Acta Phys. -Chim. Sin. ›› 2012, Vol. 28 ›› Issue (01): 105-110.doi: 10.3866/PKU.WHXB201228105

• ELECTROCHEMISTRY AND NEW ENERGY • Previous Articles     Next Articles

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
  • 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).

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