ABSTRACT
Three-dimensional (3D) ternary Li4Ti5O12, a Li+-based battery anode, shows a large direct-gap semiconductor with Eg d ∼ 2.98eV. This system exhibits an unusual lattice symmetry (triclinic crystal), band structure, charge density, and density of states. First-principles calculations can present the atom-dominated valence and conduction bands, the spatial charge distribution, and the atom- and orbital-decomposed van Hove singularities. These properties are utilized for accuracy identifications of multi-orbital hybridizations in Li–O and Ti–O bonds. The large bonding fluctuations and the highly anisotropic configurations could create an extremely nonuniform chemical environment, which induces very complicated hopping integrals. Besides, the developed theoretical framework is available to fully understand the diversified essential properties of cathodes and electrolytes of oxide compounds.
