V–151
FY 2014 Annual Progress Report
DOE Hydrogen and Fuel Cells Program
Wenbin Gu (Primary Contact), Matthew Mench,
Michael Hickner, Satish Kandlikar, Thomas Trabold,
Jeffrey Gagliardo, Anusorn Kongkanand,
Vinod Kumar, Ruichun Jiang, Swami Kumaraguru
General Motors
895 Joslyn Ave.
Pontiac, MI 48340
Phone: (585) 953-5552
Email: wenbin.gu@gm.com
DOE Managers
Donna Ho
Phone: (202) 586-8000
Email: Donna.Ho@ee.doe.gov
David Peterson
Phone: (720) 356-1747
Email: David.Peterso[email protected]
Technical Advisor
John Kopasz
Phone: (630) 252-7531
Email: kopasz@anl.gov
Contract Number: DE-EE0000470
Subcontractors
• PennStateUniversity,UniversityPark,PA
• UniversityofTennessee,Knoxville,TN
• RochesterInstituteofTechnology,Rochester,NY
• UniversityofRochester,Rochester,NY
Project Start Date: June 1, 2010
Project End Date: May 31, 2014
Overall Objectives
Investigate and synthesize fundamental understanding of
transport phenomena at both the macro- and micro-scales for
the development of a down-the-channel model that accounts
for all transport domains in a broad operating space.
Fiscal Year (FY) 2014 Objectives
Characterize saturated relationships in state-of-the-art •
fuel cell materials.
Obtain a comprehensive down-the-channel validation •
dataset for a parametric study material set.
Develop multidimensional component models to output •
bulk and interfacial transport resistances.
Demonstrate integrated transport resistances with a one •
plus one-dimension (1+1D) fuel cell model solved along a
straightgasowpath.
Identify critical parameters for low-cost material •
development.
Technical Barriers
This project addresses the following technical
barriers from the Fuel Cells section of the Fuel Cell
TechnologiesOfceMulti-YearResearch,Development,and
Demonstration Plan:
(B) Cost
(C) Performance
Technical Targets
Thisprojectsupportsfundamentalstudiesofuid,
proton and electron transport with a focus on saturated
operating conditions. Insights gained from these studies
are being used to develop modeling tools that capture
fundamental transport physics under single and two-phase
conditions. The primary deliverables are:
Validated cell model including all component physical •
and chemical properties.
Public dissemination of the model and instructions for •
exerciseofthemodel.
Compilation of the data generated in the course of model •
development and validation.
Identicationofrate-limitingstepsandrecommendations•
for improvements to the plate-to-plate fuel cell package.
FY 2014 Accomplishments
Obtained validation data set for baseline materials with •
low Pt-loaded cathode
Establishedorrenedseveralone-dimensional•
relationships based on parametric and characterization
methods developed within the project.
Demonstrated improved down-the-channel 1+1D model •
prediction with new relationships integrated.
Published validation, parametric studies, and •
characterization data to a project website at: www.
pemfcdata.org.
G G G G G
V.G.3 Investigation of Micro- and Macro-Scale Transport Processes for
Improved Fuel Cell Performance
Gu – General Motors
V.G Fuel Cells / Transport Studies
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INTRODUCTION
The transport physics associated with fuel cell
operation are widely debated amongst researchers because
comprehensive micro/nano-scale process validation is very
difcult.Furthermore,fuelcelloperationhasastrong
interdependencebetweencomponentsmakingitdifcultto
separate the key relationships required for predictive models
withexsitumethods.Generally,avalidatedmodelthat
predicts operation based on known design parameters for fuel
cell hardware and materials is highly desired by developers.
Such a model has been proposed by many research groups
fordry(lessthan100%relativehumidityexhaust)operation
with moderate success; however these modelers unanimously
assert that their ability to predict wet operation is limited
by two-phase component-level understanding of transport
processes. Additionally, as two-phase models continue to be
rened,benchmarkingprogressisdifcultduetoincomplete
validation datasets.
