| 초록 |
To synthesis nitrogen-doped graphene, urea is one of the effective materials as nitrogen source. In this study, we use urea-based nitrogen-doped graphene nanosheets (NGS) as anode material for lithium sulfur cells. Nitrogen doped graphene was synthesized by facile solid-states thermal reaction of graphene oxide and urea. For comparison, thermally reduction of graphene oxide without nitrogen source was carried out. The prepared NGS was then added into sulfur suspension to embed elemental sulfur between graphene sheets. The morphology of the composite was examined by scanning electron microscopy (SEM), transition electron microscopy (TEM). Functional groups and bonding characterization were scanned by X-ray photoelectron spectroscopy (XPS). Electrochemical properties were also characterized by cyclic voltammetry (CV) in 1M LiTFSI electrolyte. Nitrogen atoms of graphene could be attributed to high capacity and stability of lithium-sulfur battery. |
