Scientific direction Development of key enabling technologies
Transfer of knowledge to industry

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Compressed Sensing for ultrasonic imaging: disruptive method development and prototyping

Département Imagerie Simulation pour le Contrôle (LIST)

Laboratoire Méthodes CND

01-01-2020

PsD-DRT-19-0099

olivier.mesnil@cea.fr

In non-destructive ultrasonic testing, multi-element sensors are used for the inspection of structures to ensure the safety of people and infrastructures. Currently, one of the driving factor of an ultrasonic method is the number of elements of the sensor, influencing the speed and efficiency of the inspection but also the cost and the volume of the equipment. This project aims at developing a prototype of a multi-element sensor with a limited number of elements compared to current state of the art equipment, without losing imaging resolution. To achieve this goal, Compressed Sensing (CS), a recent technique of signal processing allowing to go beyond the traditional sampling theorems and to reconstruct data from severely undersampled measurements, will be used. The ultrasonic inspection procedure will need to be entirely rethought to meet the CS requirements, specifically the sparsity of the measured data and the incoherence of the measurement process. The expected results is a significant reduction (of the order of 5) of the number of elements to conduct imaging, which would be a true revolution in NDT with direct applications in various industrials sectors. The following laboratories, all located in Saclay (France) of the CEA (the French atomic commission), will participate to the project: the NDT department for its expertise in multi-element ultrasonic testing and Neurospin and Cosmostat for their expertises in the field of CS, mainly applied to medical RMI imaging and astrophysics, respectively. The collaboration between these three labs, each among the worldwide leading institutes in their respective fields, will ensure the creation of a new and disruptive family of sensors.

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Li-rich transition metal sulphides as high capacity cathode materials for all-solid-state lithium batteries

Département de l'Electricité et de l'Hydrogène pour les Transports (LITEN)

Laboratoire Matériaux

01-01-2020

PsD-DRT-19-0101

frederic.lecras@cea.fr

This post-doctoral work aims at the comprehensive study of a new family of Li+ intercalation materials Li[LixTi1-x]S2 (LTS) et the assessment of their performance in all-solid-state lithium batteries based on Li2S-P2S5 glass-ceramic electrolytes. Preliminary results obtained in the lab highlight similarity in the electrochemical behaviour of these compounds with the one of their oxide counterparts, i.e. Li2MnO3-LiMO2 (M=Ni, Co,...): a dual anion- and cation-based redox process, accompanied by a more or less progressive activation, and resulting in a high reversible capacity (~300 mAh/g). The main goals of the proposed study will be (i) to achieve a clear understanding of the phenomena at stake in these materials and their influencing parameters, (ii) to optimize the materials (modification of the composition, of the particle morphology,?) in order to reach practical performance close to the theoretical ones and (iii) to assess the electrochemical behaviour when embedded in an all-solid-state device (structural evolution of LTS, LTS/LPS interfaces, cohesion of the system). Different techniques will be used for the synthesis/preparation and the structural (XRD, XPS, Raman, RPE, (XAS, EXAFS)...), chemical (Auger nanoprobe, ToF-SIMS, ICP...) and electrochemical characterization of materials, interfaces and battery components. The first part of this work (6-8 months) will be carried out at ICMCB (Bordeaux), whereas the second one, which will focus on the preparation of electrodes and all-solid-state batteries, will be conducted at CEA (Grenoble).

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Advanced tandem time of flight mass spectrometry for microelectronic applications

Département des Plateformes Technologiques (LETI)

Autre laboratoire

01-01-2020

PsD-DRT-19-0115

jean-paul.barnes@cea.fr

The CEA LETI seeks to recruit a post-doctoral researcher to work on the development of advanced time of flight secondary ion mass spectrometry applications (TOF-SIMS). The candidate will work on a new TOF-SIMS instrument equipped with tandem MS spectrometry, in-situ FIB and Argon cluster sputtering. The research project will be focused around the following topics ? Developing methods to correlate TOF-SIMS with AFM, XPS and Auger ? Improving the sensitivity and efficiency of fragmention of the tandem MS spectrometer ? Developing 3D FIB-TOF-SIMS applications and improving the spatial resolution. The candidate will also have access to the wide range of state of the art instruments present on the nanocharacterisation platform as well as bespoke samples coming from the advanced technology branches developed at the LETI. The candidate will also benefit from a collaboration with the instrument supplier.

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Optical sensor development for in-situ and operando Li-ion battery monitoring

Département de l'Electricité et de l'Hydrogène pour les Transports (LITEN)

Laboratoire Analyse électrochimique et Post mortem

01-01-2020

PsD-DRT-19-0121

olivier.raccurt@cea.fr

To improve the battery management system, it is required to have a better knowledge of the physical and chemical phenomena inside the cells. The next generation of cells will integrate sensors for deepest monitoring of the cell to improve the performances, safety, reliability and lifetime of the battery packs. The main challenge is thus to measure relevant physico-chemical parameters in the heart of the cell to get a direct access to the real state of the cell and thus to optimize its management. To address this challenge, a research project will start at CEA at the beginning of 2020 to develop innovative optical sensors for Li-ion battery monitoring. He / She will participate, in a first step, to the development of optical probes and their integration on optical fibres. The work will focus on the synthesis of a photo-chemical probe (nanoparticle and/or molecule) as active part of the sensor. Then, theses probes will be put on the optical fibre surface to form the sensor. The candidate will also participate to the realization of an optical bench dedicated to the testing of the sensors. In a second step, he / she will work on integrating the sensors into the Li-ion cells and test them in different conditions. The objective is to demonstrate the proof of concept: validation of the sensors efficiency to capture the behaviour of the cell and correlate it to electrochemical measurements.

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