Fuel Cells Thomas G. Benjamin J. David Carter Argonne National Laboratory Technology Management Association of Chicago Arlington Heights, IL February 5,

Fuel Cells

Thomas G. BenjaminJ. David Carter

Argonne National Laboratory

Technology Management Association of Chicago Arlington Heights, IL

February 5, 2007

2

Outline

The US Energy PictureFuel Cells- Definition and HistoryTypes of Fuel CellsPEM Fuel CellsLearning DemonstrationParting ShotsHydrogen StorageResources

3

http://www.eia/doe/gov/emeu/aer/pdf/sec1_3.pdf

2004 U.S. Energy Flow in Quadrillion BTUs

4

U.S. Domestic Energy Deficit (2004)

Total Energy Use = 99.7 Quadrillion BTU*

Total Energy Production = 70.4 Quadrillion BTU

Shortfall = 29.5 QBTU

Petroleum shortfall = 27.7 QBTU

2/3 of oil consumption is related to transportation*101.9 Quads used in 2005

5

U.S. Demand and Dependence on Foreign Oil Driven by Transportation Sector

Note: Domestic production includes crude oil, NG plant liquids, refinery gain, and other inputs, consistent with AER Table 5.1. Source: Transportation Energy Data Book: Edition 24, ORNL-6973, and EIA Annual Energy Outlook 2006, Feb. 2006.

Mill

ion

bar

rels

pe

r d

ay

0

2

4

6

8

10

12

14

16

18

20

22

1970 1975 1980 1985 1990 1995 2000 2005 2010 2015 2020 2025 2030

Marine

Rail

Actual Projection

Cars

Air

Light Trucks

Heavy Vehicles

U.S. Production 1: Crude + NG Plant Liquids + Refinery Gain

Off-Road

U.S. Production 2: Coal Liquids + Other

6

0 1,000 2,000 3,000 4,000 5,000 6,000

H2 from Central Nuclear to H2 FCV

H2 from Central Coal with Seq. to H2 FCV

Central Wind Electro to H2 FCV

Central Biomass to H2 FCV

Distributed Wind Electro to H2 FCV

NG Distributed H2 FCV

Diesel HEV

Gasoline HEV

Current GV

Well-to-Wheel Petroleum Energy Use (Btu/mi.)

Well to Pump

Pump to Wheel

Comparative Vehicle Technologies: Well-to-Wheels Petroleum Energy Use

7

0 100 200 300 400 500

H2 from Central Nuclear to H2 FCV

H2 from Central Coal with Seq. to H2 FCV

Central Wind Electro to H2 FCV

Central Biomass to H2 FCV

Distributed Wind Electro to H2 FCV

NG Distributed H2 FCV

Diesel HEV

Gasoline HEV

Current GV

Well-to-Wheel Greenhouse Gas Emissions (g/mi.)

Well to Pump

Pump to Wheel

Comparative Vehicle Technologies: Well-to-Wheels Greenhouse Gas Emissions

Domestic useComputer = 150 W

Refrigerator = 800 W

House = 2-10 kW

Small Building = 250 kW

TransportationHonda Insight = 60 kW

Corvette = 300 kW

Hummer = 420 kW

Heavy Truck = 400-750 kW

How much power do we need?

1 horsepower (hp) = 2500 BTU/h

3/4 kilowatt (kW)

9

Power Generation Options

Nuclear Plant1 GW

Hoover Dam120 MW

Photovoltaic Plant4 MW

Fuel Cell Modules1W to 2 MW

Largest windmills3 MW

Coal-fired Power Plant

1 GW

10

Outline

The US Energy PictureFuel Cells- History and DefinitionTypes of Fuel CellsPEM Fuel CellsLearning DemonstrationParting ShotsHydrogen StorageResources

11

Reid describes first Alkaline FC (using KOH electrolyte)Reid describes first Alkaline FC (using KOH electrolyte)

Sir William Grove invents first fuel cell (H2SO4 + Pt Electrodes, H2 and O2)Sir William Grove invents first fuel cell (H2SO4 + Pt Electrodes, H2 and O2)

Jacques develops FC for household useJacques develops FC for household use

Nernst first uses Zirconia as a solid electrolyteNernst first uses Zirconia as a solid electrolyte

