Topic 01-20 : Ca and Mg batteries: improvement of performances by interface engineering

The research project aims at improving the electrochemical performances of Ca and Mg metal anodes, with a careful focus on the relation between SEI chemical composition/morphology and electrochemical performances. Different electrolyte formulations and pre-passivation strategies will be investigated to obtain the best passivation layer for Ca and Mg plating/stripping properties and define the best strategies to prepare it (in-situ or through pre-passivation). The overall project will be divided in three main sequences :

1)  Simple electrolyte formulations will be studied allowing to clearly establish the influence of the solvent, nature and concentration of the Mg or Ca salt and additives on the passivation layer.
2)  Pre-passivation strategies of the metal anodes will be scrutinized to obtain the best plating/stripping performances (coulombic efficiency and kinetics).
3)    Pre-passivated metal anodes will be tested in more complex electrolyte formulations aiming at improving the cations mobility within the electrolyte, decreasing desolvation energy barrier and improving oxidation resilience.

At each step, surface/interface chemical characterization and electrochemical performance assessment will be of prime importance, with dedicated specialized tools (XPS in the lab and at synchrotron, ToF-SIMS for surface/interface analysis, cyclic voltammetry, galvanostatic cycling and electrochemical impedance spectroscopy for electrochemical measurements).

To reach this goal, the PhD student will be based at IPREM (Pau) (75% time) and will do periodic research travels at ICMAB (Barcelone) (25% time)."