Diagnostic study of sulfur poisoning in solid oxide fuel cell anodes based on total harmonic distortion analysis

Solid oxide fuel cells (SOFCs) have attracted considerable attention owing to their high efficiency and fuel flexibility. However, the consequent reduction in service life and an increase in failure mechanisms, such as degradation caused by sulfur impurities in the fuel, have hindered the development of SOFCs on an industrial scale. Electrochemical impedance spectroscopy (EIS) can be used to obtain a rough overview of the fuel cell performance but requires specialized data processing for unambiguous identification. In contrast, the total harmonic distortion analysis (THDA) approach provides additional higher-order response signals and offers considerable potential in diagnosing sulfur poisoning of SOFC anodes. Consequently, we explored the test parameters for THDA applications in diagnosing sulfur poisoning in SOFC anodes. The results showed that the THD values significantly increased after sulfur poisoning of the anode in the 0.01–30 Hz range. Furthermore, long-term monitoring at 1, 10, and 20 Hz confirmed the reliability of THD for diagnosing the mechanism of sulfur poisoning in SOFC anodes. This work provides a diagnostic basis for SOFC sulfur poisoning and is expected to promote research on advanced diagnostic techniques and sulfur poisoning mechanisms.