树脂炭包覆石墨作为锂离子电池负电极的研究

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

以液相浸渍法在天然鳞片石墨（ＮＦＧ）表面包覆酚醛树脂后进行热处理，制备了酚醛树脂炭包覆石墨材料．将这种材料作为锂离子电池的负极材料，运用恒电流充、放电法，粉末微电极循环伏安法考察了其在１Ｍ ＬｉＰＦ_６／ＥＣ＋ＤＥＣ（１：１）电解液中的充、放电性能，并分析了工艺条件中不同热处理温度（ＨＴＴ）对其充、放电性能的影响．实验结果表明，经ＨＴＴ＝９００℃热处理的酚醛树脂炭包覆石墨材料的第三次稳定放电容量（Ｄ_３）为 ２１３．７５ｍＡｈ／ｇ，第三次充、放电效率（η_３）为８８．６９％；并且循环寿命较长，可作为高性能锂离子电池的负极材料．

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.