Acta Phys. -Chim. Sin. ›› 2017, Vol. 33 ›› Issue (9): 1781-1788.doi: 10.3866/PKU.WHXB201705041

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First-Principles Study:the Structural Stability and Sulfur Anion Redox of Li1-xNiO2-ySy

Hui-Jun YAN,Biao LI,Ning JIANG,Ding-Guo XIA*()   

  • Received:2017-03-30 Published:2017-07-05
  • Contact: Ding-Guo XIA E-mail:dgxia@pku.edu.cn
  • Supported by:
    the New Energy Project for Electric Vehicle of National Key Research and Development Program, China(2016YFB0100200);National Natural Science Foundation of China(51671004)

Abstract:

Ni-rich layered oxides are the preferred cathode materials for high-energy-density lithium-ion batteries currently used in electric vehicles. In this paper, we present a systematic first-principles evaluation of the deintercalation process in the Li1-xNiO2-ySy. The partial density of states (PDOS) characters of the electrons near the Fermi level, redox behaviors, and thermal stability have been investigated within the GGA+U scheme. The results show that the introduction of sulfur alleviates the lattice distortion during charging, suppresses nickel migration, and enhances the stability of oxygen according to the contribution of sulfur anion redox to the charge compensation for the overcharged Li1-xNiO2-ySy. This study provides a new insight on improving the stability of Ni-rich cathode materials by tuning of the electrochemical behaviors based on sulfur anion redox.

Key words: Anion doping, Sulfur redox, Structural stability, Thermal stability, Transition metal migration

MSC2000: 

  • O641