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 Na 2 S 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 Mo 4/3 B 2 T x 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 Na 2 S on MBenes provided supplementary active sites for ion adsorption and suppressed the shuttle effect of Na 2 S, 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 Na 2 S adsorption offered novel insights for the rational design of high-performance transition metal sulfide anodes for SIBs.