钛基钠离子电池负极材料的合成与表征
发布时间：2019-01-08 17:41
【摘要】：得益于较高的能量密度和转化效率,锂离子电池已经被广泛地应用于便携式电子设备和电动交通工具中。近年来,可再生清洁能源的迅猛发展,推动了储能技术的革新。与锂离子电池相比,钠离子电池能量密度略低,但由于其拥有更丰富的资源储量和更低的成本,成为了当下储能技术领域研究的热点。若实现循环寿命的突破,它将成为新一代储能电池的有力竞争者。在钠离子电池负极体系中,钛基钠离子电池负极材料多为嵌入式反应机理,拥有结构稳定、体积变化较小、种类繁多等优势,但此类材料通常本征电导率较低,循环和倍率性能仍有待提高。本论文重点围绕钛基钠离子电池负极材料中的Na2Ti307和P2型Na0.66[Li0.22Ti0.78]O2进行了制备与改性的研究。第一章首先介绍了钠离子电池的发展历程、工作原理和关键组成部分。另外,还对钠离子电池的正负极材料进行了详细的介绍。重点介绍了几类脱嵌反应机理的正负极材料,并结合其发展近况论述了本文的研究背景与选题思路。第二章介绍了本论文中所使用的试剂材料以及仪器设备,并详细说明了锂/钠锂离子电池的组装方法及电化学性能测试。第三章采用一种简单的湿化学工艺路线,成功地制备出了钛基钠离子电池负极材料:原位碳网络复合的Na2Ti307。与传统的水热法和固相反应法相比,该方法条件更加温和,并能充分利用原料钛酸四丁酯中的有机官能团,无需添加额外的碳源,即可在材料表面获得均匀的原位碳网络。原位碳网络的存在,显著提高了材料的循环和倍率性能。第四章采用第三章的方法,成功地制备出了另一种钛基钠离子电池负极材料:原位碳网络复合的Na0.66[Li0.22Ti0.78]O2。通过优化通气速率与煅烧温度,解决了由于管式炉在高温下漏气而导致产物无法残碳的问题,成功在材料表面获得了原位碳网络。此外,本章还对该材料首次放电容量的构成进行了分析。最后,为了进一步提高材料电子导电性,我们对材料开展了碳包覆以及与碳纳米管的复合探索,发现改性后样品在首次库伦效率维持不变,但其倍率性能显著提高,各倍率下比容量均提高了 10 mAh g-1以上。第五章首次利用丙烯酸热聚合方法制备了高容量锂离子电池负极材料Li2MoO4,并采用了一种简单的方法对其进行了均匀的碳包覆,改性后材料循环和倍率性能明显提高。第六章总结归纳了本论文的创新和不足,并对未来研究工作进行了展望。
[Abstract]:Lithium ion batteries have been widely used in portable electronic devices and electric vehicles due to their high energy density and conversion efficiency. In recent years, the rapid development of renewable clean energy has promoted the innovation of energy storage technology. Compared with lithium-ion batteries, the energy density of sodium ion batteries is slightly lower, but it has become a hot spot in the field of energy storage technology because of its abundant resource reserves and lower cost. If the cycle life breakthrough is realized, it will become a powerful competitor of the new generation energy storage battery. In the negative electrode system of sodium ion battery, titanium based sodium ion battery anode materials are embedded reaction mechanism, have the advantages of stable structure, small volume change, various kinds of materials, but the intrinsic conductivity of such materials is usually low. Cycle and rate performance still need to be improved. In this thesis, the preparation and modification of Na2Ti307 and P2 type Na0.66 [Li0.22Ti0.78] O2 in anode materials of titanium-based sodium ion batteries were studied. In the first chapter, the development, working principle and key components of sodium ion battery are introduced. In addition, the anode and negative materials of sodium ion battery are introduced in detail. Several kinds of positive and negative materials for deintercalation reaction mechanism are introduced, and the research background and topics of this paper are discussed in the light of their recent development. In the second chapter, the reagents and equipments used in this thesis are introduced, and the assembly method and electrochemical performance test of lithium / sodium lithium ion battery are described in detail. In chapter 3, a simple wet chemical process was used to successfully prepare the anode material of titanium based sodium ion battery: in situ carbon network composite Na2Ti307.. Compared with the traditional hydrothermal method and solid state reaction method, the conditions of this method are more mild, and the organic functional groups in tetrabutyl titanate can be fully utilized, and a homogeneous in-situ carbon network can be obtained on the material surface without adding additional carbon sources. The existence of in situ carbon network improves the cycling and rate performance of the material. In chapter 4, we successfully fabricate another kind of anode material of titanium-based sodium ion battery, Na0.66 [Li0.22Ti0.78] O2, which is composed of in situ carbon network. By optimizing the ventilation rate and calcination temperature, the problem that the product can not remain carbon due to the leakage of gas in the tube furnace at high temperature was solved, and the in-situ carbon network was successfully obtained on the surface of the material. In addition, the composition of the first discharge capacity of the material is analyzed in this chapter. Finally, in order to further improve the electronic conductivity of the materials, we explored the carbon coating and the composite with carbon nanotubes. It was found that the first Coulomb efficiency of the modified samples remained unchanged, but the rate performance of the modified samples was significantly improved. The specific capacity was increased by more than 10 mAh g ~ (-1). In chapter 5, the high capacity lithium ion battery anode material Li2MoO4, was prepared by thermal polymerization of acrylic acid for the first time, and a simple method was used to cover it uniformly. The cyclic and rate properties of the modified materials were improved obviously. The sixth chapter summarizes the innovation and deficiency of this paper, and prospects the future research work.
