A bi-functional micro-porous layer with composite carbon black for PEM fuel cells

Micro-porous layers (MPLs) prepared with different carbon materials were investigated. By the analysis of morphology, wettability and pore structure, the characteristics of each gas diffusion layer (GDL) were compared. A high efficiency bi-functional MPL with composite carbon black consisting of 20 wt.% Black Pearls 2000 carbon and 80 wt.% Acetylene Black carbon is proposed to enhance the transportation of both reactant gases and liquid water. Furthermore, a novel GDL with a gradient in porosity formed by adding MPLs with different carbon loadings on the catalyst layer side and on the flow field side is suggested for improved liquid water removal.