Rapid Charge鈥揇ischarge Property of Li4Ti5O12鈥揟iO2 Nanosheet and Nanotube Composites as Anode Material for Power Lithium-Ion Batteries

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• 作者：Ting-Feng Yi ; Zi-Kui Fang ; Ying Xie ; Yan-Rong Zhu ; Shuang-Yuan Yang
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2014
• 出版时间：November 26, 2014
• 年：2014
• 卷：6
• 期：22
• 页码：20205-20213
• 全文大小：584K
• ISSN：1944-8252

文摘

Well-defined Li₄Ti₅O₁₂鈥揟iO₂ nanosheet and nanotube composites have been synthesized by a solvothermal process. The combination of in situ generated rutile鈥揟iO₂ in Li₄Ti₅O₁₂ nanosheets or nanotubes is favorable for reducing the electrode polarization, and Li₄Ti₅O₁₂鈥揟iO₂ nanocomposites show faster lithium insertion/extraction kinetics than that of pristine Li₄Ti₅O₁₂ during cycling. Li₄Ti₅O₁₂鈥揟iO₂ electrodes also display lower charge-transfer resistance and higher lithium diffusion coefficients than pristine Li₄Ti₅O₁₂. Therefore, Li₄Ti₅O₁₂鈥揟iO₂ electrodes display lower charge-transfer resistance and higher lithium diffusion coefficients. This reveals that the in situ TiO₂ modification improves the electronic conductivity and electrochemical activity of the electrode in the local environment, resulting in its relatively higher capacity at high charge鈥揹ischarge rate. Li₄Ti₅O₁₂鈥揟iO₂ nanocomposite with a Li/Ti ratio of 3.8:5 exhibits the lowest charge-transfer resistance and the highest lithium diffusion coefficient among all samples, and it shows a much improved rate capability and specific capacity in comparison with pristine Li₄Ti₅O₁₂ when charging and discharging at a 10 C rate. The improved high-rate capability, cycling stability, and fast charge鈥揹ischarge performance of Li₄Ti₅O₁₂鈥揟iO₂ nanocomposites can be ascribed to the improvement of electrochemical reversibility, lithium ion diffusion, and conductivity by in situ TiO₂ modification.

Keywords:

lithium-ion battery; Li₄Ti₅O₁₂; TiO₂; rapid charge鈭抎ischarge property; rate capability