---
_id: '7325'
abstract:
- lang: eng
  text: Our experimental results shown here disprove that finite diffusion can generally
    be assumed in ac impedance models for H2/air-polymer electrolyte fuel cells (PEFCs)
    to account for the diffusive transport of oxygen through the gas diffusion layer
    (GDL) toward the air electrode. It is shown that the amplitude of the oxygen concentration
    oscillation created as a consequence of superimposed ac current at the air electrode
    is not zero at the channel/GDL interface but extends into the gas channels, at
    least below modulation frequencies of fmod=10 Hz . By this, sinusoidal oxygen-concentration
    oscillations within the cathode gas channels are excited locally along the flow
    field. Due to the forced air convection in the cathode flow-field channels, a
    coupling via the gas phase occurs downstream of the flow field. The coupling strongly
    affects the local and by this the overall impedance response of the cell and evokes
    the formation of a low-frequency arc in H2/air-PEFC impedance spectra. Based on
    the experimental results, a qualitative model is presented explaining the local
    impedance response of a segmented 200cm2H2/air PEFC.
article_number: B383
article_processing_charge: No
article_type: original
author:
- first_name: I. A.
  full_name: Schneider, I. A.
  last_name: Schneider
- first_name: Stefan Alexander
  full_name: Freunberger, Stefan Alexander
  id: A8CA28E6-CE23-11E9-AD2D-EC27E6697425
  last_name: Freunberger
  orcid: 0000-0003-2902-5319
- first_name: D.
  full_name: Kramer, D.
  last_name: Kramer
- first_name: A.
  full_name: Wokaun, A.
  last_name: Wokaun
- first_name: G. G.
  full_name: Scherer, G. G.
  last_name: Scherer
citation:
  ama: 'Schneider IA, Freunberger SA, Kramer D, Wokaun A, Scherer GG. Oscillations
    in gas channels: Part I. The forgotten player in impedance spectroscopy in PEFCs.
    <i>Journal of The Electrochemical Society</i>. 2007;154(4). doi:<a href="https://doi.org/10.1149/1.2435706">10.1149/1.2435706</a>'
  apa: 'Schneider, I. A., Freunberger, S. A., Kramer, D., Wokaun, A., &#38; Scherer,
    G. G. (2007). Oscillations in gas channels: Part I. The forgotten player in impedance
    spectroscopy in PEFCs. <i>Journal of The Electrochemical Society</i>. The Electrochemical
    Society. <a href="https://doi.org/10.1149/1.2435706">https://doi.org/10.1149/1.2435706</a>'
  chicago: 'Schneider, I. A., Stefan Alexander Freunberger, D. Kramer, A. Wokaun,
    and G. G. Scherer. “Oscillations in Gas Channels: Part I. The Forgotten Player
    in Impedance Spectroscopy in PEFCs.” <i>Journal of The Electrochemical Society</i>.
    The Electrochemical Society, 2007. <a href="https://doi.org/10.1149/1.2435706">https://doi.org/10.1149/1.2435706</a>.'
  ieee: 'I. A. Schneider, S. A. Freunberger, D. Kramer, A. Wokaun, and G. G. Scherer,
    “Oscillations in gas channels: Part I. The forgotten player in impedance spectroscopy
    in PEFCs,” <i>Journal of The Electrochemical Society</i>, vol. 154, no. 4. The
    Electrochemical Society, 2007.'
  ista: 'Schneider IA, Freunberger SA, Kramer D, Wokaun A, Scherer GG. 2007. Oscillations
    in gas channels: Part I. The forgotten player in impedance spectroscopy in PEFCs.
    Journal of The Electrochemical Society. 154(4), B383.'
  mla: 'Schneider, I. A., et al. “Oscillations in Gas Channels: Part I. The Forgotten
    Player in Impedance Spectroscopy in PEFCs.” <i>Journal of The Electrochemical
    Society</i>, vol. 154, no. 4, B383, The Electrochemical Society, 2007, doi:<a
    href="https://doi.org/10.1149/1.2435706">10.1149/1.2435706</a>.'
  short: I.A. Schneider, S.A. Freunberger, D. Kramer, A. Wokaun, G.G. Scherer, Journal
    of The Electrochemical Society 154 (2007).
date_created: 2020-01-15T12:22:31Z
date_published: 2007-02-09T00:00:00Z
date_updated: 2021-01-12T08:13:05Z
day: '09'
doi: 10.1149/1.2435706
extern: '1'
intvolume: '       154'
issue: '4'
language:
- iso: eng
month: '02'
oa_version: None
publication: Journal of The Electrochemical Society
publication_identifier:
  issn:
  - 0013-4651
publication_status: published
publisher: The Electrochemical Society
quality_controlled: '1'
status: public
title: 'Oscillations in gas channels: Part I. The forgotten player in impedance spectroscopy
  in PEFCs'
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 154
year: '2007'
...