New hybrid and ionic polymer electrolytes for lithium metal solid state batteries

Abstract

The rising need for the development of the electric transportation requires batteries with higher energy densities. Lithium metal batteries look to be the most promising technology. Nonetheless, common organic liquid electrolytes cannot be used, due to their poor chemical stability towards the lithium and the formation of dendrites. Solid state batteries, where the liquid electrolyte is replaced by a solid ionic conductor, enable to reach higher energy density, are safer and can mitigate dendrites formation. In this thesis, we report new hybrid and polymer solid electrolytes to couple with a lithium metal anode. For this purpose, we developed ionic polymer matrices based on poly(ethylene glycol) derivatives. For the hybrids, we choose to use garnet nanoparticles Li7La3Zr2O12 (LLZO) as active inorganic fillers. The performance of the hybrid and polymer solid electrolytes was carried out in lithium symmetrical solid-state batteries. The study of voltage shapes at different current densities reveals about the homogeneity of Li stripping/plating processes and the formation of Li dendrites.