Proton exchange membrane fuel cell of integrated porous bipolar plate-gas diffusion layer structure: Entire morphology simulation

The structure design and optimization of proton exchange membrane (PEM) fuel cells are crucial for achieving the ultimate power density goal to meet the commercial demand. In this study, the performance characteristics of an innovative PEM fuel cell design, integrated porous bipolar plate (BP)-gas diffusion layer (GDL) structure, were studied using a three-dimensional (3D) fuel cell model that incorporated the entire morphology of the integrated structure and was validated against experimental polarization data. In this design, the conventional GDL component (e.g., carbon paper) was eliminated and a metal foam material (pore size: 60 and 80 pores per inch (PPI); porosity: 0.9) served as both the BP/flow field and GDL. This novel design significantly increased the cell power density compared to conventional "BP + GDL" fuel cells, owing to its ability to reduce mass transfer and electron conduction resistances. Furthermore, the reduction in overall cell thickness due to GDL elimination contributed to an enhanced power density. Decreasing the pore size (e.g., from 60 to 80 PPI) was found to benefit the cell power output and uniform distributions of oxygen and current density, etc.