Effects of Operation Modes on High Temperature PEM Fuel Cell Stack Degradation

This study focuses on investigating the performance change of a high temperature proton exchange membrane fuel cell (HT-PEMFCs) stack at different operation modes. A HT-PEMFC stack consisting of 30 single cells was tested both at constant load (0.4Acm-2) and dynamic load (0.05Acm-2- 0.4Acm-2) conditions at a temperature of 160 ℃ and hydrogen as anode fuel. Besides, the effect of impurities on the stack was also investigated by feeding a methanol reformate mixture to the stack anode as fuel for both constant and dynamic operation. The results reveal that the stack performance was stable after 120h of both constant and dynamic operation with hydrogen, while the stack performance decreased greatly when the stack was fed with dry reformate on the anode. Significant degradation rates of 94.4 µV h-1for constant operation, while the degradation was 200 times higher in dynamic operation with reformate gas.