制备并表征了双(三氟乙氧基磺酰)亚胺{[N(SO2OCH2CF3)2]-, TFESI-}和双(六氟异丙氧基磺酰)亚胺({N[SO2OCH(CF3)2]2}-, HFPSI-)2个阴离子的10种碱金属盐,并采用示差扫描量热仪(DSC)和热重分析仪( TGA)研究了其相变行为和热稳定性。测试了LiTFESI和LiHFPSI与碳酸乙烯酯( EC)/碳酸甲乙酯(EMC)(3:7,体积比)组成的电解液的电导率、氧化电位及对铝箔的腐蚀性。结果表明,所制备的碱金属盐均具有较高的纯度和热分解温度(>200℃)及较低的熔点(117~211℃); LiTFESI-EC/EMC和LiHFPSI-EC/EMC电解液均具有较高的电导率和氧化电位,并对铝箔具有良好的钝化性能,有可能作为锂离子电池的导电盐或添加剂。
Two series of alkali salts of bis(polyfluoroalkyloxysulfonyl)imides, alkali bis(2,2,2-trifluoroetho-xysulfonyl)imides{M[N(SO2OCH2CF3)2], MTFESI} and alkali bis[(1,1,1,3,3,3-hexafluoro-2-propoxy) sulfonyl] imides( M{N [ SO2 OCH ( CF3 ) 2 ] 2}, MHFPSI ) ( M=Li, Na, K, Rb, Cs ) , were prepared and characterized by NMR, IR and elemental analysis. Thermal properties of the neat salts were investigated by differential scanning calorimetry ( DSC ) and thermogravimetric analysis ( TGA ) . The fundamental physico-chemical properties of nonaqueous electrolytes of lithium bis(polyfluoroalkyloxysulfonyl)imides are studied. The results indicate that the alkali bis ( polyfluoroalkyloxysulfonyl ) imides show high thermal stability and low melting point. The electrolytes of 1.0 mol/L lithium salt in a mixture of ethylene carbonate( EC)/ethyl methyl carbonate(EMC) (3: 7, volume ratio) show medium conductivities, high oxidation potentials and do not corrode Al in the high potential region of 3-5 V( vs. Li+/Li) .