Flow channel design in a proton exchange membrane fuel cell: From 2D to 3D

Flow channel design has attracted more and more attention with the evolution of fuel cell technology. Compared with conventional 2D flow channel, 3D flow channel has been proved to improve the performance of proton exchange membrane fuel cell with great enhancement of reactant transport in many researches. In this paper, flow fields of parallel 2D, simplified 3D and 3D with inclination are presented to study the transport and distribution characteristics of reactant and water inside a fuel cell, and efficiency evaluation criterion is proposed to evaluate the superiority of the flow channel design. It is found that 3D flow fields are superior compared with parallel 2D flow channel, with improved capacity of mass transfer, uniform water distribution and advanced water removal ability. The performance improvements of both 3D flow channel designs become significant at elevated current density, with the output voltage increasing to 4.4% at 1.6 A cm^?2 and up to 10% at 2 A cm^?2. Compared with 3D flow channel with inclination, simplified 3D flow channel shows smaller pressure drop, and it has better performance than that of 2D flow channel. Considering both the performance and flow resistance, simplified 3D flow channel performs the best with high efficiency and easy-processing, thus it is the future direction of flow design.