表面修饰的天然石墨用作锂离子电池嵌锂阳极

针对天然石墨阳极存在的首次充放电效率低这一应用问题，提出了采用聚合物表面修饰石墨的新方法．结果发现：通过在天然石墨表面修饰聚二甲基硅氧烷，加速了石墨阳极表面钝化膜的形成，降低了电极第一周充放电时的不可逆容量损失，从而提高了电极的首次充放电效率．当石墨表面的聚二甲基硅氧烷修饰量为5％时，电极在保持可逆容量基本不变的情况下，第一周充放电效率提高了13％．此外修饰石墨电极的循环性能也得到了显著改善．

Surface modified natural graphite as intercalating anode for Li-ion batteries

A new approach was proposed to modify the surface structure of natural graphite by use of polymer adsorption and thereby to improve the initial charge-discharge efficiency of natural graphite anode in Li-ion battery. The experimental result showed that the surface modification of graphite anode by polydimethylsiloxane could effectively suppress the initial irreversible reactions and accelerated the SEI film formation, and therefore greatly improved the first charge-discharge efficiency. In comparison with the bare graphite electrode, the modified graphite electrode exhibited a 13%-reduced irreversible capacity in the first charge-discharge cycle, while the reversible capacity almost remained unchanged. In addition, the surface modification also improved the cycling stability during subsequent cycles.