Imidazolium Based Ionic Liquid Electrolytes for Li-Ion Secondary Batteries Based on Graphite and LiFePO₄

Abstract

This manuscript reports the development of a safe and green lithium-ion battery using lithium iron phosphate (LiFePO4) as a positive electrode, graphite (Cgr) as a negative electrode, and an Ionic Liquid (IL) electrolyte solution based on 1-hexyl-3-methylimidazolium bis(trifluoromethanesulfonyl)-imide (C1C6ImNTf2). Vinylene carbonate (VC) was tested as an electrolyte additive. The electrochemical stability of (C1C6ImNTf2) and their binary mixture referred as (Li)(C1C6ImNTf2) were investigated. In addition the electrochemical behavior of the graphite electrode was studied through cyclic voltammetry experiments in the presence and absence of VC co- additive. Complementary cycling tests demonstrated the benefic effect of VC on the charge-discharge performances for the full Lithium ion configuration based on Cgr/LiFePO4.