摘要:锂离子电池作为一种新型绿色能源,近年来得到迅速发展。锂离子电池的性能在很大程度上取决于正负极材料、电解液及隔膜的选择和制备。橄榄石型LiFePO4材料因其有来源广泛、价格低廉、放电电压平稳、循环性能和安全性能优异等众多优点,成为了新一代最具发展前景的锂离子电池正极材料。本文以合成性能优良的LiFePO4材料为目标,利用溶剂热法合成工艺,以乙二醇与水的比例变化,配制不同的溶剂,探索不同的溶剂合成材料对LiFePO4的影响;碳包覆后合成了LiFePO4/C复合材料;运用XRD、SEM和循环伏安测试,对不同溶剂合成LiFePO4材料的结构和性能进行了研究。初始反应物浓度为0.25molL-1,乙二醇与水的比例为19:1,温度180℃反应10h。该工艺条件下合成的样品经后续碳包覆热处理后表现出较为优异的电化学性能。31040
毕业论文关键词锂离子电池 正极材料 磷酸铁锂 溶剂热法 溶剂
The exploration of different solvents of synthetic material
Abstract: Lithium-ion battery, a type of green energy, rapid development in recent years. Lithium-ion battery performance depends in large part on electrodes, electrolyte and membrane selection and preparation of materials. LiFePO4 olivine materials because of their extensive sources, low price, stable discharge voltage, cycle with excellent performance and security, and many other advantages, become the most promising next-generation lithium-ion battery cathode materials. This synthesis of LiFePO4 material with excellent performance as the goal, use of solvothermal synthesis, ratio of glycol to water changes, different kinds of solvents, exploring the effects of different solvent for synthetic material LiFePO4; after the carbon-coated LiFePO4/C composites using XRD, SEM and cyclic voltammetry test for different solvent LiFePO4 material structure and properties were studied. Initial concentrations of reactants for 0.25molL-1, proportion of glycol and water is 19:1, reaction temperature 180 ℃ 10h. Synthesized this process samples after subsequent heat treatment of carbon-coated show more superior electrochemical performance.
Keyword: Lithium-ion battery; Cathode material; Lithium iron phosphate; Solvothermal method; Solvent.
目录
1 绪论 1
1.1锂离子电池的发展现状 1
1.1.1锂离子电池组成及工作原理 1
1.1.2锂离子电池的特点 2
1.2锂离子电池正极材料 2
1.2.1钴系正极材料 3
1.2.2 镍系正极材料 4
1.2.3 锰系正极材料 4
1.2.4 磷酸体系化合物 5
1.3 LiFePO4正极材料的研究进展 6
1.3.1 LiFePO4的结构 6
1.3.2 LiFePO4的充放电机理 6
1.3.3 LiFePO4的制备方法 8
2 实验部分 10
2.1测试仪器、试剂 10
2.1.1实验合成原料 10
2.1.2 主要实验仪器 10
2.2溶剂热法合成LiFePO4正极材料 11
2.2.1溶剂对LiFePO4合成的影响 12
2.2.2制备LiFePO4正极材料 12
2.2.3 LiFePO4正极材料的碳包覆 13
2.2.4 管式加热炉的使用 14
2.2.5 电极的制备 14
2.3表征测试方法 15
2.3.1 X射线衍射 15
2.3.2 扫描电电镜测试(SEM) 15
2.4 LiFePO4电化学性能测试 16
2.4.1电化学性能测试步骤 16
3 实验结果与讨论 17
3.1 X射线衍射图谱 17 不同溶剂合成材料的探索:http://www.youerw.com/cailiao/lunwen_27059.html