Abstract
Systematic experiments have been carried out to study the performance of the novel sodium titanate (Na.sub.2Ti.sub.3O.sub.7) nanotube/Nafion.sup.[R] composite membrane (5 wt% Na.sub.2Ti.sub.3O.sub.7) in a single direct methanol fuel cell (DMFC) at different operating temperatures, methanol concentrations, air flow rates, methanol flow rates, and cathode humidification temperatures. The experimental results showed that the composite membrane outperform pure Nafion.sup.[R] membranes with the same thickness, Nafion.sup.[R]112, under all the operating conditions. Furthermore, under some operating conditions, the new composite membranes even outperform Nafion.sup.[R]117, a much thicker membrane. These experimental results have proved that the new composite membrane is superior to pure Nafion.sup.[R] membrane in DMFCs and the addition of Na.sub.2Ti.sub.3O.sub.7 nanotubes into Nafion.sup.[R] is an effective way to improve membrane performances.
