Enhanced Performance for Li & Na Ion Battery Anodes by Charge Modulation of Interface Through SiC4 and SiN1C3 Active Centers on Silicon Nitrogen Co-Doped Graphene

Abstract

Heteroatom doping of graphene is a powerful approach to develop high-performance Li and Na ion battery anodes. In this study, silicon-nitrogen co-doped graphene (Si−N−GN) nanostructures were successfully synthesized via a rational and scalable solvothermal process. The performances of Si−N−GN in Na⁺ and Li⁺ half-cells were investigated in detail by advanced electrochemical techniques and the obtained results were analyzed in terms of Si−N−GN surface properties, reaction kinetics, and electrode/interface interactions. Si−N−GN exhibited a superior capacity of 540 mAh g⁻¹ at a current density of 0.5 A g⁻¹ for Li⁺ and improved rate capability for both Li⁺ and Na⁺ which are linked with the increased interlayer spacing and enlarged graphene sheets upon Si-doping. Importantly, the capacity increased with the number of cycles owing to surface electron density redistribution and Si−N−GN/SEI interactions, supported by DFT.