摘要
通过简单高能球磨和高温热解法制备了锂离子电池Si/C电极复合材料,聚丙烯腈(PAN)包覆的纳米颗粒(Si@PAN)与多壁碳纳米管(MWCNTs)混合,制得Si@环化PAN/MWCNTs(Si@c-PAN/MWCNTs)复合材料作为锂离子电池的负极材料。包覆在纳米Si外层的高温热解后的PAN能够有效缓冲Si在充放电过程中巨大的体积变化产生的应力,同时MWCNTs作为Si@c-PAN的基体阻止Si@c-PAN颗粒的团聚,也提高了Si@c-PAN/MWCNTs复合材料电极的导电性能。电化学测试结果表明,Si@c-PAN/MWCNTs复合材料电极在电流密度为0.2 A/g时,其首次放电比容量达到2 098 mA·h/g,库伦效率达到86%;循环50次后Si@c-PAN/MWCNTs复合材料电极的可逆比容量仍能够达到1 278 mA·h/g,在2 A/g放电时其比容量为600 mA·h/g,仍保持良好的循环稳定性。
Si/C electrode composites were prepared by simple high-energy ball milling and high-temperature pyrolysis.The polyacrylonitrile(PAN)coated nano Si particles(Si@PAN)were mixed with multi-walled carbon nanotubes(MWCNTs)to prepare Si@cyclized-PAN/MWCNTs(Si@c-PAN/MWCNTs)composites as the anode material for lithium ion battery.A thin layer of c-PAN was coated on Si nanoparticles to efficiently accommodate a large volume change of Si particles in cycles.The MWCNTs network functions as matrix for Si@c-PAN nano particles,which not only prevent the agglomeration of Si@c-PAN particles,but also improve the electrical conductivity of electrodes significantly.The electrochemical tests show that the first discharge specific capacity of the Si@cPAN/MWCNTs composite electrode is 2098 mA•h/g at the current density of 0.2 A/g and the initial coulomb efficiency is 86%.After 50 cycles,the reversible specific capacity of Si@c-PAN/MWCNTs composite electrode maintains at 1278 mA•h/g.When the current rate reaches 2 A/g,the specific capacity of Si@c-PAN/MWCNTs composite electrode keeps at 600 mA•h/g,exhibiting good cycle stability.
作者
魏成成
孙晓刚
梁国东
黄雅盼
胡浩
徐宇浩
WEI Chengcheng;SUN Xiaogang;LIANG Guodong;HUANG Yapan;HU Hao;XU Yuhao(School of Mechantronics Engineering,Nanchang University,Nanchang 330031,China;Nano Carbon Co.Ltd.,Nanchang 330031,China)
出处
《复合材料学报》
EI
CAS
CSCD
北大核心
2020年第6期1450-1457,共8页
Acta Materiae Compositae Sinica
基金
江西省科技厅资助项目(20142BBE50071)
江西省教育厅资助项目(KJLD13006)。
关键词
SI
聚丙烯腈
碳纳米管
锂离子电池
比容量
Si
polyacrylonitrile
multi-walled carbon nanotubes
lithium-ion battery
specific capacity
