Microplasma-assisted bottom-up synthesis of graphene nanosheets with superior sodium-ion storage performance

Abstract

A microplasma-assisted chemical vapor deposition technique is used to produce graphene nanosheets (denoted as MPGNSs). This bottom-up synthesis is a one-step, facile, green, and continuous process. The obtained MPGNSs have higher crystallinity, less defects, and higher tap density compared to those of conventional reduced graphene oxides (RGOs). Galvanostatic intermittent titration and cyclic voltammetry techniques are used to explore the effects of the aforementioned material properties on the electrochemical Na⁺ storage behavior. MPGNSs are able to deliver a high capacity of 250 mA h g⁻¹ (@0.03 A g⁻¹) and show excellent rate capability (110 mA h g⁻¹@5 A g⁻¹), with both values being clearly superior to those of the RGOs synthesized via a top-down graphite exfoliation method. A highly promising anode material for sodium-ion batteries is thus proposed in this work.