摘要
通过高温固相法在硬炭表面包覆沥青热解炭,制备锂离子电池负极材料。SEM测试显示,硬炭包覆上沥青热解炭后表面形貌发生了明显变化。由例得到,硬炭表面包覆的沥青热解炭的平均厚度为300nm。当硬炭表面包覆上沥青热解炭后(硬炭与沥青的质量比为2:1),首次库仑效率由55%提高到70%,可逆容量也有所提高。研究发现,硬炭在高倍率下的容量和循环稳定性比石墨好。
A composite material was prepared through hard carbon coated by pitch-pyrolyzed carbon.And its performance was investigated as an anode material of lithium ion batteries.The results of SEM and TEM measurements showed that the surface of hard carbon was coated by pitch - pyrolyzed carbon with an average thickness of 300 nm. The initial coulombic efficiency of the obtained composite (hard carbon: pyrolyzed carbon = 2 : 1 in weight ratio)is enhanced to 70%,which was better than that of the bare hard carbon of 50% .The results show that both its cycling stability and reversible capacity at high rates are improved in comparison with that of graphite.
出处
《炭素》
2010年第3期27-32,共6页
Carbon
基金
国家863资助项目(No.2009AA11A105)
关键词
锂离子电池
负极
硬炭
包覆
沥青
lithium ion battery
anode
hard carbon
coating
pitch