advanced mea’s for enhanced operating conditions, amenable ... · 2 /g) • nstf catalyst...

Advanced MEA’s for Enhanced Operating Conditions, Amenable to High Volume Manufacture

3M/DOE Cooperative Agreement No. DE-FC36-02AL67621

Mark K. DebeFuel Cell Components Program, 3M Company

May 24, 2004

3

This presentation does not contain any proprietary or confidential information.

Project Objectives : 5/03 – 5/04

Development of high performance, lower cost membrane electrode assemblies (MEA’s) qualified to meet demanding system operating conditions of higher

temperature and little or no humidification, with less precious metal catalysts, and higher durability membranes than current state-of-the-art constructions.

• Durable, lower cost MEA’s for operation in the range of 85 < T < ~ 120ºC: - develop next generation, thin film, ultra-thin layer catalyst electrodes (NSTF)- optimize PFSA based ionomers modified for enhanced durability at low RH- match MEA components for enhanced performance under demanding cond.- utilize roll-good fabrication processes for lower cost

• Development of MEA’s for operation in the range of 120 < T < 150ºC:- new PEM’s that do not rely on standard modes of aqueous proton conduction- understanding relationships between materials, proton conductivity, T and RH - screening materials and fabrication processes

-2-2004 DOE Hydrogen, Fuel Cells & Infrastructure Technologies Review May 24-27, 2004

Advanced MEA’s for Enhanced Operating Conditions, Amenable to High Volume Manufacture 3

Budget FY04

Budget3M/DOE Cooperative Agreement No. DE-FC36-02AL67621

($ million)

Contractor DOE Total

Total project 2.03 6.99 9.03

FY04 0.66 2.44 3.10

2004 DOE Hydrogen, Fuel Cells & Infrastructure Technologies Review May 24-27, 2004


Technical Barriers and Targets Addressed by This Project

O. Stack Material and Manufacturing CostReduced catalyst costs: Reduced Pt with nanostructured thin film (NSTF) catalysts Simplified process: single step, high volume, dry, roll-good processing

P. DurabilityEnhanced catalyst support stability: 3M NSTF - whisker support particles ~ graphiteEnhanced catalyst surface area stability at high T: Thin film nature of NSTF electrodesEnhanced oxidative stability of PEM: 3M PFSA ionomer with additives

Q. Electrode PerformanceEnhanced cathode performance: 5x gain in specific activity of 3M NSTF catalyst Reduced mass transport loss at high current density: Ultra-thin layer NSTF electrodes

R. Thermal and Water managementMatched MEA components for sub-saturation operation

Relevant targets for fuel cell stack system for 2010 (Table 3.4.4 of MY RD&D Plan)

Barriers for components

Cost : $35/kWDurability : > 5000 hoursPrecious metal loading : 0.2 g/rated kW



Approach

Task 1 is directed at advancing the state-of-the-art in cathode structures and modified PFSA based PEM’s to stretch the limits of current MEA technology to 85 <T< 120 oC, drier operating conditions, with less Pt.

• Development of advanced cathode catalysts using combinatorial and other screening methods:Thin film Pt ternaries coated on novel nanostructured thin film support particles and incorporated as ultra-thin layer electrodes into new PFSA based PEM’s, for high performance at high temperature

• Development of new membranes based on 3M’s novel PFSA ionomer, with specific additives and chemistries to obtain enhanced oxidative stability under drier, hotter operating conditions

• Optimization of catalyst coated membrane assemblies and gas diffusion layers for high current density operation under low RH

• Use of pilot scale roll-good fabrication processes for catalysts, membranes and GDL’s• 3D, two phase modeling of MEA’s and flow fields to optimize low RH operation• Air management system modeling and prototype development to evaluate P vs flow rate constraints

Task 2 focuses on development of high temperature membranes that do not use water from humidified gases for H+ transport and matching components to take the MEA into a new operating range of T >120°C.

