硅酸盐学报

表面活性剂对Li7La3Zr2O12包覆富锂锰基层状正极材料的影响

单位：1. 黄冈师范学院化工学院湖北黄冈 438000 2. 广西师范大学化学与药学学院广西桂林 541004

分类号：TM912.9

出版年,卷(期):页码：2016,44(4):493-497

DOI：10.14062/j.issn.0454-5648.2016.04.02

摘要：

采用锂镧锆氧(Li7La3Zr2O12)快离子导体包覆Li1.2Mn0.54Ni0.13Co0.13O2正极材料，获得了核壳结构复合材料，并探讨表面活性剂在包覆过程的作用机制。利用热重分析、X射线粉末衍射、扫描电子显微镜和电化学性能测试等方法进行结构和性能分析。结果表明，以Tween 20为表面活性剂，600 ℃合成的Li7La3Zr2O12包覆的富锂正极复合材料的粒径均匀，首次放电比容量达273.2 mA•h/g，1C倍率下45次循环后的容量保持率为86.6%，显示出较好的电化学性能。Li7La3Zr2O12快离子导体壳层提高了电极/电解液界面Li+的扩散速率，抑制了电解质与活性材料之间的副反应，进而提高了材料的首次Coulomb效率和循环稳定性。

Fast lithium ion conduction of Li7La3Zr2O12 was applied to modify Li1.2Mn0.54Ni0.13Co0.13O2 cathode material to form a core-shell structure. The effect of surfactant on the morphology, electrochemical performance of the cathode materials and fuel cell was investigated. The results show that the cathode material synthesized with a surfactant Tween 20 and sintered in 600 ºC exhibits uniform particle size and improved electrochemical performance. This cathode material has an initial discharge specific capacity of 273.2 mA•h/g with capacity retention of 86.6% after 45 cycles at 1C rate. The improvement of the electrochemical performance can be attributed to the shell-structured Li+ superconductive layer, which form the cathode-electrolyte interface layer with enhanced Li+ diffusion, thus reduce side reactions between cathode material and electrolyte, improve the initial Coulombic efficiency and long-term cycling stability.

基金项目：

国家自然科学基金项目(51474110，51364004)；湖北省教育厅科学研究计划青年人才项目(Q20142901)

作者简介：

彭继明(1984—)，女，硕士。

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