论文总字数：19460字

摘 要

近年来，锂离子电池等储能装置迅速发展至商业化，新型的储能装备钠离子电池因此也得到了广泛关注。由于钠元素储量十分丰富，且与锂化学性质及其相似，因此有较好的市场潜力与经济应用价值。

负极材料是电池的关键组成之一，其性能的优异会直接影响各类电池的电容量与工作电压。转化型材料的理论比容量较高、形貌可调控；且过渡金属氧化物更绿色安全，常用于作为钠离子电池的负极材料。但它在循环反应过程中，不可避免会发生较大的体积膨胀，导致材料发生粉化、脱落，电容量因此衰减迅速。

本论文首先选用了不同的碳源对SnO₂进行碳包覆，通过对比实验选择最佳碳源。接着对SnO₂@Glu进行二次改性，选取石墨烯以及碳纳米管分别与SnO₂@Glu合成SnO₂复合物，对其进行一系列的表征检测与电化学性能测试。最终在0.1 A g^-1的电流密度下，使电池充放电循环100次，测得其比容量有305 A h g^-1，大大提高了它的电化学性能。

关键词：钠离子电池 二氧化锡 碳包覆 石墨烯

Preparation and properties of carbon-coated tin dioxide/ graphene composites

Abstract

In recent years, energy storage devices such as lithium ion batteries have rapidly developed to commercialization. The new type of energy storage equipment, sodium ion battery, has also received extensive attention. Since the sodium element reserves are very rich, and its chemical properties are similar to lithium, it has good market potential and economic application value.

The negative electrode material is one of the key components of the battery, and its excellent performance will directly affect the capacity and operating voltage of various batteries. Conversion materials have higher theoretical specific capacity and adjustable morphology; and transition metal oxides are greener and safer, and are often used as anode materials for sodium ion batteries. However, during the cyclic reaction process, it will inevitably undergo a large volume expansion, resulting in powdering and shedding of the material, and the capacitance will therefore decay rapidly.

In this thesis, different carbon sources were first used to coat SnO₂ with carbon, and the best carbon source was selected by comparing experiments. In addition, SnO₂@Glu was subjected to secondary modification, and graphene and carbon nanotubes were selected to synthesize SnO₂ composites with SnO₂@ Glu, respectively, and subjected to a series of characterization tests and electrochemical performance tests. Ultimately, the sodium-ion battery was charged and discharged 100 times at a current density of 0.1 A g^-1, and its specific capacity was measured to be 305 A h g^-1, which greatly improved its electrochemical performance.

Key words: Sodium-ion battery; Tin dioxide; Carbon coating; Graphene

目录

摘要 I

Abstract II

第一章 绪论 1

1.1引言 1

1.2钠离子电池概述 2

1.2.1锂和钠材料的主要特征对比 2

1.2.2钠离子电池的研究进展 2

1.2.3钠离子电池的结构与反应机理 3

1.3钠离子电池的负极材料 4

1.3.1转化型材料 4

1.3.2其他类型材料 5

1.4 二氧化锡负极材料 6

1.4.1 二氧化锡的空间结构与反应机理 7

1.4.2二氧化锡负极材料改性研究 8

1.5课题的研究意义及内容 9

第二章 实验部分 10

2.1实验试剂与设备 10

2.1.1实验试剂 10

2.1.2实验设备 11

2.2材料合成 12

2.2.1二氧化锡材料的合成 12

2.2.2三种SnO₂@C的合成 12

2.2.3 SnO₂@Glu/G和SnO₂@Glu/CNT的合成 13

2.3电极的制备与电池的组装 13

2.3.1工作电极的制备 13

2.3.2电池的组装 14

2.4实验分析检测方法 14

2.4.1 X 射线衍射测试 14

2.4.2热重分析 15

2.4.3扫描电镜测试 15

2.5恒流充放电测试电化学性能 15

第三章 实验结果与讨论 16

3.1 SnO₂@C的表征分析和电化学性能研究 16

3.1.1热重分析和形貌表征 16

3.1.2 SnO₂@C的电化学性能研究 17

3.2 SnO2@Glu/G和SnO2@Glu/CNT的表征分析 18

3.2.1晶相分析 18

3.2.2热重分析和形貌表征 19

3.3 SnO₂@Glu/G和SnO₂@Glu/CNT的电化学性能研究 20

3.4本章小结 21

参考文献 23

致谢 25

第一章 绪论

1.1引言

近年来，各种电子设备以及电动汽车颇受人们的青睐，随着科技的进步，人们也越来越依赖电子产品。新能源汽车产业与信息技术产业的兴起，使得电池产业不断朝着小型化、轻型化、动力型、储能型及绿色安全的方向发展。

自上世纪九十年代以来，锂离子电池便迅速发展至商业化，且在 “十二五”规划期间，锂离子电池等新能源行业也成为了新兴发展产业。当前国际市场中，由于锂离子电池在“新能源”领域中的市场需求不断扩展，与锂资源相关的产品需求量也与日俱增，每年大约以7%~8%的速度增长，因此锂资源的供应也日益紧张。

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