Fuel Cells and Fuel Cells and Hydrogen Hydrogen StorageStorage

Brian NinnemanBrian Ninneman2/7/20052/7/2005

http://www.ecoworld.com/Home/articles2.cfm?TID=255

OverviewOverview

Introduction to Fuel CellsIntroduction to Fuel Cells Fuel Cells in the Automotive Fuel Cells in the Automotive

IndustryIndustry Types of Fuels and Hydrogen Types of Fuels and Hydrogen

StorageStorage In the News…In the News…

HistoryHistory Invented in the early 1840’s by Sir William Invented in the early 1840’s by Sir William

Robert Grove Robert Grove [1][1]

In 1890’s Nernst develops the first solid oxide In 1890’s Nernst develops the first solid oxide fuel cellfuel cell

Relatively few documented cases of fuel cell Relatively few documented cases of fuel cell breakthroughs between mid-1800’s and 1950’sbreakthroughs between mid-1800’s and 1950’s

Resurgence of alkaline fuel cells created by Resurgence of alkaline fuel cells created by General Electric for Gemini and Orbiter space General Electric for Gemini and Orbiter space programs programs [2][2]

In the 60’s DuPont designed the membrane In the 60’s DuPont designed the membrane still used in most PEM fuel cells today, Nafion still used in most PEM fuel cells today, Nafion ®®

In the 80’s there was a breakthrough in the In the 80’s there was a breakthrough in the reduction of catalyst amount neededreduction of catalyst amount needed

5 Types of Fuel Cells5 Types of Fuel Cells

Phosphoric AcidPhosphoric Acid Alkaline Alkaline Solid OxideSolid Oxide Molten CarbonateMolten Carbonate Proton Exchange Proton Exchange

MembraneMembrane

Solid Oxide FC Solid Oxide FC [1][1]

Uses a hard ceramic material of zirconium Uses a hard ceramic material of zirconium oxide combined with ytrria as electrolyteoxide combined with ytrria as electrolyte

Operating temperature of 1,000Operating temperature of 1,000ooCC Operates at 45-60% efficiency, 85% with Operates at 45-60% efficiency, 85% with

cogenerationcogeneration Mainly used for industrial applications, Mainly used for industrial applications,

may be used in automobiles as an may be used in automobiles as an auxiliary power unitauxiliary power unit

Power output of 100 kWPower output of 100 kW

Molten Carbonate FC Molten Carbonate FC [1][1]

Uses liquid solution as electrolyte, Uses liquid solution as electrolyte, usually Liusually Li++, Na, Na++, and/or K, and/or K++ carbonates carbonates

Operating temperature of 650Operating temperature of 650ooCC Operates at 40-60%, 85% with Operates at 40-60%, 85% with

cogenerationcogeneration Produces water and carbon dioxideProduces water and carbon dioxide Mainly used for stationary power Mainly used for stationary power

generationgeneration Power output of 10 kW to 2 MWPower output of 10 kW to 2 MW

Proton Exchange Proton Exchange Membrane FC Membrane FC [1][1]

Utilizes a polymer membrane as the Utilizes a polymer membrane as the electrolyte (poly-perflourosulfonic acid, electrolyte (poly-perflourosulfonic acid, NafionNafion® [3]® [3] ) )

Operate at much lower temperatures, Operate at much lower temperatures, ~80~80ooCC

Operates a 35-60%, 85% cogenerationOperates a 35-60%, 85% cogeneration Produces waterProduces water Mainly used in mobile applicationsMainly used in mobile applications Power output of 50-250 kWPower output of 50-250 kW

PEM FC Design PEM FC Design ComponentsComponents

Membrane/Electrode Membrane/Electrode AssemblyAssembly

Gas Diffusion LayerGas Diffusion Layer Bipolar platesBipolar plates

http://www.fuelcellcomponents.com

DuPont Conductive Plates, http://www.dupont.com/fuelcells/products/plates.html

Operation of PEM FCOperation of PEM FC

http://www.fueleconomy.gov/feg/fcv_PEM.shtml

PEM FC Design PEM FC Design [4][4]

Membrane should have high proton Membrane should have high proton conductivity and low water conductivity and low water permeabilitypermeability

Electrodes function best when made Electrodes function best when made of noble metal catalystsof noble metal catalysts

Optimal channel geometry for Optimal channel geometry for cathode side of bipolar platingcathode side of bipolar plating Minimizing width between channelsMinimizing width between channels Decreasing channel cross-sectionDecreasing channel cross-section Increasing channel depthIncreasing channel depth

PEM FC Design (Cont.) PEM FC Design (Cont.) [4][4]

Water ManagementWater Management Drying leads to decreased performance of Drying leads to decreased performance of

the cell from decreased conductancethe cell from decreased conductance Saturation with water causes degradation of Saturation with water causes degradation of

fuel cell materials, decreases mass transferfuel cell materials, decreases mass transfer Heat ManagementHeat Management

Increasing the temperature is often used to Increasing the temperature is often used to vaporize water and increase mass transportvaporize water and increase mass transport

The waste heat from PEM’s is of limited The waste heat from PEM’s is of limited usage because of little temperature usage because of little temperature differencedifference

Energy Efficiency Energy Efficiency [1,2][1,2]

0

10

20

30

40

50

60

% Efficiency

SteamLocomotive

CombustionEngine

MilitaryJets

GasTurbine

Fuel Cells

Efficiency ratings for different power plants

Efficiency cont.Efficiency cont.

