以二(三氟甲基磺酰)亚胺锂为基底的室温熔融盐电解质热学及电化学性质的比较研究

Comparative Studies on Thermal and Electrochemical Properties of Room-temperature Molten Salt Electrolytes Based on LiTFSI with Urea and Its Derivatives

制备了一系列二 (三氟甲基磺酰 )亚胺锂 [Li N( SO2 CF3 ) 2 ,Li TFSI]与尿素及其衍生物形成的新型室温熔融盐电解质 ,并对其热学性质及电导率进行了比较研究 .受甲基取代基的影响 ,Li TFSI-甲基脲体系的共熔温度最低 ,为 -38℃ .Li TFSI-尿素体系的室温电导率最高 ,为 1 .74× 1 0 - 4 S/ cm,5 0℃电导率为 1 .2 4×1 0 - 3 S/ cm.

Thermal and electrochemical properties of new room-temperature molten salt electrolytes based on LiTFSI with urea and its derivatives have been studied. These electrolytes appear as liquid at room temperature though they are composed of two solids. DSC analysis shows that the eutectic temperature of LiTFSI and methylurea is about -38 ℃, lower than those of LiTFSI-urea and LiTFSI- 1,3-dimethylurea. The conduction behavior of these electrolytes has been evaluated by AC impedance spectroscopy. With increasing numbers of methyl of urea, the conductivities of these room-temperature molten salt electrolytes decrease accordingly. The conductivity of LiTFSI/urea eutectic compound is 1.74×10 -4 S/cm at 25 ℃ and 1.24×10 -3 S/cm at 50 ℃.