Heterostructure and doping dual strategies engineering of MoSSe@VS nanosheets aggregated nano-roses for super sodium-ion batteries.

Herein, selenium (Se)-doped MoSSe@VS nanosheets aggregated nano-roses were successfully prepared from a simple hydrothermal process and the subsequent selenium doping process. The hetero-interfaces between MoSSe and VS phase can effectively promote the charge transfer. Meanwhile, the different redox potentials of MoSSe and VS 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 MoSSe@VS heterostructure exhibits excellent rate capability and long-term cycling stability with the capacity of 533.9 mAh g at 0.5 A g and a reversible capacity of 424.5 mAh g after 1000 cycles at 5 A g, demonstrating potential application as anode material for SIBs.