A triazole-based polymer electrolyte membrane for fuel cells operated in a wide temperature range (25-150 °C) with little humidification

The development of polymer electrolyte membrane (PEM) fuel cells that can be operated over a wide temperature range without the need for humidification is highly desirable for vehicle applications to overcome the problems associated with CO poisoning and water management. Here we report a novel PEM based on 1H-1,2,4-triazole grafted polysiloxane doped with phosphoric acid and reinforced with porous expanded-polytetrafluoroethylene (ePTFE) film. Both bulk resistances and interfacial polarization resistances of the fuel cells based on this membrane were determined using impedance spectroscopy. Results indicate that the proton conductivities of the PEM have little dependence on operation temperature while the PEM fuel cells demonstrated good performance under very low humidity in a wide temperature range (from room temperature to more than 100 °C). The triazole-based new PEM may dramatically simplify the fuel-cell systems, offering great potential for mobile applications.