Etude et mise au point de membranes électrolytiques à base de liquides ioniques pour systèmes électrochromiques flexibles, Study and set-up of ionic liquid based electrolytic membranes for flexible electrochromic devices

N° d’ordre : 3678
THÈSE
PRESENTEE A
L’UNIVERSITÉ BORDEAUX I
ECOLE DOCTORALE DES SCIENCES CHIMIQUES
par Sandrine Duluard
POUR OBTENIR LE GRADE DE
DOCTEUR
Spécialité : Physico-chimie de la matière condensée.


STUDY AND SET-UP OF IONIC LIQUID BASED ELECTROLYTIC MEMBRANES
FOR FLEXIBLE ELECTROCHROMIC DEVICES



Soutenance prévue le 21 novembre 2008
Après avis de :
A. Rougier, Université d’Amiens Rapporteur
M. Subramanian, Oregon State University Rapporteur
C. Biver, Essilor International
G. Campet, CNRS-ICMCB
C. Delmas, CB
M.-H. Delville, CNRS-ICMCB
U. Posset, Fraunhofer Institute
L. Servant, Université Bordeaux 1


-2008-






We must learn to live together as brothers or perish together as fools

Nous devons apprendre à vivre ensemble comme des frères,
sinon nous mourrons ensemble comme des idiots

Martin Luther King, 1964

ii Contents
___________________________________


Acknowledgements / Remerciements
Introduction
List of symbols, abbreviations and acronyms
List of main products


Chapter I. Electrochromic devices: context, objectives and state of the art ...............................1
I. 1. Context of the study.............................................................................................................3
I. 1. 1. Light modulation devices ........................................................................................3
I. 1. 2. Electrochromism developments ..............................................................................6
I. 1. 3. The Nanoeffects project...........................................................................................7
I. 1. 4. Interest of plastic substrates.....................................................................................9
I. 1. 5. ECD for lowering energy consumption...................................................................9
I. 2. Electrochromism principle and key parameters ................................................................10
I. 2. 1. Electrochromism principle ....................................................................................10
I. 2. 2. Types of ECD ........................................................................................................11
I. 2. 3. Important parameters.............................................................................................12
I. 3. State of the art....................................................................................................................14
I. 3. 1. Conductive substrates for ECDs............................................................................14
I. 3. 2. Electrolytes ............................................................................................................16
I. 3. 3. Electrochromic materials.......................................................................................25
I. 4. Conclusion.........................................................................................................................30
References.................................................................................................................................32

Chapter II. Electrolytes based on BMIPF and BMITFSI ionic liquids with LiTFSI lithium 6
salt and PMMA polymer.37
II. 1. Introduction ......................................................................................................................39
II. 2. Electrolyte preparation .....................................................................................................41
II. 2. 1. Products ....................................................................................................41
II. 2. 2. Electrolyte preparation procedure ............................................................41
II. 3. Thermo-mechanical characterisation ...............................................................................43
II. 3. 1. DSC measurements ..................................................................................43
II. 3. 2. Adhesive properties of the membrane electrolyte....................................48
II. 4. Membrane transparency ...................................................................................................49
II. 5. XRD analysis....................................................................................................................50
II. 6. Homogeneity of deposited membranes............................................................................51
II. 7. Ionic conductivity of the electrolytes51
II. 7. 1. Electrochemical Impedance Spectroscopy (EIS) principle ......................51
II. 7. 2. EIS measurements procedure ...................................................................53
II. 7. 3. Ionic conductivity results .........................................................................54


iii
II. 8. ATR-IR and Raman study................................................................................................73
II. 8. 1. ATR / IR and Raman spectra ...................................................................73
II. 8. 2. Determination of TFSI- “free” anion and ion pair populations................75
II. 8. 3. Determination of C=O “free” and C=O coordinated populations............75
+II. 8. 4. Li solvation in (1-x)(BMI-TFSI),xLiTFSI ionic liquids .........................77
+II. 8. 5. Li solvation in LiTFSI / PMMA binary mixtures...................................81
+II. 8. 6. Li solvation in LiTFSI / BMITFSI plasticized PMMA membranes.......83
II. 9. Diffusion coefficient measured by PGSE-NMR..............................................................88
II. 9. 1. NMR spectra.............................................................................................89
II. 9. 2. Diffusion coefficient in liquid electrolyte LiTFSI/BMITFSI...................92
II. 9. 3. Diffusion coefficient in gel electrolytes (LiTFSI / BMITFSI / PMMA)102
II. 10. Conclusion....................................................................................................................104
References...............................................................................................................................106


Chapter III. Electrochromic thin films synthesis and properties in ionic liquid electrolyte:
PEDOT, Prussian Blue and Prussian Blue analogue ..............................................................109
III. 1. Introduction...................................................................................................................111
III. 2. PEDOT..................................................................................................................
III. 2. 1. Introduction to PEDOT.....................................................................................111
III. 2. 2. PEDOT deposition methods .............................................................................115
III. 2. 3. Studied films .....................................................................................................120
III. 2. 4. Electrochemical measurements of PEDOT films .............................................120
III. 2. 5. Optimization of PEDOT films thickness ..........................................................122
III. 2. 6. Comparison of the different deposition routes for PEDOT films.....................126
III. 2. 7. Improvement of the PEDOT films adhesion and homogeneity........................132
III. 2. 8. Conclusion on PEDOT .....................................................................................136
III. 3. Counter electrode: Prussian Blue and its analogue.......................................................137
III. 3. 1. Strategy for the counter electrode: interest of PB and analogues. ....................137
III. 3. 2. Brief history of PB and analogues ....................................................................137
III. 3. 3. Formula, structure and electrochromic aspect ..................................................138
III. 3. 4. PB and InHCF as-deposited films.....................................................................142
III. 3. 5. Electrochemical and electrochromic properties................................................151
III. 3. 6. Conclusion on PB and InHCF counter-electrodes............................................158
III. 4. Conclusion ....................................................................................................................159
References...............................................................................................................................161

Chapter IV. Complete devices: set-up and characterization...................................................165
IV. 1. Introduction...................................................................................................................167
IV. 2. Preparation of complete devices...................................................................................167
IV. 2. 1. Specificity of the PEDOT-Prussian Blue system .............................................167
IV. 2. 2. Sequence of device preparation.....................