Reinforced Polyphenylene Ionomer Membranes Exhibiting High Fuel Cell Performance and Mechanical Durability

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Developing advanced membranes is crucial for efficient and durable fuel cell technology.
• Existing reinforced aromatic ionomer membranes face limitations in performance under low humidity conditions and mechanical robustness.

Purpose of the Study:

• To prepare and characterize novel reinforced membranes (SPP-QP-PE) for enhanced fuel cell applications.
• To evaluate the proton conductivity, mechanical properties, and fuel cell performance of the new membranes.

Main Methods:

• Fabrication of sulfonated polyphenylene-polyethylene (SPP-QP-PE) membranes using a push coating method.
• Characterization of membrane properties including proton conductivity, ion exchange capacity, and mechanical toughness (elongation at break).
• Testing fuel cell performance under various conditions, including low relative humidity (30% RH) at 80 °C, and assessing durability through wet-dry cycles.

Main Results:

• Dense, uniform, transparent, and thin SPP-QP-PE membranes were successfully prepared.
• The SPP-QP-PE membranes exhibited very high proton conductivity, enabling high fuel cell performance even at 80 °C and 30% relative humidity.
• Mechanical toughness was significantly improved, with a 7.1-fold increase in elongation at break compared to bare SPP-QP, demonstrating durability over 3850 wet-dry cycles.

Conclusions:

• The reinforced SPP-QP-PE membranes offer a superior combination of proton conductivity, mechanical toughness, and gas impermeability.
• These membranes show excellent performance and durability in fuel cells, particularly under challenging low-humidity operating conditions.
• The developed membranes represent a significant advancement for practical fuel cell applications.