• Synthesis and characterization of fluorinated conductivity-enhancing additives, and inorganic proton conductors as electrolyte replacements for water

• Incorporation of mixtures of those electrolytes into various polymer and microporous media• Fuel cell performance characterization of catalyzed membranes



Safety

3M’s established procedures regarding safety-related issues include:• Hazard Reviews to ensure compliance with corporate environmental,

health, and safety requirements:– New or modified facilities, equipment, & processes – Fabrication & testing equipment– Laboratory & Manufacturing

• New Product Introduction system– Risk assessment process in the design and production of products– Life Cycle Management process– Change Management

No unusual safety issues have been encountered to-date on this project.



Project Timeline

Q1 Q2 Q2 Q4 Q5 Q6 Q7 Q8 Q9 Q10 Q11 Q12 Q13 Q14 Q15 Q16CY2002 CY2003 CY2004 CY2005

Task 1.0 Medium Temperature MEA Development , 85 < T < 120 oCM1. NSTF catalyst composition and support characteristics down-selectedM2. Modified 3M PEM and additives down-selectedM3. Electrode backing and GDL coating down-selectedM4. Pilot scale quantities of roll-goods fabricated for initial stack testingM5. Short stack testing completed

Task 2.0 High Temperature MEA Development, T> 120oCM6. Down-selection of electrolyte additives M7. Down-selection of membrane matrix media and processM8. Selection of anode and cathode catalysts for high temperature PEMM9. Final high temperature testing completed of medium sized MEA’s

Task 3.0 Scale-up of optimized process for integrated MEA component fabricationM10. Scale-up/optimization of fabrication processes for PEM, catalyst, CCM, GDLM11. Completion of final MEA’s characterized in full-scale short stack

M1M2 M4

M3M5 M7

M6M11

M8M9

M10 today



Selected Technical Accomplishments 5/03-5/04 : NSTF Catalysts• 40 new NSTF PtAxBy ternary catalyst constructions fabricated and evaluated (~ 100 total)• 17 large area combinatorial library arrays fabricated and evaluated on NSTF support films• Documented 5x gain in specific activity of NSTF over Pt/Carbon by three methods:

– RRDE at LBNL and 50cm2 cells at 3M• Eliminated mass transport losses under H2/air at 2 A/cm2 with ultra-thin NSTF electrodes• Determined stable phases of PtM binary and PtAB ternaries in acid baths and fuel cells• Demonstrated electrochemical and high temperature stability of NSTF catalyst surface areas• Identified critical path for GDL/catalyst improvements to reach 2010 DOE performance targets

0 50 100 150 200 250 3000.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

0.55

From 75C, 0 psig, H2/air PDS-back scan curves

95% confidence bands

Pt deposition process 2J = (0.0129 + 0.00039) * ECSA

R = 0.993, 7 Samples

LANL, 6/2000 DOE REVIEW80C, 41 psia H2/O220% Pt/Carbon

Pt deposition process 1J = (0.0101 + .00025) * ECSAR = 0.8767, 41 samples

J = (0.00162 + .000063) * ECSAR = 0.839, 3M MEA's with dispersed carbonsupported Pt (30 samples)

J (A

/cm

2 ) at

0.8

13 v

olts

Electrochemical Surface Area (cm2/cm2 - planar)

NSTF Cathode Specific Activity:J(.813V)/ECSA = 10.1 + .25 mA/cm2-Pt Dispersed Cathode Specific Activity: J(.813V)/ECSA =1.62 + 0.06 mA/cm2-Pt

NanoStructured Thin Film(NSTF)Thin Layer Catalysts- no carbon- no ink layer- organic crystalline whisker

support particles- thin film catalyst coating- all dry roll-good processing- 5x gain in specific activity- <1µm electrode thickness

Method 2



• Seven 3M nanostructured thin film catalyst samples were characterized by LBNL with their rotating ring disc electrode method - 1 baseline Pt and 6 PtAB ternaries: • LBNL’s RRDE measurements agree well with 3M’s two methods of specific activity measurement in 50 cm2 cells: NSTF specific activity is ~ 5 x larger than Pt/Carbon catalysts.• Specific activity of these Pt ternaries is same as pure Pt coated whiskers.

