Synthesis and characterization of Zr-doped LiNi0.4Co0.2Mn0.4O2 cathode materials for lithium ion batteries
Synthesis and characterization of Zr-doped LiNi0.4Co0.2Mn0.4O2 cathode materials for lithium ion batteries
复制标题
DOI：
10.1039/c5ra14376d
复制
发表时间：
2015-09
期刊：
影响因子：
3.9
通讯作者：
Qiyuan Chen;Chenqiang Du;D. Qu;Xin-he Zhang;Zhiyuan Tang
中科院分区：
文献类型：
--
作者：
Qiyuan Chen;Chenqiang Du;D. Qu;Xin-he Zhang;Zhiyuan Tang
采用溶胶-凝胶法合成了Li（Ni0.4Co0.2Mn0.4）1− xZrxO 2（x = 0，0.01）。采用SEM、XRD、充放电测试、循环伏安（CV）和电化学阻抗谱（EIS）等方法对样品的形貌、结构和电化学性能进行了表征。X射线衍射图谱表明，取代元素略微增大了层间距，并获得了更高程度的有序晶体形式。掺杂样品Li（Ni0.4Co0.2Mn0.4）0.99Zr0.01O2具有良好的电化学性能。在0.2C、0.5C、1.0C和2.0C下的初始放电容量分别为162.4 mA h g − 1、157.5 mA h g − 1、135.3 mA h g − 1、124.3 mA h g−1。50次循环后，在相应速率下的容量保持率分别为80.5%、70.9%、73.4%和68.5%。电化学性能的提高主要归因于Li+扩散速率的提高和晶体结构的改善。
Li(Ni0.4Co0.2Mn0.4)1−xZrxO2 (x = 0, 0.01) was synthesized by a typical sol–gel method. The morphology, structure and electrochemical properties were characterized by SEM, XRD, charge–discharge tests, Cyclic Voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The X-ray diffraction patterns showed that the substituted elements slightly enlarged the interlayer spacing and obtained a higher degree of the well-ordered crystallographic form. The doped sample Li(Ni0.4Co0.2Mn0.4)0.99Zr0.01O2 delivered good electrochemical properties. The initial discharge capacities were 162.4 mA h g−1, 157.5 mA h g−1, 135.3 mA h g−1, 124.3 mA h g−1 at 0.2C, 0.5C, 1.0C and 2.0C, respectively. After 50 cycles, the capacity retentions were 80.5%, 70.9%, 73.4% and 68.5% at the corresponding rates, respectively. The improved electrochemical performance could be ascribed to the enhanced diffusion rate of Li+ and improved crystal structure.