高能球磨制备硅/人造石墨复合材料

Preparing silicon /artificial graphite composite via high energy ball-milling

以硅粉（Si）和人造石墨（AG）为原料，通过高能球磨制备了锂离子电池用Si／AG复合材料。SEM、XRD和充放电测试结果表明：复合材料呈嵌入型，硅含量越多，粘连在石墨表面的硅颗粒相应增多，复合效果越差；球磨基本上未破坏硅和石墨的结构。硅含量在5％～40％时，复合材料的脱锂比容量随着硅含量的增加先增大、后降低；电流为0．2C，、电压为0．001～2．000V时，复合材料的首次脱锂比容量为528—1700mAh／g，库仑效率为70％～80％；循环10次后，复合材料循环性能基本稳定，第40次循环的可逆比容量为309—567mAh／g。

Silicon （Si）/artificial graphite （AG） composite for Li-ion battery was prepared via high energy ball-milling using silicon powder and AG as raw materials. Results of SEM, XRD and charge-discharge tests showed that composite was embedded type ,with the increasing of Si content, Si particle which conglutinated on the surface of graphite increased, the composite effect was worse ; the structure of Si and graphite was not destroyed by ball-milling. When Si content was in 5% - 40%, the specific lithium extraction capacity of composite was increased firstly and then decreased with the increasing of silicon content. When the current was 0. 2 C5 , the voltage was 0. 001 ~ 2. 000 V, the initial specific lithium extraction capacity of composite was 528 - 1 700 mAh/g and the coulombic efficiency was about 70% -80%. The cycle performance of composite was stabled after 10 cycles,its reversible specific capacity at the 40th cycle was 309 ~ 567 mAh/g.