A novel interlayer-expanded tin disulfide/reduced graphene oxide nanocomposite as anode material for high-performance sodium-ion batteries

Mo4/3B2Tx boosting the electrochemical kinetics and Na2S adsorption of SnS anode in sodium ion batteries

SnS with high theoretical capacity, large lamellar spacing, and favorable voltage plateau is considered as a highly prospective anode material for sodium-ion batteries (SIBs). Nevertheless, the unsatisfied intrinsic conductivity and damaging volume variation during cycles restricted its specific capacity and potential application. In this work, a synergistic sodium storage of interfacial engineering and Na2S adsorption was proposed to boost the electrochemical kinetics of SnS by vertically growing SnS@C nanosheets on MBenes. The experimental and theoretical calculation results verified that the nanosheets, heterogeneous interface, and charge transfer between Mo4/3B2Tx and SnS offered rapid ion diffusion pathways and ameliorated the intrinsic conductivity, promoting the electrochemical kinetics. The sufficient sulfur vacancies and strong adsorption ability of Na2S on MBenes provided supplementary active sites for ion adsorption and suppressed the shuttle effect of Na2S, improving the electrochemical capacity and reversibility. Consequently, the MBenes-SnS@C anode delivered high capacities of 411 mAh g-1 at 1 A g-1 and 420 mAh g-1 after 100 cycles at 0.5 A g-1. The synergistic sodium storage mechanism arising from interfacial effects and Na2S adsorption offered novel insights for the rational design of high-performance transition metal sulfide anodes for SIBs.