Study on counter-flow mass transfer characteristics and performance optimization of commercial large-scale proton exchange membrane fuel cells

Insufficient reaction during the counter-flow process of large-scale proton exchange membrane fuel cells significantly impacts their performance and durability, and small-scale fuel cells of the kind usually studied in the laboratory do not reflect counter-flow characteristics of large-scale fuel cells accurately. Therefore, we designed a commercial large-scale flow field with 305 cm2 of active area for use in fuel cells. And a novel three-dimensional multiphase model has been developed for the calculation of internal current density, water content, and carbon corrosion in fuel cells. The effectiveness of the model in predicting the spatial current density of large-scale fuel cells was also verified through experiments. We elucidated its counter-flow mass transfer characteristics, validating our conclusions with machine learning. The results found that a higher cathode stoichiometric ratio reduces the reaction hotspot area of the fuel cell, reducing its performance, but optimizing the flow field improves this problem. Our new flow field design improves fuel cell secondary distribution under counter-flow intake, reduces pressure drop by 21%, and increases net power by 8.1%. It optimizes physical and chemical processes inside the fuel cell, reduces carbon corrosion rate, and achieves a balance between durability and performance.