物理化学学报 >> 2012, Vol. 28 >> Issue (01): 105-110.doi: 10.3866/PKU.WHXB201228105

电化学和新能源 上一篇    下一篇

石墨烯掺杂LiFePO4电极材料的合成及其电化学性能

徐科, 申来法, 米常焕, 张校刚   

  1. 南京航空航天大学材料科学与技术学院, 南京 210016
  • 收稿日期:2011-07-26 修回日期:2011-10-12 发布日期:2011-12-29
  • 通讯作者: 张校刚 E-mail:azhangxg@163.com
  • 基金资助:

    国家重点基础研究发展计划项目(973) (2007CB209703), 国家自然科学基金(20873064, 21173120, 21103090), 江苏省普通高校科研创新计划(CXZZ11_0204)及南京航空航天大学博士学位论文创新与创优基金资助(BCXJ11-10)

Synthesis and Electrochemical Performance of Graphene Modified LiFePO4 Cathode Materials

XU Ke, SHEN Lai-Fa, MI Chang-Huan, ZHANG Xiao-Gang   

  1. College of Material Science and Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, P. R. China
  • Received:2011-07-26 Revised:2011-10-12 Published:2011-12-29
  • Contact: ZHANG Xiao-Gang E-mail:azhangxg@163.com
  • Supported by:

    The project was supported by the National Key Basic Research Program of China (973) (2007CB209703), National Natural Science Foundation of China (20873064, 21173120, 21103090), Jiangsu Innovation Program for Graduate Education, China (CXZZ11_0204), and Outstanding Doctoral Dissertation in Nanjing University of Aeronautics and Astronautics, China (BCXJ11-10).

摘要: 采用水热辅助法合成石墨烯改性的LiFePO4多孔微球电极材料. 并对材料进行了X射线衍射(XRD), 扫描电子显微镜(SEM), 透射电子显微镜(TEM), 傅里叶变换红外(FT-IR)光谱, 充放电等表征. 从结果可以看出在2 mol·L-1 LiNO3电解液体系中单纯包碳的LiFePO4微球在1C、50C倍率时的比容量分别为137、64 mAh·g-1,而石墨烯改性的LiFePO4微球的比容量分别为141、105 mAh·g-1, 表现出较好的倍率特性. 恒流循环充放电测试60 次后两种材料容量保持率分别为70.2%、83.7%. 说明掺杂石墨烯构成的三维导电网络能明显改善LiFePO4的电化学性能.

关键词: LiFePO4, 石墨烯, 水热法, 锂离子电池

Abstract: Graphene-modified mesoporous LiFePO4 microsphere composites were synthesized by a hydrothermal method and subsequent annealing. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectroscopy, and galvanostatic charge-discharge techniques were used to characterize the morphology, structure and electrochemical performance of the resulting composites. The graphene-modified LiFePO4 microspheres exhibited a high discharge capacity of 141 mAh·g-1 at 1C, and 105 mAh·g-1 at 50C, while LiFePO4/C only delivered 137 mAh·g-1 at 1C, 64 mAh·g-1 at 50C in an aqueous electrolyte of 2 mol·L-1 LiNO3. The graphene-modified LiFePO4 exhibited excellent cyclability compared with LiFePO4/C, with a capacity retention of about 83.7% after 60 cycles versus about 70.2% for LiFePO4/C. The improved electrochemical performance is attributed to the formation of a three-dimensional (3D) graphene network.

Key words: Lithium iron phosphate, Graphene, Hydrothermal, Li-ion battery

MSC2000: 

  • O646