High capacity Li[Ni0.8Co0.1Mn0.1]O2 synthesized by sol-gel and co-precipitation methods as cathode materials for lithium-ion batteries
High capacity Li[Ni0.8Co0.1Mn0.1]O2 synthesized by sol-gel and co-precipitation methods as cathode materials for lithium-ion batteries
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DOI：
10.1016/j.ssi.2013.07.023
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发表时间：
2013-11-01
影响因子：
3.2
通讯作者：
Vullum-Bruer, Fride
中科院分区：
文献类型：
--
作者：
Lu, Huaquan;Zhou, Haitao;Vullum-Bruer, Fride
采用溶胶-凝胶法和共沉淀法制备了层状Li[Ni0.8Co0.1Mn0.1]O-2正极材料。比较了两种材料的结构、形态和电化学性能。XRD谱图表明，溶胶-凝胶法和共沉淀法均形成了具有良好层状特性的单相材料。Rietveld细化表明两种材料的阳离子无序性存在一定差异，其中溶胶-凝胶法合成的样品显示出较低的Li/Ni阳离子无序性。SEM和BET测量表明，与共沉淀样品相比，溶胶-凝胶样品由相对较少的聚集颗粒组成，具有更大的BET表面积。电化学测试表明，溶胶-凝胶法制备的材料具有稍好的电化学性能，初始放电容量为200 mAh。在0.5 C的循环速率下，循环50次后的容量保持率为82.2%，在5 C时的容量保持率更高。溶胶-凝胶合成材料性能的提高可能是由于低Li/Ni无序结合高表面积，后者增加了电解质与活性材料之间的界面接触面积。考察了煅烧条件对材料结构和电化学性能的影响。通过提高焙烧气氛中O-2的浓度或增加空气的流量来改善电化学性能，显示出开发低成本高质量正极材料合成路线的潜力。(C) 2013 Elsevier B.V.版权所有
Layered Li[Ni0.8Co0.1Mn0.1]O-2 cathode materials have been prepared by sol-gel and co-precipitation methods. The structural, morphological and electrochemical properties of the materials were compared. The XRD patterns show that both the sol-gel and the co-precipitation method formed single phase materials with good layered characteristics. Rietveld refinement reveals some differences in cation disorder between the two materials, where the sample synthesized by the sol-gel method shows lower Li/Ni cation disorder. SEM and BET measurements show that the sol-gel sample consists of relatively less aggregated particles giving larger BET surface area compared to the co-precipitation sample. Electrochemical tests indicate that the material prepared by the sol-gel method has slightly better electrochemical properties, with an initial discharge capacity of 200 mAh.g(-1) and capacity retention of 82.2% after 50 cycles at a cycling rate of 0.5 C, as well as better capability at 5 C. The improved performances of the sol-gel synthesized material may be attributed to the low Li/Ni disorder combined with high surface area, the latter increasing the interfacial contact area between the electrolyte and the active material. Effects of calcination conditions on the structure and electrochemical performance of the materials were also investigated. The electrochemical performance was improved by either increasing the O-2 concentration in the calcination atmosphere, or by increasing the flow rate of air, showing the potential of developing low-cost synthesis routes for high-quality cathode materials. (C) 2013 Elsevier B.V. All rights reserved.