Heteroatom-Doped Carbon Spheres from FCC Slurry Oil as Anode Material for Lithium-Ion Battery

A facile injected pyrolysis strategy to synthesize heteroatom-doped carbon spheres (CSs) with good conductivity is proposed by using the fluid catalytic cracking slurry oil (FCCSO) as the carbon source through a pyrolysis reaction process at 700-1000 degrees C. The structures of CSs are characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The effect of preparation conditions on the morphology and its electrochemical properties of CSs acting as the anode material for lithium-ion battery (LIBs) are investigated. The XPS measurement results show that the CSs mainly contain C, N, O, and S elements. With the increase of pyrolysis temperature, the particle size of CSs decreases but the graphitization degree of CSs increases. As the anode material for LIBs, CSs show excellent electrochemical performance with a maximum reversible capacity of 365 mAh/g and an initial coulombic efficiency of 73.8% at a low current density of 50 mA/g. The CSs exhibit excellent cycling stability in a current range of 50 mA/g to 2 A/g, and still can maintain a stable reversible capacity of 347 mAh/g when the current is cycled back to 50 mA/g. This is mainly ascribed to the existence of suitable heteroatom content and unique spherical structure of CSs. The heteroatom-doped CSs can provide a new choice for the preparation of high efficiency anode materials for LIBs.