School of Material Science and Chemical Engineering,Tianjin Polytechnic University,Tianjin 300160,China; 2.Key Laboratory for green Chemical Technology of State Education Ministry,School of Chemical Engineering & Technology,Tianjin University,Tianjin 300072,China
Anode materials for Li-ion secondary batteries were prepared by treating mesocarbon microbeads (MCMBs) in presence of CoCl2 at a temperature below 1000℃. They were characterized by Raman spectroscopy and X-ray diffraction. Results indicated that the heat treated samples belonged to low temperature carbons, but micro-crystals on the surface of the treated MCMBs became ordered. The reversible discharge capacity of the MCMBs was significantly improved, the coulombic efficiency was increased from 52.2% to 86.7%, and the cycling performance became better. These improvements were ascribed to the ordered structure on the surface of the treated samples that tended to prevent the electrolyte molecules from penetrating into the inside of the MCMBs, and as a result, reduced the irreversible electrochemical reactions.