Thermoelectric generators based on ionic liquids

Edith Laux (School of Engineering – HE-Arc Ingénierie, HES-SO // University of Applied Sciences Western Switzerland) ; Stefanie Uhl (School of Engineering – HE-Arc Ingénierie, HES-SO // University of Applied Sciences Western Switzerland) ; Laure Jeandupeux (School of Engineering – HE-Arc Ingénierie, HES-SO // University of Applied Sciences Western Switzerland) ; Pilar Pérez López (School of Engineering and Architecture (HEIA-FR), HES_SO // University of Applied Sciences Western Switzerland) ; Pauline Sanglard (School of Engineering and Architecture (HEIA-FR), HES_SO // University of Applied Sciences Western Switzerland) ; Ennio Vanoli (School of Engineering and Architecture (HEIA-FR), HES_SO // University of Applied Sciences Western Switzerland) ; Roger Marti (School of Engineering and Architecture (HEIA-FR), HES_SO // University of Applied Sciences Western Switzerland) ; Herbert Keppner (School of Engineering – HE-Arc Ingénierie, HES-SO // University of Applied Sciences Western Switzerland)

Looking at energy harvesting using body or waste heat for portable electronic or on-board devices, Ionic liquids are interesting candidates as thermoactive materials in thermoelectric generators (TEGs) because of their outstanding properties. Two different kinds of ionic liquid, with alkylammonium and choline as cations, were studied, whereby different anions and redox couples were combined. This study focussed on the intention to find non-hazardous and environmentally friendly ionic liquids for TEGs to be selected among the thousands that can potentially be used. Seebeck coefficients (SEs) as high as − 15 mV/K were measured, in a particular case for an electrode temperature difference of 20 K. The bottleneck of our TEG device is still the abundance of negative SE liquids matching the internal resistance with the existing positive SE-liquids at series connections. In this paper, we show further progress in finding increased negative SE liquids. For current extraction from the TEG, the ionic liquid must be blended with a redox couple, allowing carrier exchange in a cyclic process under a voltage which is incuced by the asymmetry of the generator in terms of hot and cold electrodes. In our study, two types of redox pairs were tested. It was observed that a high SE of an ionic liquid/redox blend is not a sufficient condition for high power output. It appears that more complex effects between the ionic liquid and the electrode determine the magnitude of the final current/power output. The physico-chemical understanding of such a TEG cell is not yet available.


Mots-clés:
Type d'article:
scientifique
Faculté:
Ingénierie et Architecture
Ecole:
HE-Arc Ingénierie Haute école Arc Ingénierie
HEIA-FR Haute école d’ingénierie et d’architecture de Fribourg
Institut:
ChemTech - Institut des technologies chimiques
Classification:
Ingénierie
Date:
2018
Pagination:
5 pages
Titre du document hôte:
Journal of Electronic Materials
DOI:
ISSN:
1543-186X
Le document apparaît dans:



 Notice créée le 2018-03-20, modifiée le 2018-03-27

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