Description du projet
Matériau de stockage d’énergie en couches minces pour les capteurs IdO
L’importance du stockage de l’énergie ne cesse de croître à mesure qu’augmente le nombre de dispositifs IdO. Les capteurs autonomes requièrent des batteries à haute densité énergétique, à haute tension et de longue durée de vie. Bien que les batteries actuelles disposent d’une capacité élevée, elles ne peuvent pas se décharger et se recharger rapidement. En revanche, les condensateurs peuvent dégager plus rapidement de l’énergie, mais leur densité d’énergie est plus faible. Le projet CITRES, financé par l’UE, tentera d’obtenir le meilleur des deux mondes. Les chercheurs introduiront des défauts dans de minces films d’un matériau appelé ferroélectrique relaxeur. Le traitement des relaxeurs en couches minces améliore le claquage de la rigidité diélectrique. Une haute densité d’énergie peut être obtenue dans ce type de matériau en maximisant la polarisation et en minimisant les courants de fuite.
Objectif
The goal of CITRES is to provide new energy storage devices with high power and energy density by developing novel multilayer ceramic capacitors (MLCCs) based on relaxor thin films (RTF).
Energy storage units for energy autonomous sensor systems for the Internet of Things (IoT) must possess high power and energy density to allow quick charge/recharge and long-time energy supply. Current energy storage devices cannot meet those demands: Batteries have large capacity but long charging/discharging times due to slow chemical reactions and ion diffusion. Ceramic dielectric capacitors – being based on ionic and electronic polarisation mechanisms – can deliver and take up power quickly, but store much less energy due to low dielectric breakdown strength (DBS), high losses, and leakage currents.
RTF are ideal candidates: (i) Thin film processing allows obtaining low porosity and defects, thus enhancing the DBS; (ii) slim polarisation hysteresis loops, intrinsic to relaxors, allow reducing the losses. High energy density can be achieved in RTF by maximising the polarisation and minimising the leakage currents. Both aspects are controlled by the amount, type and local distribution of chemical substituents in the RTF lattice, whereas the latter depends also on the chemistry of the electrode metal.
In CITRES, we will identify the influence of substituents on electric polarisation from atomic to macroscopic scale by combining multiscale atomistic modelling with advanced structural, chemical and electrical characterizations on several length scales both in the RTF bulk and at interfaces with various electrodes. This will allow for the first time the design of energy storage properties of RTF by chemical substitution and electrode selection.
The ground-breaking nature of CITRES resides in the design and realisation of RTF-based dielectric MLCCs with better energy storage performances than supercapacitors and batteries, thus enabling energy autonomy for IoT sensor systems.
Champ scientifique
- natural sciencescomputer and information sciencesinternetinternet of things
- engineering and technologymaterials engineeringcoating and films
- engineering and technologyelectrical engineering, electronic engineering, information engineeringelectronic engineeringsensors
- engineering and technologymaterials engineeringceramics
- natural scienceschemical sciences
Mots‑clés
Programme(s)
Régime de financement
ERC-COG - Consolidator GrantInstitution d’accueil
8010 Graz
Autriche