一种新型聚合物电解质中离子传递及界面性质研究  

Ion Transport and Interfacial Properties of a Novel Polymer Electrolyte

作　　者：王占良[1] 唐致远[1] 

机构地区：[1]天津大学化工学院,天津300072

出　　处：《高校化学工程学报》2003年第3期248-253,共6页Journal of Chemical Engineering of Chinese Universities

摘　　要：合成了聚（甲基丙烯酸甲酯-丙烯腈-甲基丙烯酸锂）（简记为PMAML）聚合物基质材料，以PMAML和聚偏氟 乙烯混合物为基质制备了新型复合聚合物电解质，其中增塑剂为碳酸乙烯酯和碳酸二甲酯，锂盐是LiBF4。用刮刀 在玻璃板上涂膜得到取合物膜，把聚合物基质膜在电解质溶液中浸渍后成为聚合物电解质膜。采用限制扩散方法测 试了电解质中离子的扩散系数，由稳态极化法测得了迁移数。所制聚合物电解质中锂离子的扩散系数和迁移数分别为 2.67×10-7cm2·s-1和0.53。通过交流阻抗技术研究了聚合物电解质与电极间界面性质，Li/GPE/Li的界面阻抗随放置 时间延长而增大，Li/GPE/MPCF的界面阻抗随电极的电位降低而减小。组装了聚合物电解质锂离子电池，测试结果表 明，该聚合物电解质具有较好的离子传输性质和电化学性能，能用作锂离子电池的电解质。Poly (methyl aerylate-co-aerylonitrile-co-lithium methacrylate) (hereinafter abbreviated to PMAML) was synthesized, and gel polymer electrolytes (GPE) comprising PMAML and PVDF blend as polymer matrix, ethylene carbonate (EC) and dimethyl carbonate (DMC) as plasticizer and LiBF4 as salt were prepared. Polymer membranes of PMAML and PVDF-HFP blend were prepared by pouring the paste onto glass plate with a doctor blade, and then immerging the polymer electrolyte membranes in the liquid electrolyte solution to obtain the polymer electrolyte membranes. The transference number of lithium ion in the polymer electrolyte was measured by the restricted diffusion experiment, diffusion coefficient was obtained by the steady state polarization method, and the corresponding results were 0.53 and 2.67×10-7 cm2&middots-1, respectively. The interface properties between the polymer electrolyte and the electrode were investigated by AC impedance method. The interface impedance of Li/GPE/Li cell increased with storage time, while that of Li/GPE/MPCF cell decreased with the decrease of potential of the negative electrode. The lithium ion batteries with polymer electrolyte were assembled. The polymer electrolyte based on PMAML and PVDF-HFP blend exhibits good transport properties and electrochemical performance, so this polymer electrolyte is feasible to be used in lithium ion batteries.

关 键 词：聚合物电解质 锂离子电池 交流阻抗 界面性质 

分 类 号：O646[理学—物理化学] TB324[理学—化学]