Missions

Li-ion batteries are at the heart of the energy transition, but their lifetime and safety still need to be improved, which requires a detailed understanding of their degradation mechanisms. Our laboratory has advanced the study of key phenomena such as solid–electrolyte interphase (SEI) formation and electrolyte degradation by using optical sensors like Fiber Bragg Gratings (FBG) and Tilted Fiber Bragg Gratings (TFBG). The latter exploit the evanescent waves generated at the fiber surface, providing enhanced sensitivity to interfacial processes and internal chemical reactions within the battery.

Activités

-The postdoctoral project aims to extend this approach by developing TFBG sensors coated with thin metallic films (Au, Ag) or transparent conducting oxides (ITO, AZO, FTO). These vacuum-deposited coatings will impart both conductive and plasmonic properties to the TFBGs, enabling them to serve simultaneously as working electrodes and spectroscopic probes. This architecture will make it possible to study key electrochemical reactions such as lithium alloying or electrodeposition (e.g., Prussian Blue), while benefiting from plasmonic enhancement of spectroscopic sensitivity.

In parallel, functionalizing TFBGs with MOFs (ZIFs) and amine groups will allow the capture and detection of gases released during SEI formation, particularly CO₂, which can be identified in the form of carbamates. By combining TFBG technology with numerical methods, this project opens new pathways for real-time observation of interfaces in commercial batteries, providing both fundamental insights and diagnostic tools for the next generation of energy storage systems.

Compétences

PhD degree in electrochemistry or optics. The candidate should demonstrate a strong aptitude for experimental work and the ability to adapt to problems across different fields. Proficiency in English is required.

Contexte de travail

The project is funded by the RS2E and led by the CSE laboratory. Most of the experimental work will be carried out at CSE, which has recognized expertise in the field of batteries, particularly in lithium reactivity mechanisms, interface engineering, cell assembly, and the exploration of new chemistries beyond Li-ion (such as Na-ion and all-solid-state batteries). Collaborations with IEMN and the University of Mons are planned for the fiber coating processes.