碳纳米管与石墨烯协同改性天然石墨及其电化学性能

Combination Carbon Nanotubes with Graphene Modified Natural Graphite and Its Electrochemical Performance

以碳纳米管和氧化石墨烯为原料,二者按5∶3混合超声分散再高温还原制备碳纳米管/石墨烯/天然石墨(CNTs/rGO/NG)锂离子复合负极材料。采用扫描电镜(SEM)、X射线衍射(XRD)、红外光谱(FTIR)和电化学测试等分析技术对复合材料的形貌、结构、电化学进行表征。结果表明:石墨烯和碳纳米管在天然石墨表面形成三维立体网络结构。与纯天然石墨相比,CNTs/rGO/NG复合材料具有良好的倍率性能和循环寿命,在0.1C时首次放电比容量为479mAh/g,可逆容量达473mAh/g,循环100次后容量为439.5mAh/g,容量保持率为92%,在0.5,1,5C不同电流倍率时容量依次为457,433,394mAh/g。

The CNTs/rGO/NG composite lithiumion battery anode material was synthesized by thermal reducing,using graphene oxide(GO)and carbon nanotubes(CNTs)as precursors for a 5∶3proportion.The morphology,structure,and electrochemical performance of the composite were characterized by scanning electron microscopy(SEM),X-ray diffractometry(XRD),Fourier transform infrared spectra(FTIR)and electrochemical measurements.The results show that reduced graphene oxide and carbon nanotubes form a perfect three-dimensional network structure on the surface of natural graphite.CNTs/rGO/NG composite has good rate performance and cycle life,compared with pure natural graphite.The initial discharge capacity of designed anode is 479mAh/g at 0.1C,the reversible capacity up to 473mAh/g after 100 cycles,the capacity is still 439.5mAh/g,the capacity retention rate is 92%,and the capacity is 457,433,394mAh/g at 0.5,1,5C,respectively.