A High-Performance Membrane Electrode Assembly for PEM Fuel Cell with Poly (ether sulfone) Nanofibers As Effective Membrane Reinforcements

Abstract

Direct membrane deposition is introduced as a novel polymer electrolyte membrane fabrication method. This method is extended to fabricate a high-performance membrane electrode assembly for polymer electrolyte membrane fuel cell with poly (arylene ether sulfone) nanofibers as effective membrane reinforcements. The nanofibers are directly electrospun onto gas diffusion electrodes. By spray-coating ionomer dispersion into the pore space of nanofiber mats, composite membranes of 15 μm thickness are fabricated. The introduction of the electrically and ionically insulating nanofibers do not hamper the cell performance. At 80 ℃ and 75% relative humidity, the power density of the fuel cell employing direct membrane deposition, 2.85 W/cm 2 , is about 1.36 times higher than that of the reference fuel cell (2.09 W/cm 2 ) with Nafion ® 211. Its cell resistance (28 mΩ·cm 2 ) is much lower than that of the membrane electrode assembly fabricated by the catalyst coating membrane method (46 mΩ·cm 2 ). The performance differences between two fabrication methods are systematically analyzed by electrochemical impedance spectroscopy. Even though the thickness of the polymer electrolyte (15 μm) is much lower than that of Nafion ® 211, it shows much higher internal short resistance because of the existence of nanofibers.

Key findings

• ▸The power density of the fuel cell employing direct membrane deposition is about 1.36 times higher than that of the reference fuel cell with Nafion 211.
• ▸The cell resistance of the membrane electrode assembly fabricated by direct membrane deposition is much lower than that of the catalyst coating membrane method.
• ▸The introduction of electrically and ionically insulating nanofibers does not hamper the cell performance.

Keywords

Identifiers

DOI

10.1149/ma2019-02/34/1526

Journal

ECS Meeting Abstracts

Year

2019