Multi-Factor Optimization of Nickel Foam Flow Fields: Insights into Structural and Surface Modifications for High-Performance PEMFCs.

The performance of proton exchange membrane fuel cells (PEMFC) can be significantly influenced by the physical properties of the flow field design. In this study, nickel foam with varying physical parameters-compression (porosity), pore size, hydrophobicity, and anti-corrosion surface treatments-are systematically investigated to evaluate their influence on PEMFC electrochemical performance, water management, and corrosion resistance. The results reveal that moderate compression (67%), corresponding to a porosity of 85%, offers the optimal balance between electrical conductivity and mass transport, achieving the highest power density of 0.918 W cm and a conductivity formation factor 23% higher than uncompressed samples. Excessive compression may cause ligament fractures and occluded cavities, reducing water management capabilities, and increasing parasitic loss and mass transport resistance. Furthermore, smaller pore sizes result in increased concentration losses, primarily due to higher fluid resistance, complex diffusion pathways, and water retention. Hydrophobic surface modification via polytetrafluoroethylene increased water removal efficiency but at the expense of ohmic losses, with excessive loading hindering water transfer and blocking pores. Among various anti-corrosion coatings, graphene emerged as the optimal choice, providing superior hydrophobicity, corrosion resistance, and electrical conductivity. These findings offer valuable insights for enhancing PEMFC performance and durability.