SnS nanoparticles anchored on nitrogen-doped carbon sheets derived from metal-organic-framework precursors as anodes with enhanced electrochemical sodium ions storage

Abstract Tin monosulfide (SnS) has emerged as a promissing host material toward sodium-storage for its low cost and high capacity. Nevertheless, unavoidable capacity fading as well as poor rate capability have severely hindered the extended practical application of SnS. Carbon coating is an effective strategy to address these issues. In this paper, a SnS coupled with nitrogen-doped carbon hybrid (SnS/NCS) has been fabricated through an easy template method with a 2D tin-based metal organic framework (Sn-MOF) as precursor. By an annealing and sulfuration treatment, ultrasmall SnS nanoparticles are well in-situ formed and embedded onto MOF-derived nitrogen-doped carbon sheets. Conductive carbon components can provide electron expressway and robust mechanical support. Furthermore, the confining effect of carbon matrix on SnS nanoparticles effectively alleviates the volume expansion. Having profited from the desirable nanostructures, SnS/NCS anode achieves an extremely improved electrochemical property for sodium-storage. At the end of 150 cycles under a current density of 100 mA g−1, SnS/NCS remains a high capacity of ~522 mAh g−1. Besides, even at a large current density of 1000 mA g−1, SnS/NCS still keeps a capacity of ~321 mAh g−1 after finishing 200 cycles of test and achieves an enhanced rate capability.