In situ TEM observation of the electrochemical lithiation of N-doped anatase TiO2 nanotubes as anodes for lithium-ion batteries,Journal of Materials Chemistry A

当前位置： X-MOL 学术 › J. Mater. Chem. A › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

In situ TEM observation of the electrochemical lithiation of N-doped anatase TiO2 nanotubes as anodes for lithium-ion batteries
Journal of Materials Chemistry A ( IF 10.7 ) Pub Date : 2017-09-22 00:00:00 , DOI: 10.1039/c7ta05877b
Minghao Zhang _{1,

2,

3,

4,

5} , Kuibo Yin _{1,

2,

3,

4,

6} , Zachary D. Hood _{1,

2,

3,

4,

7} , Zhonghe Bi _{2,

3,

4,

8} , Craig A. Bridges _{2,

3,

4,

8} , Sheng Dai _{2,

3,

4,

8} , Ying Shirley Meng _{4,

5,

9,

10} , Mariappan Parans Paranthaman _{2,

3,

4,

8} , Miaofang Chi _{1,

2,

3,

4}

Affiliation

Due to their high specific capacity and negligible volume expansion during cycling, anatase titanium dioxide (a-TiO₂) nanotubes have been considered as a prime candidate for anodes in lithium-ion batteries. However, their rate capability for electrochemical cycling is limited by the low electronic conductivity of a-TiO₂ nanotubes. Here, we show that a desirable amount of nitrogen doping can significantly enhance the electronic conductivity in a-TiO₂ nanotubes, resulting in improvements in both the capacity stability and the rate capability at fast charge–discharge rates. Electron energy loss spectroscopy revealed a high doping concentration of nitrogen (∼5%) by substituting for oxygen ions in a-TiO₂ nanotubes. The lithiation mechanism of N-doped a-TiO₂ nanotubes was further investigated using in situ transmission electron microscopy, where a three-step lithiation mechanism was revealed. Lithium ions initially intercalate into the a-TiO₂ lattice structure. Further insertion of lithium ions triggers a phase transformation from a-TiO₂ to orthorhombic Li_0.5TiO₂ and finally to polycrystalline tetragonal LiTiO₂. Our results reveal that nitrogen doping significantly facilitates lithiation in TiO₂ through enhanced electronic conductivity, while the structural and chemical evolutions during the lithiation process remain similar to those of undoped TiO₂.

中文翻译：

N掺杂锐钛矿型TiO ₂纳米管作为锂离子电池阳极的电化学锂化的原位TEM观察

由于它们的高比容量和在循环过程中可忽略的体积膨胀，锐钛矿型二氧化钛（a-TiO ₂）纳米管被认为是锂离子电池阳极的主要候选材料。然而，对于在电化学循环的速率能力由一个-TiO 2的低的电子传导性限制₂纳米管。在这里，我们表明，理想的氮掺杂量可以显着提高a-TiO ₂纳米管中的电子电导率，从而改善容量稳定性和快速充放电速率下的速率能力。电子能量损失谱显示通过取代a-TiO _2中的氧离子，氮的掺杂浓度高（约5％）。纳米管。利用原位透射电子显微镜进一步研究了N掺杂的a-TiO ₂纳米管的锂化机理，揭示了三步锂化机理。锂离子最初嵌入a-TiO ₂晶格结构中。锂离子的进一步插入触发了从a-TiO ₂到正交晶体Li _0.5 TiO ₂并最终到多晶四方LiTiO _2的相变。我们的结果表明，氮掺杂显着促进了TiO _2中的锂化通过提高电子电导率，而在锂化过程中的结构和化学演变仍与未掺杂的TiO ₂相似。

更新日期：2017-09-22

点击分享查看原文

点击收藏

公开下载

阅读更多本刊最新论文本刊介绍/投稿指南11