摘要本文采用高温固相法制备出改性的尖晶石钛酸锂(Li4Ti5O12)负极材料,并对制备出的材料电化学性能进行系统性的研究,以便获得电化学性能优良的负极材料。实验过程中使用XRD、SEM等来分析材料的组成与表面形貌;利用充放电循环、交流阻抗等来检测所制备出材料的电化学性能。本课题采用Cu2+与Cr3+双离子取代来对Li4Ti5O12进行改性,运用纳米球磨工艺制备出颗粒的大小均匀一致,通过控制煅烧温度与煅烧气氛来研究改性后Li4Ti5O12的各项电化学性能,探索出最佳的制备工艺。33881
实验结果表明,在850℃煅烧温度下氢气气氛条件下制备出的负极材料电化学性能最佳。主要合成了Li3Ti4CuCrO12,铜全部溶进晶体里,形成了固溶体。该电池首次放电比容量达到240.1 mAh/g,充放电过程中有明显的充放电平台。
毕业论文关键词:锂离子电池;钛酸锂(Li4Ti5O12);改性;掺杂;高温固相法;电化学性能
Novel anode material based on Li4Ti5O12
Abstract
In this thesis,the modified spinel lithium titanate (Li4Ti5O12) anode materials were prepared by high-temperature solid-state reaction, The electrochemical properties of the prepared materials were systematically studied in order to obtain the anode materials with good electrochemical properties. In the process of the experiment, the composition and surface morphology of the materials were characterized by XRD, SEM analysis, and the electrochemical properties of the materials were detected by charge discharge cycle and AC impedance. In this experiment, Cu2+ and Cr3+ were substituted to modify Li4Ti5O12,and the using ball milling process for preparation of uniform particle size. The electrochemical properties of the modified Li4Ti5O12 were studied by controlling the calcination temperature and calcination atmosphere, and exploring the best of preparation technology.
The experimental results show that the electrochemical performance of the anode materials prepared under the condition of 850 C calcination temperature is the best. Li3Ti4CuCrO12 was main synthesized, and the copper dissolved into the crystals forming a solid solution. The initial discharge capacity of the battery was 240.1 mAh/g, and the charge -discharge platform of the charge-discharge process were obvious.
Keywords:Lithium ion battery, Lithium titanate(Li4Ti5O12), Modification, Doping, High-temperature solid-state reaction, Electrochemical performance
目 录
1 绪论 1
1.1 引言 1
1.1.1 锂离子电池的研究进展 1
1.1.2 锂离子电池的结构及工作原理 2
1.2 锂离子电池负极材料 3
1.2.1 锂离子电池负极材料研究现状 3
1.2.2 碳负极材料 3
1.2.3 锡基负极材料 4
1.2.4 硅基负极材料 4
1.3 锂离子电池负极材料Li4Ti5O12的研究进展 4
1.3.1 Li4Ti5O12的结构及电化学性能 5
1.3.2 Li4Ti5O12的制备方法 6
1.3.3 Li4Ti5O12的改性 7
1.4 课题的主要内容 8
1.4.1 课题研究的目的和意义 8
1.4.2 课题研究内容 9
1.4.3 实验方案设计 9
2 实验及表征 10
2.1 实验原料 10
2.2 实验仪器 11
2.3 材料制备 11
2.4 电极的制备与电池的装配 12
2.5 材料的表征 13
2.5.1 粒度分析 13
2.5.2 X射线衍射分析 13
2.5.3 扫描电镜分析(SEM) 13
2.6 电化学性能测试 14 基于钛酸锂的新型负极材料:http://www.youerw.com/cailiao/lunwen_31188.html