First-principle Study on Sr-doped LiNi0.5Mn1.5O4

Applying supersoft pseudopotential plane wave method of the first principle based on functional theory to investigate the band and density of states of LiNi0.5Mn1.5O4 and Sr2+ doped LiNi0.5Mn1.5O4.Theoretical caculations demonstrated that LiNi0.5Mn1.5O4 is a conductor material as well as the site of Mn doping Sr2+ will increase the bands number of LiNi0.5Mn1.5O4.Furthermore,after LiNi0.5Mn1.5O4 doping Sr2+,it will help to shorthen bond length between Mn-O and Ni-O bond, making the crystal structure more stable. The distance of Li-O bond is elongated, which will benefit the diffustion in the 3D channel thereby increasing the electronic conductivity and the rate performance of LiNi0.5Mn1.5O4.According to electronic density analysis, the hybridization of Mn 3d and O 2p states is more obvious, which indicating that the covalent bond formed by the two atoms is stronger and the crystal structure is not easily collapsed, thereby improving the cycle stability of the material.