Superior electrochemical performance of ultrasmall SnS2nanocrystals decorated on flexible RGO in lithium-ion batteries

Abstract

A hybrid structure involving efficient plentiful ultrasmall SnS₂ nanocrystals decorated on flexible reduced graphene oxide (RGO) has been successfully realized via a simple refluxing method. Compared to previous studies, the ultrasmall SnS₂ nanocrystals can compactly and orderly cover the RGO nanosheets, increasing the loading number of SnS₂ per unit area of the RGO substrates. The ultrasmall SnS₂ nanocrystals@RGO nanocomposites were investigated as electrode materials for lithium-ion batteries. In this hybrid structure, RGO was not only used as a solid support to uniformly distribute the SnS₂ nanocrystals, but also as a carrier to accelerate electron transport. In addition, the uniform size and homogeneous SnS₂ nanocrystals on the RGO nanosheets reduced electrode polarization, resulting in excellent electrochemical performance for lithium-ion batteries. A specific capacity up to 1034 mA h g⁻¹ was realized from an ultrasmall SnS₂ nanocrystals@RGO electrode even after 200 cycles at 0.1 C. Importantly, the ultrasmall SnS₂ nanocrystals@RGO electrode showed excellent capacity retention for up to 450 cycles even at a high rate of 5 C. The cost-effective synthesis of SnS₂ nanocrystals@RGO and excellent electrochemical performance indicates the great potential for this type of nanocomposites as an active electrode for lithium-ion batteries.