Crack-Engineered Microporous Layer for Mitigating Cathode Flooding in Polymer Electrolyte Fuel Cells
Young Je Park, Won Young Choi, Seong Hyun Park, Hyunguk Choi, Seo Won Choi, Jy-Young Jyoung, Eunsook Lee, Jae‐Il Park, Min Jae Ko, Kang Taek Lee, Chi‐Young Jung
Abstract
Crack engineering within the microporous layer (MPL) of the gas diffusion layer (GDL) has emerged as a promising strategy to alleviate severe cathode flooding in polymer electrolyte fuel cells (PEFCs), especially under high current operation. Here, we report a connected-crack MPL architecture that forms continuous liquid water highways, extending from the catalyst layer (CL) to the GDL backing layer, effectively separating the liquid/gas transport. Three-dimensional reconstruction using X-ray computed tomography reveals that the microengineered cracks significantly reduce flooding at the CL-MPL interface by providing efficient drainage. Compared to the noncrack GDL, the connected-crack GDL (C-GDL) exhibits 20% higher peak power density of 1.23 W cm –2 . Pore-scale simulations further validate the antiflooding capabilities of C-GDL, showing a 25-fold enhancement in water removal. This crack-engineered GDL thus offers an efficient and scalable route to water management challenges, enabling robust and high-performance PEFCs suitable for heavy-duty vehicle electrification.