Performance of proton exchange membrane fuel cells with honeycomb-like flow channel design

Abstract

A honeycomb-like flow channel was proposed and investigated for the performance of proton exchange membrane fuel cells (PEMFCs). The effects of various thicknesses and porosities of the gas diffusion layer (GDL) on the honeycomb-like flow channel were studied. Compared with parallel and serpentine flow channels, the honeycomb-like flow channel exhibited the lowest oxygen non-uniformity value of 0.59 at 0.4 V, and the pressure drop was 6.9 times lower than that of the serpentine flow channel. The current density was 8034.9 A/m2, which was 14.0% and 10.4% higher than that of the parallel and serpentine flow channels. For a porosity of 0.4, the decrease in GDL thickness from 0.58 to 0.38 mm for the honeycomb-like flow channel facilitated oxygen diffusion, and the current density increased from 7717.2 to 8034.9 A/m2; the oxygen mass fraction gradually increased at the cathode channel but decreased at the center of the honeycomb-like structure. At a thickness of 0.38 mm, the porosity increased from 0.2 to 0.6, leading to a decrease in the oxygen non-uniformity value from 0.89 to 0.42. For a porosity of 0.6, the current density was 8787 A/m2, which was 60% and 9.4% greater when compared with the porosities of 0.2 and 0.4.