Performance and durability of sulfonated poly(arylene ether sulfone) membrane-based membrane electrode assemblies fabricated by decal method for polymer electrolyte fuel cells

The combination of Nafion-based electrode and hydrocarbon-based membrane is an ideal choice for researcher in making membrane electrode assemblies (MEAs) containing alternative membranes replacing Nafion for polymer electrolyte fuel cells (PEFCs) due to their intrinsic properties. This advantage, however, is limited by the incompatibility between the membrane and the electrode, which results in MEA performance decay and low durability. In this study, we propose fabrication of MEA made of sulfonated poly(aryl ether sulfone) (SPES) membrane and Nafion-based electrode using the decal process. The decal process was found to be very effective in forming good interface between SPES and the electrode, although hot pressing temperature was relatively low (140 °C). The SPES-MEA revealed comparable performance to conventional Nafion-MEA at high humidity, indicating negligible contact resistance in the SPES–electrode interface. Open circuit voltage (OCV) drop of SPES-MEA during OCV holding at 40% RH for 200 h was from 0.975 V to 0.8 V, implying slight chemical degradation of SPES leading to increased hydrogen crossover in the membrane. However, it seems that the interfacial damage between the SPES and Nafion electrode in the SPES-MEA is negligible during the OCV test. Nonetheless, further investigation is necessary to confirm the long-term stability of the SPES-MEA fabricated by the decal process under harsher conditions such as dry/wet and freeze/thaw cycling.