High Performance, Durable, Low Cost Membrane Electrode Assemblies for … · 2013-05-04 · 3M High Performance, Durable, Low Cost MEAs. 2013 DOE Hydrogen, Fuel Cells, Vehicles Program

3M High Performance, Durable, Low Cost MEAs. 2013 DOE Hydrogen, Fuel Cells, Vehicles Program AMR, May 14-18

High Performance, Durable, Low Cost Membrane Electrode Assemblies for

Transportation Applications

Andrew Steinbach 3M Company

May 15th, 2013

Project ID: FC104

This presentation does not contain any proprietary, confidential, or otherwise restricted information

2013 Annual Merit Review DOE Hydrogen and Fuel Cells and

Vehicle Technologies Programs


Project Overview Timeline

• Project start: 9/1/12 • Project duration: 3 years • Percent Complete: 20%

Barriers A. MEA Durability B. Stack Material & Mfg Cost C. MEA Performance

DOE Technical Targets Electrocatalyst (2017)

• Mass Activity: 0.44A/mg • Inv. Spec. Power: 0.125g/kW(rated) • PGM Total Loading: 0.125mg/cm2 • Electrocatalyst, Support Durability:

< 40% Activity, ECSA Loss MEA (2017)

• Q/∆T: 1.45kW/ºC • Cost: $9/kW • Durability w/cycling: 5000 hrs • Performance @ 0.8V: 0.300A/cm2 • Rated Power: 1W/cm2

Budget • Total project funding $4.307MM

- $3.445 MM DOE - $0.862 MM Contractor

• Funding Received FY12: $2.859MM • Funding for FY13: $1.04MM

(Est. non-FFRDC expend.; DOE share)

Partners • Lawrence Berkeley Nat’l Lab.(A. Weber) • Michigan Technological Univ. (J. Allen) • Johns Hopkins Univ. (J. Erlebacher) • Oak Ridge Nat’l Lab. (D. Cullen) • Argonne Nat’l Lab. (R. Ahluwalia)

2


Relevance and Approach Relevance (Objective): Development of a durable, low-cost, robust, and high performance membrane electrode assembly (MEA) for transportation applications, able to meet or exceed the 2017 DOE targets.

Approach: Optimize integration of advanced anode and cathode catalysts, based on 3M’s nanostructured thin film (NSTF) catalyst technology platform, with next generation PFSA PEMs, gas diffusion media, and flow fields for best overall MEA performance, durability, robustness, and cost. Primary Focus Topics: NSTF Cathode Post-Processing Optimization (Dealloying, Annealing) NSTF Anode Catalyst Composition , PGM Content Sensitivity PEM-Electrode Integration Studies Anode GDL Characterization, Modeling for Cold-Startup Optimization Integration of 2012, 2013(March) Best of Class NSTF MEAs Project Initiation at 3M and Partners MEA Integration Diagnostics (Segmented Cell; HOR Kinetic Studies; Water Balance)

Integration: Includes optimization of existing components and processes via reasonable and known means – NO COMPONENT DEVELOPMENT.

3


Relevance and Approach – Project Tasks

Task Task Description Status/ Timing

1 Component integration towards MEA ¼ power, rated power, and Q/∆T targets.

In Progress/ On Target

2 GDL and interfacial layer integration towards cold start up and transient response targets.

Starting/ Delayed

3 Water management modeling for cold start In Progress/ On Target

4 Overall Best of Class MEA Integration; component interaction mechanism studies.

In Progress/ On Target

5 Component/MEA durability evaluation; Rated-power performance loss mitigation.

Started/ Delayed

6 Short stack eval. of integrated MEAs for rated power, cold/freeze-start, transient response.

Not Started/ Delayed

7 Project management In Progress/ On Target

8 Relative cost and manufacturing assessment Not Started/ On Target

A. Durability

B. Cost

C. Perform.

**************** **************** **************** **************** **************** **************** **************** ****************

4

• Tasks Address Barriers of Durability, Cost, and Performance • Strong Emphasis on Cold-Startup, Load Transient (2,3), and Performance Durability (5).


Milestone, Go/No-Go Goals and Status

Milestone ID

Project Quarter Project Milestone Mar. ’13 Status

/ % Complete BUDGET PERIOD 1 (Sept. ‘12-June ‘14)

6.1 2 Baseline MEA: Short Stack Evaluation Complete. 25% 1.1 7 Component Candidates Meet Interim Performance/Cost Goals 33% 2.1 7 Component Candidates Meet Interim Cold-Startup Goals 5% 5.1 7 Component Candidates Meet Interim Durability Goals 20% 3.1 7 GDL Model Validation With 2 or More 3M Anode GDLs 20% 6.2 7 Interim Best of Class MEA: Short Stack Evaluation Complete. 0%