Baur constructs first Molten Carbonate FCBaur constructs first Molten Carbonate FC

Allis-Chalmers Manufacturing Company demonstrates a 20-horsepower FC powered tractorAllis-Chalmers Manufacturing Company demonstrates a 20-horsepower FC powered tractor

General Electric develops first Polymer Electrolyte FC (PEFC) Nafion first introduced – more stable PEM FC constructedGeneral Electric develops first Polymer Electrolyte FC (PEFC) Nafion first introduced – more stable PEM FC constructed

Space applications: AFC used in Apollo missions, PEM used in Gemini missionsSpace applications: AFC used in Apollo missions, PEM used in Gemini missionsOil crisis creates new impetus for FC funding, PAFC and MCFC developed initiallyOil crisis creates new impetus for FC funding, PAFC and MCFC developed initially

First commercial power plant begins operation (200kW PC25 PAFC)First commercial power plant begins operation (200kW PC25 PAFC)

18391839

18961896

19001900

19021902

19211921

19621962

19651965

19731973

19921992

19591959

20022002 FC systems entering several test marketsFC systems entering several test markets

12

Photographs from FC History

US Army MCFC, 1966Allis-Chambers PAFC engine, 1965

William Grove's drawing of an experimental “gas battery“, 1843

William Jacques' carbon battery, 1896

A Fuel Cell is similar to a rechargeable battery

Fuel cell: reactants supplied continuously and electrodes invariant

Overall Fuel Cell Reactions:

H2 + O2 H2O + heat + electrons

Fuel Cell_ +

Air

H2

H2O Storage cell: reactants self contained

and electrodes consumed

Lead-Acid Battery Reaction

Pb + PbO2 + H2SO4 2 PbSO4 + 2 H2O

+ _

H2SO4Pb Pb

Storage Cell

Fuel Cell – Electrochemical energy conversion device in which fuel and oxidant react to generate electricity without any consumption, physically or chemically, of its electrodes or electrolyte.

14

Bip

ola

r P

late

Ca

tho

de

+

An

od

e - Ele

ctr

oly

teH+

H+

HYDROGEN (H2)

OXYGEN (O2)

Bip

ola

r P

late

O-

O-

e -

H+ O-

e -

e -

e -

e - e -

WATER (H2O) + HEAT

H2 2H+ + 2e-½O2 + 2H+ + 2e- H2O

H+

PEMFC: Protons formedat the anode diffuse throughthe electrolyte and react with electrons and oxygen at the cathode to form water and heat.

15

Single cells are arranged into “stacks” to increase total voltage and power output

Cathode: O2 + 4H+ + 4e- 2H2O 1.2 VAnode: 2H2 4H+ + 4e- - 0 V

Total Cell: 2H2 + O2 2H2O 1.2 V per cell

Power = Volts X Amps

Ballard PEFC Stack

16

Fuel Cell System

FuelProcessor

Fuel CellStack

Spent-GasBurner

Thermal & Water Management

Air

Air

Fuel

H2

Exhaust

Electric Power Conditioner

17

Fuel

Processor

H2-rich gas

CO = 15% CO < 10 ppmCO < 0.5%FUEL

REFORMERCXHY+H2O+O2H2+CO

WGS REACTORCO+H2OCO2+H2

PROX REACTORCO+O2CO2

H2-rich gas

CO = 15% CO < 10 ppmCO < 0.5%FUEL

REFORMERCXHY+H2O+O2H2+CO

WGS REACTORCO+H2OCO2+H2

PROX REACTORCO+O2CO2

Power

Bip

ola

r P

late

Cat

ho

de

+

An

od

e -

Ele

ctro

lyte

H+

H+

HYDROGENOXYGEN

Bip

ola

r P

late

e -e -

O2

O2

O2

e -

H+

Bip

ola

r P

late

Bip

ola

r P

late

Cat

ho

de

+

An

od

e -

Ele

ctro

lyte

H+H+

H+H+

HYDROGENOXYGEN

Bip

ola

r P

late

Bip

ola

r P

late

e -e -e -e -

O2O2

O2O2

O2O2

e -e -

H+H+

Fuel Processor BARRIERS Fuel processor start-up/ transient

operation Durability Cost Emissions and environmental

issues H2 purification/CO cleanup

Fuel processor system integration and efficiency

On-Board Fuel Processing

18

Fuel Cell Challenges

Durability Cost Electrode Performance Water Transport Within the Stack Thermal, Air and Water Management Start-up Time and Energy

Cost and durability present two of the more significant technical barriers to the achievement

of clean, reliable, cost-effective systems.

