微膨胀炭微球复合材料的制备及其电化学性能研究
发布时间：2018-08-19 11:15
【摘要】：本文通过低温氧化法和水热还原制备了层间距较大的微膨胀炭微球,同时将氧化炭微球与锡复合制备出复合材料。利用冷场扫描电子显微镜、透射电子显微镜、X-射线衍射仪、X-射线光电子能谱、拉曼光谱测试、恒电流充放电测试、循环伏安测试和交流阻抗测试对制备出的材料进行形貌及结构和电化学性能进行分析和研究。结果显示,成功通过低温氧化水热还原制备出微膨胀炭微球,通过改变水热还原的温度下,能够有效地调节微膨胀炭微球的层间距,并能够使炭微球的球体结构不被破坏,作为钠离子电池负极材料具有良好的电化学性能和优异的循环特性。在电流密度20 mA/g下,水热180℃处理的膨胀炭微球具有最好的比容量和循环性能,可逆比容量在199.2 mAh/g,同时在电流密度100 mA/g下循环1000次后,容量保持率达到90%以上,具有优越的循环寿命。作为锂离子电池负极材料时,可逆容量较高的样品是在150℃和180℃水热还原的炭微球,在电流密度20mA/g下,充电比容量分别为698.7 mAh/g、664.3 mAh/g,远远高于石墨的实际比容量。成功制备了不同复合量的锡碳复合材料,同时当锡碳质量比为1:1时具有最好的循环性能和较好的比容量,在100 mA/g电流密度下循环220次后比容量达到550 mAh/g,容量保持率在95%以上,具有优越的循环性能,也提升了炭材料的可逆比容量,同时具有较好的倍率性能,在大电流密度1A/g下,放电比容量达到 230.3 mAh/g。
[Abstract]:In this paper, micro-expanded carbon microspheres with large interlayer spacing were prepared by low-temperature oxidation and hydrothermal reduction, and composite materials were prepared by combining carbon oxide microspheres with tin. X-ray photoelectron spectroscopy (XPS), Raman spectroscopy (Raman spectroscopy), constant current charge and discharge (CCL) measurements were performed by means of cold field scanning electron microscope, transmission electron microscope and X ray diffractometer. The morphology, structure and electrochemical properties of the prepared materials were studied by cyclic voltammetry and AC impedance measurements. The results showed that the microexpanded carbon microspheres were successfully prepared by low temperature oxidation hydrothermal reduction. By changing the hydrothermal reduction temperature, the interlayer spacing of the microexpanded carbon microspheres could be adjusted effectively, and the spherical structure of the carbon microspheres could not be destroyed. As anode material of sodium ion battery, it has good electrochemical performance and excellent cycling characteristics. At the current density of 20 mA/g, the expanded carbon microspheres treated at 180 鈩，
本文编号：2191495
[Abstract]:In this paper, micro-expanded carbon microspheres with large interlayer spacing were prepared by low-temperature oxidation and hydrothermal reduction, and composite materials were prepared by combining carbon oxide microspheres with tin. X-ray photoelectron spectroscopy (XPS), Raman spectroscopy (Raman spectroscopy), constant current charge and discharge (CCL) measurements were performed by means of cold field scanning electron microscope, transmission electron microscope and X ray diffractometer. The morphology, structure and electrochemical properties of the prepared materials were studied by cyclic voltammetry and AC impedance measurements. The results showed that the microexpanded carbon microspheres were successfully prepared by low temperature oxidation hydrothermal reduction. By changing the hydrothermal reduction temperature, the interlayer spacing of the microexpanded carbon microspheres could be adjusted effectively, and the spherical structure of the carbon microspheres could not be destroyed. As anode material of sodium ion battery, it has good electrochemical performance and excellent cycling characteristics. At the current density of 20 mA/g, the expanded carbon microspheres treated at 180 鈩，
本文编号：2191495
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