________________________________________________________________________________

Electrochemical Power Sources for fighting Global Warming

Bruno ScrosatiLaboratory for Advanced Batteries

and Fuel Cell Technology

21%

24%

36%

4%

7%

6% 1% 0.5%

21%

24%

36%

4%

7%

6% 1% 0.5%

21%

24%

36%

4%

7%

6% 1% 0.5%

The energy forms used in the World today

Italy

Fin

lan

d

Fra

nce

Germ

an

y

Gre

ece

Neth

erl

an

ds

Port

ug

al

UK

Sp

ain

Sw

ed

en

0

100

200

300

400

500

600

Production from fossil and nuclear sources

Production from renewable sources

The production from renewable sources in Europe / TWh (2005)

Derived from “Nuova Energia”N. 6, 2006

UE 1

5B

elg

ium UK

Neth

erl

an

ds

Irela

nd

Lu

xem

bu

rgG

erm

an

yG

reece

Fra

nce

Italy

Sp

ain

Port

ug

al

Den

mark

Fin

lan

dS

wed

en

Au

stri

a

0

10

20

30

40

50

60

70

80

2005 data aims for 2012

The production from renewable sources in Europe:comparison between 2005 data and the aims for 2010(% over consumptions)

Derived from “Nuova Energia”N. 6, 2006

21%

24%

36%

4%

7%

6% 1% 0.5%

21%

24%

36%

4%

7%

6% 1% 0.5%

21%

24%

36%

4%

7%

6% 1% 0.5%

The energy forms used in the World today?

Gba

/ yea

rG

ba/ y

ear

Worldwide production of oil & natural gas

26%9%

2%

43%79%

66%49%

19%

8%

Percentage of total0 50 100

OPEC

US

ConsommationProductionRéserves

26%9%

2%

43%79%

66%49%

19%

8%

0 50 100

Others

OPEC

US

ConsumptionProductionReserves

26%9%

2%

43%79%

66%49%

19%

8%

Percentage of total0 50 100

OPEC

US

ConsommationProductionRéserves

26%9%

2%

43%79%

66%49%

19%

8%

0 50 100

Others

OPEC

US

ConsumptionProductionReserves

World World oiloil reservesreserves//consumptionconsumptionHousehold

17%Others

21%

Air5.4%

Industry26% Roads

44%

Sea3.5%

Railways4%

C8H18 + 12.5 O2 8CO2 + 9 H20----------- NOx

C.O.V

Household17%

Others21%

Air5.4%

Industry26% Roads

44%

Sea3.5%

Railways4%

Household17%

Others21%

Air5.4%

Industry26% Roads

44%

Sea3.5%

Railways4%

C8H18 + 12.5 O2 8CO2 + 9 H20----------- NOx

C.O.V

C8H18 + 12.5 O2 8CO2 + 9 H20----------- NOx

C.O.V

C8H18 + 12.5 O2 8CO2 + 9 H20----------- NOx

C.O.V

DetailedDetailed oiloil consumptionconsumption

Oil: social and economic stakes

..to better implement renewable energies in our day-to-day livesSun doesn’t shine on demands…Wind doesn’t blow every days..

Cost-efficient, long-life, high-power energy electrochemical power sources (e.g. batteries or fuel

cells) are urgently needed!

To control environment pollution and..

1% 0.5%6%4% 1% 0.5%6%4%

How we can we address the CO2 issue and control the pollution in urban area ?

Among other actions, the replacement of a large fraction of internal combustion vehicles with controlled-emission (hybrid car) or zero emission (hydrogen car) is urgently needed!

Advanced energy storage systems, i.e. cost-efficient, long-life, high-power energy storage systems, i.e., batteries or fuel cells, are needed to meat this goal!

WHY HEV?

Source : International Energy Agency - http://omrpublic.iea.org/ - Feb 2006

Crude Oil Demand, worldwide, million tons, 1973-2005

0

500

1000

1500

2000

2500

3000

3500

4000

4500

1973 2005

Mill

ion

tons

per

yea

r

Transport Others

Price of the WTI barrel of oil, US $

0

10

20

30

40

50

60

70

1973 2000 2005 2006(Prev.)

US

$ /

barr

el

CO2 Emissions from fuel combustions, Million tons of

carbon, worldwide, 1970-2005

0

5000

10000

15000

20000

25000

30000

1970 2005

Mill

ion

tons

of C

From A. Madani, BATTERIES 2006, Paris, June 2006

HEV MARKET

HEV sold per year, units, worldwide,2000 - 2005

0

50.000

100.000

150.000

200.000

250.000

300.000

350.000

200020012002200320042005

Uni

ts

TOYOTA OTHERS

HEV sold per year, units per country,2000-2005

0

50.000

100.000

150.000

200.000

250.000

300.000

350.000

200020012002200320042005

Uni

ts

USA JAPAN EUROPE OTHERS

HEV MARKET WORLDWIDE GROWTH 04/05: +86%

Source : The Rechargeable Battery Market 2005-2015, AVICENNE, March 2006From A. Madani, BATTERIES 2006, Paris, June 2006

FOTO HYBRID CAR

.

