The polymer electrolyte membrane (PEM) fuel cell is a versatile alternative for the decarbonization of the transportation sector. However, high cost and limited durability of materials hinder widespread adoption. This thesis comprises two studies that aim to address both cost and durability of PEM fuel cells via the design of tailored gas diffusion layers (GDLs).
First, electrospinning is presented as a platform to fabricate and design tailored GDLs with pore size gradients for the improved high current performance of PEM fuel cells. Specifically, the novel graded GDL was found to reduce ohmic resistance and improve mass transport performance. Next, the durability of electrospun GDLs was investigated via an ex situ accelerated degradation procedure. The degraded GDLs exhibited reduced hydrophobicity due to loss of surface groups and reduced electrical conductivity due to carbon degradation. This thesis offers insight into designing next generation, durable GDLs with tailored structures for PEM fuel cells.