In the current work, our team is developing
characterization tools for saturated relationships based on the
evolution of a dry 1+1D model for accurate wet prediction
[1]. To complement this work we are also developing a
comprehensive validation dataset based on a wide proton
exchangemembranefuelcell(PEMFC)operatingspace.As
dataandmodelingreachanalform,theseareuploadedtoa
project website at www.pemfcdata.org. All characterization
and validation work is conducted with common material sets
thatrepresentcurrentandnextgenerationsofPEMFCdesign.
APPROACH
Thisprojectisorganizedaroundbaselineandnext-
generationmaterialsets.Thesematerialsdeneparametric
bounds for component and integrated down-the-channel
modeling efforts. The baseline material set was chosen based
onthecommercialstateoftheartthatexiststoday.The
next-generationmaterialsetconsistsoftransportimpacting
parametric changes that are in line with the DOE 2015 targets
for reduced cost while improving durability and performance.
Forcharacterizationandvalidationexperiments,astandard
protocol was also developed to enable the team to conduct
experimentswiththesameboundaryconditions.
Therstphaseofthisprojectwasexperimentally
focused on characterization work that is organized by
transportdomain,comprisingthinlmionomers,bulk
membranes, porous electrodes, gas diffusion layers (GDLs)
andowdistributionchannels.Thespecicsofthese
relationships were outlined previously [2]. In anticipation of
this integrated model, validation data sets are being collected
inparallelwithsmallscalehardwarespecicallydesigned
to include automotive stack constraints [3]. Currently with
theseexperimentalmethodsestablished,workbecomesmore
modeling focused as the physical mechanisms that govern
the observed transport phenomenon are described multi-
dimensionally at the component level and evaluated with a
1+1D fully integrated model. This work continuously guides
parametric studies with novel material changes.
RESULTS
Validation Data
In the auto-competitive material set tested for model
validation, a number of parameters, including membrane
thickness, anode GDL, cathode catalyst layer composition,
oweldland/channelgeometryandmanifoldexitheaders,
are changed from the baseline material set. Hence, the
performance difference between the two material sets
represents a compounded effect of all changes being made
at once. To de-convolute the effects of high diffusion
resistance anode GDL and cell design differences used in
DOE automotive competitive cell builds from low Pt-loaded
cathode catalyst layer effects, a parametric study cell built
with low Pt-loaded cathode and other baseline materials was
tested using the standardized project protocol that varies
outlet temperature, inlet relative humidity, outlet pressures,
and current density [4]. Compared to the baseline cell, the
parametric study cell yielded lower cell voltage and less
productwatertothecathodeoweld.Thelowervoltage
results primarily from lower Pt loading and slightly higher
high-frequency resistance (HFR). And less product water to
thecathodeoweldappearstobeconsistentwithhigher
temperature gradient caused by the lower cell voltage and
thus higher heat generation rate. However, both baseline and
parametric study cells demonstrate same trend in down-the-
channel current distribution, suggesting that lower Pt-loaded
cathode in the auto-competitive material set would not be
responsible for the opposite trend in current distribution
associated with the auto-competitive cell at low temperatures.
Instead, the highly tortuous anode diffusion medium is most
likely the cause.
Transport in Thin Ionomer Films
With focus on elucidating the structural features
andtransportpropertiesofthinionomerlms,wehave
performedextensivegravimetricandvolumetricswelling
studiestounderstandhowthesethinlmsbasedon
peruorinatedsulfonicacid(PFSA)ionomersuptakewater
andhavecomparedthepropertiesofthinionomerlmsto
what is known about PFSA-based membranes. The focus on
water uptake and swelling is because the transport properties
of these materials is determined in large part by their
hydration. We have found that the water uptake of PFSA-
basedthinlmsvarieswiththickness,substratetype,and
processing conditions. To understand the swelling processes
in more depth, we have undertaken measurements of polymer
chain alignment using Fourier transform infrared (FTIR) and
ellipsometry. These techniques were chosen because they
can be adapted to electrochemical measurements to study
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thebehaviorofthinlmsunderpotentialcontrol,which
is ongoing work. Shown in Figure 1 is the FTIR spectra of
50-nmand5-nmNaon
®
lms.TheSO
3
/CF
3
side chain peaks
areenhancedinthethinlmspectraindicatingalignment
ofthesemoietiestowardsthesurfaceinthethinnestlms
[5]. Similar observations have been made by studying
thebirefringenceofNaon
®
lmsusingspectroscopic
ellipsometry [6]. Our goal is to be able to measure the
dynamicbehaviorofthesethinlmsasafunctionof
potential, which can be detected by changes in their FTIR or
ellipsometric spectra. These types of measurements focusing
on the features of the ionomer-substrate interface may lead to
abetterunderstandingofwhytheoxygentransportresistance
at low platinum loading occurs. This work on the structure of
thethinlmsandhowthestructurecorrelateswithswelling
and ultimately other transport properties complements
our collaborative work with Lawrence Berkeley National
Laboratoryonscatteringstudies[7]asafunctionoflm
processing conditions and substrate type.
