Ultra-Stable TiNb 2 O 7 Anodes Enabled by Sb Doping and Nanostructuring for Ultrafast-Charging Lithium-Ion Batteries

Niobium titanium oxide (TiNb 2 O 7 , TNO) has emerged as a promising anode material for fast-charging lithium-ion batteries (LIBs). However, its long-term durability under extreme fast-charging conditions remains a challenge. In this study, we demonstrate that the ultrafast-charging performance of TNO can be significantly enhanced through a combination of electrospinning and Sb doping. The optimized Sb-doped TNO anode (TNO-7.5% Sb) delivers a high discharge capacity of 138 mAh·g −1 after 3,000 cycles at 10 C, with an outstanding capacity retention of 81.2%. Furthermore, in a full-cell configuration with an NCM811 cathode (NCM811//TNO-7.5% Sb), a high capacity of 116.1 mAh·g −1 is maintained after 300 cycles at 1 C, along with a Coulombic efficiency of 88.7%. The exceptional electrochemical performance is attributed to the shortened Li + diffusion distance enabled by the one-dimensional nanostructure, coupled with enhanced ionic conductivity and optimized ion transport pathways resulting from successful Sb doping. This work highlights the potential of Sb-doped TNO as a practical anode material for commercial fast-charging LIBs.