STUDY ON CONDUCTANCE IMPROVEMENT OF THE CATHODE MATERIALS OF LiCo0.92M0.08O2 (M=Ni, Zn) BY AB INITIO CALCULATIONS

Electronic structures of LiCo 0.92 M 0.08 O 2 ( M=Ni , Zn ) have been studied by the first principle theory based on the density-functional theory in this paper in order to understand their electronic conductivity improvement mechanism. Their DOS (density of state) and PDOS (partial density of state) have been calculated and compared with those of LiCoO 2 . The calculated results show that although the total DOS maintain unchanged, the distributions of DOS and PDOS are different from those of the undoped LiCoO 2 . DOS of [Formula: see text] of Co -3d electrons in LiCo 0.92 M 0.08 O 2 ( M=Ni , Zn ) increases while [Formula: see text] and t 2g decrease, and O atoms have more closed-shell characteristics and become more highly ionized, which induce the conductivity enhancement of LiCoO 2 after it is M -doped. A possible reason, which is the charge compensation mechanism, is adopted for explaining this improvement.