锂离子电池多孔硅／碳复合负极材料研究

以硅粉、镁粉和葡萄糖为原料，采用高温固相烧结工艺及水热法制备了循环性能优异的锂离子电池多孔硅／碳复合负极材料．利用X射线衍射仪（XRD）、扫描电子显微镜（SEM）对样品物相和微观形貌进行表征，研究了无定形碳包覆量对产物电化学性能的影响．无定形碳的存在，不仅对多孔硅粉的三维孔隙结构起到了支撑作用，也可有效改善复合材料的导电性能并有效缓冲电化学嵌／脱锂过程中多孔硅颗粒所产生的体积效应．电化学性能测试表明，10次循环后，多孔硅／碳复合负极材料平均每周次容量衰减为0．41%，100次循环后其可逆容量仍可维持在608．7mA·h／g．

Study of Porous Si/C Composite Anode for Lithium Ion Batteries

Excellent cyclic performance carbon-coated porous silicon （c-PS） intended for the fabrication of lithium ion battery anode were synthesized by high temperature solid-state sintering process and hydrothermal method using glucose as carbon source. The phase composition and micro-morphology of the samples were characterized by the X-ray diffractometer （XRD）; and scanning electron microscope （SEM）; and different mass ratios of Si/C were discussed. The structural stability of porous silicon are sustained; and the electrical conductivity and volume change during repeated cycles of lithium insertion/extraction of composite materials are significantly improved after modification of amorphous carbon. After 100 cycles, the c-PS maintained a reversible capacity of approximately 608.7 mA· h/g with a capacity attenuation rate of 0.41% per cycle after 10 cycles.