Electrolytic Properties and Application to Lithium Battery of Solutions with Sydnone Compounds

研究了碳酸乙酯(EC)-碳酸二甲基酯（DMC）等摩尔二元混合物与3-甲基sydnone （3-MSD）和3-乙基sydnone （3-ESD）组成的三元溶剂体系中锂电极的电导率和充放电特性。电解液有LiClO_4、LiPF_6、LiBF_4、LiCF_3SO_3、LiN(CF_3SO_2)_2、LiN(C_2F_5SO_2)_2。在3-MSD和3-ESD的摩尔比为0.5时，电解质电导率下降的顺序为LiPF_6>LiClO_4>LiN(CF_3SO_2)_2和LiN(C_2F_5SO_2)_2>LiBF_4>LiCF_3SO_3。在3-MSD和3-ESD的摩尔比为0.5时，具有大阴离子的1 mol dm^<-3> LiN(CF_3SO_2)_2和LiN(C_2F_5SO_2)_2电解质的电导率大于6-7 mS cm^<-1>。在含有LiClO_4、LiBF_4、LiCF_3SO_3和LiN（CF_3SO_2）的EC-DMC等摩尔二元混合物中加入3-MSD和3-ESD可有效提高锂电极循环效率。通过扫描电镜（SEM）发现，循环效率与Ni（工作）电极上形成的膜的形态和厚度有关。此外，利用x射线光电子能谱（XPS）发现薄膜中含有一定的氮化合物。

The electrolytic conductivity and charge-discharge characteristics of the lithium electrode were examined in the ternary solvent systems made up of ethylene carbonate (EC)-dimethylcarbonate (DMC) equimolar binary mixture with 3-mehylsydnone (3-MSD) and 3-ethylsydnone (3-ESD). The electrolytes used are LiClO_4, LiPF_6, LiBF_4, LiCF_3SO_3, LiN(CF_3SO_2)_2, and LiN(C_2F_5SO_2)_2. The order of the decrease in conductivities of ternary solvent electrolytes at mol ratio 0.5 of 3-MSD and 3-ESD is LiPF_6>LiClO_4>LiN(CF_3SO_2)_2 and LiN(C_2F_5SO_2)_2>LiBF_4>LiCF_3SO_3. The 1 mol dm^<-3> LiN(CF_3SO_2)_2 and LiN(C_2F_5SO_2)_2 electrolytes with large anions show the moderate conductivities of more than 6-7 mS cm^<-1> at mol ratio 0.5 of 3-MSD and 3-ESD.An addition of 3-MSD and 3-ESD to the EC-DMC equimolar binary mixture containing LiClO_4, LiBF_4, LiCF_3SO_3, and LiN(CF_3SO_2) is effective for the rise in lithium electrode cycling efficiency. It is found by using scanning electron microscope (SEM) that the cycling efficiency is dependent on the morphology and thickness of the film formed on the Ni (working) electrode. In addition, the film was found to be containing a certain nitrogen compound by using X-ray photoelectron spectroscope (XPS).