Effect of applied current density on the degradation behavior of anode-supported flat-tubular solid oxide fuel cells

The effects of applied current density on the long-term performance degradation behavior of anode-supported flat-tubular type solid oxide fuel cells (SOFCs) are studied. Durability tests on the anode-supported SOFCs are conducted galvanostatically at 800 °C as a function of applied current density (200, 450, 700 and 1000 mAcm^-2) for the duration of 1000 h. The performance degradation during the long-term test assessed by a voltage loss over time greatly increases with higher applied current density. The combined impedance spectroscopy and post-test characterization results show that the accelerated degradation at high current density is due to enhanced Ni particles coarsening in the anode, the formation of insulating phase between cathode and electrolyte, and evolution of fine particles in the cathode. Systematic degradation analysis conducted in the present study provides profound insight into the electrochemical performance decay of the anode-supported flat-tubular SOFCs.