Low Cost PEM Fuel Cell Metal Bipolar Plates

CH Wang

TreadStone Technologies, Inc.

Fuel Cell Project Kickoff Meeting

Oct. 1, 2009

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• TreadStone is a small business technology spin-out of Sarnoff Corporation in March 2006

• The metal corrosion protection technology has been developed for over 5 years. The US Patent (US 7,309,540) was issued on Dec. 8, 2007. More patent applications have been filed.

• The technology has been evaluated by various clients and used in portable fuel cell power systems.

Corporate Mission

Achieving continuous growth in profits, revenue and net worth through the commercialization of new technologies for the energy market.

Corporate Background

TreadStone Background and Mission

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Project Objectives

• Overall Objective: Develop lower cost metal bipolar plates to meet performance target and 2015 cost target (<$3/kW)– Develop C-steel or Al based metal

bipolar plates.

– Reduce or eliminate Au usage.

– Optimize the process for large scale manufacture.

– Demonstrate our metal plate application in portable, stationary and automobile fuel cell systems.

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Plate

Cleaning

Plate

Coating

Stamp

Cathode

Stamp

Anode

Laser

Weld

Leak

Check

Man

ufa

ctu

rin

g C

os

t ($

/ p

late

)

Capital CostLabor Overhead CostMaintenance CostBuilding CostTooling CostEquipment CostUtility CostDirect LaborMaterial Cost

SS Cost

Gold Cost

Cost Breakdown of TreadStone’sCurrent SS Plate

• Bipolar plate cost: $1.41/plate-- $3.53/kW (based on 1000mW/cm2)

• Meet 2010 Target < $5/kW• Need Improvements to meet

2015 Target < $3/kW

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Technical Targets

Characteristic Unit 2010 Target 2015 Target

Cost $ /kW 5 3

Weight kg/kW <0.4 <0.4

H2 Permeation Flux cm3.sec-1.cm-2 <2 x 10-6 <2 x 10-6

Corrosion mA/cm2 <1 <1

Electrical Conductivity S /cm >100 >100

Resistivity ohm.cm <0.01 <0.01

Flexural Strength MPa >25 >25

Flexibility % deflection at mid-span 3-5 3-5

• It is proven that metal plates can reduce the fuel cell stack weight and volume.

• Key barriers for metal bipolar plates: corrosion resistance and resistivity at low cost

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Technical Approaches

• Use small conductive, corrosion resistant materials as conductive points (conductive vias) to cover a small portion of metal surface

• Use non-conductive, corrosion resistant materials to cover majority surface of the metal plates

Conventional graphite plate stack

Conductiv e v ias

Metal Core

Gas Diffusion Layer

Conducting

graphite

MEA

Bipolar pla te

Gas Diffusion Layer

MEA

Air Air

H2 H2

Air Air

H2 H2

Non conductiv ecoating

Conductiv e v ias

e- e-e- e- e-e-

TreadStone metal plate stack

Electron

current Electron

current

Conventional graphite plate stack

Conductiv e

Metal Core

Gas Diffusion Layer

Conducting

graphite

MEA

Bipolar pla te

Gas Diffusion Layer

MEA

Air Air

H2 H2

Air Air

H2 H2

Non conductiv ecoating

Conductiv e

e- e-e- e-e- e-e-e-e- e- e-e- e-e- e-e-e-e-

metal plate stack

Electron

current Electron

current

Conventional graphite plate stack

Conductiv e v ias

Metal Core

Gas Diffusion Layer

Conducting

graphite

MEA

Bipolar pla te

Gas Diffusion Layer

MEA

Air Air

H2 H2

Air Air

H2 H2

Non conductiv ecoating

Conductiv e v ias

e- e-e- e-e- e-e-e-e- e- e-e- e-e- e-e-e-e-

TreadStone metal plate stack

Electron

current Electron

current

Conventional graphite plate stack

Conductiv e

Metal Core

Gas Diffusion Layer

Conducting

graphite

MEA

Bipolar pla te

Gas Diffusion Layer

MEA

Air Air

H2 H2

Air Air

H2 H2

Non conductiv ecoating

Conductiv e

e-e- e-e-e-e- e-e- e-e-e-e- e-e- e-e-e-e- e-e- e-e-e-e-

metal plate stack

Electron

current Electron

current

Gold Vias Cover

1.1% Surface area

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0 50 100 150 200 250 300

Gold Vias Diameter mm

Co

nta

cti

ng

Resis

tan

ce

mW

.cm

2

2.4% Gold Coverage

1.2% Gold Coverage

250,000 vias/in2

10,000 vias/in2

2,500 vias/in2

125,000 vias/in2

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1,250 vias/in2

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Cell Test Shut-off

for 6.5 months

Restart the test at higher

current density

Single Cell Performance using Treadstone’s SS Plate

TreadStone SS Plate Standard SS Plate Ion Content

(mg/l) Anode Cathode Anode Cathode

Chromium < 0.01 < 0.01 < 0.01 < 0.01

Iron < 0.01 < 0.01 < 0.01 0.04

Nickel < 0.01 < 0.01 0.15 0.38

Condensation Water Analysis

Achieved 8200 hrs (3500 hrs operation +

4700 hrs stand-by) long term stability test

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Cost Study of TreadStone’s SS Plate

