石墨粉的嵌锂性能及颗粒结构研究

研究了若干种通过不同制备方法获得的石墨粉的电化学嵌锂性能 ,得到一种高比容量的锂离子蓄电池负极材料 ,组装成扣式电池以 0 .32mA·cm-2 充放电时 ,前 10次平均放电比容量可达 35 5mAh·g-1。对各种石墨粉做了XRD、SEM和BET比表面积等结构测试 ,讨论了石墨颗粒的结构与其嵌锂性能的关系 ,认为石墨化度高、微晶尺寸小、颗粒内有大量微裂缝且粒径分布合理的石墨粉具有更高的可逆嵌锂容量。

Study on the lithium-stored properties and particle structures of graphite powder

Graphite powder obtained from a graphite stick in different ways had larger lithium-stored capacity than original graphite powder for making the graphite electrode. Using LiCoO2 as positive electrode, the best graphite powder exhibits average discharge capacity of 355 mAh· g- 1 after 10 cycles at 0.32 mA· cm 2. The structure and morphology of graphite particles were also investigated by XRD, SEM, and BET. The results show that graphite powder with smaller interlayer (d002) distance and crystallite size, a large amount of micro-scopic fissure structure in the particle and appropriate particle size, are favorable for large lithium-stored capaci-ty.