Towards high performance lithium storage anodes: Design strategy for carbon coated SnS–SnO2/rGO nanocomposites

Abstract

The new anode materials for lithium-ion batteries (LIBs), nanocomposites of carbon-coated SnS and SnO₂ riveted on rGO sheets (denoted as C@(SnS–SnO₂/rGO)), were constructed by effective, facile, and low-cost techniques. Benefiting from the dual-carbon modification (rGO and carbon coating layer), the C@(SnS–SnO₂/rGO) nanocomposites exhibited significantly improved rate capability and cycle stability as compared to uncoated SnS–SnO₂/rGO materials. At a current density of 100 mA g⁻¹ after 300 cycles, especially, the C@(60SnS–SnO₂/rGO) nanocomposite delivered a higher reversible capacity of ∼637 mAh g⁻¹ as compared to the uncoated 60SnS–SnO₂/rGO composite (∼359 mAh g⁻¹). Even at a high current density of 1000 mA g⁻¹, the C@(60SnS–SnO₂/rGO) nanocomposite anode still provided a high reversible capacity of ∼574 mAh g⁻¹ after 300 cycles and the capacity continuously increased to ∼674 mAh g⁻¹ after 500 cycles. The outstanding electrochemical performances of the new nanocomposites made them good candidates for use as high-performance anode materials. Moreover, the present research provides insights for the structural design of Sn compound-based composite electrodes which will be important for the future development of high-performance LIB anode materials.