Synthesis and electrochemical characterization of 2D SnS2/RGO as anode material in sodium-ion batteries

Abstract

Sodium ion batteries (SIB) have wide applications in the field of energy storage due to their low cost. Currently, due to its higher theoretical discharge capacity, tin and tin-based compounds are expected to become SIB anode materials. Here, 2D SnS2 nanosheets with thickness of about 20 nm loaded on reduced graphene oxide (RGO) material (SnS2/RGO) was synthesized by a hydrothermal method, which display superior properties. When the denseness of current is 100 m A/g, the discharge capacity of the first cycle is as high as 956.1 m Ah/g, and the initial Coulombic efficiency is up to 60.0%. From the third cycle to the 200th cycles, the capacity decline rate of each cycle is about 0.13%; after 200 cycles the discharge capacity is still 443.4 m Ah/g. This outstanding performance is ascribed to the composite structure of SnS2/RGO, which helps to alleviate the stress of volume change during sodium ion insertion and extraction and enhances the conductivity of the SnS2 material.