Enhanced Electrochemical Performances of LiFePO4/C via V and F Co-doping for Lithium-Ion Batteries
Enhanced Electrochemical Performances of LiFePO4/C via V and F Co-doping for Lithium-Ion Batteries
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DOI：
10.1063/1674-0068/29/cjcp1507163
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发表时间：
2016-07
影响因子：
1
通讯作者：
Tao-tao Zhan;C. Li;Y. Jin;S. Xiao
中科院分区：
文献类型：
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作者：
Tao-tao Zhan;C. Li;Y. Jin;S. Xiao
采用原位聚合法结合两步烧结工艺制备了LiFe 1 −xVx（PO 4）（3−y）/3Fy/C复合材料。采用X射线衍射、傅里叶变换红外光谱、扫描电镜、充放电测试和电化学阻抗谱等研究了V、F共掺杂对LiFePO 4/C结构、形貌和电化学性能的影响。结果表明，V、F共掺杂并没有破坏LiFePO 4/C的橄榄石结构，但可以稳定晶体结构，降低电荷转移电阻，提高Li离子扩散速度，进一步提高LiFePO 4/C的循环性能和高倍率性能。
Based on the method of in situ polymerization synthesis combined with two-step sintering process, LiFe1−xVx(PO4)(3−y)/3Fy/C was prepared. The effects of V and F co-doping on the structure, morphology, and electrochemical performances of LiFePO4/C were investigated by X-ray diffraction, Fourier transform infrared spectra, scanning electron microscope, charge/discharge tests, and electrochemical impedance spectroscopy, respectively. The results indicated that the V and F co-doping did not destroy the olivine structure of LiFePO4/C, but it can stabilize the crystal structure, decrease charge transfer resistance, enhance Li ion diffusion velocity, further improve its cycling and high-rate capabilities of LiFePO4/C.