Ultrafine Sb Pillared Few-Layered Ti₃C₂T_x MXenes for Advanced Sodium Storage

Pillaring technology has proven to be an effective strategy to improve the electrochemical performance of MXene-based composites, especially the rate performance due to the enlarged interlayer spacing. Taking the larger radius of sodium ions into account, it is urgent to develop pillared MXene-based composites for sodium-ion batteries (SIBs). To fully deliver high rate performance of pillared MXenes and high capacity of Sb in SIBs, in this work, we exquisitely decorate ultrafine Sb particles onto flexible few-layered Ti₃C₂T_x (f-Ti₃C₂T_x) nanosheets to fabricate Sb pillared Ti₃C₂T_x (Sb/p-Ti₃C₂T_x) composites through facile electrostatic adsorption followed by the annealing process. Benefiting from the enhanced kinetics properties by highly conductive pillared f-Ti₃C₂T_x and ultrafine Sb nanoparticles, the composites exhibit a reversible charge capacity of 438.1 mAh g^–1 at 50 mA g^–1 and a high retention rate of 126.6 mAh g^–1 at 2 A g^–1. Furthermore, the strong interaction between Sb and Ti₃C₂T_x via Ti–O–Sb chemical bonding endows the composites with high structural stability, leading to good cycling sustainability. More importantly, for the first time, we succeed in integrating dual advantages of the few-layered state of MXenes and pillaring technology in MXene-based composites for SIBs. This work supplies an effective modification strategy to conquer the drawbacks of Sb anodes and achieve exploitation of pillared few-layered MXene composites in SIBs, promoting the commercial process of MXenes in SIBs.