Carbon corrosion induced fuel cell accelerated degradation warning: From mechanism to diagnosis

The degradation rate of fuel cell performance changes from linear to nonlinear, which plays a role in the poor durability of fuel cells. Little research has been reported on the mechanism and diagnostic methods for the accelerated degradation of commercial fuel cells. An early warning method of fuel cell accelerated degradation based on the high-potential holding test is studied in the present paper. The difference in decay rate between the electrochemical surface area and activation resistance are used to provide early warning of fuel cell failure. In addition, a 1200 h accelerated stress test was used to validate the mechanism of accelerated performance decay. Scanning electron microscopy observations show that carbon corrosion makes the structure more fragile in the region of linear degradation. When the fragile catalyst layer can no longer withstand the packing force, structural collapse and electrolyte filling can result in a sudden decrease in performance. A three-stage degradation mechanism is proposed for analyzing the sudden decrease in performance in a proton exchange membrane fuel cell.