Novel binary room-temperature complex electrolytes based on LiTFSI and organic compounds with acylamino group

Binary room-temperature complex electrolytes have been synthesized based on lithium bis(trifluoromethane sulfone) imide [LiN(SO2CF3)(2), LiTFSI] and organic molecules with amide (acylamino) groups such as ethyleneurea, acetamide, etc. The thermal properties and electrochemical performances of the complex systems are evaluated with differential scanning calorimetry (DSC), ac impedance spectroscopy, cyclic voltammetry (CV), and in a test electric double layer capacitor, respectively. DSC analysis shows that the eutectic temperatures of most complex systems are below 0 degrees C. The ionic conductivities of these complex systems exceed 10(-3) S/cm at room temperature. Analysis of their CV behavior indicates that the electrochemical stability windows of these electrolytes are over 4 V. These complex systems prove to be promising candidates of electrolytes for supercapacitor and other electrochemical devices. (c) 2005 The Electrochemical Society.