MWCNTs reinforced Nafion® membrane prepared by a novel solution-cast method for PEMFC

An improved solution-cast method is presented to prepare multi-wall carbon nanotubes (MWCNTs)/Nafion® reinforced membrane with different MWCNTs content (from 1 to 4 wt.%). MWCNTs were oxidized by H2O2 and sodium hydroxide (NaOH) was added into the MWCNTs/Nafion®/N,N-dimethylacetamide (DMAC) solution. The long-term stability of the resulting dispersions was much better than the unmodified dispersions. The as-cast membrane was observed by scanning electron microscope (SEM). The MWCNTs were uniformly dispersed in the Nafion® resin. The tensile strength and the elongation at break were greatly improved for the reinforced membranes compared to the recast Nafion® membranes (54 and 27%, respectively). The fuel cell performance of the reinforced membranes with different MWCNTs contents was also tested at 80 °C under fully humidified conditions. By comparing the mechanical properties, proton conductivity and fuel cell performance of the reinforced membranes, we concluded that the content of MWCNTs in the reinforced membranes should not exceed 3 wt.%. The MWCNTs/Nafion® reinforced membrane with 3 wt.% MWCNTs content showed the best mechanical characteristics and excellent fuel cell performance.