物理化学学报 >> 2010, Vol. 26 >> Issue (11): 2962-2966.doi: 10.3866/PKU.WHXB20101101

电化学 上一篇    下一篇

负载Cr2O3的H2Ti2O5·H2O纳米管的制备及其作为锂离子电池正极材料的电化学性能

贺勇, 唐子龙, 张中太   

  1. 清华大学材料科学与工程系, 新型陶瓷与精细工艺国家重点实验室,北京100084
  • 收稿日期:2010-06-25 修回日期:2010-08-25 发布日期:2010-10-29
  • 通讯作者: 唐子龙 E-mail:tzl@tsinghua.edu.cn
  • 基金资助:

    国家高技术研究发展计划项目(863) (2007AA03Z235)资助

Preparation and Electrochemical Performance of H2Ti2O5·H2O/Cr2O3 Nanotubes as AnodeMaterials for Lithium-Ion Batteries

HE Yong, TANG Zi-Long, ZHANG Zhong-Tai   

  1. State Key Laboratory of New Ceramics and Fine Processing, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084, P. R. China
  • Received:2010-06-25 Revised:2010-08-25 Published:2010-10-29
  • Contact: TANG Zi-Long E-mail:tzl@tsinghua.edu.cn
  • Supported by:

    The project was supported by the National High-Tech Research and Development Programof China (863) (2007AA03Z235).

摘要:

限制纳米电极材料倍率性能的一个重要因素是, 在大电流下充放电时,纳米结构可能坍塌, 造成容量迅速衰减. 通过异价离子的掺杂或第二相的负载有可能弥补纳米材料的这一缺陷. 本文以含有Cr2O3的锐钛矿TiO2为原料,通过超声化学-水热法, 制备了负载Cr2O3的H2Ti2O5·H2O纳米管. 采用X 射线衍射(XRD)和透射电镜(TEM)对制得的H2Ti2O5·H2O/Cr2O3纳米管的晶体结构和微观形貌进行了表征和分析. 恒流充放电测试显示,H2Ti2O5·H2O/Cr2O3(5%(w, 质量分数))纳米管作为锂离子电池阳极材料具有优异的循环稳定性及倍率性能. 在150 mA·g-1的电流密度下, H2Ti2O5·H2O/Cr2O3纳米管的首次放电容量达到288 mAh·g-1; 120 次循环后, 充放电容量仍保持在145 mAh·g-1. 在1500 mA·g-1的电流密度下, 首次放电容量为178 mAh·g-1; 600 次循环后, 充放电容量保持在80 mAh·g-1 以上; 继续在150 mA·g-1电流密度下充放电30 个循环, 充放电容量达到155 mAh·g-1,显示出充放电容量的可回复性. 循环伏安测试结果表明, H2Ti2O5·H2O/Cr2O3纳米管的充放电过程由法拉第赝电容反应控制. 该一维纳米结构在锂离子电池和非对称电容器领域显示出良好的应用前景.

 

关键词: 纳米管, H2Ti2O5·H2O/Cr2O3, 强碱水热反应, 电化学嵌锂, 倍率性能

Abstract:

One problem that limits the rate capabilities of lithium-ion batteries is that despite the small size of the nanocrystalline particles in the electrode material, the crystalline structure might collapse during repetitive Li+ intercalation and extraction leading to the deterioration of charge and discharge performance under high currents. The prevention of this destruction has been attempted by substituting constituent atoms with other atoms to stabilize the structure in various transition metal oxide systems. In this work, H2Ti2O5·H2O/Cr2O3 compounds with nanotubes morphology were prepared by low temperature alkali-hydrothermal processing from anatase-type TiO2 with the addition of 5% (w) Cr2O3. The crystal structure and morphology of the as-prepared H2Ti2O5·H2O/Cr2O3 nanotubes were investigated by X-ray diffraction and transmission electron microscopy, respectively. Electrochemical lithium insertion cycling tests showed excellent cycling stability and an improved rate capability. The capacity of the first cycle was 288 mAh·g-1, and over 145 mAh·g-1 capacity remained after 120 cycles at 150 mA·g-1. At a current of 1500 mA·g-1, the capacity of the first cycle was 178 mAh·g-1. Over 80 mAh·g-1 capacity remained after 600 cycles at 1500 mA·g-1; furthermore, the capacity could come back to 150 mAh·g-1 at 150 mA·g-1 after 600 cycles at 1500 mA·g-1, which was close to the result for the cell that was immediately discharged/charged at 150 mA·g-1. The Cr2O3 particles, as the second phase, can improve the structural stability and high-rate capability of the H2Ti2O5·H2O nanotubes. These novel one-dimensional nanostructured materials may find promising applications in lithium-ion batteries and in electrochemical cells.

 

Key words: Nanotube, H2Ti2O5·H2O/Cr2O3, Alkali-hydrothermal reaction, Electrochemical lithium-ion insertion, High-rate capability

MSC2000: 

  • O646