Numerical investigation of tapered flow field configuration to improve mass transport and performance of proton exchange membrane fuel cell

Abstract

To increase the oxygen mass transport, water removal, and cell performance of proton exchange membrane fuel cells, tapered flow field configurations (FFCs) considering porous medium thickness (PMT) and thermal contact resistance (TCR) are proposed. In this work, the impact of the tapered FFC on the internal electrochemical process and overall cell performance is quantitatively explored using a three-dimensional multiphase fuel cell model. The tapered FFC is compared without and with account for both the PMT and the TCR between bipolar plates and gas diffusion layers. Compared to the conventional FFC, an increased ratio of the side length for the inlet to that for the outlet (LI/O) for the tapered FFC, addressing both the PMT and the TCR improves hydrogen, and oxygen delivery, water removal, and cell performance. The tapered FFC design with a LI/O of 1.2 is superior to all other tapered FFC designs in terms of uniformity of reactants, with an improvement in pressure drop by 68.74%, current density by 7.57%, and power density by 12.63%. These improvements result in an overall enhancement of cell performance.