Influence of Ru substitution on Li-rich 0.55Li2MnO3•0.45LiNi1/3Co1/3Mn1/3O2 cathode for Li-ion batteries
Influence of Ru substitution on Li-rich 0.55Li2MnO3•0.45LiNi1/3Co1/3Mn1/3O2 cathode for Li-ion batteries
复制标题
DOI：
10.1016/j.electacta.2012.06.118
复制
发表时间：
2012-10-01
影响因子：
6.6
通讯作者：
Lu, Li
中科院分区：
文献类型：
--
作者：
Song, Bohang;Lai, Man On;Lu, Li
采用传统共沉淀法合成了掺杂微量Ru的富锂阴极0.55Li(2)MnO(3)中心点0.45LiNi(1/3)Co(1/3)Mn(1/3)O(2)或以固溶体形式Li(Li0.20Mn0.54Ni0.13Co0.13)O-2。采用电感耦合等离子体发射光谱（ICP）、x射线衍射（XRD）和场发射扫描电镜（FESEM）对材料进行了结构和形态表征。根据Rietveld细化结果，Ru掺杂导致Li2MnO3和LiNi1/3Co1/3Mn1/3O2组分的晶格常数发生变化。电化学测试表明，Li(Li0.19Mn0.54Ni0.13Co0.12Ru0.01)O-2具有最佳性能，特别是在高速率下。在500毫安g(-1)（2℃）的电流密度下，实现了高达182毫安g（-1）的放电容量，在接下来的700次循环中，每次循环的容量衰减低至0.06%。这种改善与从原始Li2MnO3组分转移的尖晶石样区域的突出出现有关，其中Ru通过增强Li在Li2MnO3和LiNi1/3Co1/3Mn1/3O2组分中的扩散能力来促进相变。电化学阻抗谱（EIS）分析也证实了锂扩散的改善。(C) 2012 Elsevier Ltd.版权所有。
Li-rich cathode 0.55Li(2)MnO(3)center dot 0.45LiNi(1/3)Co(1/3)Mn(1/3)O(2) or written in a solid solution form Li(Li0.20Mn0.54Ni0.13Co0.13)O-2 doped with trace Ru is synthesized using a traditional co-precipitation method. The structural and morphological characterizations are carried out by employing inductively coupled plasma emission spectrometry (ICP), X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). Ru doping causes variation of lattice constants in both Li2MnO3 and LiNi1/3Co1/3Mn1/3O2 components according to the results of Rietveld refinement. Electrochemical measurement shows that Li(Li0.19Mn0.54Ni0.13Co0.12Ru0.01)O-2 possesses the best performance, especially at high rate. A discharge capacity as high as 182 mAh g(-1) at a current density of 500 mA g(-1) (2 C) is achieved with a capacity fade of as low as 0.06% per cycle in the following 700 cycles. Such improvement is associated with the prominent appearance of spinel-like regions transferred from the original Li2MnO3 component in which Ru facilitates the phase transformation via enhancing the ability of Li diffusion in both Li2MnO3 and LiNi1/3Co1/3Mn1/3O2 components. The improvement in Li diffusion is also confirmed from the electrochemical impedance spectroscopy (EIS) analysis. (C) 2012 Elsevier Ltd. All rights reserved.