Hard Carbon Derived from Coal Tar Pitch for Use as the Anode Material in Lithium Ion Batteries

A hard carbon (HC) material was prepared from isotropic coal tar pitch (CTP) by a simple oxidation-carbonization two-step method. Structural analysis showed that the CTP-HC material was a kind of microporous carbon, which was poorly crystallized and contains some graphite-like micro-crystallites. The CTP-HC was investigated as the anode material for lithium ion battery and the reversible capacity of CTP-HC was 576 mAh g−1 with a corresponding coulombic efficiency of 69.5%. After 30 cycles, the reversible capacity of 350.8 mAh g−1 was still achieved. Moreover, the CTP-HC delivered a high reversible capacity of 145 mAh g−1 at a charging rate of 5C (1860 mAh g−1), which is much better than that (36 mAh g−1) of commercial graphitized mesocarbon microbeads (g-MCMB). The excellent electrochemical performance is attributed to the high porosity and the graphite-like micro-crystallites