4.1 Go/No-Go 7

Interim Best of Class MEA Meets Go/No-Go Goals: 1) ≤ 0.135mgPGM/cm2 (Total) 2) Rated Power, Q/∆T: 0.659V@ 1.41A/cm2, 90ºC, 1.5atm H2/Air

99% 0.137mgPGM/cm2

0.658V BUDGET PERIOD 2 (June ‘14 – Aug. ‘15)

1.2 11 Component Candidates Meet Project Performance/Cost Goals 0% 2.2 11 Component Candidates Meet Project Cold-Startup Goals 0% 5.2 11 Component Candidates Meet Project Durability Goals 0% 4.2 11 Best of Class MEA Meets All Project Goals 0%

3.2 12 MEA Cool Start Model Validation with 2 or more 3M MEAs. 0%

6.3 12 Best of Class MEA: Short Stack Evaluation Complete. 0%

8.1 12 Relative Cost Savings Report – Final Best of Class MEA Relative to 2012 MEA. 0%

0 Deliverable 12 Final Best of Class MEA Short Stack Delivered to Evaluation Site. 0%

Q1 Q2 Q3 Q4 Q5 Q6 Q7 Q8 Q9 Q10Q11Q12Q13Kick off

Go NG

End

5


Accomplishments and Progress Improved Activity, Rated-Power Capable ORR Catalysts (Task 1.1): Post-Process Optimization (Surface Energetic Treatment (SET))

0.00 0.05 0.10 0.150.0

0.2

0.4

0.6

0.8

1.0 Previous GenerationAfter Surface Energetic Treatment

ORR

Mas

s Ac

tivity

(A/m

g) in

MEA

Cathode PGM (mg/cm2)

Impact of SET on Pt3Ni7 ORR Mass Activity

DOE 2017Target

Previous GenerationAs Deposited

0.00 0.05 0.10 0.150.0

0.2

0.4

0.6

0.8

1.0 Previous GenerationAfter Surface Energetic Treatment

Current Gen.After Surface Energetic Treatment

Current Gen.As Deposited

ORR

Mas

s Ac

tivity

(A/m

g) in

MEA

Cathode PGM (mg/cm2)

Impact of SET on Pt3Ni7 ORR Mass Activity

DOE 2017Target

Previous GenerationAs Deposited

• Mass Activity of previous generation Pt3Ni7/NSTF increased significantly after SET. • SET: NSTF-compatible

continuous annealing process.

• PREVIOUS WORK – DE-FG36-07GO17007.

• Current generation

Pt3Ni7/NSTF activity, as-deposited, higher than previous, but benefit of SET not yet demonstrated.

Focus of current work is determination of factors to achieve entitlement activity.

6


Accomplishments and Progress Improved Activity, Rated-Power Capable ORR Catalysts (Task 1.1): SET Induces Significant Structural Changes of Pt3Ni7/NSTF Cathodes

• To date, mass activity relatively unaffected by SET process parameters evaluated.

• Monotonic changes observed in specific area, crystallite size, and lattice constant.

MEA evaluation of larger grained

materials in progress.

7

0 20 40 60 80 1000

10

20

300.30

0.35

0.40

0.45

0.50

12

14

16

18

20

Series 1 Series 2 Series 3

FCC

Latti

ceCo

nsta

nt (A

ng)

Pt (1

11) X

tallit

eSi

ze (n

m)

0 20 40 60 80 1003.66

3.68

3.70

3.72

Activity and XRD Trends of Pt3Ni7/NSTF After SET

ORR

Mas

s Ac

tivity

@ 1

050s

(A/m

g Pt)

SET Treatment Level (Arb. Units)

DOE 2017 Target

Mas

s Sp

ecific

Surfa

ce A

rea

(m2 /g

)


Accomplishments and Progress Improved Activity, Rated-Power Capable ORR Catalysts (Task 1.1): TEM Confirms Grain Growth After SET

50 nm50 nm

20.39nm

15.80nm

17.95nm

15.77nm

12.50nm

24.18nm

9.21nm

9.77nm

5.55nm

8.06nm

• Preliminary 3M TEM imaging confirms significant grain growth after SET. • Analysis at ORNL in progress to quantify surface faceting and surface composition.

50 nm50 nm

4.70nm

10.25nm

0.00nm

4.38nm

4.70nm

10.25nm

0.00nm

Untreated SET(2)-70

8


Accomplishments and Progress Improved Activity, Rated-Power Capable ORR Catalysts (Task 1.1): Post-Process Optimization (Dealloying) @ Johns Hopkins (J. Erlebacher)

As-deposited, MEAs with Pt3Ni7/NSTF cathodes have higher activity but lower peak power than Pt68(CoMn)32 ( Ni diss.)

