Performance of Coal-derived Spherical Porous Carbon as Anode Materials for Lithium Ion Batteries

Abstract

Spherical porous carbon nanomaterials is a promising candidate as anode materials for next-generation LIBs due to its large specific surface area which decreases the lithium ion transport distance. Spherical porous carbon nanomaterials with uniform morphology were prepared by arc-discharging followed by chemical activation using coal as precursor. The as-prepared spherical porous carbon samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), Raman spectrope (Raman), the nitrogen adsorption-desorption, galvanostatic charge and discharge method and so on. The result indicated that the spherical porous carbon materials have high specific capacity of 1188.9 mAh/g, which exceeds the commercial mesophase carbon spheres (372 mAh/g). Moreover, the spherical porous carbon nanomaterials also afford excellent cyclic stability and a reversible capacity of 844.9 mAh/g remains ever after 200 charge/discharge cycles at current density of 100 mA/g. The excellent electrochemical performance of coal based spherical porous carbon may be originated from the graded pore structure, which can provide more storage space for lithium ion, thus improving the capacity and cycle stability of the electrode.