Could λ-Ti3O5 with lamellar and channel microstructure characteristics determine the excellent properties of LIBs? The first-principles study of λ-Ti3O5 lithiation mechanism

While people are searching for potential electrode materials for Li-ion batteries (LIBs), it is controversial whether the microstructure is a critical factor of electrochemistry property. λ-Ti3O5 is an example due to its lamellar and channel microstructure characteristics to discuss whether the microstructure characteristic is the critical factor of properties of LIBs. The intercalation/de-intercalation mechanisms and diffusion behavior of Li-ion in λ-Ti3O5 are studied by DFT. The binding energies with the different number of Li-ions are from − 3.1 to − 2.2 eV, and the volume changes are from 0.1% to 1.3%, indicating λ-Ti3O5 is stable during lithiation. The supercell and (001) slab of λ-Ti3O5 is constructed to investigate the diffusion behaviors of Li-ion in bulk and Li-ion escaping from the system, respectively. The former energy barriers are about 1.0 eV, and the latter energy barriers are above 2.0 eV, suggesting it is difficult for Li-ion to diffuse in or escape from the system. It presumably can be inferred that the microstructure is not the critical factor of diffusion property for electrode materials. More studies are needed to optimize the performance of λ-Ti3O5 as an electrode material, such as interionic distance and strength of bonding.