Bip

ola

r P

late

Cat

ho

de

+

An

od

e -

Ele

ctro

lyte

H+

H+

HYDROGENOXYGEN

Bip

ola

r P

late

e -e -

O2

O2

O2

e -

H+

Bip

ola

r P

late

Bip

ola

r P

late

Cat

ho

de

+

An

od

e -

Ele

ctro

lyte

H+H+

H+H+

HYDROGENOXYGEN

Bip

ola

r P

late

Bip

ola

r P

late

e -e -e -e -

O2O2

O2O2

O2O2

e -e -

H+H+

Power

19

Outline

The US Energy PictureFuel Cells- Definition and HistoryTypes of Fuel CellsPEM Fuel CellsLearning DemonstrationParting ShotsHydrogen StorageResources

20

Five major types of fuel cells

Fuel Cell TypeTemperature

ApplicationsElectrolyte / Ion

Polymer Electrolyte Membrane

(PEM)

60 - 100° C Electric utility Portable power TransportationPerfluorosulfonic acid / H+

Alkaline (AFC)

90 – 100° C Military SpaceKOH / OH-

Phosphoric Acid (PAFC)

175 – 200° C Electric utilityDistributed power TransportationH3PO4 / H+

Molten Carbonate (MCFC)

600 – 1000° C Electric utilityDistributed power(Li,K,Na)2CO3 / CO2

-

Solid Oxide (SOFC)

600 – 1000° C Electric utilityDistributed power

APUs(Zr,Y) O2 / O-

21

Alkaline Fuel Cell (AFC)

Applications

Space TransportationFeatures

High performance Very sensitive to CO2

Expensive Pt electrodesStatus

“Commercially” available

AFCs from Apollo & SpaceshuttleSpacecrafts-- NASA

EquationsCathode: ½O2 + H2O + 2e¯ → 2OH¯

Anode: H2 + 2OH¯ → 2H2O + 2e¯

22

Phosphoric Acid Fuel Cell

EquationsCathode: ½O2 + 2H+ + 2e¯ → H2O

Anode: H2 → 2H+ + 2e¯

Applications Distributed power plants Combined heat and power Some buses

Features Some fuel flexibility High efficiency in cogeneration (85%) Established service record Platinum catalyst

Status Commercially available but expensive Excellent reliability and availability Millions of hours logged

UTC Fuel Cells 200-kW

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EquationsCathode: ½O2 + CO2 + 2e¯ → CO3

=

Anode: H2 + CO3= → 2H2O + CO2 +

2e¯ Fuel Cell Energy MCFC stack

Molten Carbonate Fuel Cells

Applications Distributed power plants Combined heat and power

Features Fuel flexibility (internal reforming) High efficiency High temperature good for cogeneration Base materials (nickel electrodes) Corrosive electrolyte

Status Pre-Commercially available but expensive

24

EquationsCathode: O2 + 2e¯ → 2O=

Anode: H2 + O= → H2O + 2e¯

Solid Oxide Fuel CellsApplications Truck APUs Distributed power plants Combined heat and power

Features Slow start – subject to thermal shock High temperature High power density (watts/liter) Can use CO and light hydrocarbons directly “Cheap” components, solid electrolyte Low-yield manufacture

Status Vehicle APUs

25

EquationsCathode: ½O2 + 2H+ + 2e¯ → H2O

Anode: H2 → 2H+ + 2e¯

Polymer Electrolyte Fuel Cells

Applications Transportation, Forklifts, etc. Power backup systems Consumer electronics with methanol fuel

Features Quick start Low temperature Expensive Pt electrodes Easy manufacture Operating window limits 53-67% thermal efficiency

Status Vehicle demonstrations underway Stationary/backup power “commercially” available

