氮掺杂及PEG包覆对CNT/S材料储锂性能的影响

Effect on the lithium storage performance of CNT/S materials by N-doped and PEG-coated

摘要:

以硫代氨基脲为氮源,用高温退火法对碳纳米管实现氮掺杂,利用PEG对掺氮复合材料(NCNT/S)进行外包覆。采用X射线衍射仪(XRD),扫描电子显微镜(SEM),X射线光电子能谱仪(XPS)对复合材料进行了表征。结果表明高温退火使氮有效地掺入碳纳米管中,而碳纳米管仍保持原本征形貌。电化学测试表明：掺氮后复合电极首次放电比容量明显提高,达到882.5 mAh.g_-1,90次循环过后具有89.46%的容量保持量,而PEG包覆使掺氮复合电极首次放电比容量提高至1109.7 mAh.g_-1,经过90次循环放电比容量仍保持在995.2 mAh.g_-1。这说明掺氮和PEG包覆均能很好地改善复合材料的电化学性能。

Abstract:

The N-doped carbon nanotube was prepared by high-temperature annealing, using the thiosemicarbazide as a nitrogen source. Then, the nitrogen-doped composite (NCNT/S) were outer coating by PEG. The structure and morphology of NCNT/S was detected by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and scanning electron microscope (SEM). The results show that: the nitrogen atoms effectively doped in carbon nanotubes by the high-temperature annealing method, and the carbon nanotube also kept the intrinsic morphology and structure. Electrochemical test results show that: the conductive properties of composites materials were enhanced by N-doped. The initial discharge capacity arrived to 882.5 mAh.g_-1, and it maintained 89.46% after 90 cycles. It further enhanced by PEG-coated, and the initial discharge capacity increased to 1109.7 mAh.g_-1, the discharge capacity retention ratio in 995.2 mAh.g_-1 after 90 cycles. The N-doped and PEG-coated can significantly improve the electrochemical properties of the CNT/S composite materials.