Description du sujet de thèse

Objectives:
The main goal of this project is to develop new imaging and analytical acquisition methods as well as a new in situ platform for the study of radiation sensitive battery materials and dynamic processes. Electron microscopes can probe the atomic scale changes occurring at interfaces that determine materials performance. A main challenge to probing the interfacial chemical and structural changes defining electrochemical processes is the high sensitivity to the electron beam of the battery materials, of the electrolyte and of the newly formed compounds upon lithiation. New acquisition and processing methodologies are required to gain insight into the structural evolution, charge transfer and SEI formation in batteries under operation conditions. This project will focus on developing and combining workflows: 1) for multiframe image analysis and processing and 2) for beam damage monitoring and quantification, in order to aid with the implementation of novel scanning strategies for STEM-EELS acquisition of battery interfaces 3) for realizing graphene liquid cells to access solid-liquid interfaces at high resolutions and apply the new AI based acquisition methods to investigate them.

Job description / Activities:
You will conduct systematic beam damage measurements and quantify the chemical and structural changes occurring on the negative electrode material and the liquid on electron beam irradiation using advanced scanning configurations and STEM-EELS.
You will develop new workflows for quantitative, standardised analysis of images and spectra and data processing procedures.
You will prepare high quality samples in moisture free conditions and using graphene liquid cells and develop new solutions for in situ electron microscopy of solid-liquid interfaces.
You will interact regularly with collaborators at the Data and AI group at Thermo Fisher Scientific, to optimize tested acquisition settings and assist on the development of new data-informed scanning strategies using sample knowledge developed during this PhD thesis work.
You will have access to unique imaging and analytical electron microscopy capabilities in the IMN. Imaging and spectroscopy analysis will be performed using scanning transmission electron microscopy (STEM) and electron energy loss spectroscopy (EELS) thanks to the Nant'Themis (S)TEM (Thermo Fisher Scientific Themis Z G3). This probe corrected microscope is equipped with specialized holders for operando measurements and transfer of air sensitive samples, with low dose mode and highly sensitive detectors (iDPC, direct detection of electrons).

Contexte de travail

This PhD thesis is funded as part of a new EU program named OPINCHARGE. This HORIZON-RIA program brings together 10 world-leading research and technology organizations across Europe with the aim to develop new characterization methodologies for next-gen battery materials.
The host laboratory is the Institute of Materials of Nantes Jean Rouxel (IMN, UMR 6502, http://www.cnrs-imn.fr). The IMN is a joined research centre between CNRS and the Nantes University, composed by over 200 staff members including over 120 permanent staff members (professors, CNRS researchers, engineers) and around 80 PhD students and postdoctoral researchers. The successful PhD candidate will benefit from interaction with numerous colleagues working on a number of fields of material sciences through experiments using a myriad of advanced characterization techniques and through simulations. Through the OPINCHARGE project, the PhD candidate will join the electrochemical storage and conversion of energy (ST2E) group; a renowned research group working on the development and characterisation of Li-ion batteries (silicon, high Ni oxides, organic based…). The PhD student will be supervised both by a professor in this group (Philippe Moreau) and by a CNRS researcher greatly experienced in the understanding of electron beam interaction with beam-sensitive materials, including liquids (Patricia Abellan). The PhD student will have direct and easy access to the electron microscopy facility at IMN allowing the development of cutting-edge experiments in the domain.
The successful candidate will collaborate closely with a postdoctoral researcher working full time on developing novel scanning strategies for STEM acquisition and several senior researchers from the Data and AI group (D&AI) at Thermo Fisher Scientific. Thermo Fisher Scientific, Netherlands, is the major European manufacturer of electron microscope and the D&AI group will contribute to the OPINCHARGE project by providing AI driven application features for analytical Transmission Electron Microscopy (TEM) to perform operando and in situ analysis of battery interfaces.

Le poste se situe dans un secteur relevant de la protection du potentiel scientifique et technique (PPST), et nécessite donc, conformément à la réglementation, que votre arrivée soit autorisée par l'autorité compétente du MESR.

Contraintes et risques

No risks nor constrains
Travel abroad for meetings with European partners.

Informations complémentaires

Profile and requirements:
You hold a MSc in the physics, materials science or related disciplines.
You have some experience in characterization by electron microscopy techniques.
You have good computational skills and can use complex image processing and analysis tools.
Your knowledge of materials chemistry is sufficient to take into account the specificities brought by compounds found in lithium batteries and the reaction they might lead to.
You have a special taste for delicate, precise and challenging experiments and are very perseverant.
You enjoy hands-on experimental as well as computational work.
You can interact fluently in English with other researchers so that they can bring you their contribution to the OPINCHARGE project and you can give yours to them.
You are quality-oriented, conscientious, creative, and cooperative, with a taste for scientific rigor.
You are able to communicate to different audiences.
Experience in operando measurements and spectroscopies would be a plus without it being mandatory.

All applications must be sent through the “portail emploi CNRS” and must include a CV and a cover letter outlining your motivation.