SCI和EI收录∣中国化工学会会刊

Chin.J.Chem.Eng. ›› 2015, Vol. 23 ›› Issue (1): 315-320.DOI: 10.1016/j.cjche.2014.03.001

• MATERIALS AND PRODUCT ENGINEERING • Previous Articles     Next Articles

High tap density of Ni3(PO4)2 coated LiNi1/3Co1/3Mn1/3O2 with enhanced cycling performance at high cut-off voltage

Yan Cui, Shengming Xu   

  1. Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China
  • Received:2013-09-09 Revised:2014-03-04 Online:2015-01-24 Published:2015-01-28
  • Contact: Shengming Xu
  • Supported by:

    Supported by the National Natural Science Foundation of China (51074096).

High tap density of Ni3(PO4)2 coated LiNi1/3Co1/3Mn1/3O2 with enhanced cycling performance at high cut-off voltage

Yan Cui, Shengming Xu   

  1. Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China
  • 通讯作者: Shengming Xu
  • 基金资助:

    Supported by the National Natural Science Foundation of China (51074096).

Abstract: The LiNi1/3Co1/3Mn1/3O2 is first obtained by the controlled crystallization method and then coatedwith Ni3(PO4)2 particles. The effects of the coating on rate capability and cycle life at high cut-off voltage are investigated by electrochemical impedance spectroscopy and galvanostatic measurements. The element ratio of Ni:Mn:Co is tested by inductively-coupled plasma spectrometer (ICP) analysis and it testified to be 1:1:1. It is indicated that Ni3(PO4)2-coated LiNi1/3Co1/3Mn1/3O2 has an outstanding capacity retention, where 99% capacity retention is maintained after 10 cycles at 5C discharge rate between 2.7 V and 4.6 V. The electrochemical impedance spectroscopy (EIS) results show that the current exchange density i0 of the coated sample is higher than that of LiNi1/3Co1/3Mn1/3O2, which is beneficial to its electrochemical performances. All the conclusions show that the Ni3(PO4)2 coating can prominently enhance the high rate performance of the LiNi1/3Co1/3Mn1/3O2, especially at high cut-off voltage.

Key words: LiNi1/3Co1/3Mn1/3O2 cathode material, Electrochemistry, Ni3(PO4)2 coating, High tap density, High rate discharge capacity

摘要: The LiNi1/3Co1/3Mn1/3O2 is first obtained by the controlled crystallization method and then coatedwith Ni3(PO4)2 particles. The effects of the coating on rate capability and cycle life at high cut-off voltage are investigated by electrochemical impedance spectroscopy and galvanostatic measurements. The element ratio of Ni:Mn:Co is tested by inductively-coupled plasma spectrometer (ICP) analysis and it testified to be 1:1:1. It is indicated that Ni3(PO4)2-coated LiNi1/3Co1/3Mn1/3O2 has an outstanding capacity retention, where 99% capacity retention is maintained after 10 cycles at 5C discharge rate between 2.7 V and 4.6 V. The electrochemical impedance spectroscopy (EIS) results show that the current exchange density i0 of the coated sample is higher than that of LiNi1/3Co1/3Mn1/3O2, which is beneficial to its electrochemical performances. All the conclusions show that the Ni3(PO4)2 coating can prominently enhance the high rate performance of the LiNi1/3Co1/3Mn1/3O2, especially at high cut-off voltage.

关键词: LiNi1/3Co1/3Mn1/3O2 cathode material, Electrochemistry, Ni3(PO4)2 coating, High tap density, High rate discharge capacity