Electrochemical Behavior of Some Lanthanides in Imide Room-Temperature Molten Salt Systems

Room temperature molten salt systems containing bis(trifluoromethanesulfone) imide (TFSI) are expected to be the alternative supporting electrolytes for electroplating and lithium rechargeable batteries because of their attractive characteristics, such as wide electrochemical potential window, high ionic conductivity, high thermal stabili ty, negligible vapor pressure and hydrophobic nature. From these favorable properties, the redox flow batteries having high energy density may be also proposed by using the redox reactions of transition metals in the TFSI-based molten salt systems. However, few redox reactions of transition metals have been reported in the TFSI-based molten salt systems. In this study, the redox reactions of some lanthanides were examined as the candidates for the half cell reactions of the redox flow batteries using 1-ethyl-3methylimidazolium and 1-n-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfone) imide (EMITFSI and BMPTFSI) molten salt systems.