The charge/discharge characteristics of a carbon anode were studied in a lithium ion battery system based on the effects of a graphite structure developed by heat energy. A carbon precursor (pitch) was synthesized from pyrolysis of fuel oil, after which a carbonization/graphitization treatment at 1,000-2,400 °C was carried out on the carbon anode. The lithium storage mechanism of carbonized materials treated under 1,300 °C was noted not by the space between the graphite layers but the cavity in the carbon materials. This indicates higher capacity and high speed charge-discharge performance capabilities than graphite. For graphitized materials treated at 2,400 °C, lithium ions are mainly inserted between the layers of the graphite, forming an interlayer structure. Based on the suggested mechanisms, it is noted that the charge/discharge of lithium ions can be controlled based on control of the graphite structure.