Kinetic behavior of LiFePO4/C cathode material for lithium-ion batteries
Kinetic behavior of LiFePO4/C cathode material for lithium-ion batteries
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DOI：
10.1016/j.electacta.2007.10.069
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发表时间：
2008-06-01
影响因子：
6.6
通讯作者：
Tang, Zhiyuan
中科院分区：
文献类型：
--
作者：
Gao, Fei;Tang, Zhiyuan
采用喷雾干燥和后退火的方法合成了LiFePO4/C复合正极材料。通过X射线衍射(XRD)和扫描电子显微镜(SEM)对产物的晶体结构和形貌进行了表征。使用电化学阻抗谱（EIS）研究LiFePO4/C电极的充放电动力学。结果表明，充放电过程中电阻的增加与FePO4相的出现密切相关，并且LiFePO4/C电极的欧姆电阻、电荷转移电阻和锂离子扩散系数在长时间的循环测试中没有发生太大变化，表明电池具有相对优越的循环性能。还使用 EIS 研究了电池温度对 LiFePO4/C 电极电化学反应行为的影响。已证实，电池温度对阻抗的影响主要是由于高温下锂离子扩散的增强。 (C) 2008 Elsevier Ltd. 保留所有权利。
The composite cathode materials of LiFePO4/C were synthesized by spray-drying and post-annealing method. The crystalline structure and morphology of products were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The charge-discharge kinetics of LiFePO4/C electrode was investigated using electrochemical impedance spectroscopy (EIS). The results show that the increment of the resistance has a close relation to the appearance of the FePO4 phase during charge-discharge course, and that the ohmic resistance, charge transfer resistance and lithium-ion diffusion coefficients of the LiFePO4/C electrode do not change much by extended cycling tests, implying a relatively superior cyclability of the battery. The effect of cell temperature on the electrochemical reaction behaviors of LiFePO4/C electrode was also investigated using the EIS. It is confirmed that the effect of the cell temperature on the impedance results mainly front the enhancement of the lithium-ion diffusion at elevated temperatures. (C) 2008 Elsevier Ltd. All rights reserved.