0.0 0.5 1.0 1.50.6

0.7

0.8

0.9

1.0

Cell V

olta

ge (V

olts

)

Current Density (Amps/cm2)

Pt68(CoMn)32/NSTF0.15mgPGM/cm2

Pt3Ni7/NSTF0.15mgPGM/cm2

As Made

80/68/68C, 150/150kPa H2/Air, CS2/2.5GDS(120s/pt)

0.0 0.5 1.0 1.50.6

0.7

0.8

0.9

1.0


Dealloyed

Cell V

olta

ge (V

olts

)

Current Density (Amps/cm2)

Pt68(CoMn)32/NSTF0.15mgPGM/cm2


As Made

80/68/68C, 150/150kPa H2/Air, CS2/2.5GDS(120s/pt)

Current practice dealloying improves peak power; still insufficient to achieve 1W/cm2.

Objective: Dealloying Optimization-Improve Peak Power, Maintain Activity, w/ Scalable Process.

Background – Previous Work

9

Initial work @ JHU (start Feb. ‘13) Electrochemical dealloying of PtxNiy/NSTF to determine entitlement specific area, stable residual Ni content.

-0.8 -0.6 -0.4 -0.2 0.0 0.2 0.4 0.6-3

-2

-1

0

1

2

0.125mgPGM/cm2 Pt3Ni7

0.085mgPGM/cm2 PtxNiy

0.1M H2SO4, 5mV/s, Steady State

Spec

. Cur

rent

(mA/

mg)

Potential (E v. Hg/HgSO4)


Accomplishments and Progress

MEA Cond. Pt6Ni4 Dealloyed Pt4Ni6 As Dep. Pt3Ni7

Improved Activity, Rated-Power Capable ORR Catalysts (Task 1.1): Microscopy Reveals Structural Evolution of Pt3Ni7/NSTF (ORNL, D. Cullen)

• Dramatic porosity increase, Ni loss after MEA conditioning.

Dealloying Development

Needed to Achieve MEA-Conditioned

State, Ex-Situ

• Current practice

dealloying induces less porosity, Ni loss than MEA conditioning.

10


Accomplishments and Progress Durable, Ultra-Low PGM NSTF Anode Catalyst (Task 1.2): PGM Content and Composition Sensitivity Study Completed

0.0 0.5 1.0 1.50.5

0.6

0.7

0.8

0.9

0.0 0.5 1.0 1.50.5

0.6

0.7

0.8

0.9

0.0 0.5 1.0 1.50.5

0.6

0.7

0.8

0.9

Anode PGM (mg/cm2) Baseline 0.05 PtCoMn

0.005 0.01 0.02 0.03

Cell V

olta

ge (V

olts

)

J (A/cm2)

Influence of NSTF Anode Composition, Loading on H2/Air PerformancePtCoMn Pt3Ni7

J (A/cm2)

Pt

80/68/68C, 7.35/7.35psig H2/Air, CS(2,100)/CS(2.5, 167) Galvanodynamic Scan (120s/pt; high->low J only)Anode: Stated. Cathode: 0.10mgPGM/cm2 PtCoMn/NSTF. PEM: 3M 24u 825EW. GDL: 3M 2979.

J (A/cm2)

• Pt, PtCoMn, and Pt3Ni7 at 0.02mgPGM/cm2 comparable to baseline 0.05mgPGM/cm2 PtCoMn. • Project Goal of ≤ 0.02mgPGM/cm2 Achieved. • At further reduced PGM, performance has significant loading, composition dependence.

• 0.01mgPGM/cm2: Pt3Ni7 , PtCoMn >> Pt • 0.005mgPGM/cm2: Pt3Ni7 >> PtCoMn

11


Accomplishments and Progress Durable, Ultra-Low PGM NSTF Anode Catalyst (Task 1.2): Support Optimization Needed for Ultra-Low PGM NSTF Anodes

0.00 0.02 0.04 0.060.0

0.5

1.0

1.5

2.0

PtCoMn/NSTF Pt3Ni7/NSTF Pt/NSTF

Mea

s J

@ 0

.5V

(A/c

m2 )

Anode PGM (mg/cm2)Large performance reduction below

0.02mgPGM/cm2 is concern for robustness and performance

durability.

Typically-used NSTF support not optimized for ultra-low PGM anodes.

Modified NSTF generated.

0.00 0.02 0.04 0.060.0

0.5

1.0

1.5

2.0

PtCoMn/NSTF Pt3Ni7/NSTF Pt/NSTF Pt3Ni7/NSTF*

Mea

s J

@ 0

.5V

(A/c

m2 )

Anode PGM (mg/cm2)

Modified NSTF Support

Performance Improvement with Modified Support – Further Gain Possible?

