Point-cavity-like carbon layer coated SnS nanotubes with improved energy storage capacity for lithium/sodium ion batteries

Tin monosulfide (SnS) is known as a prospective anode material for lithium/sodium ion batteries due to its high capacity, low cost, and easy preparation. Carbon coating is a powerful strategy to improve poor electronic conductivity and alleviate the large volume expansion of the SnS, thus achieving high electrochemical performances. However, the commonly used carbon coatings strategies usually generate interstices between the SnS and carbonaceous material, interrupting electron and ion transfer and unsatisfied accommodation of volume expansion. Herein, point-cavity-like carbon coated SnS nanotubes (CN/SnS) were synthesized by a close-knit mechanism using polyvinylpyrrolidone (PVP) and carbon nitride (g-C 3 N 4 ) as carbon sources. The carbonyl group in PVP can form hexahydroxylated stannyl compound with Sn 2+, and the amine group can generate C N bond with the g-C 3 N 4 template in an aqueous solution, respectively. The unique construction of CN/SnS can successfully reinforce the electron and ion transfer capability and accommodate volume expansion. The reformative effectivity dramatically improves the energy storage properties of SnS electrode for LIBs/SIBs. The CN/SnS electrode can deliver high specific capacities of 547.7 mAh g −1 at 1.0 A g −1 after 300 cycles for lithium-ion batteries and 298.2 mAh g −1 at 0.1 A g −1 after 200 cycles for sodium-ion batteries, respectively. The structure design is practical and feasible, which could be used to develop high-performance transition metal sulfide/carbon composite anodes for LIBs and SIBs.