High-Performance Fuel Cell Operable at 120 °C Using Polyphenlyene Ionomer Membranes with Improved Interfacial...

Area of Science:

• Materials Science
• Electrochemistry
• Chemical Engineering

Background:

• Proton exchange membrane fuel cells (PEMFCs) require stable membranes for efficient operation.
• Current membranes face challenges with performance and durability at high temperatures (>100 °C) and low humidity.

Purpose of the Study:

• To design and evaluate a novel sulfonated polyphenylene ionomer membrane (SPP-QP-f) for high-temperature and low-humidity PEMFC applications.
• To assess the proton conductivity, interfacial compatibility, and fuel cell performance of the SPP-QP-f membrane.

Main Methods:

• Synthesis of a sulfonated polyphenylene ionomer membrane with tetrafluorophenylene groups (SPP-QP-f).
• Proton conductivity measurements under various temperature (80-120 °C) and relative humidity (20-95% RH) conditions.
• Fabrication and testing of PEMFCs using the SPP-QP-f membrane, including performance and durability assessments.

Main Results:

• The SPP-QP-f membrane demonstrated superior proton conductivity compared to state-of-the-art perfluorinated membranes and non-fluorinated polyphenylene membranes.
• Enhanced interfacial compatibility between the SPP-QP-f membrane and catalyst layers led to high cathode catalytic activity.
• The fuel cell equipped with SPP-QP-f achieved a maximum power density of 390 mW cm⁻² at 120 °C and 30% RH.
• The membrane exhibited excellent durability, maintaining performance under accelerated degradation conditions (100 °C, 30% RH) for 1000 hours.

Conclusions:

• The SPP-QP-f membrane is a promising candidate for high-temperature and low-humidity PEMFC operation.
• Its superior conductivity, catalytic activity, and durability address key limitations in current fuel cell technology.