Effect of compressive force on the performance of a proton exchange membrane fuel cell

Abstract

The effect of the compressive force on the performance of a proton exchange membrane fuel cell has been examined experimentally. The performance has been evaluated on two polarization regions of the cell: ohmic and mass transport. Cell voltage and current density as a function of pressure were measured under constant load and various inlet air humidity conditions. The pressure distribution on the surface of the gas diffusion layer was measured using a pressure detection film and the results show that increasing the pressure improves the performance of the cell. The improvement of the cell voltage in the ohmic region was found to be greater than that in the mass transport region, whereas for the cell current density, the mass transport region exhibited higher change. The increase in the cell specific power in the ohmic and mass transport regions, as pressure increases from 0 to 2M^Nm-2, is estimated to be 9 and 18mWcm⁻², respectively. However, the fuel cell performance in these two regions declined dramatically when excessive pressure (≥5 MNm⁻²) was applied. The mass transport region proved to be more susceptible to this sharp decline under excessive pressure than the ohmic region.