Nitrogen-doped carbon and reduced graphene oxide co-decorated SnS2 nanoplates for high efficiency lithium/sodium ion storage

Laminated metal sulfide is a unique material with a graphite-like structure and good storage capacity for both lithium and sodium ions. However, the inherent low electrical conductivity and severe volume expansion of SnS 2 lead to poor electrochemical properties, further limiting practical applications. In this work, a nitrogen-doped carbon (NC) and reduced graphene oxide (rGO) co-decorated SnS 2 nanoplatelets (SnS 2 /NC-rGO) using dopamine (PDA) and graphene oxide (GO) as carbon sources are cleverly designed. SnS 2 /NC wrapped with rGO is synthesized via hydrothermal followed by calcination. This design not only increases the electrical conductivity of the composite but also provides more pathways for ions/electrons. Furthermore, the larger specific surface area of the composite allows better contact between the electrolyte and the electrode, which further enhances the redox dynamics of lithium ions/sodium ions. Thanks to this structure, the charge/discharge specific capacity of the SnS 2 /NC-rGO composite electrode is 1215.8/1220.7 mAh g −1 after 200 cycles at 0.1 A g −1 . The superior sodium storage performance has also been demonstrated in sodium-ion batteries, where a high specific capacity of 501.6 mAh g −1 can be achieved after 80 cycles at a current density of 0.1 A g −1 .