A Poly(ethylene carbonate)/Lithium Bis(fluorosulfonyl)imide/Titanium Oxide Composite Electrolyte Containing a Pyrrolidinium-based Ionic Liquid

We describe electrochemical properties of a new quaternary poly(ethylene carbonate)/lithium bis(fluorosulfonyl)imide (LiFSI) mixture-based electrolyte containing TiO 2 and N -methyl- N -propyl-pyrrolidinium bis(fluorosulfonyl)imide (Pyr 13 FSI). Incorporation of TiO 2 and Pyr 13 FSI assured a reasonable ionic conductivity of close to 10 -5 S cm -1 at 30 o C with favorable Li transference number ( t Li+ ) of 0.35 measured by an electrochemical method. A relatively fast conduction of Li cation in comparison with that of FSI anion was also proved by a study combining a solid-state NMR with a pulse field gradient (pfg) technique. In addition, anodic stabilities up to about 3.75 and 4.5 V vs. Li/Li + were demonstrated at 40-60 o C and 30 o C, respectively.