应用化学

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硫掺杂二氧化钛/碳化钛复合材料的制备及储锂性能

黄继梅,孟瑞晋,杨金虎()   

  1. 同济大学化学科学与工程学院 上海 200092
  • 收稿日期:2018-04-24 出版日期:2018-07-24
  • 通讯作者: 杨金虎
  • 基金资助:
    国家自然科学基金(21273161)上海自然科学基金(17ZR1447800)资助

Preparation and Lithium Ion Storage Performance of Sulfur-Doped Titanium Dioxide/Titanium Carbide Composite

Jimei HUANG,Ruijin MENG,Jinhu YANG()   

  1. School of Chemical Science and Engineering,Tongji University,Shanghai 200092,China
  • Received:2018-04-24 Published:2018-07-24
  • Contact: Jinhu YANG
  • Supported by:
    Supported by the National Natural Science Foundation of China(No.21273161), Natural Science Foundation of Shanghai(No.17ZR1447800)

摘要:

通过二维层状Ti3C2的原位水热氧化和气相硫化反应,制备了硫掺杂二氧化钛/碳化钛(S-TiO2/Ti3C2)复合材料,并用于电化学储锂。 结果表明,二氧化钛纳米颗粒原位生长在碳化钛片层上,且硫成功掺杂到二氧化钛中。 这种S-TiO2/Ti3C2复合结构作为锂离子电池的负极材料,表现出较好的电化学性能。 在0.2 A/g的电流密度下循环100圈后,放电比容量稳定在288 mA·h/g,远高于纯Ti3C2和TiO2/Ti3C2电极的放电比容量。 S-TiO2/Ti3C2复合材料表现出的较高比容量和良好的循环性能,主要归因于复合材料的特殊纳米结构优势:二氧化钛原位生长在碳化钛上,使复合材料具有稳定良好的接触界面,能够促进电子的快速转移,同时可以有效避免循环过程中两种组分的分离;硫在二氧化钛中的掺杂可以提高二氧化钛的导电性,并引入缺陷,提高反应活性。 此研究工作为二维材料的原位转化及复合提供了新的思路和研究方法。

关键词: 硫掺杂, 二氧化钛, 二维过渡金属碳化物, 复合材料, 锂离子电池

Abstract:

Sulfur-doped titanium dioxide/titanium carbide(S-TiO2/Ti3C2)composites were prepared via in-situ hydrothermal oxidation and chemical vapor phase sulfurization using two-dimensional layered Ti3C2 as the raw material. The results show that the TiO2 nanoparticles in situ grew on the Ti3C2 nanosheets and sulphur was successfully doped into titanium dioxide. The S-TiO2/Ti3C2 composite as anode material for lithium ion batteries exhibits superior electrochemical performance. A discharge specific capacity of 288 mA·h/g can be obtained after 100 cycles at a current density of 0.2 A/g, which is much higher than those of TiO2/Ti3C2 and pure Ti3C2 electrodes. The outstanding cycle stability and discharge specific capacity of the S-TiO2/Ti3C2 electrode are attributed to following reasons:TiO2 nanoparticles electrically contacting Ti3C2 nanosheets can facilitate the interfacial electron transfer and effectively avoid the separation of the two components during the cycle. In addition, S-TiO2 can improve the conductivity of the TiO2 and produce some defects to enhance the reactivity. This work provides a new strategy for the preparation of two-dimensional composite materials through an in-situ transformation.

Key words: sulfur doping, titanium dioxide, two-dimensional transition metal carbides, composite, lithium-ion batteries