Using SESANS to discover the PEM fuel cell catalyst layer's structure & porosity

The anode and cathode catalyst layer of a PEM fuel cell should possess a porous structure, which influences the mass transport of the gasses towards the surface of the platinum catalyst. Furthermore, water is present in the catalyst layers, where an inappropriate structure can cause flooding within the catalyst layer. The mass transport of the gasses and flooding of the catalyst layer influence the performance and durability of the PEM fuel cell.

During our previous measurement at ISIS, we were able to do a SESANS measurement on a complete single fuel cell. The results clearly indicate that features can be measured with the SESANS on a higher length scale compared to the standard SANS. Also in literature, the SESANS has already been proven to be a good technique to analyze the bulk structures in polymer-carbon nanocomposites. For our SESANS measurement on the single fuel cell, the membrane can highly possible be excluded because no features are expected on the larger scale. However, the catalyst layers with different porosities are expected to play a role on the length scale measured by the SESANS. Therefore, it would be desired to evaluate further if the SESANS would be a novel measurement method to extract information of the PEM fuel cell catalyst layer’s structure.