Surface modification of Li(Li0.17Ni0.2Co0.05Mn0.58)O2 with CeO2 as cathode material for Li-ion batteries
Surface modification of Li(Li0.17Ni0.2Co0.05Mn0.58)O2 with CeO2 as cathode material for Li-ion batteries
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DOI：
10.1016/j.electacta.2014.04.181
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发表时间：
2014-07
影响因子：
6.6
通讯作者：
W. Yuan;Han Zhang;Qian Liu;G. R. Li;X. P. Gao
中科院分区：
文献类型：
--
作者：
W. Yuan;Han Zhang;Qian Liu;G. R. Li;X. P. Gao
富锂层状氧化物作为先进的锂离子电池正极材料具有重要意义。本文采用喷雾干燥法制备了富锂层状Li(Li0.17Ni0.2Co0.05Mn0.58)O2，并用CeO2纳米粒子对其进行了修饰。结果表明，随着CeO2含量的增加，CeO2纳米晶在Li(Li0.17Ni0.2Co0.05Mn0.58)O2表面以孤立的纳米颗粒或厚的CeO2层的形式存在。纳米CeO2修饰后的Li(Li0.17Ni0.2Co0.05Mn0.58)O2具有较低的表面电荷转移电阻、较大的放电容量和较高的初始库仑效率。尤其是CeO2含量为1wt%的改性样品表现出最佳的循环稳定性和高倍率放电能力。此外，纳米CeO2的表面修饰在一定程度上提高了阴极脱硫态的热稳定性，这是由于初始电荷产生的氧气能够被吸附并储存在Li(Li0.17Ni0.2Co0.05Mn0.58)O2表面的纳米CeO2中。
Li-rich layered oxides are of great importance as cathode materials for advanced lithium ion batteries. In this work, Li-rich layered Li(Li0.17Ni0.2Co0.05Mn0.58)O2oxide is synthesized by a spray-drying method, and modified subsequently with CeO2nanoparticles. It is demonstrated that the surface of the Li(Li0.17Ni0.2Co0.05Mn0.58)O2oxide is modified with CeO2nanocrystallites, which exist as isolated nano-particles or a thick CeO2layer with increasing CeO2content. After the surface modification with CeO2nanoparticles, Li(Li0.17Ni0.2Co0.05Mn0.58)O2oxide presents lower surface charge transfer resistance, larger discharge capacity and higher initial coulombic efficiency. In particular, the modified sample with 1 wt % CeO2shows the optimized cycle stability and high-rate discharge capability. In addition, the thermal stability of the cathode at delithiated state is improved to a certain extent by the surface modification with CeO2nanoparticles, which is attributed to that the oxygen generated from the initial charge can be absorbed and stored in CeO2nanoparticles on the surface of Li(Li0.17Ni0.2Co0.05Mn0.58)O2.