锂离子电池负极材料钛酸锂的合成与改性研究
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子电池，负极材料，合成，改性，碳包覆，Mg 掺杂
1
山东科技大学硕士学位论文
Abstract
Abstract
Due to the advantages of no-pollution, high power density, low self-discharge, lithium-ion battery has been widely applicated in the fields of mobile telephone, portable electronic products, and hybrid kinetic vehicles. Li4Ti5O12 used as lithium-ion battery anode material has a spinel structure , it is a kind of insertion electrode material . It has been regarded as the most promising cathode material in the lithium-ion battery result from its high stability, fast charge-discharge and high security. In this paper, the phylogeny, structure and work principium of lithium-ion batteries were summarized. The lithium-ion battery materials containing cathode and anode materials were introduced. The material characteristics, construction and lithium insertion mechanism, merits and drawbacks, synthesis methods and application of anode material Li4Ti5O12 were generally described. In the experiment ,the Li4Ti5O12 samples were obtained by sintering Li2CO3 and amorphous TiO2 at different temperatures for 16h..The results of TG-DSC, XRD and SEM analysis showed that the calcination temperature should be mastered in 800℃～900℃ to obtain pure Li4Ti5O12 phase. In contrast of the performance of Li4Ti5O12 samples seperately perapared by Li2CO3 and LiNO3, it can be detected that Li2CO3 was the optimal original lithium material. The Li4Ti5O12 samples perapared by sintering Li2CO3 and anatase TiO2 with variational value of Li/Ti at different temperatures for 16h were measured by electrochemical performance test, XRD and SEM. It confirmed that the electrochemical peformance, crystal structure and surface morphology were changed along with the increasing content of lithium, and the Li4Ti5O12 sample with 2% excessive Li calcinated at 875℃ had the best capability. Because of low inherency conductivity of Li4Ti5O12 material, for the sake of enhancing its capability, the electronic conductivity and ion conductibility should be improved by modification. In this experiment, carbon coating and Mg-doping were used to modify the Li4Ti5O12 samples including different Li content..The electrochemical performance research， phase construction and morphology characterization were performed on the products. In conclusion, the charge-discharge capacibility of Li4Ti5O12/C sample changed a little while the impedance was 10 times more than Li4Ti5O12 sample resulting into reduce the conductivity and diffusion speed of Li ion. And , falling charge-discharge capacity, increasing impedance and particle size were reflected in the Mg-doping Li4Ti5O12 samples while the content of Mg dopped in the samples increased. Contrastively, the sample obtained at 875℃ with 1% Mg relative to Li has the best performance.
分类号： TM911 U D C ：
密
级： 公
开
单位代码： 10424
学 位 论 文
锂离子电池负极材料 Li4Ti5O12 的合成 与改性研究
郭桢
申请学位级别：硕士学位 指导教师姓名：谷 亦 杰
专业名称：材料工程 职 称：教 授
山 东 科 技 大 学
二零一一年六月
论文题目：
锂离子电池负极材料 Li4Ti5O12 的合成 与改性研究
2
山东科技大学硕士学位论文
Abstract
Keywords: Li4Ti5O12, lithium-ion battery, anode material, synthesis, modification, carbon-coating, Mg-doping
3
山东科技大学硕士学位论文
目录
目
录
1 绪论 ......................................................................................................................................... 1
负极化合物有li图12锂离子电池工作原理示意图fig12schemecommonlithiumionbattery锂离子电池采用lipf通过的隔膜而电极材料会与电解液在固液相界面上发生反应形成一层覆盖于电极材料表面的钝化层具有固体电解质的特征是电子绝缘体却是li可以经过该钝化层自由地嵌入和脱出所以这层膜被称为固体电解质界面膜sei膜负极碳材料与电解液发生界面反应生成sei膜并持续生长知道足够的厚度和致密性能够阻止溶剂山东科技大学硕士学位论文绪论分子的共插入保证电极循环的稳定性和电池充放电过程的延续
Supervisor: Professor Gu Yijie
College of Material Science and Engineering
June 2011
声
明
本人呈交给山东科技大学的这篇硕士学位论文，除了所列参考文献和世人 所公认的文献外，全部是本人在导师指导下的研究成果。该论文资料尚没有呈 交于其它任何学术机关作鉴定。
Signature: Date:
山东科技大学硕士学位论文
摘要
摘
要
