高性能锂离子电池SiO/C/G复合负极材料研究

以一氧化硅、蔗糖及天然石墨为原料, 通过高能球磨和热解工艺制备了电化学性能优异的SiO/C/G复合负极材料。采用X射线衍射仪(XRD)和扫描电子显微镜(SEM)对复合材料的物相和形貌进行了表征。所制备的复合材料中, 纳米SiO颗粒(＜50 nm＝被无定形碳粘结并均匀分散在石墨鳞片上。电化学性能测试表明, 该复合材料100次循环后, 可逆容量高达1108.9 mAh/g, 容量保持率为103.8%。优异的电化学性能主要归因于纳米SiO颗粒在无定形碳基体中的均匀分布、无定形碳基体的缓冲作用和石墨相对复合材料导电性能的改善。

High-performance SiO/C/G Composite Anode for Lithium Ion Batteries

Silicon monoxide/carbon/graphite (SiO/C/G) composite with high capacity and excellent cycling performance has been successfully synthesized via high-energy mechanical milling and followed pyrolysis of silicon monoxide/sucrose/natural graphite mixture. The phase composition and morphology of the samples were characterized by X-ray diffractometer (XRD) and scanning electron microscope (SEM). Nano-sized (<50 nm) SiO particles were bonded by amorphous carbon and homogenously dispersed on graphite flakes in the as-prepared composite. After 100 cycles, the composite electrode kept a reversible capacity of 1108.9 mAh/g with the capacity retention of 103.8%. Uniform distribution of SiO particles in the amorphous carbon matrix, better buffering effect of carbon matrix and enhanced electrical conductivity are responsible for the superior electrochemical performance.