Chinese Journal of Applied Chemistry ›› 2020, Vol. 37 ›› Issue (10): 1181-1186.DOI: 10.11944/j.issn.1000-0518.2020.10.200116

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Fade Mechanism of Ternary Lithium Ion Power Battery

YANG Taoa, LIU Wenfengb,c, MA Mengyuec, DONG Hongyub*, YANG Shutingb*   

  1. aHe′nan Lithium Power Co.,Ltd;bSchool of Chemistry and Chemical Engineering,He′nan Normal University;cThe Battery Research Institute of Henan,Xinxiang,He′nan 453000,China
  • Published:2020-10-01 Online:2020-09-30
  • Contact: DONG Hongyu, associate professor; Tel/Fax:0373-3326439; E-mail:donghy373@163.com; Research interests:advanced energy materials
    Co-corresponding author:YANG Shuting, professor; Tel/Fax:0373-3326439; E-mail:shutingyang@foxmail.com; Research interests:advanced energy materials

Abstract: Failure analysis is an effective way to analyze the failure phenomena caused by complex physical and chemical changes during battery cycling, optimize the material preparation and the manufacturing processes of battery, and improve the cycle performance. In this paper, after dismantling and analyzing the ternary nickel cobalt manganese (NCM, LiNi0.5Co0.2Mn0.3O2) lithium ion power battery (NCM LIPB) at 1 C in the voltage range of 3~4.2 V for 1000 cycles, it is found that the capacity loss of the cathode electrode is about 2.73%, and the capacity loss of anode electrode is about 2.4%. Comparing the X-ray diffraction and field emission scanning electronic microscope results of cathode and anode electrodes before and after cycling, capacity fade of cathode is mainly caused by the breakage of particles and the structural transformation of the NCM layer. The capacity fade of anode is generated by the damage of graphite layer structure, which is caused by the continuous Li+ de-intercalation during cycling. Moreover, the positive transition cation dissolves and deposits on the surface of electrodes, and catalyzes the side reaction of electrolyte/electrode interface to result in excessive film formation and loss of active lithium, which affects the dynamics of electrode process, one of the reasons for battery failure.

Key words: ternary cathode materials, fade mechanism, ion dissolution, power battery, lithium ion battery