锂离子电池以其无污染、能量密度高、自放电小等优点，在移动电话、便携电子产 品、混合动力设备等领域得到了广泛的应用。锂离子电池负极材料 Li4Ti5O12 是一种具有 尖晶石结构的嵌入型电极材料，并因其高稳定性、快速充放电、高安全性等成为最有前 景的新型锂离子电池负极材料。 本文综述了锂离子电池的发展历史、 结构与工作原理， 简要介绍了锂离子电池材料， 包括正极材料和负极材料，概述了负极材料 Li4Ti5O12 的材料特性、结构与嵌锂机制、优 缺点、制备方法及应用。实验中采用 Li2CO3、无定形 TiO2 在不同温度下烧结 16h，得到 Li4Ti5O12 样品，通过 TG-DSC、XRD、SEM 分析得出烧结温度控制在 800℃～900℃才能 得到纯晶相 Li4Ti5O12；对比分析采用 Li2CO3 和 LiNO3 在相同制度下得到的 Li4Ti5O12 样 品，得出，Li2CO3 是最合适的锂源。 Li2CO3 为锂源， 锐钛矿型 TiO2 为钛源， 设定不同的锂钛比， 在不同温度下烧结 16h， 对所得样品进行电化学性能测试、XRD 测试、SEM 测试，通过分析得出，随着锂含量 的增加，合成产物的电化学性能、晶体结构、表面形貌发生较大变化，当锂过量 2%、 烧结温度为 875℃时得到的 Li4Ti5O12 样品性能最好。 由于 Li4Ti5O12 材料的固有电导率低，可以通过改性来提高其电子电导性和离子传导 性，以达到增强其性能的目的。实验中采用碳包覆和金属 Mg2+掺杂两种方法对含锂量不 同的 Li4Ti5O12 样品进行改性， 并对产物进行电化学性能研究、 晶体结构表征和形貌表征。 Li4Ti5O12/C 样品的充放电性能随锂含量的增加发生较小的变化，阻抗却是纯相 Li4Ti5O12 样品的 10 倍，降低了电导率和锂离子扩散速率。随 Mg2+掺杂量的增加，掺镁 Li4Ti5O12 样品的充放电容量降低，阻抗增大，颗粒尺寸变大，这样就得出当 n(Mg):n(Li)=1%，烧 结温度为 875℃时得到性能最好的样品。
作者姓名： 郭 桢 专业名称： 材料工程 指导教师： 谷亦杰
入学时间： 2009 年 9 月 研究方向： 新能源材料 职 称： 教 授
论文提交日期：2011 年 6 月 论文答辩日期：2011 年 6 月 3 日 授予学位日期：
INVESTIGATION ON SYNTHESIS AND MODIFICATION OF Li4Ti5O12 AS THE ANODE MATERIAL FOR LITHIUM-ION BATTERIES
A Dissertation submitted in fulfillment of the requirements of the degree of
MASTER OF ENGINEERING
from
Shandong University of Science and Technology
by
Guo Zhen
硕士生签名： 日 期：
AFFIRMATION
I declare that this dissertation, submitted in fulfillment of the requirements for the award of Master of Philosophy in Shandong University of Science and Technology, is wholly my own work unless referenced of acknowledge. The document has not been submitted for qualification at any other academic institute.
1
山东科技大学硕士学位论文
Abstract
Abstract
Due to the advantages of no-pollution, high power density, low self-discharge, lithium-ion battery has been widely applicated in the fields of mobile telephone, portable electronic products, and hybrid kinetic vehicles. Li4Ti5O12 used as lithium-ion battery anode material has a spinel structure , it is a kind of insertion electrode material . It has been regarded as the most promising cathode material in the lithium-ion battery result from its high stability, fast charge-discharge and high security. In this paper, the phylogeny, structure and work principium of lithium-ion batteries were summarized. The lithium-ion battery materials containing cathode and anode materials were introduced. The material characteristics, construction and lithium insertion mechanism, merits and drawbacks, synthesis methods and application of anode material Li4Ti5O12 were generally described. In the experiment ,the Li4Ti5O12 samples were obtained by sintering Li2CO3 and amorphous TiO2 at different temperatures for 16h..The results of TG-DSC, XRD and SEM analysis showed that the calcination temperature should be mastered in 800℃～900℃ to obtain pure Li4Ti5O12 phase. In contrast of the performance of Li4Ti5O12 samples seperately perapared by Li2CO3 and LiNO3, it can be detected that Li2CO3 was the optimal original lithium material. The Li4Ti5O12 samples perapared by sintering Li2CO3 and anatase TiO2 with variational value of Li/Ti at different temperatures for 16h were measured by electrochemical performance test, XRD and SEM. It confirmed that the electrochemical peformance, crystal structure and surface morphology were changed along with the increasing content of lithium, and the Li4Ti5O12 sample with 2% excessive Li calcinated at 875℃ had the best capability. Because of low inherency conductivity of Li4Ti5O12 material, for the sake of enhancing its capability, the electronic conductivity and ion conductibility should be improved by modification. In this experiment, carbon coating and Mg-doping were used to modify the Li4Ti5O12 samples including different Li content..The electrochemical performance research， phase construction and morphology characterization were performed on the products. In conclusion, the charge-discharge capacibility of Li4Ti5O12/C sample changed a little while the impedance was 10 times more than Li4Ti5O12 sample resulting into reduce the conductivity and diffusion speed of Li ion. And , falling charge-discharge capacity, increasing impedance and particle size were reflected in the Mg-doping Li4Ti5O12 samples while the content of Mg dopped in the samples increased. Contrastively, the sample obtained at 875℃ with 1% Mg relative to Li has the best performance.
