Influence of oligo(ethylene oxide) substituents on pyrrolidinium-based ionic liquid properties, Li(+) solvation and transport.

The presence of oligoether functional groups in the cations of ionic liquids has a significant effect on Li(+) coordination. In this work, a series of N-alkoxylether-N-methyl pyrrolidinium bis(trifluoromethanesulfonyl)imide ionic liquids were synthesized to investigate the effect of the number of ether units on Li(+) coordination and transport. The nature of Li(+) coordination was elucidated through the combination of Raman spectroscopy and heteronuclear Overhauser effect NMR spectroscopy.

A combined theoretical and experimental study of the influence of different anion ratios on lithium ion dynamics in ionic liquids.

In this paper, we investigate via experimental and simulation techniques the transport properties, in terms of total ionic conductivity and ion diffusion coefficients, of ionic liquids doped with lithium salts. They are composed of two anions, bis(fluorosulfonyl)imide (FSI) and bis(trifluoromethanesulfonyl)imide (TFSI), and two cations, N-ethyl-N-methylimidazolium (emim) and lithium ions. The comparison of the experimental results with the simulations shows very good agreement over a wide temperature range and a broad range of compositions.

Polymerizable ionic liquid with state of the art transport properties.

The physicochemical properties of diallyldimethylammonium-bis(trifluoromethanesulfonyl)imide (DADMATFSI) and its binary mixture with LiTFSI are presented herein, also showing this novel compound as a polymerizable room temperature ionic liquid with excellent transport properties for Li(+) ions. In particular, results of pulsed field gradient (PFG)-NMR diffusion experiments and impedance measurements show that DADMATFSI exhibits state of the art properties of ionic liquids. Similar ionic diffusion coefficients and a similarly high conductivity as seen in the benchmark compound N-butyl-N-methylpyrrolidinium-bis(trifluoromethanesulfonyl)imide (PYR14TFSI) are observed.

Fluorosulfonyl-(trifluoromethanesulfonyl)imide ionic liquids with enhanced asymmetry.

New ionic liquids with an asymmetric anion, fluorosulfonyl-(trifluoromethanesulfonyl)imide (FTFSI), were prepared and their chemical-physical properties were investigated. The ionic liquids based on N-methyl-N-propylpyrrolidinium, PYR(13), N-butyl-N-methylpyrrolidinium, PYR(14), and N-methoxyethyl-N-methylpyrrolidinium, PYR(12O1), exhibit high electrochemical stability (>5.5 V on platinum) and thermal stability (>250 °C in N(2) and >200 °C in O(2)).