Transport in Diffusion Materials
We developed an empirical relationship for effective
thermal conductivity of partially saturated diffusion
mediaviaexsitumaterialtesting[8].Additionally,we
experimentallydeterminedcapillarydrainagefunctions
of liquid water from the catalyst layer, micro-porous
layer,andtheinterfacialdomains[9].Utilizingthehigh
resolution neutron imaging facility at the National Institute
ofStandardsandTechnology,wecompletedextensivein
situ characterization of the impacts of diffusion media
design,ow-eldinterfacearchitecture,andaging,covering
anextremelywiderangeofoperationaltestconditions.In
particular, diffusion media aged in situ for over 2,500 hours
has been tested with neutron imaging and show additional
water storage during operation. The water balance was found
to shift in the aged material from the anode to the cathode, as
shown in Figure 2. To understand what has caused the change
in water balance, energy dispersive X-ray spectroscopy and
X-ray photoelectron spectroscopy were used to determine
changes in chemical makeup and surface morphology. The
resultsindicateanincreaseincarbon-oxygenbondingand
increasedsurfacefunctionalization.Theseoxygengroups
can be responsible for increasing the hydrophilicity of the
Figure 1. FTIR-Attenuated total reflectance spectrum of 50-nm thick and
5-nm thick Nafion
®
thin films showing the change in the CF
3
(backbone) and
SO
3
/CF
3
(side chain) peak ratios with thickness.
Figure 2. Saturation profiles for baseline fresh (upper) and 2,666 hr aged
(lower) GDL/MEA packages at 60°C. Test conditions: 1.2 A/cm
2
, 95|95%
(An|Ca) constant inlet relative humidity for pressure tests, 150|150 kPa (An|Ca)
constant exhaust pressure for concentration gradient tests, constant flow rate at
an equivalent stoichiometry ratio of 2:2 at 1.2 A/cm
2
. Profiles are summed along
entire imaged area.
Gu – General Motors
V.G Fuel Cells / Transport Studies
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DOE Hydrogen and Fuel Cells Program
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surface, increasing water retention and wicking action. Both
anode and cathode GDLs were tested, and the cathode GDL
was more affected by ageing. Finally, a GDL component
level multi-phase computational model has been developed to
address the need for meso-scale modeling within this media.
A statistical approach using percolation theory was used to
construct appropriate model porous domain structures, and
a Lattice-Boltzman approach was used to determine the
effective tortuosity and gas-diffusivity of these domains.
Additionally, X-ray microscopy was used to determine the
three-dimensional morphology of the GDL structure, which
can then be directly used as the computational domain in
the model. Future publications are being prepared based on
the results which demonstrate the prediction of effective
diffusivity and tortuosity for the real media morphology as a
function of saturation. This result can then be correlated and
linked with macroscopic performance models to obtain high-
speed predictive performance modeling with greater GDL
leveltransportdelity.
