Tailoring Nitrogen Terminals on MXene Enables Fast Charging and Stable Cycling Na-Ion Batteries at Low Temperature

Sodium-ion batteries stand a chance of enabling fast charging ability and long lifespan while operating at low temperature (low-T). However, sluggish kinetics and aggravated dendrites present two major challenges for anodes to achieve the goal at low-T. Herein, we propose an interlayer confined strategy for tailoring nitrogen terminals on Ti(3)C(2) MXene (Ti(3)C(2)-N(funct)) to address these issues. The introduction of nitrogen terminals endows Ti(3)C(2)-N(funct) with large interlayer space and charge redistribution, improved conductivity and sufficient adsorption sites for Na(+), which improves the possibility of Ti(3)C(2) for accommodating more Na atoms, further enhancing the Na(+) storage capability of Ti(3)C(2). As revealed, Ti(3)C(2)-N(funct) not only possesses a lower Na-ion diffusion energy barrier and charge transfer activation energy, but also exhibits Na(+)-solvent co-intercalation behavior to circumvent a high de-solvation energy barrier at low-T. Besides, the solid electrolyte interface dominated by inorganic compounds is more beneficial for the Na(+) transfer at the electrode/electrolyte interface. Compared with of the unmodified sample, Ti(3)C(2)-N(funct) exhibits a twofold capacity (201 mAh g(−1)), fast-charging ability (18 min at 80% capacity retention), and great superiority in cycle life (80.9%@5000 cycles) at − 25 °C. When coupling with Na(3)V(2)(PO(4))(2)F(3) cathode, the Ti(3)C(2)-N(funct)//NVPF exhibits high energy density and cycle stability at − 25 °C. [Image: see text] SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s40820-022-00885-7.