Analytical Model for Concentration (Pressure) Impedance of a Low-Pt PEM Fuel Cell Oxygen Electrode.

In this study, a model for concentration/pressure impedance ζ of the cathode catalyst layer of a low-Pt PEM fuel cell is developed. The model is based on transient oxygen mass transport equations through the cathode catalyst layer modeled as a single pore with a thin Nafion film covering the pore surface. This structure is used to simulate oxygen transport through the catalyst layer depth and through the ionomer film covering Pt/C agglomerates in low-Pt cells.

Impedance Spectroscopy Measurements of Ionomer Film Oxygen Transport Resistivity in Operating Low-Pt PEM Fuel Cell.

The work presents a model for local impedance of low-Pt proton exchange membrane fuel cells (PEMFCs), including cathode pore size distribution and O transport along pores and through a thin ionomer film covering Pt/C agglomerates. The model was applied to fit the local impedance spectra of low-Pt fuel cells operated at current densities from 100 to 800 mA cm and recorded by a segmented cell system. Assuming an ionomer film thickness of 10 nm, the fitting returned the product of the dimensionless Henry's constant of oxygen dissolution in ionomer by the oxygen diffusivity in the ionomer ().

Correction: Nafion film transport properties in a low-Pt PEM fuel cell: impedance spectroscopy study.

[This corrects the article DOI: 10.1039/C9RA07794D.].

PEM fuel cell distribution of relaxation times: a method for the calculation and behavior of an oxygen transport peak.

A simple numerical method for the calculation of the distribution of relaxation times (DRT) for PEM fuel cell impedance is developed. The method combines the Tikhonov regularization technique and projected gradient iterations. The method is illustrated by calculating DRT for the synthetic impedance of two parallel RC-circuits and for Warburg finite-length impedance.

Nafion film transport properties in a low-Pt PEM fuel cell: impedance spectroscopy study.

Unexpected over-linear transport loss in low-Pt PEM fuel cells has been a subject of numerous studies and discussions in literature. Most of the authors agree that these losses are due to oxygen transport in the Nafion film covering Pt/C agglomerates in the cathode catalyst layer (CCL). We develop a model for PEM fuel cell impedance, which takes into account oxygen transport through the film.