Lithium insertion behavior of carbon nanowalls by dc plasma CVD and its heat-treatment effect

Lithium insertion behavior of carbon nanowall (CNW), which is a two-dimensional carbon nanostructures, was studied by cyclic voltammetry and charge/discharge measurements. It was found that CNW had reversible capacities of more than 200 mAh/g with stable charge/discharge potential like that of graphite even though the materials were produced at low temperature of 973 K. It was also found that CNW showed good responses of lithium insertion/extraction reaction because of their small and uniform particle size with well oriented graphene in nanometer scale. Heat treatment of CNW was found to purify the CNW from by-product amorphous carbon phase and the effect on their charge/discharge property was also clarified.