Thorsmølle, Verner K.Rothenberger, GuidoTopgaard, DanielBrauer, Jan C.Kuang, DaibinZakeeruddin, Shaik M.Lindman, BjörnGrätzel, MichaelMoser, Jacques-E.2011-01-252011-01-252011-01-25201110.1002/cphc.201000819https://infoscience.epfl.ch/handle/20.500.14299/63300WOS:000286441700024Iodine added to iodide-based ionic liquids leads to extraordi- narily efficient charge transport, vastly exceeding that expect- ed for such viscous systems. Using terahertz time-domain spectroscopy, in conjunction with dc conductivity, diffusivity and viscosity measurements we unravel the conductivity pathways in 1-methyl-3 propylimidazolium iodide melts. This study presents evidence of the Grotthuss mechanism as a significant contributor to the conductivity, and provides new insights into ion pairing processes as well as the formation of polyiodides. The terahertz and transport results are reunited in a model providing a quantitative description of the conduction by physical diffusion and the Grotthuss bond-exchange process. These novel results are important for the fundamental understanding of conduction in molten salts and for applications where ionic liquids are used as charge-transporting media such as in batteries and dye-sensitized solar cells.electrolyteconducting materialsion pairsionic liquidsterahertz spectroscopytext::journal::journal article::research article