化学学报 ›› 2007, Vol. 65 ›› Issue (6): 475-480.    下一篇

研究论文

锂离子电池PMMA-VAc聚合物电解质的制备与性质研究

卢雷1, 左晓希1, 李伟善*,1, 刘建生2, 许梦清1   

  1. (1华南师范大学化学与环境学院 广州 510006)
    (2广州市天赐高新材料科技有限公司 广州 510600)
  • 投稿日期:2006-09-08 修回日期:2006-10-26 发布日期:2007-03-28
  • 通讯作者: 李伟善

Study on the Preparation and Performances of PMMA-Vac Polymer Electrolyte for Lithium Ion Battery Use

LU Lei1; ZUO Xiao-Xi1; LI Wei-Shan*,1; LIU Jian-Sheng2; XU Meng-Qing1   

  1. (1 School of Chemistry and Environment, South China Normal University, Guangzhou 510006)
    (2 Guangzhou Tinci High-Tech Materials Co., Ltd., Guangzhou 510600)
  • Received:2006-09-08 Revised:2006-10-26 Published:2007-03-28
  • Contact: LI Wei-Shan

以甲基丙烯酸甲酯(MMA)和醋酸乙烯酯(VAc)为单体, 用乳液聚合法合成聚甲基丙烯酸甲酯-醋酸乙烯酯聚合物(PMMA-VAc), 并以此聚合物制备了新型聚烯烃膜支撑的聚合物膜及聚合物电解质. 用红外光谱(FTIR)、凝胶色谱(GPC)、差热和热重分析(DSC/TG)、扫描电镜(SEM)及电池充放电实验等方法研究了聚合物、聚合物膜和聚合物电解质的性质. 红外光谱结果表明, MMA与VAc通过各自的C=C双键打开聚合成PMMA-VAc. PMMA-VAc易于分散在混合碳酸酯溶剂中并形成凝胶, 凝胶粘度随PMMA-VAc浓度的增加而增加, 当浓度为4%时成膜效果最佳. PMMA-VAc膜具有大量的微孔结构, 具有极强的吸液性能. PMMA-VAc膜具有良好的热稳定性: 在380 ℃范围内保持稳定. 聚烯烃膜支撑的PMMA-VAc膜室温下的离子电导率为1.85×10-3 S•cm-1, 用作为锂离子电池的聚合物电解质时, 电池具有良好的循环稳定性和倍率性能.

关键词: 聚合物电解质, PMMA-VAc, 制备, 锂离子电池

A copolymer, poly-methyl methacrylate-vinyl acetate (PMMA-VAc), was synthesized by emulsion polymerization with methyl methacrylate (MMA) and vinyl acetate (VAc) as monomers. With this co-polymer, polymer membrane and polymer electrolyte were prepared on the basis of polyethylene membrane. Performances of the synthesized copolymer and prepared polymer membrane and electrolyte were studied with FTIR, GPC, DSC/TG, SEM and battery charging and discharging experiments. It was found from FTIR that PMMA-VAc was formed by breaking the double bonds of monomers. PMMA-VAc can be easily dis-persed in mixed carbonates to form a gel. The viscosity of the gel increases with the content of PMMA-VAc in carbonates, and the best content of PMMA-VAc for polymer membrane is 4%. PMMA-VAc copolymer has a porous structure, which has a good electrolyte absorptivity. It is stable up to 380 ℃. The conductivity of the polymer electrolyte at room temperature is 1.85×10-3 S•cm-1. With the polymer electrolyte as the gel polymer electrolyte (GPE) of battery Li/GPE/LiCoO2, the battery shows its good cyclic stability and high rate discharge performance.

Key words: polymer electrolyte, PMMA-VAc, preparation, Li ion battery