Degradation of anode supported SOFCs as a function of temperature and current load

The degradation behavior of anode supported solid oxide fuel cells (SOFCs) was investigated as a function of operating temperature and current density. Degradation rates were defined and shown to be mainly dependent on the cell polarization. The combination of a detailed evaluation of electrochemical properties by impedance spectroscopy, in particular, and post-test microscopy revealed that cathode degradation was the dominant contribution to degradation at higher current densities and lower temperatures. The anode was found to contribute more to degradation at higher temperatures. Generally, the degradation rates obtained were lower at higher operating temperatures, even at higher current densities. A degradation rate as low as 2%/1000 h was observed at 1.7 A/cm(2) and 950 degrees C over an operating period of 1500 h. (C) 2006 The Electrochemical Society.