4f-orbital-induced electron delocalization of TiNb₂O₇ enables low temperature fast-charging Ah-level pouch cell

TiNb₂O₇ holds high safety in fast-charging lithium-ion batteries, but suffers from the sluggish electron/ion kinetics and high desolvation energy barrier, especially at low-temperature conditions. Herein, a lanthanide-regulated TiNb₂O₇ is constructed by optimizing local electronic delocalization to enhance low-temperature dynamics and Li-storage performance. In-depth DFT analysis reveals that the charge modulation of f -orbital can promote electron transfer from Li-EC to the O atoms, allowing for Li⁺ with a pronounced adsorption tendency to improve desolvation ability. In addition, the delocalization engineering shortens the band gap and decreases the migration barrier, which in turn increases electron diffusion ability, suppresses charge relaxation effects, and boosts low-temperature Li⁺ transport behavior. In view of this, La_0.01-TNO-based cells deliver enhanced specific capacity and stable low-temperature cycle life with 95.24% retention rate after 650 cycles at 3C and −30 °C. Surprisingly, a 6 Ah-level La_0.01-TNO||NCM pouch cell still achieves impressive cyclic stability with slight capacity degradation for 2000 cycles and excellent rate performance of 4.59 Ah at 5C and −30 °C, holding great promise for fast-charging and low-temperature applications. Such work opens new avenues for manipulating local electronic structure to achieve fast-charging applications at low-temperature environments.