12


Accomplishments and Progress Durable, Improved Conductivity PEMs (Task 1.3): Multi-Factor Systematic PEM Variable Study Completed

0.0 0.5 1.0 1.50.5

0.6

0.7

0.8

0.9

0.0 0.5 1.0 1.50.5

0.6

0.7

0.8

0.9

Non-supported(2) 20µ

0.125Pt3Ni7(R2RDealloy+SET)

Cell V

olta

ge (V

olts

)

J (A/cm2)80/68/68C, 7.35/7.35psig H2/Air, CS(2,100)/CS(2.5, 167)GDS(0.02->2->0.02, 10steps/decade, 120s/pt, 0.4V limit, 0.1maxJstep)Upscan (high->low J) only.

Supported(2) 20µ, (2) 14µ

825EW, w/ Additive




0512178B (3M 20u 825EW 2% Add) 0512172E (3M 20u 825EW 2% Add Supported) 0512172G (3M 14u 825EW 2% Add Supported)

0.10PtCoMn

J (A/cm2)

• Factors: PEM EW(3), additive(2), 3M support(2), thickness(3); cathode composition(2). • Two Primary Observations

1. PtCoMn: Performance Loss w/ Support and/or EW > 825 (Largely Non-Ohmic). 2. Pt3Ni7: Most Trends Similar to PtCoMn, but More Accentuated.

13


Accomplishments and Progress Durable, Improved Conductivity PEMs (Task 1.3): PEM “Effective” EW Correlation Identified; Dealloying Target Composition Identified

Pt3Ni7/NSTF Limiting J Correlates w/ “Effective” PEM Equivalent Weight

Calculated Effective PEM EW v. PtxNiy Composition

• Substantial cathode Ni dissolution greatly increases calculated PEM EW.

• Increase depends upon starting PEM EW, support, and thickness.

Correlation allows estimate of post-dealloying cathode composition needed to achieve rated power.

800 1000 1200 1400 1600 18000.75

1.00

1.25

1.50

1.75

2.00 734EW, Pt3Ni7 734EW, PtCoMn 825EW, Pt3Ni7 825EW, PtCoMn 1000EW, Pt3Ni7 1000EW, PtCoMn

Lim

iting

J (A

/cm

2 )

Effective EW (g/mol H+)PEM Thickness, Support, Starting EW

and Ni Dissolution (Pt39->Pt65)

800 1000 1200 1400 1600 18000.2

0.3

0.4

0.5

0.6

0.7

Effective EW (g/mol H+)PEM Thickness, Support, Starting EW

and Ni Dissolution (Ptx->Pt65)

Composition Target

Composition w/No Dealloying

Composition AfterCell Operation (TEM, ICP)

734EW 20u Supported PEMPt

Mol

e Fr

actio

n in

0.

125m

g PGM/c

m2 A

lloy

Composition AfterCurrent Dealloying

14


0.0 0.5 1.0 1.5 2.00.5

0.6

0.7

0.8

0.9

0.0 0.5 1.0 1.5 2.00.02

0.04

0.06

0.08

0.10

0.0 0.5 1.0 1.5 2.00.5

0.6

0.7

0.8

0.920µ Supp.20µ Unsupp.

16µ Supp.

3M 734EW 20u Unsupported 3M 734EW 16u Supported 3M 734EW 20u Supported 3M 734EW 24u Supported

Cell V

olta

ge (V

olts

)

J (A/cm2)

24µ Supp. HFR

(ohm

-cm

2 )

J (A/cm2)

80/68/68C, 7.35/7.35psig H2/Air, CS(2,100)/CS(2.5, 167)GDS(120s/pt, high->low J shown)

IR-F

ree

V (V

olts

)

J (A/cm2)

Accomplishments and Progress Durable, Improved Conductivity PEMs (Task 1.3): Perf. Variation with PtCoMn/NSTF May Be Influenced by Active Area Utilization

Ohmic Correction Unsatisfactory

ASSUMEDMEAS

AAl *

=

ρ

Cell Area

FRA

( ) ASSUMEDMEAS ARcmHFR *2 =⋅Ω

Ref. Condition AASSUMED≅AMEAS

Sig. Variation w/ PEM Mod. Variation w/ PEM

Assume HFR variation is due to variation in MEA conductive AREA rather than bulk resistivity.

( )MEAS

MEASACTIVE IA

IJ = ( ) ASSUMEDREF

MEASMEAS A

RIRIA *)(

=0 1 2 3 40.4

0.50.60.70.80.9

Cell V

olta

ge (V

olts

)

JACTIVE (A/cm2)

6 of 8 MEAsin This Series

Area Correction Satisfactory; Mechanism?

15


Accomplishments and Progress Water Management Modeling for Cold Start (Task 3): Understanding Influence of Anode Backing on NSTF MEA Cold-Startup

0 10 20 30 40 500.0

0.5

1.0

1.5

Anode GDL C

Anode GDL B

Time (sec)

Anode GDL A

J @

30C

, 0.4

0V (A

/cm

2 )

A

Significant influence of anode GDL backing on Cold-Startup with NSTF

MEAs.

