Engineering TiO₂ anodes with Fe, Co, and Mn dopants for next-generation lithium storage applications

Titanium dioxide, or TiO₂, has garnered considerable attention as an anode material in lithium-ion batteries. Its inherent structural robustness, widespread availability, and inherent safety profile make it a promising candidate. Yet, its real-world utility is often hampered by relatively sluggish lithium diffusion kinetics and restricted electronic conductivity. Here, we delve into the impact of transition-metal doping, specifically iron (Fe), cobalt (Co), and manganese (Mn), on the lithium storage capabilities of anatase TiO₂. We leverage first-principles density functional theory (DFT) to investigate. A systematic analysis is conducted to examine the lithium adsorption characteristics, diffusion routes, charge redistribution phenomena, and electronic structure modifications that result from doping. Notably, our findings indicate that each of the doped configurations exhibits enhanced Li binding energies, reduced diffusion barriers, and narrower band gaps compared to unmodified TiO₂. Notably, Mn-doped TiO₂ exhibits the most favourable diffusion energy barrier (0.38 eV), a significant theoretical capacity (388 mAh/g), and substantial charge delocalisation. Furthermore, charge density difference (CDD) mappings corroborate the amplified charge transfer dynamics occurring between Li and the host lattice in the doped frameworks, particularly accentuated in the presence of Mn. These results suggest that the rational introduction of transition-metal dopants may represent a viable avenue for optimising TiO₂-based anodes geared toward advanced lithium-ion battery technologies.