Hunter FickeDirector, DuPont Central Research and

Development, Wilmington DE, USA

Electrochromic Technology Developments for Automotive

Windows

2

Program Objective

Develop a dynamic electrochromic (EC) glazing technology that reduces cost and expands the functionality of automotive sunroofs and mirrors.

Applications: automotive mirrors, sunroofsExpansion to: architectural windows, skylights,

interior partitions, sunshades

3

Sun Roof Market Trends

Pop-ups

Sliding Panorama RoofsPanoramic Roofs

Past Today Today and future

Valu

e

Greater glass surface area being designed into automobiles including larger sunroofsCustomers prefer a more open feeling in theauto, and the perception of more interior space, but need protection from sun glare forcomfortPush toward more fully integrated comfort and convenience functionsAs glass roofs become larger, mechanical blinds become more difficult to implementAutomotive industry is open to consider EC glazing for sunroof application because of success in rearview mirrors.

Current Market : 8-10 MM units/yr30% growth in large sunroofs15% growth in all sunroofs15 to 20% increase in average size in last 4 years

Repeat purchase rate high - 78%High penetration rate in all segments

(luxury, intermediate, compact SUV)

“lighton demand”

Growing need to control light

4

Competitive Technologies

Ion migration into EC layer through a ceramic

or gel

Solid particles in a liquid drop

dispersed in a matrix. Difficult

to make and apply layer

Suspended Particle Devices (SPD)

ElectrochromicDevice (ECD)

Polymer Dispersed Liquid Crystal (PDLC)

PLC alignment in an electric

field

5

Conventional Electrochromic Device (ECD)

Electrochemical battery

Low voltage Source

(<5V)

Glass or plastic substrateTransparent conducting

oxide

Electrochromic

Ion conductor/electrolyte

Transparent conducting oxide

Glass or plastic substrate

A+

e--

+

Multilayer complex structure with liquid or

gel electrolyte

6

Technical Target: A Unique Product Offering from DuPont

Multilayered Device

ITO Glass/PET

Nickel Oxide Layer

Lithium Electrolyte Gel

WO3 Layer

ITO Glass/PET

Less complex Important cost advantage

From Current Technology to a Polymer-Based Interlayer that Directly Incorporates the EC Functionality

Current Technology

EC Interlayer

Single Layer Device

ITO Glass/PET

ITO Glass/PET

7Reynolds et al., Chem. Mater. 2000, 12, 1563.

EC Interlayer Consists of Organic MaterialsWide variety of colors possible via structural modification

D = doped state (oxidized or reduced); N = neutral state; I = intermediate state (if any)

8

Typical Light Transmittance Properties

25

35

45

55

65

75

85

95

450 500 550 600 650 700

Wavelength (nm)

% T

ran

sm

itta

nce

OFF

ON

30

40

50

60

70

80

90

0 50 100 150 200

Time (s)

% T

rans

mitt

ance

0.00E+00

1.00E-02

2.00E-02

3.00E-02

4.00E-02

5.00E-02

6.00E-02

7.00E-02

Char

ge, m

C

% T

Charge

% Light transmittance in OFF and ON states

vs. time (525 nm)

% Light transmittance in OFF and ON states through visible range

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Light Transmittance and Cyclability

Light Transmittance (%) before cycling (blue) and after more than 10,000 cycles (red)

Accelerated 10,000 Life-Cycle Test

0

10

20

30

40

50

60

70

80

0 200 400 600 800 1000 1200

Time (seconds)

% T

rans

mitt

ance

Initial %T at525 nm

Post 10,969Cycles %T at525 nm

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Integration of Butacite® Laminate and ECTechnologies

Glass

Butacite® Glass

Holds glass togetherPrevents penetration of objectsAdded Functionality:

Sentryglas® PlusSentryglas® ExpressionsSentryglas® AcousticSpallshield®

ECD Prototype

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Sunroofs with DuPont Glass Laminating

Solutions

EC Applications

EC Mirrors

Generation 1

Generation 2

12

Timeline

Discovery

VOC-> Proposal

2004 2005-2006 2007 2008

Lab demo Prototype

End Use Testing

CustomerTesting