Effect of liquid water distribution in gas diffusion media with and without microporous layer on PEM fuel cell performance

To understand the effect of liquid water accumulation on the performance of proton exchange membrane (PEM) fuel cells, in situ visualization of liquid water accumulation was performed in fuel cells having gas diffusion media (GDM) with and without microporous layer (MPL) using soft X-ray radiography. The liquid water accumulation at the interface of a catalyst layer (CL) and GDM without an MPL has a critical effect on the PEM fuel cell performance. MPL reduced water accumulation at the CL/GDM interface, resulting in a better fuel cell performance than that of the cell without MPL. (C) 2013 Elsevier B.V. All rights reserved.