In this study, the effect of the catalyst layer (CL) and the cathode microporous layer (MPL-C) porosity on the performance and water content of the polymer electrolyte membrane (PEMFC) is investigated. Monodispersed polystyrene (PS) particles are used as pore formers to fabricate CL and MPL with different degrees of porosities. Specially developed miniature Single single cells for neutron imaging experiments with an active area of 8 cm² are implemented with the in-house made catalyst coated membranes and cathode MPLs. The cathode MPLs were coated on a 29 BA substrate, and commercial 29 BC SGL were used on the anode side as the gas diffusion layers (GDLs). Neutron tomography is used to investigate the water content and distribution inside the operating fuel cells. The quantitative analysis of the water thickness under the channels of the cells at RH=120% and I=1 A^.cm^-2 is shown in figure 1.a.

It is observed that the water content has decreased for cell 3 ( CL: 10 wt.% PS, MPL: 10 Vol.% PS) compared to cell 2 ( CL: 5wt.% PS, MPL:10 Vol.% PS) and cell 1 (Reference CL and MPL (without PS)). Polarisation curves for these three cells are provided in Figure 1.b. At current densities higher than I=1 A^.cm^-2 performance has increased for cell 2 and 3 where the components had higher porosity degree compared to the cell 1 which has a reference CL and reference cathode MPL. The results show that addition of macropores could facilitate the transport of gases and the removal of water at the mass transport regions. This method is currently under investigation by the authors. Further results will be provided in the presentation.