Study on dynamics of structural transformation during charge/discharge of LiFePO4 cathode
Study on dynamics of structural transformation during charge/discharge of LiFePO4 cathode
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DOI：
10.1016/j.elecom.2007.12.024
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发表时间：
2008-02-01
影响因子：
5.4
通讯作者：
Wu, Nae-Lih
中科院分区：
文献类型：
--
作者：
Chang, Hao-Hsun;Chang, Chun-Chih;Wu, Nae-Lih
采用同步辐射X射线衍射（XRD）和电化学分析相结合的方法研究了LiFePO 4电极在有机锂离子电解液中充放电过程中的结构变化。这些数据揭示了复杂的结构转换模式，这是由于结构转换明显延迟，即使在低到中等电流率（C/10类似于1 C）。偏差的程度受充电/放电条件以及历史的影响，并且强烈的偏差似乎对电极循环寿命有害。此外，两相特性的Li+插入/提取反应被发现持续甚至在一个亚稳晶体结构。结果表明，可能是由强电子/离子位点库仑相互作用引起的域结构的存在下，如前所述。(c)2007 Elsevier B. V.保留所有权利。
Structural transformation taking place during charge/discharge of the LiFePO4 electrode in an organic Li-ion electrolyte has been studied by in situ synchrotron X-ray diffraction (XRD) concurrently with electrochemical analysis. The data reveal complex structural transformation patterns which result from significantly delayed structural transformation, even at low to moderate current rates (C/10 similar to 1 C). The extent of the deviation is affected by charge/discharge conditions as well as history, and strong deviation appears detrimental to electrode cycle life. Furthermore, the two-phase characteristic of the Li+ insertion/extraction reactions is found to persist even within one metastable crystal structure. The result suggests the presence of domain structures that are probably caused by the strong electron/ion site coulombic interaction as previously suggested. (c) 2007 Elsevier B.V. All rights reserved.