• The LBNL RDE measured mass specific surface areas (m2/g) agree well with the 3M measured values in 50 cm2 cells.

• Mass specific area depends on NSTF support whisker geometry.

0

2

4

6

8

10

12

14

16

1 2 3 4 5 6

ECSA LBL

FC ECSA

Pt Ternary Catalyst Sample Set

Pt m

ass

spec

ific

surfa

ce

area

(m2 /g

)

• NSTF catalyst Specific Activities are similar to polycrystalline bulk platinum.

Technical Accomplishments – NSTF Catalyst – Specific Activity

0.80 0.82 0.84 0.86 0.88 0.90 0.92 0.94 0.96

0.1

1

10

3M Method 1

High surface areacarbon supportedPt by LBNL-RDE

NSTF byLBNL-RDE

3M-Method 2Av. of 41 MEA's

Adv.Cat._LBNL_Spec.Act.

Spec

ific

Act

ivity

(mA/

cm2 - P

t)

E versus RHE (V)

LBNL - 3M Pt LBNL - 3M Ternary 1 LBNL - 3M Ternary 2 LBNL - 3M Ternary 3 LBNL - 3M Ternary 4 LBNL - 3M Ternary 5 LBNL - 3M Ternary 6 3M - 50 cm2 - Methods 1 & 2 LBNL- Carbon Supported HSAC



Technical Accomplishments – NSTF Catalyst – Specific Activity

* Segmented cell characterization of Dalhousie combinatorial catalyst library at 3M points to two ternaries , PtCA and PtCD , that should give a further gain in specific activity.

* Initial 50cm2 cell tests confirm an improvement in specific activity.

Combinatorial library coatings of Pt binary and ternary on NSTF support films at Dalhousie University using similar coating processes as 3M’s:

Four commonly known transition metals in Pt ternary components tested thus far in variable discrete % compositions in 50 cm2 cells, and as continuously variable combinatorial arrays tested in small area segmented cells: PtA, PtB, PtC, PtD, PtDB, PtAB, PtAD, PtCA, PtCD

0.0 0.5 1.0 1.5 2.0 2.5 3.00.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

2.2

2.4

2.6

2.8

3.0

PotentialimprovementPtCA or PtCD

Pure PtValue

Specific Activity of Segmented Cell Measurements of 50 cm2 CombinatorialLibrary Arrays of PtCA and PtCD, Averaged over Segments.

Spe

cific

Act

ivity

(A/c

m2 -P

t)

Pt - TM Structure Factor

PtCD PtCA



0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.20.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

95oC

50 cm2, Quad SerpentineCell Temperature: As statedPressure: 300/300 kPa abs. H2/AirHumidity: 60%/60% RHStoich. Flow: CS 2.0/2.5 anode/cathodeGalvanostatic: ~ 5 minutes/point until stable

80, 85, 90oC

FC8565 - graph 4

Cel

l Vol

tage

(V)

Current Density (A/cm2)

V,80,30,2/2.5,60/60 V,85,30,2/2.5,60/60 V,90,30,2/2.5,60/60 V,95,30,2/2.5,60/60

MEA

• Cathode Catalyst:0.10 mg-Pt/cm2 inPtAB ternary

• Anode Catalyst:0.15 mg-Pt/cm2

• PEM:3M-Cast Nafion36 micron thick

• GDL/EB:3M GDL on carboncloth backing:

HFR = 0.10 ohm-cm2 is~ 100% higher than norm.

Achieving high current density for high power density stacks requires minimal mass transport losses. The NSTF ultra-thin layer electrode thickness minimizes loss.