【学位授予单位】：中国科学技术大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM912
本文编号：2404922
[Abstract]:Lithium ion batteries have been widely used in portable electronic devices and electric vehicles due to their high energy density and conversion efficiency. In recent years, the rapid development of renewable clean energy has promoted the innovation of energy storage technology. Compared with lithium-ion batteries, the energy density of sodium ion batteries is slightly lower, but it has become a hot spot in the field of energy storage technology because of its abundant resource reserves and lower cost. If the cycle life breakthrough is realized, it will become a powerful competitor of the new generation energy storage battery. In the negative electrode system of sodium ion battery, titanium based sodium ion battery anode materials are embedded reaction mechanism, have the advantages of stable structure, small volume change, various kinds of materials, but the intrinsic conductivity of such materials is usually low. Cycle and rate performance still need to be improved. In this thesis, the preparation and modification of Na2Ti307 and P2 type Na0.66 [Li0.22Ti0.78] O2 in anode materials of titanium-based sodium ion batteries were studied. In the first chapter, the development, working principle and key components of sodium ion battery are introduced. In addition, the anode and negative materials of sodium ion battery are introduced in detail. Several kinds of positive and negative materials for deintercalation reaction mechanism are introduced, and the research background and topics of this paper are discussed in the light of their recent development. In the second chapter, the reagents and equipments used in this thesis are introduced, and the assembly method and electrochemical performance test of lithium / sodium lithium ion battery are described in detail. In chapter 3, a simple wet chemical process was used to successfully prepare the anode material of titanium based sodium ion battery: in situ carbon network composite Na2Ti307.. Compared with the traditional hydrothermal method and solid state reaction method, the conditions of this method are more mild, and the organic functional groups in tetrabutyl titanate can be fully utilized, and a homogeneous in-situ carbon network can be obtained on the material surface without adding additional carbon sources. The existence of in situ carbon network improves the cycling and rate performance of the material. In chapter 4, we successfully fabricate another kind of anode material of titanium-based sodium ion battery, Na0.66 [Li0.22Ti0.78] O2, which is composed of in situ carbon network. By optimizing the ventilation rate and calcination temperature, the problem that the product can not remain carbon due to the leakage of gas in the tube furnace at high temperature was solved, and the in-situ carbon network was successfully obtained on the surface of the material. In addition, the composition of the first discharge capacity of the material is analyzed in this chapter. Finally, in order to further improve the electronic conductivity of the materials, we explored the carbon coating and the composite with carbon nanotubes. It was found that the first Coulomb efficiency of the modified samples remained unchanged, but the rate performance of the modified samples was significantly improved. The specific capacity was increased by more than 10 mAh g ~ (-1). In chapter 5, the high capacity lithium ion battery anode material Li2MoO4, was prepared by thermal polymerization of acrylic acid for the first time, and a simple method was used to cover it uniformly. The cyclic and rate properties of the modified materials were improved obviously. The sixth chapter summarizes the innovation and deficiency of this paper, and prospects the future research work.
【学位授予单位】：中国科学技术大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM912
【参考文献】
相关期刊论文 前1条
1 张晶晶;余爱水;;纳米结构过渡金属氧化物作为锂离子电池负极材料（英文）[J];Science Bulletin;2015年09期
，本文编号：2404922
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