For Automobile Plate Size…

• Cost <$2.00/plate at >2M plates/yr volume

• Cost $1.41/plate at 200M plates/yr volume

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PVD Gold 3nm Treadstone Gold Coating w/Ti

Treadstone Gold Coating w/o Ti

Co

ati

ng

Co

st

pe

r B

PP

Gold Coating Costs

Cost of Capital

Overhead Labor Cost

Maintenance Cost

Building Cost

Tooling Cost

Equipment Cost

Utility Cost

Direct Labor Cost

Material Cost

PVD 3nm gold TreadStoneProcess #1

TreadStoneProcess #2

Large Scale Manufacturing Cost Analysis

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tal

Man

ufa

ctu

rin

g C

ost

($/k

g)

Annual Production Volume (1000s bipolar plates/yr)

Production Volume Sensitivity

Total Cost

Investment

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Project Timeline

Low cost conductive vias demonstrated

Full evaluation of large scale processed vias

C-steel Based Plate Demonstrated

Aluminum Based Plate Demonstrated

200W Stack Demonstrated

1 kW Stack Demonstrated

Metal Plates Demonstrated for

Automobile Applications.

Project Accomplished

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Team Members

DOE

TreadStone

• Project Management.• Metal Plate Corrosion

Protection Technology Development.

• Collaboration withIndustrial Partners

PI: Dr. CH Wang

Gas Technology Institute

• Stack Design and Demonstration using Metal Plates for Portable and Stationary Applications

Dr. Chinbay Fan

Oak Ridge National Lab.

• Corrosion Mechanism and Failure Model Study

Dr. Dane Wilson

State University of New York, Stony Brook

• Thermal Spray Process Development for Metal Plate Fabrication

Prof. Sanjay Sampath

IBIS Associates, Inc.

• Fabrication cost analysis

Mr. Tony Mascarin

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• Molded graphite plates

• Low-cost metal alloy plates

for high power density

• High performance metal plate stacks

: PEM Fuel Cells Development & Testing

• Extensive experience designing & making PEMFC stacks

o Vertically integrated in-house stack prototyping

• Comprehensive testing facilities

• Wide variety of test cells and stands

50+ years in fuel cell technology development

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ORNL, SUNY Stony Brook, and IBIS Overview

• Established in 1996 as a Materials ResearchScience and Engineering Center funded by NSF

• Host of an industrial consortium for thermalspray technology with 26 companies.

• Integrated thermal spray systems, processdiagnostics and characterization capabilities

Center for Thermal Spray Research

• Founded in 1987 by MIT professor• Experienced in materials and

manufacturing technologies analysis

Sample of Major Clients

Particle Image

Velocimetry

Particle Image

Velocimetry

Particle Image

Velocimetry

Particle Image

Velocimetry

SPT

DPV

IPP[mm

]

- 10 - 5 0 5 10 15 20x [mm]

- 20

- 15

- 10

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0

5

10

z

Flow

<2500.

<5800.

<9100.

<12300.

<15600.

<18900.

<22200.

<25400.

>25400.

Flow

z

z

0

w

injection

spray distance

3D Particle In Flight Diagnostics

exposure

window

in flight properties

crossection distributions

injection monitoring

plume position

plume T

particle melting state

Experiment

heated

substrate

sliding

direction

splat

crossection distribution

Spray Stream Guillotine

In Situ Curvature Sensor

blocker

blocker

coating modulus

and stress state

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-5.0x10-5

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1.0x10-4

1.5x10-4

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Prehea

ting

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pera

ture

(°C

)

Cu

rvatu

re (

mm

)-1

Time (s)

Coat

ing

Coolin

g

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FY2010 Budget and Go/no-go Decision

Project Budget• Total Project Budget for 2 years: $2,625,063

– Anticipated Funding for FY’10: $1,694,395

– Anticipated Funding for FY’11: $930,668

• Total Budget Break-down by Organization:

– TreadStone: $1,970,631

– GTI: $321,033

– ORNL: $100,000

– SUNY Stony Brook: $158,399

– IBIS: $75,000

Go/no-go Decision:• By Sept. 30, 2010, the Go/no-go will be made

based on following criteria

– At least one of the low cost conductive vias approaches can meet DOE’s target

– C-steel based metal plates meet DOE 2015 target

– The baseline short stack meets the power density and long-term stability requirements

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Acknowledgements

• DOE EERE Fuel Cell Team.

• Team Members. GTI, ORNL, SUNY-Stony Brook, IBIS

• Industrial Partners.