Two-dimensional hybrid composites of SnS2 with graphene and graphene oxide for improving sodium storage: A first-principles study

TL;DR

This study uses first-principles calculations to show that 2D hybrid composites of SnS2 with graphene or graphene oxide can enhance sodium-ion battery anodes by improving stability, sodium intercalation, and electronic conductance.

Contribution

It introduces a novel first-principles analysis of SnS2 hybrid composites with graphene and GO for sodium storage applications.

Findings

Graphene and GO support stable hetero-interfaces with SnS2.

Sodium intercalation occurs with low migration energy.

Electronic conductance is improved due to charge transfer.

Abstract

Among the recent achievements of sodium-ion battery (SIB) electrode materials, hybridization of two-dimentional (2D) materials is one of the most interesting appointments. In this work, we propose to use the 2D hybrid composites of SnS2 with graphene or graphene oxide (GO) layers as SIB anode, based on the first-principles calculations of their atomic structures, sodium intercalation energetics and electronic properties. The calculations reveal that graphene or GO film can effectively support not only the stable formation of hetero-interface with the SnS2 layer but also the easy intercalation of sodium atom with low migration energy and acceptable low volume change. The electronic charge density differences and the local density of state indicate that the electrons are transferred from the graphene or GO layer to the SnS2 layer, facilitating the formation of hetero-interface and improving the electronic conductance of the semiconducting SnS2 layer. These 2D hybrid composites of SnS2/G or GO are concluded to be more promising candidates for SIB anodes compared with the individual monolayers.