The physicochemical and electrochemical properties of the binary ionic liquid (IL) lithium bis(trifluoromethylsulfonyl)amide (LiTESA) dissolved in N,N-diethyl-N-methyl-N-(2-methoxyethy)ammonium bis(trifluoromethylsulfonyl)amide (DEMETFSA) were investigated The tonic conductivity of the binary IL decreased with an increase in LiTFSA concentration The self-diffusion coefficients of Li+ DEME+ and TFSA(-) dissolved in the IL were measured by using the pulsed-field-gradient spin-echo (PGSE) NMR method The self-diffusion coefficient of each ionic species was also found to decrease with increasing concentration of LiTFSA The limiting current density in the IL electrolyte was evaluated by chronoamperometry using symmetric Li vertical bar IL vertical bar Li cell The results suggest that the diffusion process of Li(I) in the IL dominates the limiting current density in the cell The highest limiting current density is achieved at a concentration of 0 64 mol dm(-3) of LiTFSA (C) 2010 Elsevier B V All rights reserved