Produce energy through electrochemistry Produce energy through electrochemistry rather than chemical combustionrather than chemical combustion

Fuel cells do not obey the efficiency Fuel cells do not obey the efficiency limitations of the Carnot Cyclelimitations of the Carnot Cycle

Increase efficiency by:Increase efficiency by: Increasing temperatureIncreasing temperature Tradeoff between efficiency and power Tradeoff between efficiency and power

densitydensity Described through the polarization curveDescribed through the polarization curve

Polarization Curve Polarization Curve [4][4]

Fuel Cells in the Fuel Cells in the Automotive IndustryAutomotive Industry

Comparing:Comparing: Availability/CostAvailability/Cost Power densityPower density LifetimeLifetime Fuel sourcesFuel sources

Hydrogen Hydrogen storagestorage

www.lynntech.com/.../ pem_fuelcell/index.shtml

Availability and CostAvailability and Cost

Until the 1980’s only high cost fuel Until the 1980’s only high cost fuel cells existed because of large amounts cells existed because of large amounts of noble metals in catalystof noble metals in catalyst

Begin to see emergence of research in Begin to see emergence of research in late 80’s for use in automobileslate 80’s for use in automobiles

PEM’s seen a main viable fuel cell for PEM’s seen a main viable fuel cell for use in automobilesuse in automobiles

Internal combustion engines cost Internal combustion engines cost ~$20/kW ~$20/kW [5][5]

Prototype fuel cells cost $3,000/kW Prototype fuel cells cost $3,000/kW [1][1]

Power Density and Energy Power Density and Energy UtilizationUtilization

Far greater power density for internal Far greater power density for internal combustion engines than fuel cells combustion engines than fuel cells [6][6]

~600 hp for 4-door sedan~600 hp for 4-door sedan ~100 hp for electric vehicle~100 hp for electric vehicle

Better energy utilization for fuel cells Better energy utilization for fuel cells [4][4]

1:1 electricity-to-heat for fuel cells1:1 electricity-to-heat for fuel cells 1:3 electricity-to-heat for internal 1:3 electricity-to-heat for internal

combustion enginescombustion engines

Power Density Power Density [2,6][2,6]

0

2

4

6

8

10

Power Density (kW/L)

SteamLocomotive

CombustionEngine

Military Jets Fuel Cells

Lifetime of Fuel Cell Lifetime of Fuel Cell [1][1]

Fuel cells last much longer than internal Fuel cells last much longer than internal combustion engines because of lack of combustion engines because of lack of moving partsmoving parts

Combustion engines last ~5,000 hours of Combustion engines last ~5,000 hours of usageusage

Fuel cells last >40,000 hours of usageFuel cells last >40,000 hours of usage Fuel cells used in the space programs in Fuel cells used in the space programs in

the 60’s have been used for 100,000 the 60’s have been used for 100,000 hours without faulty operation and hours without faulty operation and minimal maintenanceminimal maintenance

Infrastructure Infrastructure [1][1]

Oil industry currently spends $11 Oil industry currently spends $11 billion/year to maintain service station billion/year to maintain service station fleetfleet

Natural gas pipeline extension costs $5 Natural gas pipeline extension costs $5 billion/yearbillion/year

Independent studies have developed Independent studies have developed nationwide models costing $15 billion to nationwide models costing $15 billion to install infrastructure based on 1 million install infrastructure based on 1 million FC vehicles and fueling stations within 2 FC vehicles and fueling stations within 2 miles of homes for 70% of the populationmiles of homes for 70% of the population

Fuels for Fuel Cells Fuels for Fuel Cells [1,2,4][1,2,4]

Hydrogen derived Hydrogen derived from:from: Water Water MethanolMethanol EthanolEthanol Natural gasNatural gas Renewable Renewable

resources (wind, resources (wind, solar, biomass, etc.)solar, biomass, etc.)

