梳状高分子固体电解质的离子导电性研究

Study on the Ionic Conductivity of Comb Polymer Electrolytes

深入研究了交替马来酸酐共聚物多缩乙二醇酯（ＣＰ３５０）两种锂盐络合物ＣＰ３５０／ＬｉＡｓＦ＿６和ＣＰ３５０／ＬｉＰＦ＿６的离子传导性能，给出了与复阻抗谱相对应的等效电路．离子电导率随［Ｌｉ］／［ＥＯ］的变化而出现一极大值，室温下，两体系电导率极大值分别为１．３８×１０（－４），８．３２×１０（－５）Ｓ／ｃｍ．电导率随温度升高而增加．导电行为呈非－Ａｒｒｈｅｎｉｕｓ特征．阴阳离子半径之和（ｒ＿ｃ＋ｒ＿ａ）愈大，离子电导率愈高．

A comb polymer(CP350)with oligo-oxyethylene side chains was prepared from methyl vinyl ether/maleic anhydride copolymer.The ionic conductivity of CP350/LiAsF6 and CP350/LiPF6 complexes was studied as a function of temperature and[Li]/[EO]ratios.A equivalent circuit was given to interpret complex impedance spectra. At 25℃,the ionic conductivity maxima of the two systems are 1.38×10(-4),8.32×10(-5)S/cm respectively. The appearance of the conductivity maxima has been interpreted as being due to the effect of microviscosity on ion transport. lonic conduction displays non-Arrhenius behaviour.The temperature dependence of ionic conductivity was attributed mainly to the temperature dependence of charge carrier hopping,ion pairing and micro Brown motion of side chains.The larger the(rc+ra)value the salt has,the higher the conductivity of the electrolyte film is.