High rate cycling performance of lanthanum-modified Li₄Ti₅O₁₂ anode materials for lithium-ion batteries

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• 作者：Ting-Feng Yi ; Ying Xie ; Qiuju Wu ; Haiping Liu ; Lijuan Jiang ; Mingfu Ye ; Rongsun Zhu
• 关键词：Anode material ; Lithium titanium oxide ; Modifying ; Energy density ; High rate performance
• 刊名：Journal of Power Sources
• 出版年：2012
• 出版时间：15 September, 2012
• 年：2012
• 卷：214
• 期：Complete
• 页码：220-226
• 全文大小：1031 K

文摘

A micro-sized particle Li₄Ti_5?xLa_xO₁₂ (0?¡Ü?x?¡Ü?0.2) material has been synthesized by a simple solid-state method at air. The obtained Li₄Ti_5?xLa_xO₁₂ materials are Li_3xLa_2/3?xTiO₃ (LLTO)-Li₄Ti₅O₁₂ (LTO) solid solution, and well crystallized with a particle size in the range of 1-2?¦Ìm. The electronic conductivity and lithium diffusion coefficient of La-modified LTO (Li₄Ti_4.95La_0.05O₁₂) are improved because LLTO exhibits a high ionic conductivity during Li⁺ extraction. Li₄Ti_4.95La_0.05O₁₂ material shows discharge capacities of more than 206 and 197?mAh?g^?1 after 100 cycles at 1?C and 3?C charge-discharge rates, respectively. Especially, in rate performance, the Li₄Ti_5?xLa_xO₁₂ (x?=?0.1, 0.2) samples maintain capacity of about 181?mAh?g^?1 until 5?C rates after 200 cycles, while the pure LTO sample shows a severe capacity decline at corresponding rate. These results suggest that La modifying is an effective way to improve the chemical stability of the electrode in contact with the electrolyte and improve their cyclability and rate capability during long term cycling. Since high rate performance is an important factor that needs to be considered in fabricating power batteries in industry, the La-modified LTO moves closer to real and large-scale applications.