N-doped carbon-coated Tin sulfide/graphene nanocomposite for enhanced lithium storage

Abstract Tin sulfides have attracted significant interests as the anode materials of lithium-ion batteries (LIBs) due to their high capacity and layered structure. However, metal sulfides suffer from a fast capacity decay caused by the large volume change during cycling, and poor conductivity. In this work, we report on a rational design of lamellar nanostructure consisting of N-doped carbon layers, graphene nanosheets, and SnS nanoparticles. The SnS/graphene nanosheets with and without N-carbon coating have been investigated as the anode for LIBs to study the structure effect. It is found that N-carbon/SnS/graphene nanosheets deliver a high reversible capacity of 840 mA h g−1 after 150 cycles at a current density of 100 mA g−1 and higher rate properties in comparison to SnS/graphene. The improved electrochemical performances are attributed to the special lamellar structure with a combined synergic effect derived from the N-carbon coating layers and graphene nanosheets, which conduce to a faster lithium diffusion dynamics in the composite nanosheets, which has been analyzed by electrochemical impedance spectroscopy. This work propose an efficient pathway to manipulate metal sulfides based nanomaterials for use as anodes in LIBs with enhanced lithium storage performances.