Toyota Fuel Cell Forklift

26

Direct Methanol Polymer Electrolyte FC (DMFC)Applications Miniature applications Consumer electronics Battlefield

Features A subset of Polymer Electrolyte Modified polymer electrolyte fuel cell

components Methanol crossover lowers efficiency

Status Pre-Alpha to Beta testing

Endplate

O2 in

CH3OH out Cathode Anode

Bipolar plate

O2 out

CH3OH in

EquationsCathode: 1.5 O2 + 6H+ + 6e¯ → 3H2O

Anode: CH3OH + H2O → CO2 + 6H+ + 6e¯

27

Outline

The US Energy PictureFuel Cells- Definition and HistoryTypes of Fuel CellsPEM Fuel CellsLearning DemonstrationParting ShotsHydrogen StorageResources

28

Anatomy of a Proton Exchange Membrane Fuel Cell and Challenges

Electrocatalyst: High cost of platinum-based electrocatalyst Catalyst support: Loss of surface and electrode contact of

amorphous carbon under oxidative environment Component: Gas Diffusion Layer (GDL) and bipolar plates

account for 10% of stack cost

ElectrolyteAnode

GDLCathode

GDL

H2 e-

e-

H+

H2

e-

e-

O2

H2O

H2

Membrane

Catalyst

GDL

BipolarPlate

Half Cell

Carbon support

Platinum catalyst

29

Significant Barriers to PEM Fuel Cell Commercialization

Durability• Membranes, catalysts, gas diffusion media, fuel cell

stacks, and systems over automotive drive cyclesCost• Materials and manufacturing costs: catalysts,

membranes, bipolar plates, and gas diffusion layers Performance• Tolerance to impurities such as carbon monoxide,

sulfur compounds, and ammonia• Operation under higher temperature, low relative

humidity conditions as well as sub-freezing conditions

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Key Challenges Units2006 Status 2015 Target

Cost $/kW 110 30

Lifetime (durability w/ cycling) hours ~1,000 5,000

Other Challenges

Precious Metal Loading g/kW (rated) 1.1 0.2

Power Density W/L 525 650

Start-up Time to 50% of Rated Power at:

- 20oC ambient temp sec 20 30

+ 20oC ambient temp <10 5

Start-up and Shut Down Energy at: - 20oC ambient temp MJ 7.5 5

+ 20oC ambient temp n/a 1

PEM Fuel Cell System (80kWe) Development Targets for Transportation Applications

31

Cycling range: 0.4 to 0.9 V

Particle diameters: 2 to 4 nm

Some particles have a diameter of 6 nm

Particle diameters: 2 to 6 nm

Some particles have a diameter of 10 nm

Cycling range: 0.4 to 1.2 V

Effect of potential cycling on Pt dissolution/agglomeration

Increase in Pt particle size with cyclingParticle size increases with increasing potential Increased particle size leads to decreased surface area and decreased activity

0 200 400 600 800 1000 1200

Baseline:1 mil castNafion®

Reinforced Membrane(non-CS)

Reinforced CSMembrane

Reinforced Membrane+ AdvancedStabilization

Time to failure (hrs)

Test in progress

Improved durabilitywith no performance loss

32

Mitigation of sulfur poisoning of PEMFC

LANL

H2S on

H2S off

Air onAir offN2 purgeH2 on

• Anode poisoned with 1 ppm H2S• Anode is at OCV before air exposure• Air bled overnight• Cell recovered almost fully

Improved performance ofPt-alloy catalyst

0.1M HClO4

i k [

mA

cm-2

]

10

20

30

40 Pt(111)Pt3Ni(111)

60oC

0.950 0.925 0.900 0.875 0.850

E [V] vs RHE

Increased Activity: > 10x

33

Current Membranes Have Poor Conductivity at Low Relative Humidity

• Membranes with good conductivity (~0.1 S/cm) at low (25-50%) RH would reduce or eliminate externalhumidification requirements

• Simpler system lowers cost and improves durability

200.01

0.10

1.00

0 40 60 80 100Relative Humidity (%)

Co

nd

uct

ivit

y (S

/cm

)

SPTES-50 (80C)

Low EW PFSA (80C)

Nafion 112 (80C)

