新型导电盐(三氟甲基磺酰)(三氟乙氧基磺酰)亚胺锂及其非水电解液的制备与性能

A novel lithium salt, lithium(trifluoromethanesulfonyl) (trifluoroethoxysulfonyl) imide {Li [(CF3SO2) (CF3CH2OSO2) N], Li[TEO-TEST]}, and the corresponding nonaqueous electrolytes of 1. 0 mol/L Li[TFO-TESI] in a mixture of ethylene carbonate/ethyl methyl carbonate(EC/EMC, 3 : 7, volume ratio) were prepared. The structure, composition and purity of the as-prepared Li [TEO-TESI] were confirmed by nuclear magnetic resonance spectroscopy (NMR), infrared spectroscopy (IR), mass spectrometry (MS), elemental analysis(EA), and ion chromatography(IC). The thermal properties of Li [TEO-TEST] and its nonaqueous electrolytes, 1. 0 mol/L Li[TEO-TEST]-EC/EMC (3 : 7), were characterized by differential scanning calorimetry(DSC) and thermogravimetric analysis(TGA). The fundamental properties of nonaqueous electrolyte solution of Li [TEO-TEST] were characterized by electrochemical impedance spectroscopy (EIS), cyclic voltammetry(CV), chronoamperometry and scanning electron microscope(SEM). The nonaqueous electrolytes of Li[TEO-TESI] shows excellent electrochemical stability, and does not corrode Al below 4. 2 V. Both Li/synthetic graphite and synthetic graphite/LiCoO2 cells using Li[TEO-TEST] show good cycling performances at room temperature, and the graphite/LiCoO2 cells using Li [TEO-TEST] shows much better capacity retention after 100 cycles than those using LiPF6.