Journal of Inorganic Materials ›› 2018, Vol. 33 ›› Issue (7): 749-755.doi: 10.15541/jim20170461

• Orginal Article • Previous Articles     Next Articles

Surface Treatment on Structure and Property of LiNi0.8Co0.15Al0.05O2 by Silane Coupling Agent

Guang-Xin FAN1(), Ze-Ping LIU1, Yin WEN1, Bao-Zhong LIU2()   

  1. 1. School of Materials Science and Engineering, Henan Polytechnic University, Jiaozuo 454000, China
    2. College of Chemistry and Chemical Engineering, Henan Polytechnic University, Jiaozuo 454000, China
  • Received:2017-09-28 Revised:2018-01-31 Online:2018-07-10 Published:2018-06-19
  • About author:FAN Guang-Xin. E-mail: fangx@hpu.edu.cn
  • Supported by:
    National Natural Science Foundation of China (51671080, 51471065, U1304522);Program for Innovative Research Team (in Science and Technology) in the University of Henan Province (16IRTSTHN005)

Abstract:

Silane coupling agent was used to treat surface of cathode material LiNi0.8Co0.15Al0.05O2 (NCA) for lithium ion battery by a simple thermal decomposition method. Structures and properties of the materials were characterized by XRD combined with Rietveld refinement, SEM, TEM, DSC, EIS and galvanostatic charge/discharge test. The results show that amorphous SiO2 obtained by decomposition of silane coupling agent is uniformly coated on the surface of NCA whose crystal structure remain unaffected while its comprehensive properties are significantly improved especially at high temperature. In the environment of 60℃ at 0.2C and 1C rate , the discharge capacities of the coated NCA (a-NCA) are 176.4 mAh·g-1 and 158.9 mAh·g-1 respectively, whereas counterparts of the pristine NCA are slightly lower and reduced to 174.2 mAh·g-1 and 153.8 mAh·g-1, respectively. The capacity retention of a-NCA is 91.4% while that of NCA is 86.5% after 50 charge/discharge cycles. Moreover, thermal stability of a-NCA is greatly improved compared with the uncoated material under test condition of 60℃ in that the coating inhibits the side reaction between NCA surface and electrolyte which successfully restrains the surface film resistance and restricts variation of the crystal structure of material in process of cycling.

Key words: LiNi0.8Co0.15Al0.05O2, silane coupling agent, coating, electrochemical performance, thermal stability

CLC Number: 

  • TQ152