Study on Materials Prepared by Coating Carbon of Resin on Graphite Used as the Negative Electrode for Lithiusm Ion Batteries

The materials were prepared by coating the phenol formaldehyde resin on the surface of the natural flake graphite (NFG) powders using liquid-phase-impregnation and pyrolysis. The charging-discharging performance of the materials used as the negative electrode for lithium ion batteries in 1M LiPF_6/EC+DEC(1:1) electrolyte solution was investigated by means of the galvanostatic charging-discharging experiments and the cyclic voltammetsry experiments. The influence of different heat treatment temperatures (HTT) on the charging-discharging behaviour of the materials was discussed. The results show that the charging-discharging characteristics of the material heat-treated under 900℃ are as follows: the third stable discharging capacity(D_3) is 213.75mA·h/g, the third cycling efficiency (η_3) is 88.69%, and the cycling life is long. It can be used as the negative electrode for the high-performance lithium ion batteries.