Interfacial Covalent Bonding Endowing Ti₃ C₂ -Sb₂ S₃ Composites High Sodium Storage Performance

Antimony sulfide is attracting enormous attention due to its remarkable theoretical capacity as anode for sodium-ion batteries (SIBs). However, it still suffers from poor structural stability and sluggish reaction kinetics. Constructing covalent chemical linkage to anchor antimony sulfide on two-dimension conductive materials is an effective strategy to conquer the challenges. Herein, Ti₃ C₂ -Sb₂ S₃ composites are successfully achieved with monodispersed Sb2S3 uniformly pinned on the surface of Ti₃ C₂ T_x MXene through covalent bonding of Ti-O-Sb and S-Ti. Ti₃ C₂ T_x MXene serves as both charge storage contributor and flexible conductive buffer to sustain the structural integrity of the electrode. Systematic analysis indicates that construction of efficient interfacial chemical linkage could bridge the physical gap between Sb2S3 nanoparticles and Ti₃ C₂ T_x MXene, thus promoting the interfacial charge transfer efficiency. Furthermore, the interfacial covalent bonding could also effectively confine Sb2S3 nanoparticles and the corresponding reduced products on the surface of Ti₃ C₂ T_x MXene. Benefited from the unique structure, Ti₃ C₂ -Sb₂ S₃ anode delivers a high reversible capacity of 475 mAh g^-1 at 0.2 A g^-1 after 300 cycles, even retaining 410 mAh g^-1 at 1.0 A g^-1 after 500 cycles. This strategy is expected to shed more light on interfacial chemical linkage towards rational design of advanced materials for SIBs.