Elsevier

Journal of Power Sources

Volume 365, 15 October 2017, Pages 240-248
Journal of Power Sources

Experimental diagnostics and modeling of inductive phenomena at low frequencies in impedance spectra of proton exchange membrane fuel cells

https://doi.org/10.1016/j.jpowsour.2017.08.087Get rights and content
Under a Creative Commons license
open access

Highlights

  • A novel equivalent circuit model of PEM fuel cell is proposed and validated.

  • Explanation of inductive features at low frequencies in Nyquist plot is suggested.

  • Well-defined physical meanings are assigned to newly introduced model elements.

  • Simulated results agree with the expected behavior of the elements' interpretation.

Abstract

Representation of fuel cell processes by equivalent circuit models, involving resistance and capacitance elements representing activation losses on both anode and cathode in series with resistance representing ohmic losses, cannot capture and explain the inductive loop that may show up at low frequencies in Nyquist diagram representation of the electrochemical impedance spectra. In an attempt to explain the cause of the low-frequency inductive loop and correlate it with the processes within the fuel cell electrodes, a novel equivalent circuit model of a Proton Exchange Membrane (PEM) fuel cell has been proposed and experimentally verified here in detail. The model takes into account both the anode and the cathode, and has an additional resonant loop on each side, comprising of a resistance, capacitance and inductance in parallel representing the processes within the catalyst layer. Using these additional circuit elements, more accurate and better fits to experimental impedance data in the wide frequency range at different current densities, cell temperatures, humidity of gases, air flow stoichiometries and backpressures were obtained.

Keywords

Electrochemical impedance spectroscopy
Inductive phenomena
Inductive loop
Electrical equivalent circuit model
Inertia of reactant gas

Cited by (0)