On the Properties of Nafion Membranes Recast from Dispersion in N-Methyl-2-Pyrrolidone

Perfluorosulfonic acid Nafion membranes are widely used as an electrolyte in electrolysis processes and in fuel cells. Changing the preparation and pretreatment conditions of Nafion membranes allows for the optimization of their properties. In this work, a Nafion-NMP membrane with a higher conductivity than the commercial Nafion (R) 212 membrane (11.5 and 8.7 mS.cm(-1) in contact with water at t = 30 degrees C) and a comparable hydrogen permeability was obtained by casting from a Nafion dispersion in N-methyl-2-pyrrolidone. Since the ion-exchange capacity and the water uptake of these membranes are similar, it can be assumed that the increase in conductivity is the result of optimizing the Nafion-NMP microstructure by improving the connectivity of the pores and channels system. This leads to a 27% increase in the capacity of the membrane electrode assembly with the Nafion-NMP membrane compared to the Nafion (R) 212 membrane. Thus, the method of obtaining a Nafion membrane has a great influence on its properties and performance of fuel cells based on them.

Automated summary

By changing the preparation and pretreatment conditions, the properties of Nafion membranes can be optimized. In this study, a Nafion-NMP membrane with higher conductivity and comparable hydrogen permeability was obtained by casting from a Nafion dispersion in N-methyl-2-pyrrolidone. The increase in conductivity is attributed to the optimization of the Nafion-NMP microstructure, which improves the connectivity of the pores and channels system. This leads to an increased capacity of the membrane electrode assembly compared to a commercial Nafion (R) 212 membrane.