聚环氧乙烷-氯化镁复合物离子导电性和稳定性研究

用溶液浇铸法合成了MgCl_2·(PEO)_n,n=4,8,12,16和24系列复合物电解质薄膜。用DSC、TG等热分析和交流复合阻抗法研究了该系列薄膜的结构、离子导电性、吸水性和稳定性。试验表明其结构和性能受复合物组成的明显影响。经初步测定,MgC_2-PEO复合物中镁离子迁移数接近零。

Study of Ionic Conductivity and Stability ot Complexes of poly(ethylene oxide)and Magnesium Chloride

Complex films of PEO and MgCl_2 having the general formula, MgCl_2·(CH_2-CH_2O). with n=4,8,12,16 and 24, have been prepared. Their structure and properties have been studied by TG, DSC thermal analysis and A.C. complex impedance analysis. These complexes are ionic conductors. The conductivity of MgCl_2· (PEO)_(16) is the highest, about 10~(-5)(Ohm·cm)~(-1) at 80℃. The compositions of the complexes have obvious influence upon their structure and conductivity. These films are very sensitive to moisture. The absorbed water increases the conductivity of the hydrated films at room temperature. The hydration reactions are completely reversible. The materials are thermally stable until 300℃. The preliminary transport number measurement indicated that the transport number of Mg~(2+) is near zero in MgCl_2-PEO complexes and these materials principally condnct anions.