Sodium ions storage performance of PSS-rGO composites

Abstract

The functionalized graphene, with prominent capability over expansion of interlayer spacing and enhancement of sodium ion diffusivity, has gained paramount interests in fabricating anode of sodium ion batteries(SIBs). Here, a poly(sodium 4-vinylbenzenesulfonate)graphene composite(PSS-rGO) was synthesized via an in situ insertion process. The insertion structure is based on the π-π interaction between the electron of graphene and the electron of PSS, which expands the interlayer spacing of rGO and, more importantly, stabilizes the structure of the composites, restrains the stack of graphene. Beyond that, the introduced sodium sulfonate groups are capable of increasing the diffusion rate of sodium ions for fast sodium ion adsorption, ensuring superior cycling performance. The performances of the simples were characterized by scanning electron microscopy(SEM), transmission electron microscopy(TEM), X-ray diffraction(XRD), Raman spectrometer(Raman), X-ray photoelectron spectrometer(XPS), electrochemical workstation and battery detection system. The results show the PSS-rGO remains a reversible capacity of 256 mAh·g-1 at 5 A·g-1 after 6000 cycles, with an ultralow decay rate of 0.003%. This work provides a feasible avenue for exploring advanced organic-inorganic hybrid materials with high capacity, fast sodium storage and ultralong lifespan for SIBs.

Keywords

• sodium ions battery
• anode material
• graphene
• sodium sulfonate group
• in situ interaction