导　　师： 张勤;翟玉春;代克化

学科专业： 080601

授予学位： 硕士

作　　者： ;

机构地区： 东北大学

摘　　要： 锂离子电池具有能量高、寿命长、污染低等特点,在众多领域都得到了广泛的应用,已经成为目前市场便携式电子产品的主要电源,也被认为是纯电动汽车、混合动力汽车、插电式混合动力汽车等理想的电源。锰酸锂/(LiMn2O4/)、磷酸亚铁锂/(LiFePO4/)和三元材料/(Li/[NixCoyMn1-x-y/]O2/)是近几年来锂离子电池较具吸引力的三种正极材料。此外,富锂锰基化合物由于其较高的理论比容量/(250mAh·g-1/),也是极具吸引力的锂离子电池材料。从放电比容量的实际利用率、使用的时间、环境污染和价格成本方面看,橄榄石型结构的磷酸亚铁锂LiFePO4由于其低成本、资源丰富、对环境友好、电压平台适中/(相对锂金属为3.4V/),并且有着高理论比容量170mAh·g-1等优点,被认为是最有可能的锂离子动力电池材料之一。但是它也存在缺点,如低的电子、离子传导率制约电池的大电流性能,为了改善这一问题,进行LiFePO4掺杂是一种可行的方法。 本论文结合XRD、SEM、红外光谱/(FTIR/)和电化学性质测试等现代测试手段,对正极材料LiFePO4的制备、结构及电化学性能进行了系统研究。同时,对富锂锰基化合物Li1.2Mn0.54Ni0.13Co0.13O2的固相法合成进行初步的探究。 实验的第一部分以LiOH-H2O, H3PO4及FeSO4-7H2O作为反应原料进行水热法合成LiFePO4,并且对反应原料配比进行了探究,得到较佳的原料比为2.7：1：1。考察了水热反应温度、反应时间、抗氧化剂的加入量对LiFePO4//C的电化学性能、结构及形貌的影响。 利用单因素获得的反应温度为230℃,抗氧化剂加入量为0.4g,水热反应不同时间合成LiFePO4,运用红外光谱、XRD、SEM等分析方法,考察了LiFePO4随水热合成反应时间的增加,结构和粒径大小的变化。 通过正交实验确定出水热合成LiFePO4正极材料的较佳工艺条件为：水热反应温度240℃,反应时间3h,抗氧化 Lithium-ion battery with the benefits of high energy, long life and low pollution and so on has been widely used in many fields. Lithium-ion battery has become the main power of portable electronic products in current market and is also considered to be the promising power of EV, HEV and PHEV. LiMn2O4, LiFePO4and Li/[NixCoyMn1-x-y/]O2are three attractive anode materials for lithium-ion battery in recent years. In addition, Li-rich cathode material is also an attractive lithium-ion battery material owing to its high theoretical specific capacity of /(250mAh·g-1/). Considering the actual utilization of the electric discharge, life, environmental pollution, and price-cost perspective, the lithium iron phosphate LiFePO4of olivine structure with low cost, rich resource, environment friendly, voltage platform moderate /(as opposed to the lithium metal3.4V/), and has a high theoretical specific capacity170mAh·g-1and other advantages, is considered the most promising power of lithium-ion battery. But it also has some disadvantages, such as low electronic and ionic conductivity constraints battery current performance, while LiFePO4doped hydrothermal is a viable method in order to improve this problem. This paper carried out a systematic study of LiFePO4preparation, structure and electrochemical performance with modern testing means of XRD, SEM, infrared spectrum /(FTIR/) and electrochemical properties tests. At the same time, the preliminary exploration of Li1.2Mn0.54Ni0.13Co0.13O2solid-state synthesis is also preceded. The first part of the experiment began with hydrothermal method synthesis of LiFePO4by using LiOH·H2O, H3PO4, and FeSO4·7H2O as reactants, and explored the ratio of the reactants to find a better raw material ratio2.7:1:1by changing the content of Li. Investigated the influence of the hydrothermal reaction temperature, reaction time, and the amount of anti-oxidant to the electrochemical performance, structure and appearance of the product. Using the single factor of temperature230℃, the antio

关 键 词： 锂离子电池 正极材料 磷酸亚铁锂 富锂正极材料 水热合成 固相合成

领　　域： [电气工程]