Effects of the porous structures in the porous flow field type separators on fuel cell performances

Abstract

Effects of separators' several different porous flow field structures consist of spherical alloy powders on the pressure loss characteristics and the single-cell performances were investigated for the purpose of achieving the porous structure which can satisfy the conflicting properties of lower pressure loss and higher power density. Although the separator with partitions in the porous flow field, aimed at improving the uniform oxygen supply ability, indicated higher power density, its pressure loss increased compared to the basic porous flow field type separator. The separator with evenly spaced linear grooves in the porous flow field lowered its pressure loss, however, the maximum power density decreased. On the other hand, the newly designed separator with finely dispersed open space networks in the porous flow field demonstrated lower pressure loss and higher power density; i.e., 50% lower pressure loss and 40% higher power density were obtained compared to the basic porous flow field type separator.