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

摘要

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 °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 °C and 30 °C, respectively.