摘要
以天然鳞片石墨为原料,通过氧化、离心分离、低温氢气还原和超声分散处理制备了高品质的石墨烯片(1-4层)。采用透射电镜(TEM)、高分辨透射电镜(HRTEM)、傅里叶变换红外光谱(FT-IR)、拉曼光谱、X-射线衍射(XRD)等测试方法对石墨烯的结构和形貌进行了研究。通过恒流充放电、循环伏安法(CV)和交流阻抗(EIS)等手段研究了石墨烯用作锂离子电池负极材料的电化学性能。结果表明在0.2 mA/cm2的电流密度下石墨烯首次可逆比容量为1005 mAh/g,经过30个循环后放电比容量保持在609 mAh/g,在大电流密度下放电容量仍然能保持576 mAh/g,表明石墨烯负极材料具有优异的倍率性能。
We prepared high quality graphene sheets with a curled morphology consisting of a thin wrinkled paper-like structure and fewer layers （1-4 layers） has been prepared from natural graphite by oxidation, hydrogen reduction at 400 ℃ and ultrasonic treatment. Graphene sheets were investigated as anode material for lithium ion batteries by transmission electron microscopy （TEM）, high-resolution TEM, X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy and a variety of electrochemical testing techniques. The electrochemical performance testing results showed that the first reversible specific capacity of the graphene sheet electrode was as high as 1005 mAh/g at a current density of 0.2 mA/cm2. After 30 cycles the reversible specific capacity was still maintained at 609 mAh/g. Even at a high current density of 1 mA/cm^2, the reversible specific capacity could remain at 576 mAh/g after 30 cycles. These results indicate that the prepared high quality graphene sheets we prepared possess excellent electrochemical performances for lithium storage.
出处
《中国科技论文》
CAS
北大核心
2012年第3期201-205,209,共6页
China Sciencepaper
基金
国家自然科学基金资助项目(50672004)
国家高技术研究发展计划(863计划)资助项目(2008AA03Z513)
关键词
石墨烯
电化学性能
锂离子电池
负极材料
graphene sheets
electrochemical performance
lithium ion batteries
anode material
