Fe-driven phase transition enables nano-sized Wadsley-Roth FeNb11O29 anode for ultrafast 2-minute charging batteries

Niobium-based oxides show great potential in anode materials for fast-charging lithium-ion batteries, but their practical application remains hindered by intrinsically low conductivity. In this study, we successfully synthesize nano-sized Wadsley-Roth FeNb₁₁O₂₉ through Fe-driven phase transformation of Nb₂O₅, which delivers a high specific capacity (280.5 mA h g⁻¹ at 0.25 C) along with abundant redox-active sites. Moreover, the Wadsley-Roth shear structure of FeNb₁₁O₂₉ facilitates rapid Li⁺ diffusion and guarantees exceptional structural stability. Theoretical calculations further confirm that FeNb₁₁O₂₉ has a narrow band gap, which significantly enhances the conductivity. Owing to these merits, FeNb₁₁O₂₉ achieves a full charge/discharge cycle within merely 25 s at 75 C rate and retains remarkable cycling stability over 2500 cycles. As a consequence, our assembled FeNb₁₁O₂₉||LiFePO₄ full cell demonstrates ultra-long cyclability (>10000 cycles) and outstanding fast-charging capability (complete cycling within 2 min at 30 C). These findings highlight nano-sized FeNb₁₁O₂₉ as a highly promising anode candidate for next-generation fast-charging LIBs.