双(多氟烷氧基磺酰)亚胺碱金属盐的合成、表征及锂盐电解液的性质

Preparation,Characterization and Physicochemical Properties of Alkali Bis(polyfluoroalkyloxysulfonyl) imides and Electrochemical Properties of the Lithium Salts

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（＆gt;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） .