Carbon black based electrodes are generally recognized as state of the art for PEM fuel cell technology due to the high performance achieved with a relatively low Pt content. However, the catalyst carbon support is prone to carbon oxidation. This leads to a loss of the catalyst area and overall performance, along with a higher mass transport loss due to an increased flooding tendency. This phenomenon is particularly severe when the fuel cell experiences repetitive start-stop cycles. Therefore, specific countermeasures against catalyst layer carbon oxidation are required, especially for automotive and backup power applications, where the startup/shutdown rate is considerably high. The authors evaluated a basic design that uses a stack shunt. A properly modified control protocol, which includes the stack shunt, is able to avoid high cathode potential peaks, which are known to accelerate catalyst carbon support corrosion and its negative effects. During two separate durability tests, one adopting the shunt design and another using nonprotected shutdown, a 24-cell stack was subjected to continuous starts and stops for several months and its performance constantly monitored. The results show that when the shunt is used, there is a 37% reduction in the voltage degradation rate for each startup/shutdown cycle and a two-fold increase in the number of startup/shutdown cycles before an individual cell reached the specified “end of life” voltage criteria. Furthermore, ex situ FE-SEM analysis revealed cathode catalyst layer thinning, which is an indication that the emerging degradation mechanism is the catalyst support carbon corrosion, as expected. This provides further support that the constant voltage degradation rate typically experienced in PEMFCs can be primarily attributed to the catalyst support carbon corrosion rate. The proposed shunt protocol is very cost effective and does not require any substantial changes in the system. For this reason, its adoption is recommended as a viable method to decrease the catalyst support carbon corrosion rate and extend the operating life of the PEMFC stack.

References

References
1.
Williams
,
B. D.
, and
Kurani
,
K. S.
,
2007
, “
Commercializing Light-Duty Plug-In/Plug-Out Hydrogen-Fuel-Cell Vehicles: “Mobile Electricity” Technologies and Opportunities
,”
J. Power Sources
,
166
, pp.
549
566
.10.1016/j.jpowsour.2006.12.097
2.
Garde
,
R.
,
Jiménez
,
F.
,
Larriba
,
T.
,
García
,
G.
,
Aguado
,
M.
, and
Martínez
,
M.
,
2012
, “
Development of a Fuel Cell-Based System for Refrigerated Transport
,”
Energy Procedia
,
29
, pp.
201
207
.10.1016/j.egypro.2012.09.025
3.
Andùjar
,
J. M.
, and
Segura
,
F.
,
2009
, “
Fuel Cells: History and Updating. A Walk Along Two Centuries
,”
Renewable Sustainable Energy Rev.
,
13
, pp.
2309
2322
.10.1016/j.rser.2009.03.015
4.
San Martin
,
J. I.
,
Zamora
,
I.
,
San Martin
,
J. J.
,
Aperribay
,
V.
,
Torres
,
E.
, and
Eguia
,
P.
,
2010
, “
Influence of the Rated Power in the Performance of Different Proton Exchange Membrane (PEM) Fuel Cells
,”
Energy
,
35
, pp.
1898
1907
.10.1016/j.energy.2009.12.038
5.
Zhang
,
S.
,
Yuan
,
X.
,
Wang
,
H.
,
Mérida
,
W.
,
Zhu
,
H.
,
Shen
,
J.
,
Wu
,
S.
, and
Zhang
,
J.
,
2009
, “
A Review of Accelerated Stress Tests of MEA Durability in PEM Fuel Cells
,”
Int. J. Hydrogen Energy
,
34
, pp.
388
404
.10.1016/j.ijhydene.2008.10.012
6.
Wu
,
J.
,
Yuan
,
X. Z.
,
Martin
,
J. J.
,
Wang
,
H.
,
Zhang
,
J.
,
Shen
,
J.
,
Wu
,
S.
, and
Merida
,
W.
,
2008
, “
A Review of PEM Fuel Cell Durability: Degradation Mechanisms and Mitigation Strategies
,”
J. Power Sources
,
184
, pp.
104
119
.10.1016/j.jpowsour.2008.06.006
7.
Schmittinger
,
W.
, and
Vahidi
,
A.
,
2008
, “
A Review of the Main Parameters Influencing Long-Term Performance and Durability of PEM Fuel Cells
,”
J. Power Sources
,
180
, pp.
1
14
.10.1016/j.jpowsour.2008.01.070
8.
Büchi
,
F. N.
,
Inaba
,
M.
, and
Schmidt
,
T. J.
, eds.,
2009
,
Polymer Electrolyte Fuel Cell Durability (Part III—System Perspectives)
,
Springer Science and Business Media
,
New York
, pp.
467
482
.
9.
Litster
,
S.
, and
McLean
,
G.
,
2004
, “
PEM Fuel Cell Electrodes
,”
J. Power Sources
,
130
, pp.
61
76
.10.1016/j.jpowsour.2003.12.055
10.
Chaparro
,
A. M.
,
Mueller
,
N.
,
Atienza
,
C.
, and
Daza
,
L.
,
2006
, “
Study of Electrochemical Instabilities of PEMFC Electrodes in Aqueous Solution by Means of Membrane Inlet Mass Spectrometry
,”
J. Electroanal. Chem.
,
591
, pp.
69
73
.10.1016/j.jelechem.2006.03.055
11.
Reiser
,
C. A.
,
Bregoli
,
L.
,
Patterson
,
T. W.
,
Yi
,
J. S.
,
Yang
,
J. D.
,
Perry
,
M. L.
, and
Jarvi
,
T. D.
,
2005
, “
A Reverse-Current Decay Mechanism for Fuel Cells
,”
Electrochem. Solid-State Lett.
