Analysis of the effects of the gas diffusion layer properties on the effectiveness of baffled flow channels in improving proton exchange membrane fuel cells performance

Blocking cathode flow channels is employed to improve the performance of a proton exchange membrane fuel cell (PEMFC). Since diffusion resistance toward the catalyst layer plays a key role in this scenario, this work studies the impacts of the gas diffusion layer (GDL) characteristics, including thickness, porosity, permeability, and tortuosity, on the efficacy of baffled channels in enhancing the performance of PEMFCs. A Finite Volume-based code was developed to achieve this objective. Mirroring Immersed Boundary method is utilized to introduce baffles of various shapes and heights into the flow channels. The results indicate increasing the GDL thickness and tortuosity while decreasing its porosity and permeability improves the performance of the baffled channels. For instance, the effectiveness of a baffled channel with a GDL thickness of 0.0004 (m) is 0.304% versus 0.198% in the case of 0.0002 (m). In brief, when diffusion resistance is high, baffled channels are more effective.