Electrochemical impedance spectroscopy is used during operation of different polymer electrolyte membrane fuel cell (PEMFC) stack assemblies at various conditions with special interest given to the characteristic time constant τlow-f derived from the low-frequency arc of the spectra which is typically in the range of approximately 15–0.5 Hz. This was done by fitting an equivalent electrical circuit (EEC) consisting of one resistor and two RC-elements to the data. Parameter variation performed on a 90-cell stack assembly suggests that conditions leading to different air flow velocities in the flow channels affect τlow-f while other parameters like humidity influence the impedance spectrum, but not τlow-f. Comparison of the stoichiometry variation between short stack and locally resolved single cell shows similar results with the stack's time constant matching that of the cell's segments which are located off-center toward the outlet. However, a nonlinear dependency between gas flow velocity and τlow-f especially at low stoichiometric values is obvious. Results from stoichiometry variations at different pressure levels suggest that this could be attributed to the different steady-state oxygen partial pressures during the experiments. Comparison of the stoichiometry variation between different stack platforms result in similar dependencies of τlow-f on air flow rate with respect to a reference oxygen partial pressure regardless of size, flow field, geometry, or cell count of the stack. The time constant caused by oxygen diffusion through the gas diffusion layer (GDL), τGDL, was approximated and compared to τlow-f. While it was found that τlow-f ≫ τGDL at low stoichiometric values, τlow-f decreases toward τGDL at very high gas flow rates, suggesting that τGDL offsets τlow-f and becomes dominating if no oxygen concentration variation along the flow channel was present.

References

References
1.
Devlin
,
P.
, and
Kiuru
,
K.
,
2015
, “Industry Deployed Fuel Cell Powered Lift Trucks,” U.S. Department of Energy, Washington, DC, DOE Hydrogen and Fuel Cells Program Record No.
15003
.
2.
Devlin
,
P.
, and
Kiuru
,
K.
,
2015
, “DOE Hydrogen and Fuel Cells Program Record 15004: Industry Deployed Fuel Cell Backup Power (BuP),” U.S. Department of Energy, Washington, DC, DOE Hydrogen and Fuel Cells Program Record No.
15004
.https://www.hydrogen.energy.gov/pdfs/15004_industry_bup_deployments.pdf
3.
Zhang
,
J.
,
Zhang
,
L.
,
Bezerra
,
C. W.
,
Li
,
H.
,
Xia
,
Z.
,
Zhang
,
J.
,
Marques
,
A. L.
, and
Marques
,
E. P.
,
2009
, “
EIS-Assisted Performance Analysis of Non-Noble Metal Electrocatalyst (Fe–N/C)-Based PEM Fuel Cells in the Temperature Range of 23–80 °C
,”
Electrochim. Acta
,
54
(
6
), pp.
1737
1743
.
4.
Kurz
,
T.
,
Hakenjos
,
A.
,
Krämer
,
J.
,
Zedda
,
M.
, and
Agert
,
C.
,
2008
, “
An Impedance-Based Predictive Control Strategy for the State-of-Health of PEM Fuel Cell Stacks
,”
J. Power Sources
,
180
(
2
), pp.
742
747
.
5.
Lee
,
J.-h.
,
Lee
,
J.-H.
,
Choi
,
W.
,
Park
,
K.-W.
,
Sun
,
H.-Y.
, and
Oh
,
J.-H.
,
2010
, “
Development of a Method to Estimate the Lifespan of Proton Exchange Membrane Fuel Cell Using Electrochemical Impedance Spectroscopy
,”
J. Power Sources
,
195
(
18
), pp.
6001
6007
.
6.
Schneider
,
I. A.
,
Bayer
,
M. H.
, and
von Dahlen
,
S.
,
2011
, “
Locally Resolved Electrochemical Impedance Spectroscopy in Channel and Land Areas of a Differential Polymer Electrolyte Fuel Cell
,”
J. Electrochem. Soc.
,
158
(
3
), p.
B343
.
7.
Dhirde
,
A. M.
,
Dale
,
N. V.
,
Salehfar
,
H.
,
Mann
,
M. D.
, and
Han
,
T.-H.
,
2010
, “
Equivalent Electric Circuit Modeling and Performance Analysis of a PEM Fuel Cell Stack Using Impedance Spectroscopy
,”
IEEE Trans. Energy Convers.
,
25
(
3
), pp.
778
786
.
8.
Schneider
,
I. A.
,
Freunberger
,
S. A.
,
Kramer
,
D.
,
Wokaun
,
A.
, and
Scherer
,
G. G.
,
2007
, “
Oscillations in Gas Channels—Part I: The Forgotten Player in Impedance Spectroscopy in PEFCs
,”
J. Electrochem. Soc.
,
154
(
4
), pp.
B383
B388
.
9.
Schneider
,
I. A.
,
Kramer
,
D.
,
Wokaun
,
A.
