Structural and electrochemical characterization of carbonaceous mesophase spherule anode material for rechargeable lithium batteries

Abstract

Structural and electrochemical characterization of carbonaceous mesophase spherule (CMS) anode material for rechargeable lithium batteries are reported. The particles of CMS material have a spherical shape with a size range 6–20 μm . According to X-ray diffraction (XRD) studies, a typical ordered crystal structure of hexagonal graphite was observed, and two diffraction peaks, d 001 and d 002, formed after charge. The charge and discharge capacities for the CMS anode were 320 and 282 mAh g −1 , respectively, in the first cycle, and the coulomb efficiency of the CMS anode is 88%. The efficiency is close to 100% after the second cycle. CMS material shows good cycling performance as an anode material for rechargeable lithium batteries. The mechanism of the electrochemical intercalation of lithium ion in CMS anode was studied by cyclic voltammetry (CV) experiments. Four insertion steps were observed in the CMS anode for the electrochemical intercalation of lithium ions. These insertion steps correspond to the stage formation during the insertion of lithium ions into the graphite anode for rechargeable lithium batteries.