A Comparison of Physical Properties and Fuel Cell Performance of Nafion and Zirconium Phosphate/Nafion Composite Membranes

摘要

The physio-chemical properties of Nafion 115 and a composite Nafion115/Zirconium Phosphate (25wt%) membranes are compared. The composite membranetakes up more water than Nafion at the same water activity. However, the protonconductivity of the composite membrane is slightly less than that for Nafion115. Small angle X-ray scattering shows the hydrophilic phase domains in thecomposite membrane are spaced further apart than in Nafion 115, and thecomposite membrane shows less restructuring with water uptake. Despite thelower proton conductivity of the composite membranes they display better fuelcell performance than Nafion 115 when the fuel cell is operatedunder-humidified. It is suggested that the composite membrane has a greaterrigidity that accounts for its improved fuel cell performance.