First-principles study on the Li storage performance of silicon clusters and graphene composite structure

TL;DR

This study uses first-principles calculations to analyze Li storage and stability in silicon-graphene hybrid structures, revealing optimal configurations and enhanced stability for potential battery anode applications.

Contribution

It provides new insights into the stability and Li storage capacity of silicon-graphene composites, highlighting the importance of specific lattice planes and interface interactions.

Findings

Strong Si-C bonds form between silicon clusters and graphene.

The (111) silicon plane with graphene shows the best stability.

Li absorption is more favorable near silicon clusters close to graphene.

Abstract

This paper focuses on the performance of the storage of Li and the stability of the hybrid structure of different lattice planes of the silicon clusters and graphene by the first-principle theory. In this paper, we calculate the binding energy, adsorption energy and PDOS of the hybrid structure of the different height and size of the silicon clusters and graphene. We figure out that there can form strong Si-C bonds between the silicon cluster and graphene. Especially, the hybrid structure of the silicon clusters with plane (111) and graphene performs best with the highest formation energy and the outstanding stability. According to the calculation of Li absorption energy, we conclude that the location of the silicon cluster near the graphene has higher possibility and higher absorption energy of the Li storage, with the reason that the charge transfer between the lithium and the carbon and the silicon. Because of the graphene used, the deformation of the interface of the silicon clusters can be obviously reduced during the absorption of Li, which brings about a good future for the hybrid structure using for the battery anode materials.