Fabrication of a reversible SnS2/RGO nanocomposite for high performance lithium storage

Abstract

SnS₂/graphene (SnS₂/G) composites have been explored extensively as a promising candidate for Lithium Ion Battery (LIB) anodes in recent years. Previously, the SnS₂ conversion/reduction step of the reaction mechanism is generally believed to be irreversible or only partially reversible, which severely underestimates the theoretical capacity of SnS₂. In this work, SnS₂ nanoparticles have been successfully stacked on reduced graphene oxide (RGO) via a facile and effective solvothermal method using ethylene glycol as a chelant. The SnS₂/graphene nanocomposite retained many of the original 2D characteristics of the graphene nanosheets. As a result, Li⁺ storage properties were significantly improved. The SnS₂/RGO nanocomposites show a higher storage capacity of 939.0 mA h g⁻¹ after 30 cycles at a current density of 0.1 A g⁻¹, and a long-term cycle capacity of 615.5 mA h g⁻¹ even after 200 cycles at 1 A g⁻¹. The superior cycling stability of the SnS₂/RGO electrode is attributed to greater reversibility in the initial conversion reaction, ascribed to the presence of the Sn nanoparticles.