焙烧条件对碳包覆天然石墨电化学性能的影响  

Influence of roast conditions on electrochemical characterization of natural graphite coated by carbon

作　　者：裴晓英[1] 张颖[1] 韩恩山[1] 汪大云[2] 

机构地区：[1]河北工业大学化工学院,天津300130 [2]河北工业大学理学院,天津300130

出　　处：《电源技术》2012年第10期1448-1450,共3页Chinese Journal of Power Sources

摘　　要：将天然石墨(NG)用浓HNO3氧化处理后,在其表面包覆柠檬酸,在惰性气体气氛下热处理,制得了包覆改性石墨,考察了焙烧温度和焙烧时间对包覆材料性能的影响。采用X射线衍射(XRD)和恒电流充放电等手段对该材料进行结构表征和电化学性能测试,确定了最佳的改性工艺。结果表明,焙烧温度为600℃,焙烧时间为18 h时产品的循环性能较好,首次放电比容量达到492.6 m Ah/g,10次循环后的比容量仍可达到347.4 m Ah/g。Natural graphite （NG） was modified by concentrated HNO3 used as oxidant, then coated it with C6H8O7, and treated in a nitrogen gas atmosphere. The effects of two different roast conditions, i.e. roast temperature and roast time, on the performance of as coated materials were investigated. The structure and electrochemical performance of the prepared carbon-coated graphite were characterized by XRD and electrochemical performance testing to determine the best modification process. The results indicate that, when roasted at 600 ℃ for 18 h, the sample has the better cycle performance, its initial discharge capacity is 492.6 mAh/g, and the specific capacity keeps 347.4 mAh/g after 10 cycles.

关 键 词：锂离子电池 天然石墨 焙烧 柠檬酸 包覆 

分 类 号：TM912.9[电气工程—电力电子与电力传动]