Enhancing Proton Exchange Membrane Fuel Cell Performance With Roughened Cathode Channels and Novel Silicone Baffles

Efficient water management and reactant transport is critical for high‐performance proton exchange membrane fuel cells (PEMFCs). Herein, we present a synergistic strategy for flow field (FF) optimization by integrating mechanically textured surface roughness with flexible silicone baffles on the cathode FF to enhance reactant delivery and suppress flooding. Characterization techniques, including polarization curves, electrochemical impedance spectroscopy (EIS), equivalent circuit modeling (ECM), and distribution of relaxation times (DRT), are employed to evaluate performance. Results show that medium surface roughness (Ra ∼ 4 µm) optimally balances pressure drop and reactant diffusion, improving performance by 2.85% at 3A1C and 10.24% at 3A3C (where mAnC denotes m‐serpentine at the anode and n‐serpentine at the cathode). The integration of novel hydrophobic silicone baffles disrupts laminar flow, induces turbulence, and reduces mass transport resistance, resulting in performance enhancements ranging from 3.34% to 19.20%. ECM and DRT analyses reveal significant reductions in charge transfer and mass transport resistances, particularly above 0.8 A cm −2 . This dual‐engineered approach enhances reaction kinetics and mitigates electrode flooding, underscoring the conjoint influence of flow geometry, surface topography, and flow perturbation on PEMFC performance. This work establishes a multi‐scale optimization framework for FF design, offering a pathway toward high‐performance PEMFCs.