Micro Energy devices – MISE

Systematic study was done to determine conditions leading to the lowest electrode resistivity.

After several experiments, it turns out that 10% of metallic precursor lead to high conductive layer of active material (0.9ohm.cm). It was found out, after a systematic study, that the laser velocity has to be lower than 10um/s to get a continuous line of material. More especially, 8um/s was found to be the best velocity for RuO2. Electrochemical tests carried out on such as made electrode showed that expected electrochemical response was obtained which is really encouraging.

Refine experimental parameters, increase deposited active material density, carbon negative electrode réalisation (through electrophorese or laser scribing). It will be all about getting a Carbone/RuO2 hybrid system.

Nothing.

This project aims at studying and developing energy storage micro-device embeddable in clothes. Two types of devices will developed: one including a oxide based electrode together with a carbon electrode; the other one including two carbon electrode. The former will be devoted to high specific energy, the latter to high power density applications as well as wider operating temperature. In both cases new gel-like electrolytes will be realized to get all solid devices. The micro-devices processing will be performed by laser to reach performances of 5 mF cm 2 µm-1 sous 3,5 V, 10 µWh cm-2 µm-1 et/ou 100 µW cm-2 µm-1 (total volume of the component, excluding the packaging), stable for more than 10,000 cycles.
Within this project, two laboratories are involved gathering complementary skills, which take care of the five tasks of this project.
The Laboratoire de Physico-Chimie des Nano Objets de Toulouse is a laboratory which has developed knowledge on metallic nano particles and their integration in micro-devices. The Centre Interuniversitaire de recherche et d’Ingénierie des MATériaux (UMR CNRS n°5085) has got an expertise in synthesis and characterization of material for electrochemical energy storage, more especially for supercapacitors.

The expected results within the MiSE project are:
- realization of nano structured materials and well dispersed nano particles through original methods from cellulosic based colloïdal solutions . The process used here has been developed by Chaudret's group, and to the best of our knowledge has not been applied for electrochemical energy storage active materials.
- innovative use of laser scribing for micro devices realization. This a versatile and a easy to use technique which allow to achieve device dimension ranging from few mm2 up to tens of cm2. Heating of the colloidal suspension, previously deposited onto a substrate, will lead to the elimination of the cellulose together with the oxidation of the metallic particles inducing the in-situ active material formation.
- one pot flexible microsupercapactior realisation by laser transformation, operating in both extended temperature and voltage ranges (-50°C-100°C; 3.5V).