Lithium batteries can do the job…..

…provide that they can assure, high energy, low cost safety and high rates!

The hybrid car, HEV

…. however, new types of batteries having higher energy density and lower cost than Ni-MH, are urgently needed to assure high performance and market competitiveness.

A nickel-metal hydride batteries is presently used as the energy storage unit in HEVs …..

The lithium ion battery

Conventional lithium/ion batteries are based on the following electrochemical system:

Anode: grafite

Electrolyte: liquid solution of a lithium salt in an organic solvent mixture

Cathode: layered LiMO2 lithium oxide, e.g. LiCoO2

The lithium-ion rechargeable battery

Process: yC + LiCoO2 LixCy + Li(1-x)CO2 ; x ~ 0.5 ; ~ 4V

Lithium ions are exchanged between the two electrodes by reversible extraction and insertion from and in open host structures with a concomitant removal and addition of electrons.

High Power

High Capacity

Power-Tools

　Robot

Cordless-Applications

Cellular Phones& Note-PCs

Shaver

PDADSC

HEV

Mobile Applications

MP3

Camcorder

Power Applications

Lithium ion battery is the power sources of choice in a large range of consumer electronic devices!

However, lithium batteries fall short of satisfying needs for high energy for application in more demanding markets, such as efficient use of renewable energy and hybrid vehicles.If improvements in energydensity and safety are obtained, the lithium ion battery can enterin the HEV market!

Long Term HEV Battery forecast

HEV market, million units, worldwide, 2010-2015

0

1

2

3

4

5

6

2005

2007

2009

2011

2013

2015

Num

ber o

f HEV

sol

d w

orld

wid

e (M

illio

n)

0%

2%

4%

6%

8%

10%

12%

14%

16%

HEV (million) % of Li-ion

HEV BATTERY Market, M US$, Worldwide, 2005-2015

0

1000

2000

3000

4000

5000

6000

20052006200720082009201020112012201320142015

M U

S$NiMH Li-ion

From A. Madani, BATTERIES 2006, Paris, June 2006

ENERGY DENSITY

So far, the energy density of lithium ion batteries has been improved by engineering cell optimization, however, still keeping the original chemistry.

The limit has been now reached and jumps in energy density can only be obtained by renewing the overall cell chemistry.

Cathodes: Lithium manganese spinels and lithium iron phosphate phospholivines, lithium manganese layered.

Pot

entia

l vs.

Li/L

i+(V

)

Capacity (A h kg-1)

0

1

2

3

4

200 400 600 800 1000 3800 4000

GraphiteDisordered carbons

Composite alloys [Sn(O)-based]

3d-Metal oxides

Nitrides LiMyN2

Li metal

Si

MnO2 Vanadium oxides[V2O5, LiV3O8]

Olivines [LiFePO4]Li1-xNi1-y-zCoyMzO2

Li1-xCo1-yMyO2

Manganese spinels Li1-xMn2-yMyO4

Li1-xMn1-yMyO2

Cathode

Anode

Anodes: lithium metal alloys and lithium titanium oxides

Various electrode materials are suitable for progress in lithium battery technology

Courtesy of Prof. K. Kanamura, Tokyo Metropolitan University

SAFETY

Safety is still an issue for conventional C/ LiPF6-EC-DMC/ LiCoO2 lithium-ion batteries.

In addition to energy density, also safety is a keyparameter for batteris designed for HEV applications

Dell computer burnt in the conference in Osaka in June 2006

Approaches to improve safety:

Use of electrode combinations operating within the stability window of the polymer electrolyte. (plastic novel types of lithium-ion batteries)

Replacement of liquid electrolytes withlithium conducting polymer electrolytes.

Solvent-free membranes, formed by blending , poly(ethylene oxide), PEO, with a lithium salt, LiX(SPEs)

Polymer electrolytes

Two main types

Liquid-polymer hybrid membranes, formed by formed by trapping liquid solutions (e.g., a LiPF6-PC-EC solution ) in a polymer matrix (GPEs).

POLYMER ELECTROLYTES

Gel-type membranes, formed by trapping liquid solutions (e.g., a LiPF6-PC-EC solution ) in a polymer matrix (e.g. a poly(vinylidene fluoride), PVdF matrix (GPE).