Task 3 Primary Objective: Determine key material

factors and mechanism(s).

Single Cell Cool-Startup w/ NSTF MEA

16


Accomplishments and Progress Water Management Modeling for Cold Start (Task 3): Material Property Measurements Initiated at MTU(J. Allen), LBNL (A. Weber)

PTL Percolation Measurements GDL C Backing

• Material property measurements in progress; results to be incorporated into existing MTU, LBNL models.

• Methods include: Liquid percolation, capillary pressure/saturation, contact angle, adhesion force, breakthrough pressure, tomography, thermal conductivity,…

GDL Capillary Pressure/Saturation Measurements - GDL C Backing

17


Accomplishments and Progress Water Management Modeling for Cold Start (Task 3): GDL, MEA Modeling Initiated at MTU(J. Allen), LBNL (A. Weber)

Parametric modeling study initiated on effect of backing solid phase distribution on thermal, water

transport.

Percolation Model Trials

Current LBNL model captures many experimentally observed trends;

incorporation of project materials/properties in progress.

0 0.5 1.0 1.5 2.00.5

0.6

0.7

0.8

0.9

1.0

Pa = 1.0 atm (no aMPL)

0.5 atm

1.0 atm

Current Density [A/cm2]

Cell P

oten

tial [V

]1.5 atm

Pc = 1.5 atm, T = 40 °C

Influence of Anode Pressure, Anode MPL

Work under “Fuel Cell Fundamentals at Low … Temperatures” (Weber)

MPL No MPL

18


Accomplishments and Progress Best of Class Component Integration (Task 4.1): Go/No-Go Targets Approached - 2013 3M NSTF Best of Class MEA in Improved Flow Field

Significant gain in rated power, Q/∆T with

improved flow fields.

0.6

0.7

0.8

0.9

0.00 0.25 0.50 0.75 1.00 1.25 1.500.000.050.10

G/NG

2012 Best of Class NSTF MEA - 0.15mgPGM/cm2 TotalAN.:0.03Pt/NSTF. CATH.:0.12Pt3Ni7 (DEALLOY+SET). PEM: 3M 24µ 850EW. GDL: 2979/2979.

Pre-Contract Status2012 BOC MEAStandard FFs

90/84/84C, 7.35/7.35psig H2/Air, CS(2,100)/CS(2.5, 167)GDS(0.02->2->0.02, 10steps/decade, 120s/pt, 0.4V limit, 0.1maxJstep)High->low J OnlyOUTLET P CONTROL

Cell V

olta

ge(V

olts

)

Kinetic+HFR Only Pol. CurveThrough DOE 2017 Targets

HFR Needed to Achieve Target

J (A/cm2)

HFR

(ohm

-cm

2 )

0.6

0.7

0.8

0.9

0.00 0.25 0.50 0.75 1.00 1.25 1.500.000.050.10

G/NG


2012 BOC MEANew FFs



Cell V

olta

ge(V

olts

)



J (A/cm2)

HFR

(ohm

-cm

2 )

Anode PGM reduction - similar/improved

performance. Go/No Go

Metric Pre-Proj. Mar. ‘12

2012 BOC New FF

Sept. ‘12

Red. Anode New FF Mar. ‘13

≤0.135 mgPGM /cm2 0.151 0.147 0.137

≥0.659V @1.41A/cm2 0.609 0.644 0.658

1 MEA

High HFR - 50% of V gap to 2017 Power Target

Cathode Ni

Path to Target: 1) Reduce HFR (Dealloying, Thinner Supp. PEM). 2) Increase Activity (SET)

0.6

0.7

0.8

0.9

0.00 0.25 0.50 0.75 1.00 1.25 1.500.000.050.10

G/NG


0.02PtCoMn AnodeNew FFs

2012 BOC MEANew FFs



Cell V

olta

ge(V

olts

)



J (A/cm2)

HFR

(ohm

-cm

2 )

19


Collaborations Johns Hopkins University (Jonah Erlebacher) – Subcontractor •Task 1 - Pt3Ni7/NSTF dealloying optimization for improved peak power.

Lawrence Berkeley National Laboratory (Adam Weber) – Subcontractor •Task 3 - Cold startup MEA modeling. •Task 3 - GDL characterization.

Michigan Technological University (Jeffrey Allen) – Subcontractor •Task 3 - Integration of 3M anode GDLs into GDL network model. •Task 3- GDL characterization.

Oak Ridge National Laboratory (David Cullen) – Subcontractor •Task 1 - Characterization of dealloy/SET post-processed Pt3Ni7/NSTF cathodes.

