Presenter: Guiomar Hernández
Title: Fluoroethylene Carbonate Containing Electrolytes: Origin of Poor Shelf Life and Its Mitigation
Affiliation: Uppsala University
Safety and cycling stability are still the main concerns towards developing high energy density lithium metal batteries. In this regard, electrolytes play an important role as they are able to form a stable passivating layer called solid electrolyte interphase (SEI). This layer is able to suppress continuous electrolyte degradation improving the cyclability of the batteries. Although fluoroethylene carbonate (FEC) has been found to be a particularly effective SEI-forming additive, its combination with the conventional LiPF6 salt accelerates the electrolyte degradation. Herein we have study the trigger and mechanism of such degradation with liquid- and solid-state NMR. Furthermore, additives to avoid such degradation have been investigated to improve chemical and electrochemical stability of electrolytes to be used in LiNi1/3Mn1/3Co1/3O2/Li metal batteries at high temperatures.