Ideal Desired

mV

loss

at

1 A

/cm

2 fo

r 25

mic

ron

mem

bra

ne

250

25

2.5

34

Outline

The US Energy PictureFuel Cells- Definition and HistoryTypes of Fuel CellsPEM Fuel CellsLearning DemonstrationParting ShotsHydrogen StorageResources

35

Key Transportation Fuel Cell Targets

Integrated Transportation Fuel Cell Power System (80 kWe) Operating on Direct Hydrogen

• $45/kW by 2010

• $30/kW by 2015

• 5,000 hours durability by 2010 (80OC) – 150,000 miles at 30 mph

36

Objectives

– Validate H2 FC Vehicles and Infrastructure in Parallel

– Identify Current Status of Technology and its Evolution– Assess Progress Toward Technology Readiness

– Provide Feedback to H2 Research and Development

Key Targets

Performance Measure 2009 2015

Fuel Cell Stack Durability

2000 hours

5000 hours

Vehicle Range250+ miles

300+ miles

Hydrogen Cost at Station

$3/gge $2-3/ggePhoto: NRELHydrogen refueling station, Chino, CA

Technology Validation Learning Demonstrations

37

Technology Validation learning demonstrations

Courtesy K. Wipke, National Renewable Energy Laboratory

38

Representative Hydrogen Refueling InfrastructureLAX refueling station

Hydrogen and gasoline station, WA DC

Chino, CA

DTE/BP Power Park, Southfield, MI

Courtesy K. Wipke, National Renewable Energy Laboratory

39

Refueling Stations Test Vehicle/Infrastructure

09-22-06

Northern California

Southern CaliforniaFlorida

Additional Planned Stations (3)

Additional Planned Stations (4)

SE Michigan Mid-Atlantic

Additional Planned Stations (2)

Additional Planned Stations (2)

Courtesy K. Wipke, National Renewable Energy Laboratory

40

First 5 quarters of project completed:69 vehicles now in fleet operation. An

additional 62 planned for 2007-08 with 50,000-mile fuel cell systems.

10 stations installed deployment of new H2 refueling stations for this project is about 50% complete.

No major safety problems encountered.

Fuel cell durability: Maximum: 950 hours (ongoing)Average: 715 hours

Range: 100 to 190 miles

41

Outline

The US Energy PictureFuel Cells- Definition and HistoryTypes of Fuel CellsPEM Fuel CellsLearning DemonstrationParting Shots (of fuel cells)Hydrogen StorageResources

42

Stationary Fuel Cell Power Systems

Fuel Cell Energy 2 MW MCFC

Siemens-Westinghouse 100kW SOFC

UTC Fuel Cells 200kW PAFC

Ballard 250kW PEFC

Plug Power 7kW Residential PEFC

Plug Power 10 kW Residential unit

Courtesy of Breakthrough Technologies Institute: www.fuelcells.org

43

Portable Fuel Cell Power Systems

Plug Power FC powered highway road signBallard FC powered laptop

Plug Power FC powered video camera

Fraunhofer ISE Micro-Fuel Cell

Courtesy of Breakthrough Technologies Institute: www.fuelcells.org

MTI Micro Fuel Cells RFID scanner

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Outline

The US Energy PictureFuel Cells- Definition and HistoryTypes of Fuel CellsPEM Fuel CellsLearning DemonstrationParting Shots (of fuel cells)Hydrogen StorageResources

45

Current Status of Hydrogen Storage SystemsNo storage technology meets 2010 or 2015 targets

$0 $5 $10 $15 $20

$/kWh

Chemical Hydride

Complex Hydride

Liquid H2

350 bar

700 bar

Current Cost Estimates(based on 500,000 units)

2010 target

2015 target

Status vs. Targets

46

Outline

The US Energy PictureFuel Cells- Definition and HistoryTypes of Fuel CellsPEM Fuel CellsLearning DemonstrationHydrogen storageResources

47

For More Informationwww.hydrogen.energy.gov Fact sheets available in the web

site library

Find....

The latest news, reports & announcements

Status information about program solicitations

Fuel cell and hydrogen "basics" information

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Fuel Cells 2000 www.fuelcells.org

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US Fuel Cell Council www.usfcc.com

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Thank You for your attention

Fuel Cells

Coming to an application near you