Acta Phys. -Chim. Sin. ›› 2012, Vol. 28 ›› Issue (09): 2084-2090.doi: 10.3866/PKU.WHXB201207043

• ELECTROCHEMISTRY AND NEW ENERGY • Previous Articles     Next Articles

Synthesis and Characterization of Mg and Ti Ions Co-Doped Lithium Iron Phosphate and Its Lithium-Ion Batteries

WANG Zhen-Po1, LIU Wen2, WANG Yue3, ZHAO Chun-Song4, ZHANG Shu-Ping4, CHEN Ji-Tao2, ZHOU Heng-Hui2, ZHANG Xin-Xiang2   

  1. 1. National Engineering Laboratory for Electric Vehicles, Beijing Institute of Technology, Beijing 100081, P. R. China;
    2. Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China;
    3. Institute of Chemical Defense of PLA, Beijing 102205, P. R. China;
    4. Pulead Technology Industry Co., LTD., Beijing 102200, P. R. China
  • Received:2012-04-20 Revised:2012-07-04 Published:2012-08-02
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (61004092) and National High-Tech Research and Development Program of China (863) (2009AA035200).

Abstract:

Mg and Ti ions co-doped (Li0.98Mg0.01)(Fe0.98Ti0.01)PO4/C cathode material for lithium-ion batteries was prepared by a solid-state method under N2 atmosphere. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and galvanostatic charge-discharge test. Results indicated that Mg and Ti ions co-doping remarkably improved the electrochemical performance of LiFePO4, including rate capacity, temperature behavior, and cycling stability. Discharge capacities of 154.7 and 146.9 mAh·g-1 were obtained at the rates of 0.2C and 1C for half-cell tests, respectively. For 60 Ah full-cell tests, 100% of 1C capacity was maintained even at 3C rate, 89.7% and 63.1% of initial capacity at room temperature were retained at 0 and -20 °C, respectively. 89% capacity retention remained after 2000 cycles at room temperature, presenting excellent cycle stability. This investigation suggests that the present co-doping material and the resulting battery possess large discharge capacity and excellent cycling performance, making it applicable in electric vehicle (EV)/hybrid electric vehicle (HEV) and energy storage systems on a large scale.

Key words: Lithium iron phosphate, Co-doping, Rate capacity, Power battery, Energy storage battery

MSC2000: 

  • O646