Unlocking minute-scale charging in lithium-ion batteries via defect-engineered niobium-based oxides

Shear-structured niobium-based oxides are promising candidates for high-power and fast-charging lithium-ion batteries owing to their outstanding rate capabilities and structural reversibility. However, their industrial deployment remains challenging because of their relatively limited capacity and energy density, which arise primarily from poor electronic conductivity, sluggish Li⁺diffusion in the bulk, and incomplete utilization of active sites. Here we present a high-capacity anode based on micron-sized Nb₁₄W₃O_44-δ particles synthesized via a modified solid-state reaction followed by surface-oxygen-vacancy engineering. This modification significantly enhances both electronic and ionic conductivities by generating additional charge carriers, activating surface redox sites, and enabling barrier-free ion diffusion—collectively driving pseudocapacitive Li⁺storage without sacrificing structural stability. The resulting Nb₁₄W₃O_44-δ anode delivers an impressive initial capacity of 303 mAh g⁻¹, a Coulombic Efficiency exceeding 93%, and an extremely small volume change (∼0.2%). It also demonstrates remarkable capacity retention, maintaining 90% of its initial capacity after 7500 cycles at 75 C (1 C = 200 mAh g⁻¹). The LiFePO₄‖Nb₁₄W₃O_44-δ full-cell achieves an energy density of 160 Wh kg⁻¹and supports minute-scale charging for more than 2000 cycles at 10 C. Overall, this study demonstrates that surface-oxygen-vacancy engineering is a powerful strategy for enhancing the performance of shear-structured niobium-based oxide such as Ti₂Nb₁₀O₂₉, offering a pathway toward practical, high-power lithium-ion batteries.