【作者】 韩改格；

【导师】 徐又一； 朱宝库；

【作者基本信息】 浙江大学 ， 高分子化学与物理， 2006， 硕士

【摘要】 凝胶聚合物锂离子电池是在液体锂离子电池的基础上发展起来的第二代可充电锂离子电池,它不仅具有液态锂离子电池的高电压、高能量密度、长循环寿命以及清洁无污染等特点,而且电池中不存在游离的电解液,改善了液态锂离子电池可能出现的漏液、爆炸等问题,电池的外形设计组装也灵活方便,广泛应用于电动汽车、移动通讯等领域,因此,对凝胶聚合物电解质（GPE）膜的需求也日益增加,凝胶聚合物电解质膜的研究也得到了众多研究者的关注。目前,凝胶聚合物电解质膜常用的制备方法是Bellcore技术和溶液浇铸法,得到的膜具有物理交联型结构。不同于这种常规的GPE膜制备技术,本论文利用热引发聚合物方法,研究了化学交联型凝胶聚合物电解质膜的制备,希望得到具有更好的形态稳定性、热和时间稳定性的GPE膜。 首先,本文采用低分子量聚乙二醇二丙烯酸酯（PEGDA）与偏氟乙烯—六氟丙烯共聚物（PVDF-HFP）及锂盐电解液共混、过氧化苯甲酰（BPO）热引发自由基聚合,研究了具有交联网络结构的凝胶型凝胶聚合物电解质膜（GPE）的制备。利用FFIR、XRD、TGA、SEM、拉伸测试、交流阻抗等技术和手段,研究了共混型凝胶聚合物电解质膜的结构、电化学性能、以及化学交联结构对电化学性能的影响。得到了室温下离子电导率达到2.0×10^-3S/cm的共混型GPE膜。 其次,本论文从改进凝胶聚合物电解质膜的制备工艺出发,依次采用相分离法制备出PVDF-HFP微孔膜、将PVDF-HFP膜在PEGDA与电解液的混合溶液中浸泡活化、热引发聚合交联的步骤制备出具有化学交联结构的多孔型凝胶聚合物电解质膜。研究了PEGDA化学交联结构对电解质膜的热稳定性、保液性能、力学性能和离子电导率的时间稳定性的影响,及和电解液与PEGDA的相对含量与离子电导率的关系。得到了室温下离子电导率可达2.245×10^-3S/cm的多孔型GPE膜。更多还原

【Abstract】 Gel polymer lithium-ion battery （GPLB） is a novel secondary rechargeable system generating on the basis of liquid lithium-ion battery. GPLBs not only have the excellent performance of liquid lithium batteries, but also can resolve the possible problems of leakage and blast owing to no free liquid electrolyte in GPLB. It is also very convenient to design the shape at will. With the increase of power sources, the research of gel polymer electrolyte（GPE） have attracted more and more attentions. At present, the common preparation methods for PGE are Bellcore and solution-casting technology, and it is physically cross-linked for the PGE produced by Bellcore and solution-casting technology. In this dissertation, the preparation of chemical crosslink gelled polymer electrolyte membrane by thermal polymerization was investigated following two methods.The GPE membranes of better stability compared with physically cross-linked GPE membranes was desirably prepared.Firstly, gel polymer blend electrolyte films of polyethylene glycol diacrylate （PEGDA）/poly （vinylidene fluoride）-hexafluoropropene and Li⁺ electrolytes were prepared by thermal curing of using benzoyl peroxide as a catalyst. FTIR, XRD, TGA, SEM, tensile test, AC impedance were used to investigate the microstructure and electrochemical characteristics of the chemically cross-linked GPE membranes. It was also investigated that the effect of chemical crosslink on the electrochemical characteristics. The blend GPE membranes have the highest Li⁺ ionic conductivity in 2.0xl0^-3S/cmat25℃.Secondly, in order to improve the preparation process of gelled polymer electrolyte membranes, the porous gelled polymer electrolyte membranes was prepared by thermal curing the mixed solution of PEGDA/liquid electrolyte in PVDF-HFP porous membranes （via the immersion precipitation method）. The influence of chemical crosslink on the heat stability, electrolytes capability, mechanical properties and the time stability of ion conduction of porous gelled polymer electrolyte membranes were studied. The relationship between crosslink ,ratios of PEGD A/electrolytes and the ion conduction of porous GPE membranes were discussed. The ionic conductivity of these porous GPE membranes The ionic conductivity could reach 2.245x10"3S/cm at 25 °C.更多还原