Catalyst Layers for PEMFC Manufactured by Flexography Printing Process: Performances and Structure

Abstract

Abstract This article focuses on the potential of a classic printing process, flexography, for manufacturing proton exchange membrane fuel cells (PEMFCs). Gas diffusion electrodes (GDEs) are produced by deposition of a water‐based catalyst ink on a gas diffusion layer (GDL). The affinity between the ink and the GDL is quantified. Thus, the strong hydrophobic character of the GDL and the poor printability of the ink are demonstrated. However, the permeability of the GDL allows developing a multilayer protocol. The deposition by superimposition of ink layers allows control of the platinum amount and to obtain catalyst layers with a similar density of platinum nanoparticles to coated samples. At similar platinum loading, flexography and coating made catalyst layers offer similar performances, which confirm the relevance of flexography in catalyst layer manufacturing. Structural characterization shows that manufacturing protocol and process has an influence on catalyst layer microstructure. However, catalyst layer cracking and aggregation are increased with the catalyst layer thickness, diminishing the charge and gas diffusion into the catalyst layer resulting in performance degradation. Consequently, a catalyst layer with 0.46 mgPt cm –2 reaches similar performances to catalyst layers with 1.77 and 2.01 times less platinum loading.