MILD-EXFOLIATED GRAPHITE AS AN ANODE MATERIAL FOR LITHIUM ION BATTERY

摘要

Mild-exfoliated graphite (MEG) with a pyrolysis carbon coating has been prepared by low temperature heating treatment of H_2SO_4-Graphite Intercalation Compounds, which was synthesized by a chemical oxidation process under H_2O_2 addition, and then was coated with carbon film. The volume expansion of MEG was limited to less than 50% by controlling the heating temperature and the duration. XRD results showed that the grain size of MEGs decreases with the increase of treating temperature. The sample treated at 360℃ for 24 h with carbon coating could accommodate up to 378 mAh/g capacity and keep 100% capacity after 100 cycles. The cyclic voltammetry measurement indicated that the differences among the capacities of MEGs treated at different conditions were corresponding to the relative strength of the peak at 0.05 V. The porous structure analysis by BET method showed that the increase of micro-pores could make a great contribution to the enhancement of both the cycle stability and the reversible capacity.