Mass transfer enhancement and cell performance promotion of PEM electrolyzer by biomimetic lung-inspired flow field

Hydrogen energy represents a pivotal component in global energy transition strategies, with proton exchange membrane water electrolysis emerging as a key technology for sustainable hydrogen production. The optimization of flow fields critically governs the operational efficiency of proton exchange membrane electrolyzer cell (PEMEC). This study introduces a biomimetic lung-inspired flow field (LIFF) design to address challenges in mass transfer, temperature and liquid saturation uniformity index within PEMEC. A comparative analysis is conducted among three flow configurations: conventional single serpentine flow field (SSFF), interdigitated flow field (IFF), and the proposed LIFF. A multiphysics computational fluid dynamics model is employed to simulate coupled electrochemical and transport phenomena. Results demonstrate that the LIFF’s pressure-driven flow mechanism significantly enhances reactant distribution, particularly under channel ribs. At 2.3 V operation, the LIFF achieves an 8.04 times improvement in axial mass transfer coefficient compared to SSFF and 39.14% superiority over IFF. The liquid saturation uniformity index of LIFF increased by 22.04% and 4.83% compared to SSFF and IFF, respectively. The temperature uniformity index of LIFF shows improvements of 69.98% and 35.22% over SSFF and IFF. Parametric analysis reveals that increased operational temperatures improve electrochemical polarization, while higher flow rates enhance mass transport efficiency. Strategic reduction of inlet water temperature combined with increased flow rates enhances liquid saturation uniformity index and improves temperature uniformity index.