Effects of Sn doping on the structural and electrochemical properties of LiNi 0.8Co 0.2O 2 cathode materials

Abstract

LiNi 0.8Co 0.2O 2 and Sn-doped LiNi 0.8Co 0.2O 2 cathode materials are synthesized via a rheological phase reaction method. They are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), particle size analysis and electrochemical tests. The effects of Sn doping on the structural and electrochemical properties are investigated. The Sn 4+ ion occupies the Ni 3+ (or Co 3+) ion site to form Sn Ni ∙(or Sn Co ∙) defects, at the same time, part of the Ni ions are reduced to form Ni Ni′ defects to make electric charge compensation in the crystal lattice, which is beneficial for stabilizing the structure, reducing the resistance and increasing conductivity of LiNi 0.8Co 0.2O 2.