Topic 01-24 : Rational design of improved Li transport mechanisms in composite ceramicpolymer electrolytes by means of electrochemical and solid state NMR characterizations

The overall aim of this PhD research project is to develop a RT solid state battery containing a composite electrolyte.

The thesis work will first be oriented towards the development of polymer-ceramic composite solid electrolytes of different composition with the aim to elucidate and enhance the ionic transport at the interface between the ceramic filler and the polymer matrice. Several candidates will be screened and new inorganic fillers with specific surface modification will be synthesized. The chemical interphase and the Li transport between the two phases will be followed by solid-state NMR, a powerful tool that permits the non-invasive detection and quantification of the ionic exchange processes in pristine materials and during operando. In a second step, full cells will be assembled and the main interfaces with the Li metal anode and the cathode material will be studied by electrochemical as well as by ex-situ and in-situ solid state NMR methods. An efficient transfer of lithium at these interfaces is crucial to ensure high power and maintain long cycle life. In addition of synthesis and processing, the student will perform a complete physico-chemical analysis of the materials and utilize advanced electrochemical testing techniques.

The student will have the possibility to realize a stay of at least 3 months abroad and within the framework of this PhD thesis, a stay with an ALISTORE institute would be highly relevant. The student may have the opportunity to realize the research visit at the Warsaw University of Technology (Poland) to determine and understand the effect of additives molecules and specific salts complemented by their electrochemical characterization.