物理化学学报 >> 2014, Vol. 30 >> Issue (1): 8888-94.doi: 10.3866/PKU.WHXB201311072

电化学和新能源 上一篇    下一篇

C-LiFePO4/聚三苯胺复合锂离子电池正极材料的制备与性能

苏畅1, 黄启飞1, 徐立环2, 张诚1   

  1. 1 浙江工业大学绿色化学合成技术国家重点实验室培育基地, 杭州 310014;
    2 沈阳化工大学化学工程学院, 沈阳 110142
  • 收稿日期:2013-08-06 修回日期:2013-11-06 发布日期:2014-01-01
  • 通讯作者: 徐立环,张诚 E-mail:xulihuanss@163.com;czhang@zjut.edu.cn
  • 基金资助:

    国家自然科学基金(51003095,51103132)和浙江省公益性技术应用研究计划(2010C31121)资助项目

Preparation and Performances of C-LiFePO4/Polytriphenylamine Composite as Cathode Material for Lithium-Ion Batteries

SU Chang1, HUANG Qi-Fei1, XU Li-Huan2, ZHANG Cheng1   

  1. 1 State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, Zhejiang University of Technology, Hangzhou 310014, P. R. China;
    2 College of Chemical Engineering, Shenyang University of Chemical Technology, Shenyang 110142, P. R. China
  • Received:2013-08-06 Revised:2013-11-06 Published:2014-01-01
  • Contact: XU Li-Huan, ZHANG Cheng E-mail:xulihuanss@163.com;czhang@zjut.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (51003095, 51103132) and Research on Public Welfare Technology Application Projects of Zhejiang Province, China (2010C31121).

摘要:

通过低温溶剂热法和高温热处理技术合成了橄榄石结构的LiFePO4/carbon (C-LiFePO4)纳米材料. 在此基础上,通过溶液共混法制备了一种新型的聚三苯胺(PTPAn)修饰包覆的C-LiFePO4复合锂离子电池正极材料(C-LiFePO4/PTPAn). 利用X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)、电化学阻抗谱(EIS)以及恒电流充放电等测试方法,考察PTPAn 包覆量对C-LiFePO4/PTPAn 复合正极材料性能的影响. 结果表明:通过溶液共混法PTPAn能够致密地包覆在C-LiFePO4表面,形成一个有效的电子/离子传输通道从而有效提高CLiFePO4基复合材料的电化学活性. 所有样品中C-LiFePO4/10% (w) PTPAn作为正极材料呈现出最佳的电化学性能,在0.1C倍率恒流充放电下材料首次放电比容量为154.5 mAh·g-1,在10C高倍率恒流充放电下材料的放电比容量达到114.2 mAh·g-1. 当C-LiFePO4/PTPAn 复合材料表面包覆的PTPAn 含量进一步增加,复合材料的电化学性能出现下降的趋势. 电化学阻抗测试表明PTPAn包覆层明显减小了C-LiFePO4电极的电荷转移电阻.

关键词: 锂离子电池, 聚三苯胺, 正极材料, 溶液共混法, 电化学性能

Abstract:

An olivine LiFePO4/carbon (C-LiFePO4) nanocrystallinematerial was prepared using a low-temperature solvothermalmethod, followed by a high-temperature post-annealing process. Then polytriphenylamine (PTPAn)-modified C-LiFePO4 (C-LiFePO4/PTPAn) was prepared, as a composite for novel cathodes for lithium-ion batteries, by solution blending of the C-LiFePO4 nanocrystallinematerial and the electroactive conducting polymer PTPAn. The effects of PTPAn coating of the C-LiFePO4/PTPAn samples were investigated using X-ray diffraction (XRD), scanning electronmicroscopy (SEM), transmission electronmicroscopy (TEM), electrochemical impedance spectroscopy (EIS), and galvanostatic charge-discharge testing. The results indicated that the solution blending method produced a compact PTPAn coating on the C-LiFePO4, providing an effective electronic/ionic conducting pathway and enhancing the electrochemical activities of C-LiFePO4-based composites. The C-LiFePO4/10%(w) PTPAn electrode displayed an improved initial discharge capacity of 154.5mAh·g-1 at 0.1C, a superior high-rate performance discharge capacity of 114.2 mAh·g-1 at 10C, and excellent cycling stability.With further increases in the PTPAn content of the coating on the C-LiFePO4/PTPAn composite, the electrochemical properties of the composite decreased. Electrochemical impedance measurements also demonstrated that the PTPAn coating significantly decreased the charge-transfer resistance of the C-LiFePO4 electrode.

Key words: Lithium-ion battery, Polytriphenylamine, Cathode material, Solution blending method, Electrochemical property

MSC2000: 

  • O646