Enhancing the dynamic performance of proton exchange membrane fuel cells through two-phase flow experimental investigation

Efficient water transfer is crucial for enhancing the rapid response and durability of proton exchange membrane fuel cells (PEMFCs). In this paper, ex situ observation experiments and in situ dynamic performance tests of fuel cells are conducted and correlated with each other by two-phase flow pressure drop. The experimental results show that slug flow within the cathode gas flow channels (GFCs) is unfavorable to mass transfer and results in loading failure under high current densities, as identified in Design Failure Mode and Ef-fects Analysis (DFMEA). However, slug flow in GFCs of PEMFCs can be converted into film flow by reducing the hydraulic diameter of GFC, increasing the air stoichiometry ratio, and extending the loading resistance time to an appropriate value. This facilitates a successful and efficient load change process of PEMFCs under high current densities. This study provides a methodology, combines ex situ observation and in situ evaluations, identifying potential risks, which can shed light on improving the dynamic performance and devel-opment process of PEMFCs.