分类号： TM911 U D C ：
密
级： 公
开
单位代码： 10424
学 位 论 文
锂离子电池负极材料 Li4Ti5O12 的合成 与改性研究
郭桢
申请学位级别：硕士学位 指导教师姓名：谷 亦 杰
专业名称：材料工程 职 称：教 授
山 东 科 技 大 学
二零一一年六月
论文题目：
锂离子电池负极材料 Li4Ti5O12 的合成 与改性研究
2
山东科技大学硕士学位论文
Abstract
Keywords: Li4Ti5O12, lithium-ion battery, anode material, synthesis, modification, carbon-coating, Mg-doping
3
山东科技大学硕士学位论文
目录
目
录
1 绪论 ......................................................................................................................................... 1
负极化合物有li图12锂离子电池工作原理示意图fig12schemecommonlithiumionbattery锂离子电池采用lipf通过的隔膜而电极材料会与电解液在固液相界面上发生反应形成一层覆盖于电极材料表面的钝化层具有固体电解质的特征是电子绝缘体却是li可以经过该钝化层自由地嵌入和脱出所以这层膜被称为固体电解质界面膜sei膜负极碳材料与电解液发生界面反应生成sei膜并持续生长知道足够的厚度和致密性能够阻止溶剂山东科技大学硕士学位论文绪论分子的共插入保证电极循环的稳定性和电池充放电过程的延续
Supervisor: Professor Gu Yijie
College of Material Science and Engineering
June 2011
声
明
本人呈交给山东科技大学的这篇硕士学位论文，除了所列参考文献和世人 所公认的文献外，全部是本人在导师指导下的研究成果。该论文资料尚没有呈 交于其它任何学术机关作鉴定。
Signature: Date:
山东科技大学硕士学位论文
摘要
摘
要
锂离子电池以其无污染、能量密度高、自放电小等优点，在移动电话、便携电子产 品、混合动力设备等领域得到了广泛的应用。锂离子电池负极材料 Li4Ti5O12 是一种具有 尖晶石结构的嵌入型电极材料，并因其高稳定性、快速充放电、高安全性等成为最有前 景的新型锂离子电池负极材料。 本文综述了锂离子电池的发展历史、 结构与工作原理， 简要介绍了锂离子电池材料， 包括正极材料和负极材料，概述了负极材料 Li4Ti5O12 的材料特性、结构与嵌锂机制、优 缺点、制备方法及应用。实验中采用 Li2CO3、无定形 TiO2 在不同温度下烧结 16h，得到 Li4Ti5O12 样品，通过 TG-DSC、XRD、SEM 分析得出烧结温度控制在 800℃～900℃才能 得到纯晶相 Li4Ti5O12；对比分析采用 Li2CO3 和 LiNO3 在相同制度下得到的 Li4Ti5O12 样 品，得出，Li2CO3 是最合适的锂源。 Li2CO3 为锂源， 锐钛矿型 TiO2 为钛源， 设定不同的锂钛比， 在不同温度下烧结 16h， 对所得样品进行电化学性能测试、XRD 测试、SEM 测试，通过分析得出，随着锂含量 的增加，合成产物的电化学性能、晶体结构、表面形貌发生较大变化，当锂过量 2%、 烧结温度为 875℃时得到的 Li4Ti5O12 样品性能最好。 由于 Li4Ti5O12 材料的固有电导率低，可以通过改性来提高其电子电导性和离子传导 性，以达到增强其性能的目的。实验中采用碳包覆和金属 Mg2+掺杂两种方法对含锂量不 同的 Li4Ti5O12 样品进行改性， 并对产物进行电化学性能研究、 晶体结构表征和形貌表征。 Li4Ti5O12/C 样品的充放电性能随锂含量的增加发生较小的变化，阻抗却是纯相 Li4Ti5O12 样品的 10 倍，降低了电导率和锂离子扩散速率。随 Mg2+掺杂量的增加，掺镁 Li4Ti5O12 样品的充放电容量降低，阻抗增大，颗粒尺寸变大，这样就得出当 n(Mg):n(Li)=1%，烧 结温度为 875℃时得到性能最好的样品。
作者姓名： 郭 桢 专业名称： 材料工程 指导教师： 谷亦杰
入学时间： 2009 年 9 月 研究方向： 新能源材料 职 称： 教 授
论文提交日期：2011 年 6 月 论文答辩日期：2011 年 6 月 3 日 授予学位日期：
INVESTIGATION ON SYNTHESIS AND MODIFICATION OF Li4Ti5O12 AS THE ANODE MATERIAL FOR LITHIUM-ION BATTERIES
A Dissertation submitted in fulfillment of the requirements of the degree of
MASTER OF ENGINEERING
from
Shandong University of Science and Technology
by
Guo Zhen
硕士生签名： 日 期：
AFFIRMATION
I declare that this dissertation, submitted in fulfillment of the requirements for the award of Master of Philosophy in Shandong University of Science and Technology, is wholly my own work unless referenced of acknowledge. The document has not been submitted for qualification at any other academic institute.