Thermal and Electrochemical Performance of Binary Molten Salt Electrolyte Based on LiTFSI and CF_3SO_3K

摘要

A binary molten salt electrolyte based on lithium bis(perfluoromethanesulfonyl)imide [LiN(SO_2CF_3)_2, LiTFSI] and CF_3SO_3K has been prepared and characterized by thermogravimetry/differential thermal analysis (TG/DTA), electrochemical impedance spectroscopy, and cyclic voltammetry. TG/DTA shows that the thermal stability of the electrolyte is good. The eutectic temperature of the LiTFSI/CF_3SO_3K is 160__ at a molar ratio of 1:1. The conduction behavior of low LiTFSI concentration mixtures is consistent with the Arrhenius equation, while others do not conform. The ionic conductivities of all measured electrolytes exceeded 10~-2 S /cm above 250__. The electrochemical window was 4.5 V at 240__.