, and
Scherer
,
G. G.
,
2007
, “
Oscillations in Gas Channels—II: Unraveling the Characteristics of the Low Frequency Loop in Air-Fed PEFC Impedance Spectra
,”
J. Electrochem. Soc.
,
154
(
8
), pp.
B770
B782
.
10.
Reshetenko
,
T.
, and
Kulikovsky
,
A.
,
2016
, “
Comparison of Two Physical Models for Fitting PEM Fuel Cell Impedance Spectra Measured at a Low Air Flow Stoichiometry
,”
J. Electrochem. Soc.
,
163
(
3
), pp.
F238
F246
.
11.
Maranzana
,
G.
,
Mainka
,
J.
,
Lottin
,
O.
,
Dillet
,
J.
,
Lamibrac
,
A.
,
Thomas
,
A.
, and
Didierjean
,
S.
,
2012
, “
A Proton Exchange Membrane Fuel Cell Impedance Model Taking Into Account Convection Along the Air Channel: On the Bias Between the Low Frequency Limit of the Impedance and the Slope of the Polarization Curve
,”
Electrochim. Acta
,
83
, pp.
13
27
.
12.
Brett
,
D. J. L.
,
Atkins
,
S.
,
Brandon
,
N. P.
,
Vesovic
,
V.
,
Vasileiadis
,
N.
, and
Kucernak
,
A.
,
2003
, “
Localized Impedance Measurements Along a Single Channel of a Solid Polymer Fuel Cell
,”
Electrochem. Solid-State Lett.
,
6
(
4
), pp.
A63
A66
.
13.
Bao
,
C.
, and
Bessler
,
W. G.
,
2015
, “
Two-Dimensional Modeling of a Polymer Electrolyte Membrane Fuel Cell With Long Flow Channel—Part II: Physics-Based Electrochemical Impedance Analysis
,”
J. Power Sources
,
278
, pp.
675
682
.
14.
Mainka
,
J.
,
Maranzana
,
G.
,
Dillet
,
J.
,
Didierjean
,
S.
, and
Lottin
,
O.
,
2010
, “
Effect of Oxygen Depletion Along the Air Channel of a PEMFC on the Warburg Diffusion Impedance
,”
J. Electrochem. Soc.
,
157
(
11
), p.
B1561
.
15.
Yang
,
M.-C.
, and
Hsueh
,
C.-H.
,
2006
, “
Impedance Analysis of Working PEMFCs in the Presence of Carbon Monoxide
,”
J. Electrochem. Soc.
,
153
(
6
), pp.
A1043
A1048
.
16.
Springer
,
T. E.
,
Zawodzinski
,
T. A.
,
Wilson
,
M. S.
, and
Gottesfeld
,
S.
,
1996
, “
Characterization of Polymer Electrolyte Fuel Cells Using AC Impedance Spectroscopy
,”
J. Electrochem. Soc.
,
143
(
2
), pp.
587
599
.
17.
Bao
,
C.
, and
Bessler
,
W. G.
,
2015
, “
Two-Dimensional Modeling of a Polymer Electrolyte Membrane Fuel Cell With Long Flow Channel—Part I: Model Development
,”
J. Power Sources
,
275
, pp.
922
934
.
18.
Kulikovsky
,
A. A.
,
2012
, “
A Model for Local Impedance of the Cathode Side of PEM Fuel Cell With Segmented Electrodes
,”
J. Electrochem. Soc.
,
159
(
7
), pp.
F294
F300
.
19.
Gerteisen
,
D.
,
Mérida
,
W.
,
Kurz
,
T.
,
Lupotto
,
P.
,
Schwager
,
M.
, and
Hebling
,
C.
,
2011
, “
Spatially Resolved Voltage, Current and Electrochemical Impedance Spectroscopy Measurements
,”
Fuel Cells
,
11
(
2
), pp.
339
349
.
20.
Liu
,
Z.
,
Mao
,
Z.
, and
Wang
,
C.
,
2006
, “
A Two Dimensional Partial Flooding Model for PEMFC
,”
J. Power Sources
,
158
(
2
), pp.
1229
1239
.
21.
Springer
,
T. E.
,
Zawodzinski
,
T. A.
, and
Gottesfeld
,
S.
,
1991
, “
Polymer Electrolyte Fuel Cell Model
,”
J. Electrochem. Soc.
,
138
(
8
), pp.
2334
2342
.
22.
Zamel
,
N.
,
Astrath
,
N. G. C.
,
Li
,
X.
,
Shen
,
J.
,
Zhou
,
J.
,
Astrath
,
F. B. G.
,
Wang
,
H.
, and
Liu
,
Z.-S.
,
2010
, “
Experimental Measurements of Effective Diffusion Coefficient of Oxygen–Nitrogen Mixture in PEM Fuel Cell Diffusion Media
,”
Chem. Eng. Sci.
,
65
(
2
), pp.
931
937
.
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