Effect of ionomer dispersion formulation for direct membrane deposition on initial performance in LT-PEM fuel cell applications

Titelangaben

Merkel, Simon ; Bredella, Sean ; Roth, Christina ; Bernt, Maximilian ; Jurzinsky, Tilman:
Effect of ionomer dispersion formulation for direct membrane deposition on initial performance in LT-PEM fuel cell applications.
In: Electrochimica Acta. Bd. 569 (2026) . - 148891.
ISSN 0013-4686
DOI: https://doi.org/10.1016/j.electacta.2026.148891

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Abstract

This paper discusses the influence of the formulation of the ionomer dispersion for the direct membrane deposition (DMD) via knife blade coating. Extensive physical characterization of different dispersion formulations and their interaction with gas diffusion electrodes (GDEs), including rheological and contact angle measurements, were performed following a Design of Experiment (DoE) approach. Based on the findings, three different dispersions (standard, high viscosity and water-rich) were chosen for fabrication of membrane electrode assemblies (MEAs), electrochemical testing as well as physicochemical characterization by cross-sectional SEM imaging. The high viscosity and water-rich dispersions’ led to an improved ionomer layer formation on the GDE and a limited intrusion of ionomer into the pores of the electrode compared to the standard dispersion. Cells prepared with these dispersions show a higher electrochemical performance compared to a reference cell at low relative humidity (RH) due to improved proton transport in the electrode, while the performance at higher relative humidities is limited by mass transport resistances. The search for a sweet spot between a proton conductive network and unhindered mass transport is discussed in dependence of the ionomer dispersion applied.