Acta Phys. -Chim. Sin. ›› 2017, Vol. 33 ›› Issue (8): 1605-1613.doi: 10.3866/PKU.WHXB201704145

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LiFePO4-Coated Li1.2Mn0.54Ni0.13Co0.13O2 as Cathode Materials with High Coulombic Efficiency and Improved Cyclability for Li-Ion Batteries

Lei. HE1,Jun-Min. XU1,2,*(),Yong-Jian. WANG1,Chang-Jin. ZHANG1,3,*()   

  1. 1 High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230031, P. R. China
    2 School of Physical Engineering, Key Laboratory of Material Physics of Ministry of Education of China, Zhengzhou University, Zhengzhou 450052, P. R. China
    3 Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, P. R. China
  • Received:2017-03-02 Published:2017-06-14
  • Contact: Jun-Min. XU,Chang-Jin. ZHANG E-mail:junminxu@zzu.edu.cn;zhangcj@hmfl.ac.cn
  • Supported by:
    The project was supported by the Scientific Research Grant of Hefei Science Center of Chinese Academy of Sciences(2015SRG-HSC025);and National Natural Science Foundation of China(U1532267);and National Natural Science Foundation of China(U11504379)

Abstract:

In this work, we present a new design for a surface protective layer formed by a facile aqueous solution process in which a nano-architectured layer of LiFePO4 is grown on a Li-rich cathode material, Li1.2Mn0.54Ni0.13Co0.13O2. The coated samples are then calcined at 400 or 500℃ for 5 h. The sample after calcination at 400℃ demonstrates a high initial columbic efficiency of 91.9%, a large reversible capacity of 295.0 mAh·g-1 at 0.1 C (1 C=300 mA·g-1), and excellent cyclability with a capacity of 206.7 mAh·g-1after 100 cycles at 1 C. Meanwhile, voltage fading of the coated sample is effectively suppressed by protection offered by a LiFePO4 coating layer. These superior electrochemical performances are attributed to the coating layer, which not only protects the Li-rich cathode material from side reaction with the electrolyte and maintains the stability of the interface structure, but also provides excess reversible capacity.

Key words: Lithium-ion battery, Lithium-rich cathode materials, LiFePO4 coating, High Columbic efficiency, Cyclability

MSC2000: 

  • O646