Enhancing PEMFC performance through dome-like variable cross-section channels: A study on mass transfer and power density optimization

The structural optimization of channel embedded in bipolar plate is of great significance for improving the mass transfer and power density of proton exchange membrane fuel cell (PEMFC). In this paper, inspired by the dome-like architecture, a novel variable cross-section channel (CN-17) combining protrusions and conventional parallel channel (CPC) is proposed to enhance the performance of PEMFC. By changing the number of branch channels, a series of novel channels (DVCCs) are also designed, and the detailed performance study is conducted by a three-dimensional (3D) computational fluid dynamics model verified by the experiment data. Python code is used for calculating the rib area ratio and conducting statistical analysis of current density. It is found that CN-17 demonstrates an 8.31 % increase in maximum current density and a 7.36 % increase in maximum power density compared to CPC. It is also found that DVCCs accelerate the flow of reactive gas, promote the oxygen to enter the catalyst layer (CL), and uniform distribution of oxygen and current density at the GDL/CL interface. Furthermore, as the number of branch channels increases, the performance of PEMFC improves. The DVCC with 19 branch channels (CN-19) exhibits the best performance.