论文总字数：21032字

摘 要

随近年来，由于钠离子电池具有资源丰富、价格低廉、电化学性能良好等优点，其被广泛研究作为锂离子电池的合适替代品。其中，二元过渡金属氧化物NiCo₂O₄由于其高的理论比容量和优异的电子导电性而成为一种有前景的钠离子电池负极材料。然而，NiCo₂O₄较慢的储钠反应动力学严重限制了其储钠能力，导致其很少被研究。

本课题采用模板法合成有序介孔结构的NiCo₂O₄来提升其储钠性能。首先，制备出水热处理温度为40 ℃和130 ℃的有序介孔二氧化硅模板KIT-6-40和KIT-6-130，然后加入硝酸钴和硝酸镍等制备出有序介孔NiCo₂O₄-KIT-6-40和NiCo₂O₄-KIT-6-130。KIT-6模板孔系统的连通程度可通过KIT-6模板的水热处理温度来改变，在40 ℃和130 ℃水热处理温度下可得到两种对称性不同的有序介孔NiCo₂O₄，即脱耦合和耦合的有序介孔NiCo₂O₄。

在电池电化学测试中，其在100 mA g^-1电流密度下表现出高达581 mAh g^-1的放电比容量，而且在多次循环以后仍然具有较高的放电比容量以及库伦效率。NiCo₂O₄的有序介孔结构使其具有较高BET表面积和较大的孔体积，能够更方便地与电解质相接触，缩短Na离子的移动距离，有利于Na离子的传输。

关键词：NiCo₂O₄ 有序介孔 模板法 钠离子电池

Study on Sodium Storage Properties of Ordered Mesoporous NiCo₂O₄

Abstract

In recent years, sodium-ion batteries have been widely studied as suitable substitutes for lithium-ion batteries because of their advantages such as abundant resources, low cost, and good electrochemical performance. Among them, the binary transition metal oxide NiCo₂O₄ has become a promising cathode material for sodium ion batteries due to its high theoretical specific capacity and excellent electronic conductivity. However, the slower sodium storage reaction kinetics of NiCo₂O₄ severely limits its ability to store sodium, resulting in very little research.

This work uses the hard method to synthesize ordered mesoporous NiCo₂O₄ to improve its sodium storage performance. First, ordered mesoporous silica templates KIT-6-40 and KIT-6-130 were prepared at 40°C and 130°C, respectively, followed by addition of cobalt nitrate and nickel nitrate to prepare ordered mesoporous NiCo₂O₄-KIT-6-40 and NiCo₂O₄-KIT-6-130. The connectivity of the pore system for the KIT-6 template can be changed by its hydrothermal treatment temperature .Mesoporous NiCo₂O₄s with two different symmetry can be obtained with KIT-6 hydrothermally treated at two different temperatures. That is, coupled and decoupled mesoporous NiCo₂O₄.

When used as anode for sodium ion batteries, the mesoporous NiCo₂O₄ shows a discharge specific capacity up to 581 mAh g^-1 at a current density of 100 mA g^-1, and maintains a high specific discharge capacity and Coulomb efficiency after many cycles. The ordered mesoporous structure of NiCo₂O₄ have a high BET surface area and a large pore volume, which can enhance its contact with the electrolyte, shorten the distance of movement of Na ions, and facilitate the transmission of Na ions.

.

Key Words: NiCo₂O₄; Ordered mesoporous; Template method; Sodium ion battery

目 录

摘要 I

Abstract II

第一章 绪论 1

1.1 简介 1

1.2钠离子电池的基本工作原理 2

1.3钠离子电池的负极材料 3

1.4. NiCo₂O₄晶体结构 5

1.5. NiCo₂O₄材料的制备方法 5

1.6. NiCo₂O₄作为钠离子电池负极材料的研究 7

第二章 实验方法 8

2.1实验主要仪器和药品 8

2.2实验方案 10

2.3样品表征 11

2.4电池组装及性能测试 13

第三章 实验结果与讨论 15

3.1 XRD分析 15

3.2 TEM分析 18

3.3 N₂物理吸附 19

3.4 电化学测试 21

第四章 结论 24

参考文献 25

致 谢 27

请支付后下载全文，论文总字数：21032字