Experimental and numerical modeling study of the electrical resistance of gas diffusion layer-less polymer electrolyte membrane fuel cells

The gas diffusion layer (GDL)-less fuel cell composed of a corrugated-mesh shows low flooding performance even in the high current density region, since the gases are supplied more uniformly to the catalyst layer (CL) compared with the conventional fuel cells that utilize GDLs. On the other hand, the internal electrical resistance of the GDL-less fuel cell is higher than that of the conventional fuel cell, because the corrugated-mesh and the underlying microporous layer (MPL) have a low contact area with point contacts. This can greatly increase the resistance at the interface between the corrugated-mesh and MPL as well as that between the MPL and CL, compared to the conventional fuel cell where GDL can make a good contact with the MPL. In this study, the conductivities and the contact resistances of each material in the GDL-less fuel cell were measured under various mechanical compression pressures, and a coupled mechanical-electric-electrochemical model was developed to investigate the effect of electrical resistance on the fuel cell performance. We found that our model can simulate the GDL-less fuel cell well and the electric resistance contributes significantly to the polarization performance in the GDL-less fuel cell.