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通过化学浴沉积技术在碳纳米管(carbon nanotube,CNT)表面均匀环绕生长氧化镍(nickel oxide,NiO)纳米片,采用X射线衍射仪和场发射扫描电镜测试方法观察其晶体结构和微观形貌,测试表明:CNT作为核心骨架,NiO纳米片在CNT表面均匀地立体生长。通过循环伏安与恒流充放电测试发现:NiO/CNT复合材料作为锂离子电池的负极材料的比容量和循环性能有明显改善,在100 mA/g电流密度下NiO/CNT首次放电比容量1990 mAh/g,比纯NiO的1560 m Ah/g提高了27.6%,循环30次后比容量仍保持在1500 mAh/g,而NiO的衰减到285 mAh/g。其比容量和循环性能的改善,是由于CNT提高了复合材料整体的导电性能,NiO纳米片环绕生长在CNT表面上,促进活性材料与电解液的接触,增强NiO的电化学活性。
The nickel oxide (NiO) nanosheets were uniformly surrounded by chemical bath deposition on the surface of carbon nanotubes (CNTs). The crystal structure and microstructure were observed by X-ray diffraction and field emission scanning electron microscopy The results show that CNTs as the core skeleton, NiO nanosheets grow uniformly on the surface of CNTs. Through the cyclic voltammetry and constant current charge-discharge test, it was found that the specific capacitance and cycle performance of NiO / CNT composites as negative electrode material of Li-ion batteries have been significantly improved. The first discharge capacity of NiO / CNT at a current density of 100 mA / g 1990 mAh / g, 27.6% higher than that of pure NiO at 1560 mAh / g. After 30 cycles, the specific capacity remained at 1500 mAh / g, while NiO decayed to 285 mAh / g. The improvement of specific capacity and cycle performance is due to the fact that CNT improves the overall electrical conductivity of the composite material. The NiO nanosheet grows around the CNT surface to promote the contact between the active material and the electrolyte and enhance the electrochemical activity of NiO.