MWCNT@SiO_2纳米同轴电缆的制备及储锂性能

以多壁碳纳米管(MWCNT)为模板,通过正硅酸乙酯(TEOS)的水解缩聚反应制得MWCNT@SiO2纳米同轴电缆.采用透射电子显微镜(TEM)、扫描电子显微镜(SEM)和电化学测试对样品的形貌、结构及电化学性能进行表征.结果表明,MWCNT表面包覆了一层厚度均匀的多孔SiO2层,利于其获得较好的储锂性能.作为锂离子电池负极材料,MWCNT@SiO2纳米同轴电缆表现出了较高的比容量和较好的循环性能.在100 m A/g电流密度下经过80次循环,MWCNT@SiO2纳米同轴电缆的放电比容量仍高达431.7 m A·h/g,高于石墨材料的理论比容量(372 m A·h/g).

Preparation and Lithium Storage Performance of MWCNT@SiO2 Coaxial Nanocables

MWCNT@SiO2 coaxial nanocables were prepared via a facile hydrolysis-condensation process of tetraethyl orthosilicate(TEOS) with multi-walled carbon nanotubes(MWCNT) as templates. The morphology, structure and electrochemical performance of the nanohybrids were characterized by transmission electron microscopy(TEM), scanning electron microscopy(SEM), and electrochemical measurements. It is indicated that the MWCNT templates have been fully wrapped by SiO2 layer with uniform thickness and porous nature, which is beneficial for the enhanced Li-storage capabilities of the MWCNT@SiO2 nanohybrids. When evaluated as anode materials for Li-ion battery, the MWCNT@SiO2 coaxial nanocables exhibit high specific capacities and excellent cycling performance. For example, the MWCNT@SiO2 coaxial nanocables are able to deliver a high discharge capacity of 431.7 mA·h/g after 80 cycles at a current density of 100 mA/g, which is higher than the theoretical capacity of graphite(372 mA·h/g). The facile synthetic methodology and enhanced lithium-storage performances of the MWCNT@SiO2 coaxial nanocables make it an ideal anodic candidate for high-energy and long-life Li-ion batteries(LIBs).