Enhanced cycling stability of Li[Li0.2Mn0.54Ni0.13Co0.13]O2 by surface modification of MgO with melting impregnation method
Enhanced cycling stability of Li[Li0.2Mn0.54Ni0.13Co0.13]O2 by surface modification of MgO with melting impregnation method
复制标题
DOI：
10.1016/j.electacta.2012.10.111
复制
发表时间：
2013-01-15
影响因子：
6.6
通讯作者：
Gu, C. D.
中科院分区：
文献类型：
--
作者：
Shi, S. J.;Tu, J. P.;Gu, C. D.
采用熔融浸渍法制备了氧化镁包覆的Li[Li0.2Mn0.54Ni0.13Co0.13]O-2。透射电子显微镜(TEM)和X射线光电子能谱(XPS)分析表明，在层状氧化物颗粒表面包覆了良好的氧化镁涂层。尽管经过适当修饰的Li[Li0.2Mn0.54Ni0.13Co0.13]O-2的首次放电容量比未修饰的Li[Li0.2Mn0.54Ni0.13Co0.13]O-2的初始放电容量有所下降，但2wt.%的MgO涂层正极材料表现出优异的循环稳定性，在200 mAG(-1)的电流密度下，室温循环100次后的容量保持率为96.4%，60℃下50次循环后的容量保持率为94.3%。熔融浸渍法制备的氧化镁涂层有望提高锂离子电池富锂层状氧化物正极的循环稳定性。(C)2012爱思唯尔有限公司。保留所有权利。
MgO-coated Li[Li0.2Mn0.54Ni0.13Co0.13]O-2 was synthesized via melting impregnation method followed by a solid state reaction. Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) show that the MgO layer is well coated on the surface of the layered oxide particles. Although the initial discharge capacity of Li[Li0.2Mn0.54Ni0.13Co0.13]O-2 with proper MgO modification decreases compared to the bare one, the 2 wt.% MgO coated cathode exhibits the excellent cycling stability with capacity retention of 96.4% at a current density of 200 mAg(-1) after 100 cycles at room temperature and 94.3% after 50 cycles at 60 degrees C. Electrochemical impedance spectroscopy (EIS) shows that the thin MgO layer mainly reduces the charge transfer resistance and stabilizes the surface structure of active material during cycling. Melting impregnation method is promising for MgO coating to improving the cycling stability of Li-rich layered oxide cathode for Li-ion batteries. (c) 2012 Elsevier Ltd. All rights reserved.