Transport in Flow Distributor Channels
The emergence of droplets and their interaction with
the reactant channel sidewall dictate trends of GDL-channel
interfacecoverage,two-phaseowpressuredrop,and
transitionofowpatterns.Thesetrendsaredependentonthe
cornerllingofthechannelbyliquidwater.Weconducted
exsituexperimentationtoestablishcorrelationstopredict
cornerllingbehaviorasafunctionofchanneldesign
parameters and operating conditions [10]. Liquid water was
injected into a single channel that was manufactured to
match baseline and auto-competitive designs. The distance
from water injection location on the GDL to the channel
side wall, materials of GDL and channel walls, corner angle
inanauto-competitivechannel,andsupercialairvelocity
in the channel were varied. A channel corner angle of 50°
is suggested for improved water removal characteristics.
Moreover, correlations were established to predict the corner
llingbehaviorandtwo-phaseowpressuredropatthe
instant of droplet removal. A force balanced model has also
been developed to provide further insight into the dynamics
of the droplet at the time of its interaction with the channel
side wall. Consequently, a channel design was suggested to
minimize the buildup of liquid water.
Two-phase pressure drop studies from the literature
havefocusedonthefundamentalfactorsthatinuencethe
two-phaseow.However,theconditionsinthePEMFC
reactant channels are unique as there is consumption of
gaseous reactants along the length and water is continuously
introduced through the GDL. This results in a continuously
changingqualityofthetwo-phasemixture.Thereare
temperature gradients both along the length of the channel as
well as the cross section of the cell, resulting in evaporation
and condensation-driven mass transport in these directions.
A step-wise elemental modeling scheme that allows ease of
integration into the down-the-channel performance model
has been proposed, developed and validated for the prediction
of two-phase pressure drop in the reactant channels. The
modeling scheme has been tested with several fundamental
pressure drop models available in the literature. It is found
thatthemodiedEnglishandKandlikarmodel[11]works
best to predict two-phase pressure drop in PEMFC reactant
channels. Figure 3 shows that it has a mean error of 11.6%
and 40.2% for cathode and anode, respectively, over the
entire range. A mean error of 5.2% was observed for the
cathodewithafullyhumidiedinlet.
In investigating channel-scale water transport and
accumulation, both within the fuel cell active area and in
thenon-activeareasextendingallthewaytotheanodeand
Figure 3. Comparison between the modified English and Kandlikar correlation and experimental data. Cell
temperature 40°C, Orange – 0% relative humidity Inlet, Blue – 95% relative humidity Inlet, (left) Cathode Side
Pressure Drop (right) Anode Side Pressure Drop.
Anode
Cathode
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cathodeexitmanifolds,wecarriedoutexsitutwo-phase
owexperimentstounderstandpressuredropperformance
over a wide range of simulated operating conditions,
coupledwithinsituexperimentsapplyingneutronimaging
to directly measure fuel cell water content under low
temperature conditions in the range of 20 to 40
o
C [12]. It
was observed that the active area water volume is strongly
dependent on cell temperature, and temperature variation of
aslittleas0.5°Ccanproduceasignicantchangeinwater
accumulation,whichisalsoreectedinthecellvoltage.In
general, active area water decreases with increasing current
density. However, the water quantity is a function of both
cell temperature and anode/cathode pressure. Conversely,
the anode non-active water is weakly dependent on current
density, presumably because in this region there is little
drivingforcetoremovewateronceitispresent.Thisnding
has obvious implications relative to fuel cell operation
underfreezingconditions,andisindicativeofthedifculty
ofremovinganodeexitwaterduringshut-downpurge.
Furthermore,asignicantpressuredropwasseenovernon-
active area. On average, the outlet region contributes more
to the total (manifold-to-manifold) pressure drop for higher
waterowrates,suggestingthatwatermitigationstrategies
should focus on outlet non-active area as well as channel-to-
manifold interface, especially on anode side.