Technical Accomplishments – NSTF Catalyst – Low mass transport loss



Technical Accomplishments – NSTF Catalyst – Low mass transport loss

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.20.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

95oC

50 cm2, Quad SerpentineCell Temperature: As statedPressure: 300/300 kPa abs. H2/AirHumidity: 60%/60% RHStoich. Flow: CS 2.0/2.5 anode/cathodeGalvanostatic: ~ 5 minutes/point until stable

80, 85, 90oC

FC8565 - graph 4

Cel

l Vol

tage

(V)


V,80,30,2/2.5,60/60 V,85,30,2/2.5,60/60 V,90,30,2/2.5,60/60 V,95,30,2/2.5,60/60

* At the test conditions shown, there is little or no mass transport loss in the NSTF electrode layer or GDL at 2 A/cm2, assuming a Tafel slope of ~70mV/decade .* Mass transport losses in the NSTF catalyst coated membrane electrode layer are minimal with the catalyst composition and loading correctly matched to the whisker support particles.

0.27 µm

PEM

Catalyst Electrode

0.1 10.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

~ 0 mV @ 2 A/cm2

FC8565: Nanostructured Catalyst CCM, 0.25mg Pt/cm2 total per MEAPEM - Cast nafion, SDY01346-1, 36 microns: Anode - PE4122, 0.15 mg Pt/cm2

IR - Corrected

HFR

Measured

FC8565-graph 18

Tcell = 80oCH2/air Stoich = 2.0/2.5H2/air pressure = 30 psigHumidity: 60%/60%

70 mV/decadereference line

E(V)

and

Eir-

free(V

)

i(A/cm2)2004 DOE Hydrogen, Fuel Cells & Infrastructure Technologies Review May 24-27, 2004


0.2

0.4

0.6

0.8

1

1.2

1.4

0 10 20 30 40 50 60

Nanostructured 1Nanostructured 2Carbon 1Carbon 2

SEF

Nor

mal

ized

to In

itial

Val

ue

Time at 1.2 Volts (hours)

Nanostructured film – Pt/Whisker

Nanostructured film – PtD/Whisker

Carbon-2 type, 0.4 mg/cm2

Standard carbon-1 type, 0.4 mg/cm2

Normalized ECSA versus Time at 1.2 V

1.2 volts electrochemical stress test has been applied to carbon supports and the nanostructured thin film catalysts.

Nanostructured films are more electrochemically stable against loss of surface area than a standard carbon supported Pt catalyst and similar to carbon-2 type.

ECSA

Nor

mal

ized

t o In

i tial

Val

ue

0.2 mg/cm2

Technical Accomplishments – NSTF Catalyst – Surface area (ECSA) stability

ECSA measured after repeated 5 hour periods with cell polarized at 1.2V at 800C under saturated H2/N2.



0 50 100 150 200 250 300 350

-2

0

2

4

6

8

10

12

14

16

18

20

PtAB on cathode

PtAB on anode

PtCB on anode

PtCB on cathode

FC834 High Temp Durability -graph 2

FC8534 Stress Test: 120oC, GSS=0.4 A/cm2, 30/30 psig, 60%/75% RH, Flow Rate:A362/C663 sccm

CathodeSelf-cleaned

AnodeSelf-cleaned

MEAReversed

MEA Failure

EC

SA

, H2 C

ross

-ove

r, S

hort

Res

ista

nce

Time (hours)

Cathode ESCA Cath. H2 X-over (mA/cm2) Cath. Short (Kohm-cm2) Anode ECSA Anode H2 X-over (mA/cm2) Anode Short (Kohm-cm2)

• The H2 cross-over and short resistances extracted with the ECSA were very stable until the MEA failed completely.

• Both anode and cathode show some decay in surface area initially, then “self-cleaned” and ECSA recovered.

• PtCB ECSA ~ 80% of initial value after > 100 hours at 120oC. Dropped another 6% over next 125 hours.

Surface area stability at 120oC and water balance conditions: Technical Accomplishments – NSTF Catalyst – Surface area (ECSA) stability

• Multiple MEA’s tested



Dalhousie has done extensive characterization of combinatorial libraries of various binary and ternary NSTF catalysts for:• Surface and bulk compositions and structure – comparing as-made with acid

soaked and fuel cell tested catalysts,• Lattice constants vary with Pt and TM atomic fractions, before and after acid exposure,• PtXY form random, solid solutions,• Extent of bulk or surface depletion of TM depends on initial amount,• Same stable PtTM phases obtained after acid washing as after fuel cell operation.