,
8
, pp.
A273
A276
.10.1149/1.1896466
12.
Kim
,
J.
,
Lee
,
J.
, and
Tak
,
Y.
,
2009
, “
Relationship Between Carbon Corrosion and Positive Electrode Potential in a Proton-Exchange Membrane Fuel Cell During Start/Stop Operation
,”
J. Power Sources
,
192
, pp.
674
678
.10.1016/j.jpowsour.2009.03.039
13.
Hinds
,
G.
, and
Brightman
,
E.
,
2012
, “
In Situ Mapping of Electrode Potential in a PEM Fuel Cell
,”
Electrochem. Commun.
,
17
, pp.
26
29
.10.1016/j.elecom.2012.01.007
14.
Makharia
,
R.
,
Kocha
,
S. S.
,
Yu
,
P. T.
,
Sweikart
,
M. A.
,
Gu
,
W. T.
,
Wagner
,
F. T.
, and
Gasteiger
,
H. A.
,
2006
, “
Durable PEM Fuel Cell Electrode Materials: Requirements and Benchmarking Methodologies
,”
ECS Trans.
,
1
, pp.
3
18
.10.1149/1.2214540
15.
Hartnig
,
C.
, and
Schmidt
,
T. J.
,
2011
, “
Simulated Start–Stop as a Rapid Aging Tool for Polymer Electrolyte Fuel Cell Electrodes
,”
J. Power Sources
,
196
, pp.
5564
5572
.10.1016/j.jpowsour.2011.01.044
16.
Avasarala
,
B.
,
Moore
,
R.
, and
Haldar
,
P.
,
2010
, “
Surface Oxidation of Carbon Supports Due to Potential Cycling Under PEM Fuel Cell Conditions
,”
Electrochim. Acta
,
55
, pp.
4765
4771
.10.1016/j.electacta.2010.03.056
17.
Fowler
,
M.
,
Amphlett
,
J. C.
,
Mann
,
R. F.
,
Peppley
,
B. A.
, and
Roberge
,
P. R.
,
2002
, “
Issues Associated With Voltage Degradation in a PEMFC
,”
J. New Mater. Electrochem. Syst.
,
5
(4), pp.
255
262
.
18.
Atanassova
,
P.
,
Rice
,
G.
,
Shen
,
J. P.
, and
Sun
,
P.
,
2007
, “
Carbon Corrosion Effects in Fuel Cells
,” Gordon Research Conference on Fuel Cells, Bryant University, Smithfield, RI, July 22–27.
19.
Tang
,
H.
,
Qi
,
Z.
,
Ramani
,
M.
, and
Elter
,
J. F.
,
2006
, “
PEM Fuel Cell Cathode Carbon Corrosion Due to the Formation of Air/Fuel Boundary at the Anode
,”
J. Power Sources
,
158
, pp.
1306
1312
.10.1016/j.jpowsour.2005.10.059
20.
Bekkedahl.
T. A.
,
Bregoli
,
L. J.
,
Breault
,
R. D.
,
Dykeman
,
E. A.
,
Meyers
,
J. P.
,
Patterson
,
T. W.
,
Skiba
,
T.
,
Vargas
,
C.
,
Yang
,
D.
, and
Yi
,
J. S.
,
2005
, “
Reducing Fuel Cell Cathode Potential During Startup and Shutdown
,” U.S. Patent No. 6,913,845 B2.
21.
Van Dine
,
L. L.
,
Steinbugler
,
M. M.
,
Reiser
,
C. A.
, and
Scheffler
,
G. W.
,
2003
, “
Procedure for Shutting Down a Fuel Cell System Having an Anode Exhaust Recycle Loop
,” U.S. Patent No. 6,514,635 B2.
22.
Condit
,
D. A.
, and
Breault
,
R. D.
,
2003
, “
Shut-Down Procedure for Hydrogen-Air Fuel Cell System
,” U.S. Patent No. 6,635,370 B2.
23.
Balliet
,
R. J.
, and
Reiser
,
C. A.
,
2004
, “
System and Method for Shutting Down a Fuel Cell Power Plant
,” U.S. Patent No. 6,835,479 B2.
24.
Reiser
,
C. A.
,
Yang
,
D.
, and
Sawyer
,
R. D.
,
2005
, “
Procedure for Shutting Down a Fuel Cell System Using Air Purge,
” U.S. Patent No. 6,858,336 B2.
25.
Reiser
,
C. A.
,
Yang
,
D.
, and
Sawyer
,
R. D.
,
2008
, “
Procedure for Starting Up a Fuel Cell System Using a Fuel Purge
,” U.S. Patent No. 7,410,712 B2.
26.
Mench
,
M. M.
,
Kumbur
,
E. C.
, and
Veziroglu
,
T. N.
,
2011
,
Polymer Electrolyte Degradation
,
1st ed.
,
Academic
,
New York
.
27.
Chen
,
J.
,
Siegel
,
J. B.
,
Matsuura
,
T.
, and
Stefanopoulou
,
A. G.
,
2011
, “
Carbon Corrosion in PEM Fuel Cell Dead-Ended Anode Operations
,”
J. Electrochem. Soc.
,
158
, pp.
B1164
B1174
.10.1149/1.3609770
28.
Baumgartner
,
W. R.
,
Parz
,
P.
,
Fraser
,
S. D.
,
Wallnofer
,
E.
, and
Hacker
,
V.
,
2008
, “
Polarization Study of a PEMFC With Four Reference Electrodes at Hydrogen Starvation Conditions
,”
J. Power Sources
,
182
, pp.
413
421
.10.1016/j.jpowsour.2008.01.001
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