Effect of vacuum-carbonization treatment of soft carbon anodes derived from coal-based mesophase pitch for lithium-ion batteries

Development of new power anode material with both high capacity and high-rate capability for lithium-ion batteries is highly desired.In this paper,a novel soft carbon anode for rechargeable lithium-ion batteries was developed using coal-based mesophase pitch.The structures of the materials were characterized by X-ray diffraction(XRD),Raman,N2 adsorption-desorption,Scanning Electron Microscopy(SEM)and X-ray photoelectron spectroscopy(XPS).The electrochemical characteristics of the new anode material were investigated.It was found that the soft carbon anode from coal-based mesophase pitch carbonized under vacuum conditions can deliver higher energy density and higher rate capability compared to soft carbon carbonized under a nitrogen atmosphere.The enhanced electrochemical properties are attributed to smaller nanocrystallites,more porosity,defects and carbon species of the resulting anode material.