【作者】 嵇春琴；

【导师】 薛照明；

【作者基本信息】 安徽大学 ， 物理化学， 2010， 硕士

【摘要】 当前,锂离子电池被看作是未来可充电池市场中最佳的替代电池。究其原因主要是锂电池的能量密度高,寿命长,单体电压和比能量高。作为可靠环保的能源已经在小型的电源驱动设备中得以应用。这也促使锂电池的研究慢慢成为科学领域的一个焦点。锂离子电池电解质是锂离子电池的一个相当重要的组成部分,在锂电池充放电过程中,有机溶剂与电解质组成的电解液充当着锂离子电池的“心脏”,决定了电荷的传送速度和效率。因此,对于锂离子电池电解质的研究也显得格外重要。由于邻苯二酚,3-氟邻苯二酚,四氟邻苯二酚,乙二酸中含有的氧负离子能够与硼形成大的螯合阴离子,该阴离子与锂离子结合后可以生成锂硼盐,这种锂硼盐具有较好的电化学性能。论文共分五章。第一章通过文献调研,概括介绍了锂离子电池及其组成部分的研究现状及发展前景。第二章含氟类锂硼盐化合物的合成及其表征。主要是通过核磁共振对合成的锂硼盐进行表征,说明了目标产物的生成。第三章对合成的含氟类锂硼盐进行电化学性质的研究。主要是从溶解度,电导率,热稳定性,氧化电位方面进行数据分析,研究含氟类锂硼盐的电化学和热力学方面的性质。第四章利用DFT研究方法,对LBDCB及其衍生物进行了理论研究,分析了此类锂盐的分子结构与电子结构。从理论上阐述了该类锂盐的热稳性、溶解性、导电性及电化学稳定性与分子结构关系的本质。第五章结论。通过大量实验和测试结果比较得到一种电导率和氧化电位都比较高的含氟类锂硼盐,展望锂电池的商业前景。本论文最终成功合成了两种新的含氟类锂硼盐,我们对这两种新合成的锂硼盐的结构,热力学和电化学性质分别做了测试和数据分析,研究结果表明合成的两种锂硼盐都有较好的溶解性,较高的电导率和氧化电位,再结合理论计算通过对比分析,全面而系统的阐述了本课题的主要内容。更多还原

【Abstract】 The lithium-ion battery possess high operating voltage, high specific capacity and energy density which was compared to other secondary batteries. The lithium-ion battery is one of the most active research fields in modern science. Because the dihydroxybenzene and the oxalic can form an integration anion with B, they assemble new lithium salts combining with the lithium ion which should have novel structure and a good electrichemical property.The lithium-ion battery is seen as one of the best alternative batteries in the rechangeable battery market in the future. The reason is mainly on the lithium batteries which possess the high energy density, long life, high operating voltage and high specific capacity. As a reliable energy, the lithium-ion battery has been applied in small driven devices.The thesis is divided into five chapters.In the first chapter, on the basis of the large investigation of documents and analysis of summarizations, we found many lithium borates with bigπbond which is good for making up molecular designer, self-assembly more easily.In the second chapter, a series of lihium borates are synthesized which included Lithiumbis[1,2-benzenediolato(2)-O,O’-4-cyclopentene-1,2,3-trione] borate (LBDCB), Lithium[3-fluoro-1,2-benzenediolato(2-)-o,o’-4-cyclopentene-1,2,3-trione]borate (FLBDCB), Lithium[fourfluoro-1,2-benzenediolato(2-)-o,o’-4-cyclopentene-1,2,3-trione]borate(PFLBDCB). They were characterized by NMR analysis.In the third chapter, electrochemical properties of lithium borates salts with fluorine were studied. The experiment data of lithium borates had been tested by TG and cyclic voltammetry (CV) in PC, the solubility had been tested by ICP and the conductivity had been tested in different organic solvents such as PC, PC+EMC, PC+DME, PC+EC+EMC, PC+EC+DME. In the fourth chapter, using of the DFT methods, we carried on detailed theoretical researches on lithium salt LBDCB and its derivatives, and analyzed molecular structure and electronics structure of this kind of lithium salts. We also elaborated the essence of the relationships between the property (thermal stability, solubility, electric conductivity, and electrochemical stability window) and the structure.In the fifth chapter, we had succeeded in synthesizing three kinds of lithium salts. The data of experiments and tests showed that these lithium salts had higher conductivity and higher oxidized potential. Perhaps they are better electrolytes and have a great deal of uses in the field of lithium-ion batteries.In short, the structures and properties of three kinds of synthesized lithium salts had been studied in this thesis. The experimental results showed that these lithium salts might have better commercial prospects.Keywords:fluorine, croconic acid, lithium borates, electrochemical properties更多还原