Lithium-nickel cobalt oxides with spinel structure prepared at low temperature. XRD, XPS, and EIS measurements
Lithium-nickel cobalt oxides with spinel structure prepared at low temperature. XRD, XPS, and EIS measurements
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DOI：
10.1016/j.matlet.2011.11.108
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发表时间：
2012-03
影响因子：
3
通讯作者：
E. Meza;J. Ortiz;D. Ruíz-León;J. Marco;J. Gautier
中科院分区：
文献类型：
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作者：
E. Meza;J. Ortiz;D. Ruíz-León;J. Marco;J. Gautier
采用Pechini Sol-Gel法制备了LiNixCo2−xO4(x=0.2 5，0.5，0.75和1)组成的Li，Co，Ni复合氧化物。对X-射线衍射数据的Rietveld修正表明，所有的化合物都是在立方尖晶石相关氧化物的Fd3m空间群中结晶的。对这些氧化物的XPS研究表明，表面存在Ni2+、Ni3+、Co3+和Co4+离子。交流阻抗谱测定的Li+离子在氧化物晶格中的扩散系数(10−13cm2s−1≤D≤10−10cm2s−1)大于未取代的钴锂氧化物LiCo2O4的扩散系数(D=10−16cm2s−1)，与相关成分的层状氧化物的扩散系数相近。
Li, Co and Ni mixed oxides of composition LiNixCo2−xO4(x=0.25, 0.5, 0.75 and 1) were prepared at 280°C by the Pechini sol–gel method. The Rietveld refinement of the X-ray diffraction data indicated that all the obtained compounds crystallize in the Fd3m space group characteristic of cubic spinel-related oxides. XPS studies on these oxides reveal the presence of Ni2+, Ni3+, Co3+and Co4+ions at the surface. The diffusion coefficients of the Li+ion in the oxide lattice, determined by EIS measurements, are larger (10−13cm2s−1≤D≤10−10cm2s−1) than that shown by the non-substituted cobalt-lithium oxide, LiCo2O4(D=10−16cm2s−1) and present similar values to those of layered oxides of related composition.