The vibrational studies on the water channel in LiTFSI aqueous electrolyte system
2018 121st KCS General Meeting
Abstract: The highly concentrated LiTFSI(Lithium bis(trifluoromethanesulfonyl)imide) aqueous electrolyte overcome the electrochemical stability window of water(1.23 V) due to the formation of SEI that was not found in other aqueous solutions. This particular property presents the possibility of this electrolyte as a replacement for nonaqueous type electrolytes that are currently in commercial use. Many studies have focused on the formation of SEI and there is a lack of research on how Li ions can transport rapidly. In this experiment, we have investigated the role of water for Li+ transport in this highly viscous environment. Linear IR, PSPP, and 2D-IR were performed on various concentrations of electrolyte, including an OD probe that is sensitive to electrical environment. The results of the IR experiment showed that although a very high concentration of LiTFSI was present, a considerable amount of water exhibited bulk-like properties, indicating the existence of a water domain in the electrolyte. Also the results of anisotropy and spectral diffusion indicate the anionic water, on the layer TFSI- anion, acts as a lubricant to prevent electrostatic drag resulting in the fast transport of Li ion.