改性LiClO_4－（PEO）_（20）电解质锂离子迁移数的测定

采用交流阻抗和恒电位计时电流法测定了ＬｉＣｌＯ４·（ＰＥＯ）２０·（ＰＣ）１２·（ＥＣ）１２高分子电解质的锂离子迁移数。在非水溶液和高分子电解质中，锂是热力学不稳定的，表面生成一层固体电解质钝化膜，严重地影响了锂离子迁移数的准确测定。本方法避免固体电解质钝化膜的影响，给出正确的锂离子迁移数测定值，实验表明，ＬｉＣｌＯ４·（ＰＥＯ）２０·（ＰＣ）１２·（ＥＣ）１２电解质的电导率为０．８×１０－３／ｃｍ，锂离子迁移数为０．３。

Determination of Transport Number of the Modified LiClO_4- (PEO)_(20) Polymer Electrolyte

In this work a combination method of A. C. Impedance and chronoamperometry was used to determine the lithium ion transport number of LiClO_4·(PEO)_(20)·(PC)_(12)·(EC)_(12) polymer electrolyte. It is known that lithium is thermodynamically unstable in non-aqueous or polymer electrolytes, leading to the formtion of a film on lithium surface, called as solid electrolyte interphase (SEI). The presence of SEI layer will greatly influence the experimental result of lithium ion transport number. The new method avoid the effect of SEI layer, and can give correct transport number of lithium ion in the electrolyte of DCIO_4·(PED)_(20)·(PC)_(12)·(EC)_(12). The exporimental result indicates that the conducrivity of the electrolyte is 0. 8 ×10￣(-3)s/cm, Li￣+ transport number is 0. 30 at 25℃.