Reinforcement of proton-exchange membrane fuel cell performance through a novel flow field design with auxiliary channels and a hole array

A novel flow field was designed by deploying auxiliary channels inside the partially hollow ribs and drilling a series of arrayed holes on the auxiliary channels. This novel design rationally utilizes the ribs of the current collector and improves the volumetric efficiency of the parallel channels, leading to improved cell performance and homogeneity of current distribution. A three-dimensional, two-phase flow model was developed to analyze the influence of a variety of parameters on the oxygen and water saturation profiles, cell performance, and current uniformity. It was found that the combination of auxiliary channels and hole array provides an extra pathway for reactant transport and water removal. A reasonable optimization of the flow field geometry, for example, the hole size, the area ratio of arrayed holes and auxiliary channels, nonuniform distribution of arrayed holes, could further improve the cell performance and current uniformity at an extremely low pressure drop.