Argonne National Laboratory (Rajesh Ahluwalia) – Collaborator •Task 1 - NSTF HOR/HER kinetics characterization study. •3M data provided in support of Fuel Cells Systems Analysis project

20


Key Future Work – FY13, FY14 Task 1 – Integration Activities Toward ¼ Power, Performance @ rated power… •Dealloying, SET Optimization for Improved Peak Power, Activity w/ Pt3Ni7/NSTF. •PEM Integration Towards Confirmation, Resolution of Area Under-utilization. •Further Support Optimization for Ultra-Low PGM Anodes; Durable Anode Incorporation. •Systematic Study of Flow Field Land, Channel Widths on Rated Power Response.

Task 2 - Integration …. Transient Response, Cold Start Up … •Initiation of Anode GDL and Cathode Interlayer Optimization.

Task 3 - Water Management Modeling for Cold Start •Finalize Material Property Measurements, Initiate Modeling with 3M-Specific Materials.

Task 4 - Best of Class MEA Integration Activities •Best of Class Component Integration Towards Interim BOC MEA, Go/No-Go Criteria: (≤ 0.135mgPGM/cm2; Rated Power, Q/∆T: 0.659V @ 1.41A/cm2).

•Improvement in Dealloyed, SET Cathode Critical

Task 5 - Durability Evaluation and Performance Degradation Mitigation •Influence of Post-Processing on Pt3Ni7/NSTF Electrocatalyst Durability. •Irreversible Peak Power Loss Mitigation Study Initiation (Material, Operational Factors).

Task 6 - Short Stack Performance, Power Transient, and Cold Start Evaluation • Finalize Identification of Short Stack Testing Provider. • Complete Short Stack Testing of Interim Best of Class MEA.

21


Summary Performance, Cost, Durability Targets,Go/No-Go Criteria, March 2013 Status

Performance @ ¼ Power, Rated power, and Q/∆T Targets Goal ID Project Goals (units)

Target Value DOE

2013 Status (Rep. MEA)

NEW

Go/No-Go or

Interim 1 Performance @ 0.80V (A/cm2); single cell, ≥80ºC cell

temperature (50, 100, 150kPag Reactant Pressures)

0.300 0.292A ≥0.300 2 Performance at Rated Power, Q/∆T : Cell voltage at 1.41

A/cm2 (Volts); single cell, ≥88ºC cell temperature, 50kPag* 0.709 0.658A 0.659

Cost Targets 3 Anode, Cathode Electrode PGM Content (mg/cm2) ≤ 0.125 0.137A 0.135 4 PEM Ionomer Content (effective ion. thickness, microns) ≤ 16 24A 20

Cold/Freeze Startup, Power Transient Targets 5 Transient response (time from 10% to 90% of rated power);

single cell at 50°C, 100% RH (seconds) ≤ 1 TBD 5 6 Cold start up evaluated as single cell steady state J @ 30°C

[to simulate cold start to 50% of rated power @ +20°C] (A/cm2)

≥ 0.8 0.38B 0.6

7 Cold start up time … @ -20°C; short stack (seconds) ≤ 30 27C 30 8 Unassisted start from -40°C (pass/fail); short stack Pass @

-40°C Pass @ -20°CC

Pass @ -30°C

Durability Targets 9 Cycling time under 80°C MEA/Stack Durability Protocol

with ≤ 30mV Irreversible Performance Loss (hours) ≥ 5000 600D,** 2500

10 Table D-1 Electrocatalyst Cycle and Metrics (Mass activity % loss; mV loss @ 0.8A/cm2; % initial area loss)

≤-40 ≤-30 ≤-40

-67 -24

-26E

≤-40 ≤- 30 ≤-40

11 Table D-2 Catalyst Support Cycle and Metrics (Mass activity % loss; mV loss @ 1.5A/cm2; % initial area loss)

≤-40 ≤-30 ≤-40

-10 -10

-10 D

≤-40 ≤-30 ≤-40

12 Table D-3 MEA Chemical Stability: 500 hours (H2 crossover (mA/cm2); OCV loss (% Volts); Shorting resistance (ohm-cm2))

