Heterostructure and doping dual strategies engineering of MoS_1.5Se_0.5@VS₂ nanosheets aggregated nano-roses for super sodium-ion batteries

Herein, selenium (Se)-doped MoS1.5Se0.5@VS2 nanosheets aggregated nano-roses were successfully prepared from a simple hydrothermal process and the subsequent selenium doping process. The hetero-interfaces between MoS1.5Se0.5 and VS2 phase can effectively promote the charge transfer. Meanwhile, the different redox potentials of MoS1.5Se0.5 and VS2 alleviate volume expansion during the repeated sodiation/desodiation processes, which improves the electrochemical reaction kinetics and structural stability of electrode material. Besides, Se doping can induce charge reconstruction and improve the conductivity of electrode materials, resulting in improved diffusion reaction kinetics by expanding interlayer spacing and exposing more active sites. When used as anode material for sodium ion batteries (SIBs), the MoS1.5Se0.5@VS2 heterostructure exhibits excellent rate capability and long-term cycling stability with the capacity of 533.9 mAh g(-1) at 0.5 A g(-1) and a reversible capacity of 424.5 mAh g(-1) after 1000 cycles at 5 A g(-1), demonstrating potential application as anode material for SIBs.