Optimized carbon-coated LiFePO4 cathode material for lithium-ion batteries
Optimized carbon-coated LiFePO4 cathode material for lithium-ion batteries
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用于锂离子电池的优化碳包覆LiFePO4正极材料
DOI：
10.1016/j.matchemphys.2008.11.063
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发表时间：
2009-05-15
影响因子：
4.6
通讯作者：
Kuang, Q.
中科院分区：
文献类型：
--
作者：
Dong, Y. Z.;Zhao, Y. M.;Kuang, Q.
通过固相反应合成了磷酸铁锂（LiFePO4）正极材料。样品的XRD图谱表明在我们的实验条件下可以获得单相LiFePO4化合物。根据Popa理论，利用Rietveld精修的结果，可以获得微晶的形状和尺寸。结果表明，在前驱体中使用碳凝胶不会改变晶体的结构，但可以抑制颗粒生长，并在较低温度下抑制颗粒的各向异性生长。在较高温度下，碳包覆的LiFePO4表现出各向异性生长，即沿(100)晶面的生长速率比沿(111)晶面的生长速率更快。在我们的实验条件下，可以在650℃下成功合成球形碳包覆LiFePO4。电化学测试表明球形碳包覆LiFePO4具有优异的性能。在C/10倍率下其初始比容量为156.7 mAh g(-1)。在第50次循环时，可逆比容量接近151.2 mAh g(-1)（初始容量的96.5%）。 Crown 版权所有 (C) 2008 由 Elsevier B.V. 出版。保留所有权利。
Lithium iron phosphate (LiFePO4) cathode material has been synthesized by a solid-state reaction. The XRD patterns of the samples show that the single-phase LiFePO4 compounds can be obtained in our experimental conditions. According to Popa theory, using the result from Rietveld refinement, the shape and the size of crystallite can be obtained. The result shows that the use of carbon gel in precursors do not change the structure of the crystal, but it can inhibit the particle growth and restrain the anisotropy growth of the grain at a lower temperature. At a higher temperature, carbon-coated LiFePO4 shows an anisotropy growth, i.e. growth rate along (100) crystal plane is more rapid than that of (111) crystal plane. In our experimental conditions, a spherical carbon-coated LiFePO4 can be synthesized successfully at 650 degrees C. The electrochemical testing indicated that the spherical carbon-coated LiFePO4 had the excellent performance. Its initial specific capacities were 156.7 mAh g(-1) under the rate of C/10. At the 50th cycle, the reversible specific capacities were found to approach 151.2 mAh g(-1) (the ratio of 96.5% of initial capacity). Crown Copyright (C) 2008 Published by Elsevier B.V. All rights reserved.