Degradation of Anode Supported SOFCs as a Function of Temperature and Current Load

Abstract

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%∕1000h2%∕1000h was observed at 1.7A∕cm21.7A∕cm2 and 950°C950°C over an operating period of 1500h1500h .