Modeling
The two-phase, 1+1D down-the-channel model has been
improvedandtestedagainsttheexperimentaldatagenerated
from baseline, baseline with low Pt-loaded cathode, and auto-
competitivematerialsets.Duetolackofexperimentaldata
on liquid water saturation within an electrode, the electrodes
are allowed to be supersaturated and water saturation therein
is evaluated based on local relative humidity by an empirical
correlation.Usingasinglesetofparameters,themodel
agrees fairly well to all three data sets. Figure 4 compares the
predicted down-the-channel current and HFR distributions
withthemeasuredones.Signicantly,themodelcapturesthe
opposite trends in current density distribution observed for
the automotive competitive and baseline materials plus low-
loaded Pt material sets, that is caused by the highly tortuous
anode diffusion media in the automotive competitive data
set. However, the agreement for the automotive competitive
material set comes with a compromise in the agreement
for the baseline material set. More work is needed to
achieve better quantitative agreement in down-the-channel
distributions.
A parametric study was performed for cell component
optimization based on the parametric study cell validation
data using the two-phase, 1+1D down-the-channel model.
Thedesignforsixsigmaapproachwasemployedtond
optimal material properties for better cell performance [13].
Among numerous input parameters, eight were chosen to
be the control factors. For the operating condition given in
Figure 4, the following recommendation can be made for cell
component properties in reference to the baseline materials:
Thinner membrane (12 microns)•
50% lower membrane water permeability•
25% less tortuous supporting layer in the ePTFE-•
reinforced membrane
25% less tortuous GDL in the presence of liquid water•
2X GDL thermal conductivity•
2X MPL thermal conductivity•
2X coolant-to-plate thermal resistance•
50%lowerlocaloxygentransportresistance•
CONCLUSIONS AND FUTURE DIRECTIONS
A well-organized characterization, modeling and
validation framework was developed early in this project.
Therstphase(FY2011)ofexecutionwaslargelyfocused
onexperimentaldevelopment.Thefocusgraduallyshiftedto
model development while continuing to complete validation
data.Duringthenalphaseoftheproject(FY2014),results
from these methods were described with multidimensional
component models and summarized in a down-the-channel
model that is compared to a comprehensive validation
database.SpecichighlightsfromFY2014:
A new validation data set based on the baseline materials •
with low Pt-loaded cathode added to the database for
model validation.
Figure 4. Comparisons between model and data for down-the-channel
current and HFR distributions. Squares represent baseline materials with
low Pt-loaded cathode (0.1 mgPt/cm
2
); and diamonds stand for Auto-
Competitive material set. The cell operates with H
2
/Air at stoichimetry 1.5/2.0,
100/150 kPa-abs outlet pressure, 60°C coolant out temperature, 0/95% inlet
relative humidity.
0.05
0.06
0.07
0.08
0.09
0.10
0.11
0.12
0.13
0.14
0.15
0.9
1.0
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
0 3 6 9 12 15 18
HFR (Ω⋅cm²)
Current Density (A/cm²)
Distance from cathode inlet (cm)
Symbols
- data
Lines - Model
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layer of PEM fuel cells,” International Journal of Heat and Mass
Transfer, 71(10), pp. 585-592 (2014).
9. Kandlikar, S.G., E.J.See, M. Koz, P. Gopalan, R. Banerjee, “Two-
PhaseFlowinGDLandReactantChannelsofaProtonExchange
Membrane Fuel Cell,” International Journal of Hydrogen Energy, 39
(12), pp. 6620-6636 (2014).
10. Banerjee, R., and S.G. Kandlikar, “LiquidWaterQuantication
intheCathodeSideGasChannelsofaProtonExchangeMembrane
Fuel Cell Through Two-Phase Flow Visualization,” Journal of
Power Sources, 247, pp. 9-19 (2014).
11. Gopalan, P., and S.G. Kandlikar, “Modeling Dynamic
Interaction Between an Emerging Water Droplet and the Sidewall of
a Trapezoidal Channel,” Colloids and Surfaces A: Physicochemical
and Engineering Aspects, 441, pp. 267-274 (2014).
12. Gopalan, P., and S.G. Kandlikar, “Effect of Channel Materials
and Trapezoidal Corner Angles on Emerging Droplet Behavior in
ProtonExchangeMembraneFuelCellGasChannels,” Journal of
Power Sources, 248, pp. 230-238 (2014).
