摘要
将沥青煤油溶液过滤后,与天然球化石墨充分混合,蒸发溶剂后真空炭化,获得锂离子电池用沥青包覆天然石墨负极材料,实验研究发现当沥青包覆量在一定范围内时,可明显降低天然石墨的比表面积,提高石墨负极材料的循环性能,同时石墨负极材料的可逆容量及首次充放电效率明显提高。当包覆量为8%时,炭化温度为1100℃,首次充电比容量为367mAh/g,首次库仑效率为94.5%,循环20次后可逆容量保持率为92%。可见沥青包覆改性后,天然石墨材料的电化学性能得到明显改善。
Natural graphite anode material was obtained by dissolving and filtrating pitch in kerosene, mixing it sufficiently with spherical natural graphite, distilling solvent, and being carbonifled in vacuum, then was coated with a thin film of disordered carbon. Within the determined range of pitch percent, the specific surface area of natural graphite decreased. The first reversible capacity and the cycle capability of the coated graphite were improved. With pitch percent of 8%, and heat-treatment at 1 100 ~C, the first charge capacity was 367 mAh/g, the first coulomb efficiency was 94.5%. At the same time, after 20 times circulation, the hold ratio of reversible capacity was 92%. It was obvious that the electrochemistry performance of natural graphite was improved after pitch coating.
出处
《电源技术》
CAS
CSCD
北大核心
2008年第11期745-747,共3页
Chinese Journal of Power Sources
基金
辽宁省自然科学基金资助项目(20072206)
辽宁省教育厅科学技术研究项目(05L168)
关键词
锂离子电池
石墨
负极材料
石油沥青
包覆
lithium ion battery
graphite
anode material
petroleum pitch
coating
