Investigating the Structural and Electronic Properties of LiMO2 (M: Mn, Ni, Co) as Potential Cathode Materials: A DFT Study

Abstract The layered transition metal oxides formulated LiMO 2 (M: Mn, Ni and Co) are a state-of-art cathode material for lithium-ion batteries. They have attracted considerable attention due to their capability to optimize the capacity, cyclic rate, electrochemical stability, and lifetime. This paper reports the DFT+U calculations performed on LiMnO 2 , LiNiO 2 and LiCoO 2 materials. The heats of formations predict that the LiNiO 2 is the most thermodynamically stable material while the LiMnO 2 is the least thermodynamically stable material. The energy bandgap for LiNiO 2 is relatively small suggesting that the material is high in conductivity. Conversely, the energy bandgaps of LiMnO 2 and LiCoO 2 are relatively wide suggesting that the materials are low in electrical conductivity. All independent elastic constants are positive and satisfying the mechanical stability criterion. Lastly, the phonon dispersion curves display imaginary vibration along high symmetry direction for LiCoO 2 . However, the material is inferred stable with support from the elastic constants. The LiNiO 2 is the most stable material and LiCoO 2 is the least stable material.