Technical Accomplishments – NSTF Catalyst – Composition stability

• xafter in Pt1-xAx of the Pt1-xAx library plotted versus xbefore in Pt1-xAx for a library used in a fuel cell, and an identical library treated with 1M H2SO4at 80°C for 10 days. (A = Ni or Fe)

• The data points after acid treatment show no evidence for the presence of surface A atoms at any point in the library.

• Similar effects for PtXY ternaries 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1x in Pt1-xNix Before Acid Treatment

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

x in

Pt 1-

xNi x

Aft

er A

cid

Tre

atm

ent Fuel Cell

Acid Treatment



NSTF Pt specific power density entitlement is < 0.2 gPt/kW for cell voltages < 0.75 V for conditions shown with current development status.

Technical Accomplishments – Definition of Potential Pathway to DOE Targets1) Reduce EB/GDL impedances by 50% while maintaining the high permeability.2) Reduce anode loading to 0.05 mg/cm2 with same performance currently achieved with 0.15 mg/cm2.3) Double mass activity (A/g) by increasing mass specific area (m2/g) 60% and specific activity 35% while

maintaining 5x gain in specific activity (A/cm2-Pt).4) Integrated MEA with NSTF/3M-PEM optimized for higher T, lower RH operation and minimal F- release.

0.50 0.55 0.60 0.65 0.70 0.75 0.80 0.850.00.10.20.30.40.50.60.70.80.91.01.11.21.31.41.51.6

Further 20mV gain from gain in A/g.

DOE 2005 Targetat rated power

Currently measured with existing GDL/EB and

0.15mg Pt/cm2 on Anode.

DOE 2010 Target

Potential with reduction of HFR by 50% and anode loading

drop to 0.05 mg Pt/cm2.

Potential with 50% reduction of HFR

of (GDL/EB)

FC8565: Pt-Specific Power Densities (gPt/kW) achievable with HFR reduced 50% with improved GDL/EB, reduced anode loading, and 2x Gain in Mass Activity.

Cell Temperature: 80oCPressure: 30/30 psigHumidity: 60%/60%Flow: CS 2.0/2.5 anode/cathode0.10 mg/cm2 on Cathode

FC8565 - graph 30

g-P

t/kW

Cell Voltage (V)0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

+ 2X gain in A/g

50% Reduction in GDL/EB Resistance

Current

0.1 mg Pt/cm2 in PtCoFe

FC8565: Projected performance improvements assuming HFR is Reduced by 50%, Specific Activity increased 33%

and Mass Specific Area increased 60%.

HFR/2HFR

Cell Temperature: 80CPressure: 30/30 psigHumidity: 60%/60%Flow: CS 2.0/2.5 anode/cathodeGSS, ~ 5 minutes/point until stable

FC8565 - graph 14

Cel

l Vol

tage

(V)




1.E+06

1.E+07

1.E+08

1.E+09

1.E+10

25 50 75 100 125 150 175 200Temp (C)

E' (

dyne

s/cm

2 )

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

Tan

Del

ta

Nafion E'

3M Membrane E'

Nafion Tan Delta

3M Membrane Tan Delta

DMA of Cast Nafion and 3M Membrane

• Tg of 3M membrane is 25 0C higher than same equivalent weight Nafion.

• Modulus of 3M membrane > 10X higher than Nafion at 120 oC, dry.

Selected Technical Accomplishments – Membranes - PEM for 85<T<120oC • Demonstrated new PEM with higher Tg,Modulus and equivalent conductivity/permeability to

cast Nafion at same EW. New PEM shows lower F- release rates in fuel cell testing.• Additives to 3M PEM substantially increase oxidative stability and further reduce F- release.• Lower EW PEM’s fabricated with lower resistance under hotter, drier conditions.• Optimum PEM processing methods identified with NSTF catalysts for rapid start-up.• Optimum PEM processing methods identified for further reduction of F- release rates.