13. Banerjee, R., E.J. See, and S.G. Kandlikar, “Pressure Drop
and Voltage Response of PEMFC Operation under Transient
Temperature and Loading Conditions,” ECS Transactions, 58(1), pp.
1601-1611 (2013).
14. See, E.J., and S.G. Kandlikar, “Effect of GDL Material on
Thermal Gradients along the Reactant Flow Channels in PEMFCs,”
ECS Transactions, 58(1), pp. 867-880 (2013).
15. Xu, G., LaManna, J., and Mench, M.M., “Measurement of
Thermal Conductivity of Partially Saturated Diffusion Media under
Compression,” 2014 ECS Spring meeting, Toronto, Canada, May
12–16, 2014.
16. LaManna, Jacob M., Matthew M. Mench , “ Flow Field and
DiffusionMediaTortuosityInuencesonPEFCWaterBalance,”
Accepted for invited oral presentation. 2014 ECS and SMEQ Joint
InternationalMeeting,Cancun,Mexico,October5–10,2014.
17. LaManna,Jacob M., Daniel S. Hussey, David L. Jacobson,
Matthew M. Mench, “Role of Land Drainage on Water Storage in
PolymerElectrolyteFuelCellsUsingHighResolutionNeutron
Imaging,” Accepted for poster presentation.10
th
World Conference
on Neutron Radiography. Grindelwald, Switzerland, October 5–10,
2014.
18. Fenton, D.J., J.J. Gagliardo and T.A. Trabold, “Analysis of water
morphology in the active area and channel-to-manifold transitions
of a PEM fuelcell,” submitted for publication in Proceedings of the
ASME 8
th
International Conference on Energy Sustainability &
12
th
International Fuel Cell Science, Engineering and Technology
Conference, Paper ESFuelCell2014-6565, Boston, MA, June 30 –
July 2, 2014.
REFERENCES
1.Gu,W.,Baker,D.R.,Liu,Y.,Gasteiger,H.A.,“Protonexchange
membrane fuel cell (PEMFC) down-the-channel performance
model,” Handbook of Fuel Cells - Volume 5, Prof. Dr. W. Vielstich
et al. (Eds.), John Wiley & Sons Ltd. (2009).
2. Owejan, J.P., 2011 Annual Progress Report for the DOE
Hydrogen and Fuel Cells Program (2011).
Coninuedstudiesonthinionomerlmsandionomer-•
substrate interactions.
Neutron imaging data on liquid water saturation within •
GDLfortheeffectsofGDLtype,aging,andoweld
shows the impact of GDL surface properties and heat
transfer.
Validatedoweldpressuredropmodelincludesthe•
effects of water droplet-channel corner interaction, liquid
waterowpattern,andlocaloperatingcondition.
Signicantpressuredropoccursinthenon-active,•
channel-to-manifold region due to liquid water
accumulation therein; peak active area water volume
existslikelyduetogasmomentumandhydraulicforce
balance.
Down-the-channel 1+1D model improved with new •
relationships integrated, and the opposite trend in down-
the-channel current distribution associated with auto-
competitive material set successfully captured.
A parametric study performed for cell component •
optimization, and optimal material properties
recommended for better cell performance.
TheprojectendedinMay2014.Analreportisforthcoming.
FY 2014 PUBLICATIONS/PRESENTATIONS
1. Petrina, S.A. “Water Sorption, Viscoelastic, and Optical
Properties of Thin NAFION
®
Films.” Ph.D. Dissertation,
PennsylvaniaStateUniversity,2013.
2. Kusoglu, A., D. Kushner, D.K. Paul, K. Karan, M.A. Hickner,
A.Z.Weber,“ImpactofSubstrateandProcessingonConnement
ofNaonThinFilms,”Advanced Functional Materials 2014,
DOI: 10.1002/adfm.201304311.
3. Zimudzi, T.J., M.A. Hickner, “FTIR Analysis of Alignment in
NAFION® Thin Films at SiO
2
and Au Interfaces,” submitted to
J. Phys. Chem. B (2014).
4. Kushner, D.I., M.A. Hickner, “FTIR Analysis of Alignment in
NAFION® Thin Films at SiO
2
and Au Interfaces,” submitted to
Langmuir (2014).
