制备方法对石墨粉结构及嵌锂性能的影响

INFLUENCE OF FABRICATION ON THE PARTICLE STRUCTURES AND LITHIUM-STORED PROPERTIES OF GRAPHITE POWDER

由不同制备方法获得 3种石墨粉 ,对它们进行了结构分析和电化学嵌锂性能的研究 .通过 XRD、SEM和 BET比表面积等结构测试 ,发现以某种方式粉碎石墨化成型体可以获得石墨化度高、微晶尺寸小、颗粒内有大量微裂缝的石墨粉 .这种石墨粉具有高比容量和良好的循环性能 .组装成扣式电池以 0 .32 m A/ cm2充放电时 ,前 10次平均放电比容量可达35 5 m A· h/ g,可望用作锂离子电池负极材料 .

Three kinds of graphite powder were prepared in different ways.The structure and morphology of the graphite particle were investigated by XRD,SEM,and BET,It is found that the graphite powder obtained from a graphitized formation has a small interlayer(d 002 )distance and crystallite size,a large number of microscopic fissure structures in the particle,which is believed to be,suitable for a large lithium-stored capacity.Using LiCoO 2 as positive electrode,such a graphite powder exhibits an average specific discharge capacity of 355 mA·h/g after 10 cycles at 0.32 mA/cm 2.