0 5 10 15 20 25 30 35 400.002

0.003

0.004

0.005

0.006

0.007

σ / Ω

-1cm

-1time / days

High conductivity

L. Persi, F. Croce and B. Scrosati; Electrochem. Comm. 4 (2002) 92

Li4Ti5O12 / GPE/ LiFePO4

lithium ion polymer cell

A 2V lithium-ion polymer battery!

P.Reale, S. Panero, B. Scrosati,J. Garche, M. Wohlfahrt-Mehrens, M.Wachtler,

J.Electrochem.Soc, 151 (2004) A2138

The Li4Ti5O12 / GPE/ LiFePO4 battery is characterized by reliability, long life an a high degree of safety.

However, this battery does not entirely meet the requirements for use in HEV where, in addition to safety and stability, also high rate is a key parameter.

Nanotechnology is a popular path to improve the rate capability of solid-state electrodes because of the reduced lithium diffusion length.Examples are the nano-structured nano-modified titanium oxide and the Ni-substituted manganesespinel.

A.S. Aricò, P. Bruce, B. Scrosati, J-M.Tarascon, W. van SchalkwijkNature Materials, 4 (2005) 366

Hydreothermalsynthesis:

TiO2 in NaOH

400°C 4h in air

Voltage profile

morphology

Brookite structure Pbca

TiO2 + xLi+ + xe- LixTiO2 1.5V

A.R.Armstrong, G.Armstrong, J.Canales, P.G.Bruce, Journal of Power Sources 146 (2005) 501A.R.Armstrong, G.Armstrong, J.Canales, P.G.Bruce, Electrochemical and Solid-State Letters, 9(2006) A139

a

b

c

xy

z

*In collaboration with Prof P.Bruceof University of St.Andrews, UK

New type of high rate anode: nanstructured TiO2 *

Theoretical specific capacity: 335 mAhg-1

20-40nm diameter

0 50 100 150 200 250

1,0

1,5

2,0

2,5

3,0

Vol

tage

/ V

Specific capacity / mAh/g

Wet chemistry synthesis:Li+, Ni2+ and Mn2+ nitrides

¯ in water800°C 16h in air

Voltage profile

morphology

Spinel structure P4332

LiNi0.5Mn1.5O4 Li0.5Ni0.5Mn1.5O4 + 0.5Li+ + 0.5e-

Li0.5Ni0.5Mn1.5O4 Ni0.5Mn1.5O4 + 0.5Li+ + 0.5e-. 4.5 V

ab

cx yz

MnO6 LiO412d 8cNiO64b

Ni-substituted LiNi0.5Mn1.5O4 spinel

P.Reale, S. Panero, B. Scrosati, J.Electrochem.Soc, 152 (2005) A1949

Theoretical specific capacity: 146 mAhg-1

0 50 100 150

3,0

3,5

4,0

4,5

5,0

Volta

ge /

V

Specific capacity / mAh/g

TiO2 / GPE / LiNi0.5Mn1.5O4

lithium ion polymer cell

A 3V Lithium-ion Polymer Battery!

G. Armstrong, A.R. Armstrong, P.G. Bruce, P. Reale, B. ScrosatiAdv. Mater., 18 (2006) 2597

Lithium ion polymer battery

Future research trends for HEV lithiumbattery R&D progress

Develop proper electrode nanostructures (rate).

Replace conventional anode and cathode with higher capacity electrode materials(energydensity).

Replace liquid with polymer electrolytes(safety).

Zero emission hydrogen fuel cell vehicles

HighPerformance

On-Board Power

EnvironmentallyClean

HighEfficiency

LowMaintenance

Reliability

Comfort(no vibration)Low Noise

Design Freedom

General Motor’s ELECTROVAN (1967)(with 400V, 160 kW UCC Alkaline FC System, liquid H2 und O2)

FC Cars TodayFC Cars Today

Source: Prof. Panik, DC

FuelFuel cellcell operationoperation

−+ +→ eHH 222

anodeOHeHO 22 22

21

→++ −+cathode

Energy renewal (hydrogen-economy)

Environmental control ( No-emission vehicles)

Major drawback: cost the catalyst (noble metals) the polymer electrolyte membrane (Nafion™ -type)

O2

H2O

H2

H+

Load

PEM

H2O

The most promising for electric vehicle applications the Polymer Electrolyte Membrane Fuel Cell, PEMFC

40 nmCarbonsupport

Catalyst particles

electrolyte

Gas-diffusion layer

Carbon-supportedcatalyst

O2

Three-phase zone

Impregnated ionomer

Fuel cell electrode structure

Courtesy of Professor E.Peled, Tel Aviv University

The cost of the electrode structure may be controlled by using high surface area substrates on which nanoscalecatalyst (Pt, Pt-Rh) particles may be dispersed.

