Revisiting Nafion membranes by introducing ammoniated polymer with norbornene to improve fuel cell performance

Nafion-based composite membranes were prepared by introducing ammoniated polymer with norbornene (APNB) into Nafion membrane (Nafion/APNB membrane). Of the prepared membranes, the Nafion/APNB-2.5% membrane possesses good dimensional stability with a maximum swelling ratio (Sr) of 8.2%. The hydrophobic domains become more and more with increasing the APNB architecture, which in turn causes the phenomenon that Nafion/APNB-10% membrane possesses the highest ion conductivity (σ, 82.4 mS cm−1) (Nafion/APNB-2.5% of 73.8 mS cm−1, Nafion/APNB-5% of 76.4 mS cm−1). This phenomenon is due to the fact that ion clusters are aggregated and thus form highly ordered water channels, so that the protons can be efficiently transported along the center of channels and possess excellent σ. The fuel cells with the Nafion/APNB-5% membrane possess the highest power density (1106.9 mW cm−2), which indicates that the Nafion/APNB membranes have good performances for fuel cells.