Technical Accomplishments - PEM for 85<T<120oC – F- Release Rates

0.1

1.0

10.0

100.0

1000.0

3MMembraneProcess A

3MMembraneProcess B

3MMembraneProcess C

3MMembraneProcess D

Cast Nafion1000

Nafion 112Fluo

ride

Ion

Rel

ease

Rat

e (n

gram

s/m

in)

Anode Cathode

near detectibility limit

• Fluoride concentration in effluent water is up to >100 x lower for 3M membrane than Nafion.• These 3M membranes are neat, no additives for oxidative stability.

Fluoride release of various membranes. Rates reflect F- ion concentration in water collected in accelerated fuel

cell testing at 80°C, with 60oC dewpoint on anode and cathode.



0

10

20

30

40

50

60

70

80

90

100

0 0.01 0.1 0.3 3

Weight Percent Additive E

Mas

s Lo

ss a

s Pe

rcen

t of C

ontr

ol

No mass loss within experimental error for this additive at ≥ 0.3 wt. %

Technical Accomplishments - PEM for 85<T<120oC – Oxidative stability

• ~ 2 dozen additives screened by mass-loss in H2O2 soak • 5 primary candidates down-selected for MEA fuel cell F- release tests

1 M H2O2 (refreshed daily), 90 C, 5 days

3M PFSA Ionomer

Adding Additives to the 3M membrane can give further oxidative stability:

• Additive A was effective even at 0.01 wt. %.• Mass loss completely suppressed at ≥ 0.3 wt. % Additive E.



Technical Accomplishments - PEM for 85<T<120oC – Oxidative stability

0.000

0.100

0.200

0.300

0.400

0.500

0.600

0.700

Additive A Additive B Additive C Additive D Additive E Additive F Control lotA

Control lotA

Control lotB

Control lotB

AverageControl

Tota

l F- G

ener

atio

n m

icro

gram

s/m

i ControlsAdditives

Fluoride Release 90/60/60º C, Load cycled from 0 to 0.5 A/cm2

50 cm2 cell, Dispersed catalyst, 0.4/0.4 Pt/Pt, 800/1800 SCCM H2/air

• All five additives were effective in reducing F- release rates below controls• F- release rates in operating fuel cell reduced by 1-2 orders of magnitude.



Selected Technical Accomplishments – Non-aqueous Membranes for T > 120oC

Acid/Liquid –Liquid Cell Proton Conductivity

• Ab initiocalculations by J.

W. Halley (U. of MN) give close

correspondence, about 0.3 eV for the

Acid A/ Liquid X system.

• Concentration effects and Monte Carlo simulations also being studied.

• Three basic approaches: Conductivity enhancing additives in -a) polymers and b,c) two types of inorganic composites

• Fundamental characterization of proton conduction in liquid cells and MD modeling• Basic membrane conductivity characterization as a function of temperature• Membrane formation and electrolyte incorporation process development

• Eactivation = ~ 0.2 eV

0.001

0.010

0.100

2.4 2.5 2.6 2.7 2.8 2.9 31000/T(k)

Log

Con

duct

ivity

Acid A/Liquid X 10:90Acid A/Liquid X 1:2Acid B/Liquid Y 1:2Acid C/Liquid Z 10:90

120C 70C



Proton conductivity as a function of cell temperature with 80C Dew Point

0.00

0.01

0.10

1.00

70 80 90 100 110 120 130Cell temp., C

Con

duct

ivity

, S/c

m

Cast Nafion 1000

1:6 PBI/PhosacidCast Nafion +acid additive D

• T < 1000C : Conductivity of Acid D/Nafion membrane is higher than Nafion 1000 or PBI-6PA membrane.

• T > 1000C : Conductivity is higher than Nafion but below PBI-6PA.

Task 2 – Liquid additive in polymer approach Basic Membrane Conductivity Testing


• Conductivity of Membrane with Acid D is highly stable at all conditions.

• Acid additive D is stable by TGA to > 250 0C



0.000

0.002

0.004

0.006

0.008

0.010

0.012

0.014

40 60 80 100 120 140

Tem p., C

Con

duct

ivity

, S/c

m

P rocess AP rocess BP rocess C

Task 2 – Electrolytes in type 1 inorganic oxide composite approachBasic Membrane Conductivity Testing – Bone Dry.