≤2 ≤-20

>1000

-13±4 -12±5 NA D

≤2 ≤-20

>1000 13 Table D-4 Membrane Mechanical Cycle: 20k Cycles (H2

crossover (mA/cm2); Shorting resistance (ohm-cm2)) ≤2

>1000 16k±0.3k

NAD ≤3

>500

A: Mean or singular values for 3M 2013(March) Best of Class NSTF MEAs: Anode=0.02PtCoMn/NSTF, Cathode=0.117Pt3Ni7/ NSTF(Dealloy+SET), (0.137mgPGM/cm2 total), 3M 825EW 24µ PEM, Baseline 2979/2979 GDLs, ”New” FF2 Flow Field, operated at 90ºC cell temperature with subsaturated inlet humidity and anode/cathode stoichs of 2.0/2.5 and at 50,100,150kPag anode/cathode reactant outlet pressures, respectively. B: Mean values for duplicate 3M NSTF MEAs: Anode=0.05PtCoMn/NSTF, Cathode=0.10PtCoMn/NSTF, (0.15mgPGM/cm2 total), 3M 825EW 24µ PEM, Baseline 2979/2979 GDLs, Baseline Quad Serpentine Flow Field. C: OEM Stack testing results with 3M NSTF MEAs: Anode=0.10PtCoMn/NSTF, Cathode=0.15PtCoMn/NSTF (0.25mgPGM/cm2 total), 3M ionomer in supported PEM, Baseline 2979/2979 GDLs. OEM-specific enabling technology. D: Mean or singular values for 3M NSTF MEAs: Anode=0.05PtCoMn/NSTF, Cathode=0.15PtCoMn/NSTF, (0.20mgPGM/cm2 total), 3M supported 825EW PEM, Baseline 2979/2979 GDLs, Baseline Quad Serpentine Flow Field. Values with estimated standard deviation error tested in duplicate. E: Value for Single 3M NSTF MEA. Anode: 0.05PtCoMn/NSTF. Cathode=0.107Pt3Ni7/ NSTF (Dealloy+SET), 3M 825EW 24µ PEM, Baseline 2979/ 2979 GDLs, Baseline Quad Serpentine Flow Field. *: Cell performance of 0.709V @ 1.41A/cm2 with cell temperature of ≥88ºC simultaneously achieves the Q/∆T and rated power targets of 1.45kW/ºC and 1000mW/cm2, respectively. **: Single sample result. MEA failed prematurely due to experimental error.

22

23

Technical Back-Up Slides

Instruction


Target Polarization Curves Calculation

• Calculated polarization curves which simultaneously meet ¼ power, Q/∆T, and rated power targets.

• Required performance decreases as cell temperature increases to 88°C (Q/∆T)

• Q/∆T target puts strict requirements on: • Cell T (≥88°C) • HFR (≤0.04ohm-cm2)

• Peak power (1W/cm2)

occurs at < 1.5A/cm2 and >0.70V.

0.00 0.25 0.50 0.75 1.00 1.25 1.500.5

0.6

0.7

0.8

0.9

1.0

88C and Hotter

85C

Target Performance @ 80C Target performance @ 85C Target performance @ 90C Target performance @ 95C

C:\Users\us314230\Documents\DOE6\FC23951_LowTotalLoadingPt3Ni7-[Graph12]

Cell V

olta

ge (V

olts

)

J (A/cm2)

Performance Needed To Simultaneously Achieve DOE2017 MEA Targets At Various Cell Temperatures

For T>90C, increasing temperature just decreases Q/dT furtherFor T<90C, kinetics must increase to increase cell V at peak power

J, V to Achieve Rated Power, Q/dT, 1/4 Power Targets80C: 1.31A/cm2 @ 0.761V. 0.760A/cm2 @ 0.80V85C: 1.37A/cm2 @ 0.725V. 0.417A/cm2 @ 0.80V.90C: 1.41A/cm2 @ 0.709V. 0.301A/cm2 @ 0.80V95C: 1.41A/cm2 @ 0.709V. 0.301A/cm2 @ 0.80V

80C

Targets Addressed: J @ 1/4 Power (0.8V, 0.30A/cm2), Rated Power (1W/cm2), and Q/∆T (1.45kW/degC)Model Assumptions: HFR: 0.04ohm-cm2, Tafel: 70mV/dec, No MTO, 90kW Stack

JRJJLOGVV −

−=

00 07.0

CTV

VkW

TQ

rated

rated

rated

40

25.190

−

−∗

=∆

24


Performance Progression – March ‘12 to March ‘13

25

XRF Determined Pt Content for 2013 Best of Class MEA Measured on substrate prior to CCM fabrication.

Anode: PtCoMn Cathode: Pt3Ni7, Dealloy+SET

Meas. # Pt content (mg/cm2) Pt content (mg/cm2)

AVG (#) 0.019 (2) 0.116 (8) RSD (%) 1.5 2.5

0.0 0.5 1.0 1.50.6

0.7

0.8

0.9

0.0 0.5 1.0 1.50.0 0.5 1.0 1.5

0.65 0.70 0.750.10

0.15

0.20

0.25

0.30

0.65 0.70 0.75 0.65 0.70 0.75

J (A/cm2)

Cell V

olta

ge(V

olts

)

Target, 2012 NSTF BOC MEA (0.151mgPGM/cm2), Standard FF, 2012 NSTF BOC MEA (0.147mgPGM/cm2), New FF, 2013 NSTF BOC MEA (0.137mgPGM/cm2), New FF

90C Cell, y/ykPa H2/Air, CS(2,100)/CS(2.5, 167)OUTLET P CONTROL Inlet RH Set for Calculated 100% Outlet RHGDS(120s/pt). High->Low J Shown.

