Production of Sulphur-Doped Graphene Oxide as an Anode Material for Na-Ion Batteries

Sodium-ion batteries have been the focus of interest in recent years due to abundance and cost-effectiveness of sodium resources globally as opposed to lithium. In this work, sulfur-doped graphene oxide (SGO) was synthesized using a straightforward, one-step, cost-effective, and eco-friendly chronoamperometric method at room temperature. The resulting powder was then utilized as active anode material for Na-ion batteries. The surface of the synthesized SGO powder, which consists of approximately three layers with 19 sp2 hybridized carbon rings and a domain size of about 50 nm, is covalently doped with –C-SOx-C- (x = 2,3) groups. The deduced diffusion coefficient from electrochemical impedance spectroscopy and galvanostatic intermittent titration technique measurements for SGO as anode in NIBs is in the range of 10−11–10−12 cm2.s−1. At 0.1 C rate, the initial discharge capacity recorded 256.7 mAh.g−1 at 0.1 C rate. In addition, the capacity retention for long-term cycling of 100 cycles at 2 C rate was 99.85%. The unique structure of SGO allows us to achieve satisfactory anode performance in capacity and rate capability, with potential for further enhancement. Highlights SGO was used as anode for sodium ion batteries for the first time. At 0.1C-rate the initial discharge capacity of the battery was recorded 256.7 mAh.g−1. At the end of 100 cycle, capacity retention of the battery was 99.85%.at 2 C.