Preparation of nano-sized hard carbon spherule and its electrochemical property

Nano-sized hard carbon spherule (HCS) is prepared from the distilled water/ethylene glycol mixed solution by hydrothermal technique. The particle size of nano-sized HCS is 50-100 nm. Comparing with micro-sized HCS, nano-sized HCS displays larger specific surface area and well-dispersed property. Owing to huge specific surface area, nano-sized HCS shows lower charge transfer impedance than that of micro-sized HCS. However, nano-sized HCS also exhibits lower initial Coulombic efficiency due to the large contact area with electrolyte. Besides, charge-discharge cycling tests demonstrate nano-sized HCS shows high capacity retention ratio (92.7%) and high reversible lithium storage performance (525 mA h g(-1)). Therefore, it is a potential anode material for lithium-ion batteries. (C) 2011 Elsevier B.V. All rights reserved.