5.LaManna,J.M.,J.M.Bothe,F.Y.Zhang,andM.M.Mench,
“Measurement of Capillary Pressure in Fuel Cell Diffusion Media,
Micro-Porous Layers, Catalyst Layers, and Interfaces,” submitted to
J. Power Sources (2014).
6. LaManna, J.M., Chakraborty, S., Gagliardo, J.J., and
Mench, M.M., “Isolation of transport mechanisms in PEFCs
using high resolution neutron imaging,” International Journal of
Hydrogen Energy, 39(7), pp. 3387-3396 (2014).
7. Xu, G., LaManna, J.M., Clement, J.T., and Mench, M.M., “Direct
measurement of through-plane thermal conductivity of partially
saturated fuel cell diffusion media,” Journal of Power Sources, 256,
pp. 212-219 (2014).
8.Owejan,J.P.,Trabold,T.A.,andMench,M.M.,“Oxygentransport
resistance correlated to liquid water saturation in the gas diffusion
V–157
FY 2014 Annual Progress Report
DOE Hydrogen and Fuel Cells Program
V.G Fuel Cells / Transport Studies
Gu – General Motors
10. Gopalan, P., and S.G. Kandlikar, “Effect of Channel Materials
and Trapezoidal Corner Angles on Emerging Droplet Behavior in
ProtonExchangeMembraneFuelCellGasChannels,” Journal of
Power Sources, 248, pp. 230-238 (2014).
11.GrimmM.,E.J.See,andS.G.Kandlikar,“Modelinggasow
in PEMFC channels: Part I – Flow pattern transitions and pressure
dropinasimulatedexsituchannelwithuniformwaterinjection
through the GDL,” Int. J. Hydrog. Energy, 37(17), pp. 12489-12503
(2012).
12. Fenton, D.J., J.J. Gagliardo and T.A. Trabold, “Analysis of water
morphology in the active area and channel-to-manifold transitions
of a PEM fuelcell,” submitted for publication in Proceedings of the
ASME 8
th
International Conference on Energy Sustainability &
12
th
International Fuel Cell Science, Engineering and Technology
Conference, Paper ESFuelCell2014-6565, Boston, MA, June 30 –
July 2, 2014.
13.KaiYangandElHaik,Design for Six Sigma, McGraw-Hill,
2003.
3. Owejan, J.P., Gagliardo, J.J., Sergi, J.M., Kandlikar, S.G.,
Trabold, T.A., “Water management studies in PEM fuel cells, Part
I: Fuel cell design and in situ water distributions,” International
Journal of Hydrogen Energy, 34 (8), 3436-3444 (2009).
4.http://www.pemfcdata.org/data/Standard_Protocol.xls.
5. Zimudzi, T.J., M.A. Hickner, “FTIR Analysis of Alignment in
NAFION® Thin Films at SiO2 and Au Interfaces,” submitted to J.
Phys. Chem. B (2014).
6. Kushner, D.I., M.A. Hickner, “FTIR Analysis of Alignment in
NAFION® Thin Films at SiO2 and Au Interfaces,” submitted to
Langmuir (2014).
7. Kusoglu, A., D. Kushner, D.K. Paul, K. Karan, M.A. Hickner,
A.Z.Weber,“ImpactofSubstrateandProcessingonConnement
ofNaonThinFilms,”Advanced Functional Materials 2014,
DOI: 10.1002/adfm.201304311.
8. Xu, G., LaManna, J.M., Clement, J.T., and Mench, M.M., “Direct
measurement of through-plane thermal conductivity of partially
saturated fuel cell diffusion media,” Journal of Power Sources, 256,
pp. 212-219 (2014).
9.LaManna,J.M.,J.M.Bothe,F.Y.Zhang,andM.M.Mench,
“Measurement of Capillary Pressure in Fuel Cell Diffusion Media,
Micro-Porous Layers, Catalyst Layers, and Interfaces,” submitted to
J. Power Sources (2014).