Dynamic Mechanical Fatigue Behavior of Polymer Electrolyte Membranes for Fuel Cell Electric Vehicles Using a Gas Pressure-Loaded Blister

Abstract

This study reports on an innovative press-loaded blister hybrid system equipped with gas-chromatography (PBS-GC) that is designed to evaluate the mechanical fatigue of two representative types of commercial Nafion membranes under relevant PEMFC operating conditions (e.g., simultaneously controlling temperature and humidity). The influences of various applied pressures (50 kPa, 100 kPa, etc.) and blistering gas types (hydrogen, oxygen, etc.) on the mechanical resistance loss are systematically investigated. The results evidently indicate that hydrogen gas is a more effective blistering gas for inducing dynamic mechanical losses of PEM. The changes in proton conductivity are also measured before and after hydrogen gas pressure-loaded blistering. After performing the mechanical aging test, a decrease in proton conductivity was confirmed, which was also interpreted using small angle X-ray scattering (SAXS) analysis. Finally, an accelerated dynamic mechanical aging test is performed using the homemade PBS-GC system, where the hydrogen permeability rate increases significantly when the membrane is pressure-loaded blistering for 10 min, suggesting notable mechanical fatigue of the PEM. In summary, this PBS-GC system developed in-house clearly demonstrates its capability of screening and characterizing various membrane candidates in a relatively short period of time (<1.5 h at 50 kPa versus 200 h).