| 초록 |
High temperature operation of PEMFC is considered to be essential in order to minimize anode catalyst poisoning and improve heat utilization and reaction rate, and potentially simplify fuel cell water management. However, it is still not practical because of poor ionic conductivity of commercial ionomers at low humidity above 100 oC. We, therefore, prepared a thin blend membrane of commercial Nafion resin with polyvinylidene fluoride (PVdF) in the presence of solid ionic conductor such as zirconium phosphate and cesium hydrogen sulfate. Polymer blend miscibility was characterized by X-ray diffraction and thermal analysis. AC impedance spectroscopy was used to determine proton conductivity at different blend ratio and filler content. 25 cm2 unit cells were assembled using different ionomer membranes. It was found that hydrogen crossover current of blend membrane ( less than 50 μm) was much lower than that of Nafion 117 (~180 ㎛). Composite membrane showed stable cell performance over wide temperature range upto 130 oC.
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