect on the anodic microstructure of the cell before aging. (C) 2010 Elsevier B.V. All rights reserved