150kPa Outlets 200kPa Outlets

J (A/cm2)

250kPa Outlets

J (A/cm2)

Cell V (Volts)

Inv.

Spe

cific

Powe

r(g

PGM/k

W)

Cell V (Volts) Cell V (Volts)


Accomplishments and Progress Water Management Modeling for Cold Start (Task 3): GDL – MEA Model Integration

26

Water Transport in MEA model (Macro Scale )

• Effective liquid permeability “k” • Effective vapor diffusion coefficient “D”

Water Transport in GDL Model (Pore Scale)

• Poiseuille flow liquid transport • Concentration dispersion vapor transport

Proposed Integration Method

• MTU will generate lookup tables of “k” and “D” of discrete volumes from the GDL model, as function of: • Position • Local conditions (T, RH, P) • Pore morphology (size,

distribution) • LBNL will modify MEA model to

utilize lookup tables.


0.0 0.5 1.0 1.5 2.00.5

0.6

0.7

0.8

0.9

0.0 0.5 1.0 1.5 2.00.02

0.04

0.06

0.08

0.10

0.0 0.5 1.0 1.5 2.00.5

0.6

0.7

0.8

0.920µ Supp.20µ Unsupp.

16µ Supp.

3M 734EW 20u Unsupported 3M 734EW 16u Supported 3M 734EW 20u Supported 3M 734EW 24u Supported

Cell V

olta

ge (V

olts

)

J (A/cm2)

24µ Supp. HFR

(ohm

-cm

2 )J (A/cm2)

80/68/68C, 7.35/7.35psig H2/Air, CS(2,100)/CS(2.5, 167)GDS(120s/pt, high->low J shown)

IR-F

ree

V (V

olts

)

J (A/cm2)

Area Utilization Including Assumptions

Ohmic Correction Unsatisfactory

0 1 2 3 40.40.50.60.70.80.9

J Norm = JMEAS * HFR(JMEAS) / HFRREF

HFRREF: Average HFR of unsupported 734EW PEMs @ 0.1A/cm2

Cell V

olta

ge (V

olts

)J Norm (A/cm2)

ASSUMEDMEAS

AAl *

=

ρ

Cell Area

FRA

( ) ASSUMEDMEAS ARcmHFR *2 =⋅Ω

Ref. Condition

( )ACTIVEMEAS

MEASNORM JU

JJ =

THREE ASSUMPTIONS ASSUMEDMEAS AA ≤

for all J

cl ≅ρfor all J;

meas at ref condition 1≅

ASSUMED

MEAS

AA

At ref cond.

( ) ( )( )

REF

MEAS

MEAS

REFACTIVE A

JAJRRJU ==

Sig. Variation w/ PEM Mod. Variation w/ PEM

27


Accomplishments and Progress Durability Evaluation and Perf. Degradation Mitigation (Task 5): Support, Electrocatalyst Durability of 0.107mgPGM/cm2 Pt3Ni7/NSTF

0.0 0.5 1.0 1.50.50.60.70.80.91.0

0.0 0.5 1.0 1.50.50.60.70.80.91.0 Support Cycle

Initial 10k Cycles 20k Cycles 30k Cycles 40k Cycles

Cell V

olta

ge (V

olts

)

J (A/cm2)

80/68/68C, 7.35/7.35psig H2/Air, CS(2,100)/CS(2.5, 167)GDS(0.02->2->0.02, 10steps/decade, 120s/pt, 0.4V limit, 0.1maxJstep)Upscan (high->low J) only.

Electrocatalyst Cycle

Initial 100 Hours 200 Hours 300 Hours 400 Hours

Cell V

olta

ge (V

olts

)

J (A/cm2)

80/68/68C, 7.35/7.35psig H2/Air, CS(2,100)/CS(2.5, 167)GDS(0.02->2->0.02, 10steps/decade, 120s/pt, 0.4V limit, 0.1maxJstep)Upscan (high->low J) only.

048

1216Electrocatalyst Cycle

Spec

. Are

a(m

2 /g)

40% Loss

0.00.10.20.30.4

30mV Loss

40% Loss

Mas

s Ac

tivity

(A/m

g)

0 10 20 300.66

0.68

0.70

0.72

CV Cycles(/10,0000)

Cell V

@ 0

.8A/

cm2

(Vol

ts)

Hold Time @ 1.2V(Hours/10)

Support Cycle

40% Loss

40% Loss

0 10 20 30 4030mV Loss

Losses After Cycles Primarily Kinetic

Passes Specific Area,

Cell V Loss Metrics; Mass Activity Loss

Exceeds Acceptable Level

Improved M.A. durability to be

addressed within and

outside project.

28