Processing conditions affect stability of composite, conductivity, and imbibing of electrolyte.

Bone Dry

Electrolyte: Acid A/Liquid X, 90:10



Interactions and CollaborationsAdvanced Catalysts: Fabrication, Fundamental Characterization, UnderstandingDalhousie University: Prof. Jeff Dahn - Combinatorial materials fabrication and characterization of

Pt ternary catalysts applied to 3M NSTF support films.Lawrence Berkeley National Lab: P. Ross, N. Markovic, et al. - RRDE measurements of

specific activities and other fundamental properties of 3M NSTF catalysts.U. of Illinois, Urbana : Prof. A. Wieckowski - High resolution STEM and RAIR characterization of

3M NSTF catalysts.Brookhaven National Laboratory: J. McBreen - EXAFS, XANES of 3M NSTF catalysts.

Advanced Membranes: FundamentalsU. of Minnesota: Prof. Woods Halley - Theory and simulation studies for non-aqueous membrane

based proton conduction.CWRU: Prof. T. Zawodzinski - Fundamental experimental studies of proton transport in liquid and solid

proton conductors, and fundamental studies of catalyst/electrolyte ORR.

MEA Modeling: 3D Mixed Phase Modeling of Operating MEAU. of Miami: Prof. H. Liu - Extend existing 3M/U. of Miami developed MEA model to determine optimum

component properties for dry operation, adapt to treat ultra-thin electrode layers.

Air Management: Modeling and Hardware DevelopmentVairex Corp.: Understanding and development of an air management system designed for optimized

performance of 3M MEA’s operating under hot, dry conditions



Response to Previous Year Reviewers’ Comments

Q1, Q2, & Q5: Positive comments. No questions or criticisms offered.

Q3: Question about the reality of the lower F- generation rate for 3M’s PFSA membrane.Response: We have generated and shown subsets of extensive data bases documenting

the reduced F- generation rate of the 3M PFSA membrane.

Q4: “3M appears to be very possessive relative to industrial collaboratives. 3M needs to open up its innovations (re:polymers and catalysts) to neutral 3rd parties.”

Specific recommendations…: “3M’s innovations should be independently verified because, if proven out, their developments could have major impact.”

Weaknesses: “Needs to open up on the technical innovation to third party industrial firms.”

Response: We have benefited this year significantly from the independent validation by LBNL of our NSTF catalysts’ enhanced specific activity. We are working with selected customers outside the contract to incorporate NSTF catalyst based MEA’sinto their future products.



Future Work• Remainder of FY 2004

85 oC < T<120 oC MEA :- Advanced NSTF catalysts:

Complete PtAB down-selection process for highest specific activity and high temperature stability, optimize NSTF whisker support for increased m2/g, optimize EB/GDL for reduced resistance, high permeability, low RH operation.

- PEM’s: Down-selection process completed for membrane EW and additives. - MEA integration: Optimize NSTF/PEM/GDL interface- Pilot level scale-up: Fabricate pilot-scale quantities of roll-good fabricated MEA.

T>120 oC MEA :- Proton conduction: Continued fundamental studies of mechanisms in additives.- Membrane matrix formation: Focus on identified critical issues for existing approaches.- Membrane electrolyte: Synthesis and membrane matrix imbibing or filling.- MEA evaluation: Accelerate fuel cell testing and in-situ characterization.- PEM/Catalyst: Initiate studies of electrolyte/catalyst interface effects on ORR.

• FY 2005- Complete short stack testing of T <120 oC MEA, using large area MEA’s.- Scale-up and optimization of component processes for T <120 oC roll-good MEA.- Down-select MEA components for T > 120 oC MEA’s.- Complete full high temperature characterization of down-selected, T > 120 oC MEA in

medium sized area MEA’s.



advanced mea’s for enhanced operating conditions, amenable ... · 2 /g) • nstf catalyst...

Documents