HydrocarbonsHydrocarbons

Hydrogen Production Hydrogen Production [7][7]

Hydrogen StorageHydrogen Storage

Metal hydridesMetal hydrides Pressurized Pressurized

hydrogen gashydrogen gas Liquefied hydrogenLiquefied hydrogen

Metal Hydrides Metal Hydrides [2,8][2,8]

Will theoretically store 5.6 wt.% of Will theoretically store 5.6 wt.% of hydrogen using a NaAlHhydrogen using a NaAlH4 4 , presently , presently store ~3%store ~3%

Comparing the weight of the metal Comparing the weight of the metal hydride to gasoline, 5 times of the hydride to gasoline, 5 times of the hydride alone will be needed to travel hydride alone will be needed to travel similar distancessimilar distances

~ ½ an hour to charge the metal ~ ½ an hour to charge the metal hydride with hydrogenhydride with hydrogen

[8]

Hydrogen Capacity for Consecutive Charges

Pressurized GasPressurized Gas

Will store 10 wt.% Will store 10 wt.% hydrogen in light hydrogen in light weight tanks weight tanks [9][9]

Tanks utilize a Tanks utilize a carbon fiber wrap carbon fiber wrap and polymer linerand polymer liner

Currently, not able Currently, not able to store at >10,000 to store at >10,000 psipsi

[9]

Liquefied Hydrogen Liquefied Hydrogen [10][10]

Widely used in prototype vehiclesWidely used in prototype vehicles Storage conditions of 20 K and 1 barStorage conditions of 20 K and 1 bar Issues:Issues:

Need of robotic fueling stationsNeed of robotic fueling stations Amount of energy needed to liquefy the Amount of energy needed to liquefy the

hydrogenhydrogen Current research efforts involve Current research efforts involve

designing use of cryogenic tanks for both designing use of cryogenic tanks for both gas and liquid along with better gas and liquid along with better insulating materialsinsulating materials

Hydrogen Safety Hydrogen Safety [9,11][9,11]

Hydrogen has been Hydrogen has been produced and produced and transported in the transported in the U.S. >50 yearsU.S. >50 years

Hydrogen gas Hydrogen gas diffuses rapidlydiffuses rapidly

Ford Motor Co. Ford Motor Co. released a report released a report in 1997 examining in 1997 examining safety of hydrogen safety of hydrogen use in vehiclesuse in vehicles

In the news…In the news…

Aug. 10, 2004 – Ford produces 30 Aug. 10, 2004 – Ford produces 30 Ford Focus Fuel Cell Vehicles to be Ford Focus Fuel Cell Vehicles to be tested in real world tested in real world

Oct. 25, 2004 - GM designing Oct. 25, 2004 - GM designing hydrogen powered HUMMER H2hydrogen powered HUMMER H2

Jan 25, 2005 – GM and Shell team up Jan 25, 2005 – GM and Shell team up to begin production of fuel cell feel to begin production of fuel cell feel for New York for New York

Questions?Questions?

ReferencesReferences 1 – Breakthrough Technologies Institute, 1 – Breakthrough Technologies Institute, http://www.fuelcells.orghttp://www.fuelcells.org 2 – Appleby A.J., “Fuel Cell Technology and Innovation,” 2 – Appleby A.J., “Fuel Cell Technology and Innovation,” Journal Journal

of Power Sourcesof Power Sources, , v. 37, pp 223-239, 1992v. 37, pp 223-239, 1992 3 – DuPont Nafion 3 – DuPont Nafion ®® Membranes, Membranes,

http://www.dupont.com/fuelcells/products/nafion.htmlhttp://www.dupont.com/fuelcells/products/nafion.html 4 – Mennola T., “Mass Transport in Polymer Electrolyte 4 – Mennola T., “Mass Transport in Polymer Electrolyte

Membrane Fuel Cells Using Membrane Fuel Cells Using Natural Convection for Air Natural Convection for Air Supply,” Supply,” Helsinki University of Technology Publications in Engineering Physics, 2004

5 – Mench M.M., et al., “An Introduction to Fuel Cells and Related Transport Phenomena,” The Penssylvannia State University

6 – GM Fuel Cell Program Website, http://www.gm.com/company/gmability/adv_tech/400_fcv/index.html?query=fuel+cell

ReferencesReferences 7 – Conte M., 7 – Conte M., et al.et al., “, “Hydrogen Economy for a Sustainable

Development: State-of-the- Art and Technological Perspectives,” Journal of Power Sources v. 100, pp 171-187, 2001

8 – Gross K.J., 8 – Gross K.J., et al.et al., “Hydride Development for Hydrogen Storage,” , “Hydride Development for Hydrogen Storage,” Proceedings of Proceedings of the 2000 Hydrogen Program Reviewthe 2000 Hydrogen Program Review

9 – Mitlitsky F9 – Mitlitsky F, et al.,, et al., “Vehicular Hydrogen Storage using “Vehicular Hydrogen Storage using Lightweight Tanks,” Lightweight Tanks,” Proceedings of the 2000 U.S. DOE Proceedings of the 2000 U.S. DOE Hydrogen Program ReviewHydrogen Program Review

10 – Armstrong T.R., 10 – Armstrong T.R., et alet al., “Hydrogen Storage Research Activities ., “Hydrogen Storage Research Activities at Oak Ridge at Oak Ridge National Laboratory,” National Laboratory,” Safety and Economy of Hydrogen Transport Symposium. Sarov, Nizhny Novgorod Region, Russia. Aug 18-23, 2003

11 – Bain A., et al., “Direct-Hydrogen-Fueled Proton-Exchange-Membrane Fuel Cell System for Transportation Applications: Hydrogen Vehicle Safety Report,” Ford ” Ford Motor Co., May Motor Co., May 19971997