新型聚碳酸酯聚合物电解质的合成及性能研究

发布时间：2018-01-05 06:20

本文关键词：新型聚碳酸酯聚合物电解质的合成及性能研究　出处：《青岛科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：锂离子电池(LIBS)拥有高能量密度、高工作电压、长寿命、环境友好、无记忆效应等优点,是目前首选的储能装置。然而,阻碍锂离子电池进一步发展的问题主要是如何提高电池的能量密度、如何提高电池的安全性能。传统的锂离子电池中经常使用易燃、易挥发的有机小分子化合物作为电解质溶剂,因此存在着火、爆炸和泄漏等安全隐患。聚合物电解质是一种有希望替代液态电解质的选择,因为聚合物电解质拥有良好的离子电导率、卓越的电化学性能、优异的可加工性,并且不会泄漏。聚碳酸酯类聚合物电解质不仅拥有较高的离子电导率、较大的锂离子迁移数、较宽的电化学稳定窗口并且相对锂金属有良好的兼容性等优点,因此得到了广泛的关注。本文设计并合成了两种基于聚碳酸酯材料的聚合物电解质,并且应用在锂电池中。主要工作如下:1、首先通过酯交换合成了聚二乙二醇碳酸酯(PDEC),接着利用甲基丙烯酰氯与PDEC末端羟基反应得到末端被甲基丙烯酸酯修饰的聚二乙二醇碳酸酯二甲基丙烯酸酯(PDEC-DMA)大分子单体,接着通过原位聚合技术制备了凝胶聚合物电解质和全固态聚合物电解质。凝胶网状聚合物电解质(NET-PDEC)拥有较高的离子电导率(1.65×10-4 S·cm-1)、较宽的电化学窗口(4.5 V vs.Li+/Li)以及与锂金属良好的兼容性。凝胶电解质分别应用在Li/LiFePO4电池和高能量密度的Li/LiFe0.2Mn0.8PO4电池中,两类电池在室温下均表现出了良好的倍率性能和循环性能。全固态电解质应用在Li/LiFePO4电池中,电池在100 oC下呈现出优秀的循环性能。2、利用聚二乙二醇碳酸酯(PDEC)末端活性羟基与异佛尔酮二异氰酸酯反应,随后加入扩链剂乙二胺,成功制备了聚碳酸酯型聚氨酯。凝胶态聚氨酯电解质拥有较高的电化学稳定窗口(可达5 V vs.Li+/Li),60 oC下的电导率为2.93×10-4 S·cm-1。聚氨酯电解质的锂离子迁移数为0.53,并且与锂金属负极兼容性良好。最后凝胶态聚氨酯电解质被应用在Li/LiFePO4电池中,60 oC在0.1 C下循环100圈后的容量保持率为97%。
[Abstract]:Lithium ion battery (LIBS) has high energy density, high voltage, long life, environmental friendly, has no memory effect, is currently the preferred storage device. However, hinder the further development of lithium ion battery is the main problem is how to improve the energy density of the battery, such as how to improve the safety performance of the lithium ion battery. Traditional battery often used in flammable, volatile organic compounds as electrolyte solvent, so the existence of fire, explosion and leakage and other safety hazards. The polymer electrolyte is a promising alternative to liquid electrolyte choice, because the polymer electrolyte has good ionic conductivity and excellent electrochemical performance, excellent workability. And will not leak. The ionic conductivity of poly carbonate ester polymer electrolyte possesses not only high, a large number of lithium ion migration, electrochemical stability window wide and relatively Lithium metal has good compatibility and other advantages, so it has been widely concerned. This paper designed and synthesized two kinds of polymer electrolyte based on polycarbonate material, and application in lithium batteries. The main work is as follows: 1, first through the transesterification of poly glycol carbonate (PDEC), then use the methacryloyl chloride and PDEC reaction of terminal hydroxyl terminal by methyl acrylate modified poly two methyl acrylate glycol carbonate (PDEC-DMA) macromonomer, followed by in situ polymerization technology for gel polymer electrolyte and solid polymer electrolyte was prepared. The gel network polymer electrolyte (NET-PDEC) has a high ionic conductivity (1.65 x 10-4 S - cm-1), electrochemical the window wide (4.5 V vs.Li+/Li) and good compatibility with lithium metal. Gel electrolytes were used in Li/LiFePO4 cells with high energy density Li/LiFe0.2Mn0.8PO4 battery C, two types of batteries at room temperature showed the rate capability and good cycle performance. The application of all solid state electrolyte in the Li/LiFePO4 battery, the battery exhibits excellent cycle performance of.2 under 100 oC, using poly glycol carbonate (PDEC) activity and reaction of terminal hydroxyl isophorone diisocyanate. Add the chain extender, polycarbonate polyurethane was prepared. The electrochemical stability window of gel state electrolyte has higher polyurethane (up to 5 V vs.Li+/Li), the conductivity of 60 oC was the number of lithium ion migration of 2.93 * 10-4 S cm-1. polyurethane electrolyte was 0.53, and good compatibility with lithium metal anode. Finally coagulation the colloidal electrolyte was used in polyurethane Li/LiFePO4 battery, 60 oC at 0.1 C after 100 cycles the capacity retention rate is 97%.

【学位授予单位】：青岛科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O631;TM912

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