Fuel cell electrode structure

Catalyst (Pt) particle

High surfacearea carbonsubstrate

With this approach, the precious metal loading may be reduced to very low levels, e.g few mg/cm2 and, with the new technologies, to 0,5 mg/cm2.

The goal of the car companies is to reach Pt loadings even lower than this limit.

Courtesy of Prof. Tom Zavodinski, Case Western University, Cleveland, USA

Successful R&D WorkPt-Catalyst Content

TimePt content [mg/cm²]

1997 4

2002 0.1

Today(labotatory results) 0.007

Common electrolytes for PEMFCs: perfluorosulphonic membranes, e.g., NAFION®

* CF2 CF2 n CF* CF2 *x

* CF2 CF m O

CF3

O-CF2-CF2-S H+

O3

Nanoscale phase separated microstructure as determined by SAXS (small angle X-ray scattering)

K. D. Kreuer, J. Membr. Sci., 185 (2001) 2

Common electrolyte membrane: NAFION®

* CF2 CF2 n CF* CF2 *x

* CF2 CF m O

CF3

O-CF2-CF2-S H+

O3

•high chemical stability• good conductivity• high cost• transport dependent on

hydration state• methanol crossover

Assisted protonic transport:Grotthuss mechanism

Methanol crossover

New types of proton membranes, having lower cost, higher thermal stability and higher selectivity than Nafion, are urgently required!

In lithium battery technology: lithium conducting membranes formed by trapping liquid solutions (e.g., a LiPF6-PC-EC solution ) in a suitable polymer matrix (e.g. a poly(vinylidene fluoride), PVdF matrix) Gel polymer electrolytes.

Extension to fuel cell technology: proton conducting membranes formed by trapping acid solutions (e.g., H2SO4 solutions ) in suitable composite (polymer + ceramic filler) matrices. Composite gel electrolyte membranes.

The main goal is to develop low-cost, low-methanol-permeability, temperature-resistant membranes for PEMFCs (DMFCs).

Strategy

0 5 10 15 20 25 3010-4

10-3

10-2

10-1

Con

duct

ivity

/ S

cm

-1

Time / d

Room Temperature

0 4 8 12 16 2010-3

10-2

10-1

T = 85 °CT = 60 °C

T = 25 °C

Con

duct

ivity

/ S

cm-1

Time / d

35 40 45 50 55 60 65 70 750.01

0.1

1

T = 80°C

T = 50°C

Con

duct

ivity

, S/c

m

Time, days

PVA/SiOx 6:1

T = 24°C

Conductivity

Time evolution of the conductivity of composite gel-type membranes at various temperatures.A) Al2O3-added PVdF-based membrane;B) Al2O3-added PVdF-PAN-based membrane; C) SiOx-added crosslinked PVA-based membrane.

A

B

C

M.A. Navarra, S. Panero, B.Scrosati, J.Electrochem.Soc., 2006

Ionic Liquids, ILs

Sodium chloride melts at 800 oC (Hot solution). Ionic liquids melts at much lower temp (Cool solution).

NaCl IL

Liquids composed of only ions!!

Moderate polarity

Thermal/chemical stability

Solubility (affinity) with several compounds

Low viscosity

Low melting point

Ion conductive materials for

Electrochemical devices

Solventsfor

Chemical reaction

Non-volatility

Non-flammability

Variation of ion structure

High ionic conductivity

Ionic liquids

They may have …

Appearance of proticIL-based membranes

T = 60 °C

T = 25 °C

A. Fernicola, S. Panero, B.Scrosati, M.Tamada, H. Ohno, PhysChemChemPhys, submitted

IL-based membranes have a significant ionic conductivity. The conductivity increases with temperature, reaching at 130 °C high and stable values.

Conductivity of IL 60%-PVdF 40% membrane at 130 °C.

0 2 4 6 8 101E-4

1E-3

0.01

Ar atmosphere

Con

duct

ivity

[Scm

-1]

Time [days]

T = 130 °C

MPdTFSI 60%

A. Fernicola, S. Panero, B.Scrosati, M.Tamada, H. Ohno, PhysChemChemPhys, submitted

Future research trends for fuel cell R&Dprogress

Develop ionis-liquid- based membranes (thermal stability).

Develop adequate electrode nanostructure (Pt loading).

Replace conventional Nafion-based membranes (Cost, crossover).

Search of alternate, not-precious metal catalysts (Cost).

Ecologic car Prospective

Hybrid car: in the market Controlled emission

Hydrogen car: in the market by 2010 (prevision) Zero emission?

Electric car: prototypesZero emission