High-Performance Fuel Cell Operable at 120 °C Using Polyphenlyene Ionomer Membranes with Improved Interfacial Compatibility
Zhi Long, Kenji Miyatake
Abstract
While the performance and durability of proton exchange membrane fuel cells (PEMFCs) have been considerably improved over the last decade, high-temperature operation (above 100 °C) is still an issue. We designed a sulfonated polyphenylene containing tetrafluorophenylene groups (SPP-QP-f) for high-temperature and low-humidity operation of PEMFCs. Compared to state-of-the-art perfluorinated PEMs and the previous polyphenylene ionomer membrane with no fluorine-containing groups, the SPP-QP-f membrane exhibited superior proton conductivity under all testing conditions (80–120 °C, 20–95% RH). Because of the improved interfacial compatibility with the catalyst layers, the SPP-QP-f membrane induced high cathode catalytic activity. These attractive properties of the SPP-QP-f membrane resulted in high fuel cell performance (390 mW cm–2 maximum power density) at 120 °C and 30% RH. The durability was confirmed under accelerated degradation conditions (100 °C, 30% RH) for 1000 h.