Projects / Programmes
Condensed ionic liquids and their application in electrochromic devices
| Code |
Science |
Field |
Subfield |
| 2.03.00 |
Engineering sciences and technologies |
Energy engineering |
|
| Code |
Science |
Field |
| T140 |
Technological sciences |
Energy research |
| T150 |
Technological sciences |
Material technology |
ionic liquids, electrolytes, silsesquioxanes, electrochromic devices, sol-gel synthesis
Researchers (6)
Organisations (1)
| no. |
Code |
Research organisation |
City |
Registration number |
No. of publicationsNo. of publications |
| 1. |
0104 |
National Institute of Chemistry |
Ljubljana |
5051592000 |
20,982 |
Abstract
The proposed project deals with the preparation of condensed ionic liquid electrolytes based on the polyhedral oligomeric silsesquioxanes (POSS) and their application in electrochromic (EC) devices. Its fulfilment bases on the synthesis of imidazole derivatives with the sol-gel functionality. In this way, the sol-gel groups can participate in condensation reactions initiated with either hydrolysis (acid, base) or solvolysis (strong organic acids), leading first to the formation of cyclic, linear and open cube-like polyhedral siloxanes and in a more condensed form to ladder- or cube-like POSS species. The proposed project offers the possibility of investigation of imidazolium-based ionic liquids in a condensed, i.e. (quasi)-solid state. Namely, the irrepressible breaktrough of ionic liquid electrolytes in the recent years (despite their non-volatility) instigated also the need for their solidification. The functionalisation of imidazole ring with the simple sol-gel alkoxy groups is a novel approach recently introduced by our laboratory.
The main objective of this project is the application of synthesised POSS based condensed ionic liquids in EC devices with either anorganic thin film or conducting polymer (PEDOT,…) electrodes. These devices should possess fast switching times, optical modulation up to 60 % and long-term stability. Due to increased prices of oil and though the tendency for energy savings represent the EC devices a commercially perspective sector, either in the form of smart windows or for sunroofs, helmets and automotive rear-view mirrors.
Significance for science
This project is important from the point of view of synthesis of new silsesquioxane based condensed ionic liquid electrolytes. The proposed electrolytes combine the excellent properties of ionic liquids and properties of the sol-gel condensation process. In the literature, various possibilities were used for the solidification of ionic liquids, for instance addition of small molecular weight gelators, solid particles (silica nanoparticles, colloidal titania, carbon nanotubes), entrapment in various polymers or even entrapment in sol-gel network, but this networks were formed by the addition of simple alkyltrialkoxysilane sol-gel precursors to the ionic liquids. In the approach applied in this project, alkoxy groups were directly bound on imidazole ring and can take part in processes of hydrolysis (solvolysis) and condensation. The final products are silsesquioxane derivatives of ionic liquids. Introduction of other anions then iodide gives the possibility to prepare lithiated electrolytes, which were applicable in electrochromic (EC) devices with optically active electrochromic layer of conductive polymer poly(3,4-ethylendioxytiophen) (PEDOT) or WO3. As counter electrodes we prepared various thin films at low temperatures, appropriate also for deposition on ITO-plastic substates. Alkoxy-functionalised ionic liquids opened numerous possibilities to perform basic structural and electrochemical studies, studies of mechanisms of hydrolysis (solvolysis) and condensation, mechanism of conduction and the stability of electrolytes. The project is scientificaly relevant also for its synthesis part, namely, the precursors for the preparation of electrolytes were newly synthesised and are not commercialy available.
Significance for the country
Alkoxy-functionalised ionic liquids enable the preparation of electrolytes for various electrochemical cells, for example dye-sensitised photoelectrochemical cells and electrochromic (EC) devices. The investigations of these compounds enabled our cooperation in EU project Innoshade entitled “Innovative Switchable Shading Appliances based on Nano-materials and Hybrid Electrochromic Device Configurations”, (1. 9. 2008 – 31. 8. 2012), contract N° 200431. This EU project is concerned with an innovative switchable light transmittance technology and led by Fraunhofer Institut Silicatforschung, Würzburg. The aim of Innoshade project is to study the underlying nanotechnology-based processes from laboratory scale to pilot line and also to explore the possibility of application of electrochromic (EC) devices in various end-user groups. One of them is Gorenje, d.d. (partner in Innoshade) aiming to apply EC devices on their domastic appliances (refrigerator, wine cellar). Namely, EC windows can significantly diminish the amount of heat energy entering the refrigerator, because the user can over the EC window choose the desired food, while the door of the refrigirator remains closed.
Most important scientific results
Annual report
2008,
final report,
complete report on dLib.si
Most important socioeconomically and culturally relevant results
Annual report
2008,
final report,
complete report on dLib.si
