A Fast Low-Current Model for Impedance of a PEM Fuel Cell Cathode at Low Air Stoichiometry

Abstract

We report a physics-based analytical model for low-current PEM fuel cell impedance, which takes into account oxygen transport in the channel. The model is fast: fitting the model impedance to the experimental Nyquist spectrum takes about 2 minutes on a 2-GHz notebook. In addition to the transport and kinetic parameters of the catalyst layer, fitting returns the oxygen diffusion coefficient in the gas-diffusion layer and the resistivity due to oxygen transport in the channel. Maple worksheet with the fitting procedure is available for download.

Impedance Spectroscopy Characterization of Oxygen Transport in Low– and High–Pt Loaded PEM Fuel Cells

“…As discussed in Ref. 27, the total cell impedance is well approximated by the local impedance calculated at the point z * where the local current density equals the mean cell current density. Hence, we solve Eq.…”

Performance of a PEM fuel cell with oscillating air flow velocity: A modeling study based on cell impedance

“…In 2007, Schneider et al 1,2 have attracted attention of fuel cell community to "channel" impedance, a "forgotten player" in the theory of PEMFC impedance. Since that time, a number of experimental [3][4][5] and modeling [6][7][8][9][10][11][12] studies of this impedance have been published. At typical air (oxygen) flow stoichiometry of about 2, the contribution of R h to the total cell resistivity is about 15% 10 .…”

“…Since that time, a number of experimental [3][4][5] and modeling [6][7][8][9][10][11][12] studies of this impedance have been published. At typical air (oxygen) flow stoichiometry of about 2, the contribution of R h to the total cell resistivity is about 15% 10 . Clearly, lowering of R h would lead to significant improvement of the cell performance.…”

Determination of oxygen transport resistance in gas diffusion layer for polymer electrolyte fuel cells

“…23,24 Electrochemical impedance spectroscopy is a nondestructive diagnostic technique, from which the impedance of the fuel cell is measured through the response of an alternating current with varying frequency. 23,24 Electrochemical impedance spectroscopy is a nondestructive diagnostic technique, from which the impedance of the fuel cell is measured through the response of an alternating current with varying frequency.…”

“…One of the best in situ methods for fuel cell characterization is electrochemical impedance spectroscopy (EIS). 23,24 Electrochemical impedance spectroscopy is a nondestructive diagnostic technique, from which the impedance of the fuel cell is measured through the response of an alternating current with varying frequency. By building an equivalent circuit model of the fuel cell system, contributions of charge transfer, mass transport, and kinetic processes can be separated.…”