Degradation mechanism and prediction method development of the "collapse point" in proton exchange membrane fuel cell

This study investigates the "collapse point" of proton exchange membrane fuel cell (PEMFC) performance degradation through a 3000 h durability test under dynamic operating conditions. Quantitative analysis of polarization data identified mass transfer polarization deterioration as the primary cause, with high current density concentration impedance changes enabling early collapse point prediction. Results demonstrate that high current density (2000 mA cm⁻²) triggers an earlier collapse point (2200 h). Post-test characterization revealed GDL degradation, evidenced by increased Gurley values (anode: 32 to 52; cathode: 2 to 32) and reduced cathode carbon paper strength. Catalyst layer analysis showed mesopore and macropore collapse, while micropores increased due to ionomer migration and carbon corrosion. These structural changes, coupled with water management deterioration, accelerated MEA mass transfer efficiency decay, leading to irreversible performance loss. This work provides a novel approach for early collapse point prediction and mechanistic insights into PEMFC durability under dynamic conditions.