Self-assembled network polymer electrolyte membranes for application in fuel cells at 250℃

Modern H2-based energy storage and conversion devices require a polymer electrolyte membrane (PEM) fuel cell–based integrated power system with synergistic heat integration. The key issue in integrated power systems is developing a PEM that can operate at 200–300 °C. However, currently used phosphoric-acid-based high-temperature PEM fuel cells limited stability at higher operating temperatures. Herein, we introduce a cerium hydrogen phosphate (CeHP) PEM that conducts protons above 200 °C through a self-assembled network (SAN). The SAN-CeHP-PBI reached maximum power densities of 2.4 W cm-2 and operate stably for over 7000 minute without any voltage decay at 250 ℃ under H2/O2 and anhydrous conditions. The developed fuel cell can be combined with an external hydrogen generator that uses a liquid hydrogen carrier such as N-ethylcarbazole and methanol as fuel, thus achieving a high energy efficiency. The thermal stability and fuel flexibility of these SAN-CeHP-PBI demonstrate potential for commercial applications.