Speciation and dipole re-orientation dynamics of glass-forming liquid electrolytes: Li[N(SO2CF3)2] mixtures of 1,3-propanesultone or tetrahydrothiophene-1,1-dioxide.

Recently new ionic fluids such as super-concentrated electrolyte solutions, solvated ionic liquids and deep eutectic solvents attracted much attention in the field of the liquid electrolyte for the next generation electrochemical devices and processes. Basic composition of these new ionic fluids is similar among them; a large/excess amount of salt and solvent, though the solvent is sometime solid at ambient temperature. Here, we found and demonstrated LiTSFA (TFSA = (CF3SO2)2N-) mixtures of of 1,3-propanesultone (PS) or tetrahydrothiophene-1,1-dioxide (SL) yield a homogeneous liquid at room temperature at wide range of composition. In order to clarify unique high Li+ transference number in these mixtures, speciation and dipole reorientation dynamics were studied for these mixtures to be evident large scale size aggregates formation in these mixtures.