LAUSR

We have presented the results of detailed studies of oxygen vacancy and niobium (Nb) substituted spinel Li4Ti5O12 (LTO) materials using first-principles method within the framework of the density functional theory (DFT). We have shown that the ground state of oxygen vacancy and Nb substituted LTO is paramagnetic (PM), and the Nb substitution is most stable on the 16d sites of both the Li and Ti ions. We have indicated that the Nb substitution in the 16d site of Li ion become the n-type metallic material. But the oxygen vacancy containing NbT i substituted LTO is changed from the p-type to the n-type, as increased a concentration of Nb ions.