物理化学学报 >> 2003, Vol. 19 >> Issue (12): 1097-1101.doi: 10.3866/PKU.WHXB20031201

研究论文    下一篇

聚合物电解质界面性质交流阻抗研究

王占良;唐致远   

  1. 天津大学化工学院,天津 300072
  • 收稿日期:2003-05-23 修回日期:2003-07-16 发布日期:2003-12-15
  • 通讯作者: 唐致远 E-mail:zytang@tju.edu.cn

Research on the Interfacial Properties of Polymer Electrolyte by A.C.Impedance

Wang Zhan-Liang;Tang Zhi-Yuan   

  1. School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072
  • Received:2003-05-23 Revised:2003-07-16 Published:2003-12-15
  • Contact: Tang Zhi-Yuan E-mail:zytang@tju.edu.cn

摘要: 合成了一种新型聚合物基质材料聚(甲基丙烯酸甲酯-丙烯腈-甲基丙烯酸锂)(简记为PMAML),并以PMAML/PVDF-HFP(偏氟乙烯-六氟丙烯共聚合物)复合物为基质制备了聚合物电解质.利用FTIR对合成的PMAML进行结构表征,并用扫描电镜观察聚合物基质膜的表面形貌.聚合物电解质由聚合物基质膜浸渍电解质溶液得到,其室温电导率可达到2.6×10-3 S• cm-1.利用交流阻抗技术研究了聚合物电解质与锂电极间的界面性质,并考察了开路放置时间、循环伏安及恒流充电对界面阻抗的影响.结果表明,聚合物电解质与锂电极界面阻抗随放置时间的延长而增加,更新锂电极表面可降低界面阻抗,PMAML能提高界面稳定性.

关键词: 聚合物电解质, 锂离子电池, 交流阻抗, 界面性质

Abstract: A novel polymer material poly(methyl methacrylate-co-acrylonitrile-co-lithium methacrylate) (PMAML) was synthesized. The polymer electrolytes based on the blend of PMAML and PVDF-HFP (poly(vinylidene fluoride-co-hexafluoropropylene)) were prepared. The structure of PMAML was characterized by FTIR, and the surface morphology of PMAML/PVDF-HFP membrane was observed by SEM. Gelled polymer electrolytes were obtained by soaking PMAML/PVDF-HFP membrane in electrolyte solution. Ambient temperature conductivity of 2.6×10-3 S•cm-1 was obtained. The interfacial properties between the polymer electrolyte and lithium electrode were investigated by A.C. impedance. The effects of storage time, cyclic voltammetry and constant charge on interfacial impedance were studied. The interfacial resistance between polymer electrolyte and lithium electrode increased with the increasing of storage time. But the interfacial impedance decreased after the surface of lithium was refreshed by means of cyclic voltammetry or constant charge. The retention capability of electrolyte solution and the interfacial stability can be improved by introducing PMAML into PVDF-HFP.

Key words: Polymer electrolyte, Lithium ion battery, A.C. impedance, Interfacial property