Improved electrochemical performance of La0.7Sr0.3MnO3 and carbon co-coated LiFePO4 synthesized by freeze-drying process
Improved electrochemical performance of La0.7Sr0.3MnO3 and carbon co-coated LiFePO4 synthesized by freeze-drying process
复制标题
冷冻干燥法合成的La0.7Sr0.3MnO3和碳共包LiFePO4的电化学性能得到改善
DOI：
10.1016/j.electacta.2009.08.020
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发表时间：
2010-01-01
影响因子：
6.6
通讯作者：
Guo, Ruisong
中科院分区：
文献类型：
--
作者：
Cui, Yan;Zhao, Xiaoli;Guo, Ruisong
首先采用溶胶-凝胶法和冷冻干燥法合成了碳包覆的LiFePO4颗粒。然后通过悬浮混合工艺在这些颗粒上涂覆 La0.7Sr0.3MnO3 纳米层。 La0.7Sr0.3MnO3 和碳共涂覆的 LiFePO4 颗粒在还原气氛（氮气中氢气含量为 5%）中于 400 摄氏度下煅烧 2 小时。高分辨率透射电子显微镜证实，纳米层结构的 La0.7Sr0.3MnO3 与无定形碳层一起形成排列在 LiFePO4 裸露表面上的集成网络。 X射线衍射结果证明共涂层复合材料仍然保留了LiFePO4基底的结构。双涂层可以显着提高高充电/放电速率下的电化学性能。这种改进可能归因于与碳涂覆的 LiFePO4 相比，孪生纳米层涂层具有更低的电荷转移电阻和更高的电子电导率。 (C) 2009 Elsevier Ltd. 保留所有权利。
Carbon coated LiFePO4 particles were first synthesized by sol-gel and freeze-drying method. These particles were then coated with La0.7Sr0.3MnO3 nanolayer by a suspension mixing process. The La0.7Sr0.3MnO3 and carbon co-coated LiFePO4 particles were calcined at 400 degrees C for 2 h in a reducing atmosphere (5% of hydrogen in nitrogen). Nanolayer structured La0.7Sr0.3MnO3 together with the amorphous carbon layer forms an integrate network arranged on the bare surface of LiFePO4 as corroborated by high-resolution transmission electron microscopy. X-ray diffraction results proved that the co-coated composite still retained the structure of the LiFePO4 substrate. The twin coatings can remarkably improve the electrochemical performance at high charge/discharge rates. This improvement may be attributed to the lower charge transfer resistance and higher electronic conductivity resulted from the twin nanolayer coatings compared with the carbon coated LiFePO4. (C) 2009 Elsevier Ltd. All rights reserved.