摘要本论文采用两步碳热还原法合成LiVPO4F正极材料,并且研究了该材料的XRD表征和电化学性能,深入研究了温度、配体对其结构和电化学性能的影响。
首先,实验中使用偏钒酸铵、磷酸二氢铵、葡萄糖混合加热,温度从300℃—550℃逐步加热,分别在300℃下保持1h和在550℃下保持8h,成功地合成了中间体VPO4。再与LiF在700℃下煅烧0。5h,得到最终产物LiVPO4F。88426
其次,研究了不同温度和配体对其物理结构和电化学性能的影响。结果表明,温度过高不易于合成LiVPO4F,容易生产新材料,其电化学性能较差;而使用配体LiF和LiCl合成的正极材料,结构上比较相似,但后者氯原子无法与V2(PO4)3结合,导致充放电性能很差。
毕业论文关键词:锂离子电池;碳热还原法;LiVPO4F
Abstract The cathode material LiVPO4F was prepared by carbothermal reduction reaction, the research of whose XRD and electrochemical properties were analyzed in detail。 And we are focus on the effect of electrochemical properties from the changes of the temperature and the ligands。
First of all, in the laboratory, the cathode material LiVPO4F was produced with NH4VO3、NH4H2PO4 and C6H12O6, beginning with the temperature of 300℃ and ending with 550℃ where we kept in 300℃ for 1 hour and 500℃ for 8h, constantly。 On the next step, the successfully prepared VPO4 was used to produce the final LiVPO4F in a temperature of 700℃ for about 0。5h。
Secondly, synthesizing technologies of LiVPO4F with different temperature and ligands were studied。 It was found that the high temperature had no good on the preparation of LiVPO4F,which helped more on the unknown new materials with bad performance on electrochemical properties; Using different ligands, such as LiF and LiCl, made the same structure, however, had a completely poor electrochemical properties, as the latter could not connect chlorine atoms with V2(PO4)3。
Keyword:lithium-ion battery; carbothermal reduction method; LiVPO4F
目录
1 绪论 3
1。1 课题背景 3
1。2 锂电池简介 4
1。2。1 锂电池的发展历史和趋势 4
1。2。2 锂电池正极材料的选择 4
1。2。3 锂电池的工作原理 5
1。3 正极材料LiVPO4F简介 5
2 碳热还原法合成LiVPO4F及其电化学性能研究 6
2。1 引言 6
2。2 实验部分 7
2。2。1 实验仪器源Y于Y优E尔Y论L文W网wwW.yOueRw.com 原文+QQ752018.766 和设备 7
2。2。2 主要原料和试剂 8
2。2。3 LiVPO4F的合成 8
2。2。4 锂电池的制作 9
2。3 结果与讨论 10
2。3。1 表征——X-射线粉末衍射分析(XRD) 10
2。3。2 充放电性能测试 10
2。4 本章小结 12
3 磷酸钒锂盐合成的影响因素及其电化学性能 13
3。1引言 13
3。2实验部分 13
3。2。1 不同温度下材料的合成 13
3。2。2 不同配体下材料的合成 LiVPO4F锂电池电极材料的制备:http://www.youerw.com/huaxue/lunwen_160551.html