Lithium Cobalt Oxides Functionalized by Conductive Al-doped ZnO Coating as Cathode for High-performance Lithium Ion Batteries

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• 作者：Bin Shen ; Pengjian Zuo ; ^{zuopj@hit.edu.cn} ; Qin Li ; Xiaoshu He ; Geping Yin ; ^{yingeping@hit.edu.cn} ; ^{yingphit@hit.edu.cn} ; Yulin Ma ; Xinqun Cheng ; Chunyu Du ; Yunzhi Gao
• 关键词：lithium ion batteries ; lithium cobalt oxide ; Al-doped ZnO ; electronic conduction ; high discharging rate capability
• 刊名：Electrochimica Acta
• 出版年：2017
• 出版时间：10 January 2017
• 年：2017
• 卷：224
• 期：Complete
• 页码：96-104
• 全文大小：3701 K
• 卷排序：224

文摘

LiCoO2 (LCO) has been functionally modified with electronic conductive Al-doped ZnO (AZO) via a sol-gel method. The physicochemical characterization results demonstrate that the AZO layer is coated onto the surface of LiCoO2 particles successfully, and the AZO-coated LCO material shows a higher electronic conductivity than pristine sample. The LCO sample coated by 2 wt.% AZO shows the excellent cyclability with a capacity retention of 98.2% after 50 cycles in the voltage range of 2.75–4.5 V under room temperature. More importantly, this material exhibits outstanding rate capability and delivers a quite high capacity of 156 mA h g−1 at the rate of 8 C (1600 mA g−1), corresponding to 86.6% of the capacity at the rate of 0.1 C. Such superior electrochemical performance results from the effective coating of AZO layer which not only acts as a physical protection layer to stabilize the surface structure, but also supplies the conductive networks to decrease charge transfer impedance. The conducting functionalized AZO coating is a facile and efficient approach to improve the electrochemical performance of LCO at a high cut-off voltage of 4.5 V vs. Li+/Li for large-scale application of high energy density lithium ion batteries.