發(fā)布時間：2018-08-19 11:15

【摘要】：本文通過低溫氧化法和水熱還原制備了層間距較大的微膨脹炭微球,同時將氧化炭微球與錫復(fù)合制備出復(fù)合材料。利用冷場掃描電子顯微鏡、透射電子顯微鏡、X-射線衍射儀、X-射線光電子能譜、拉曼光譜測試、恒電流充放電測試、循環(huán)伏安測試和交流阻抗測試對制備出的材料進行形貌及結(jié)構(gòu)和電化學性能進行分析和研究。結(jié)果顯示,成功通過低溫氧化水熱還原制備出微膨脹炭微球,通過改變水熱還原的溫度下,能夠有效地調(diào)節(jié)微膨脹炭微球的層間距,并能夠使炭微球的球體結(jié)構(gòu)不被破壞,作為鈉離子電池負極材料具有良好的電化學性能和優(yōu)異的循環(huán)特性。在電流密度20 mA/g下,水熱180℃處理的膨脹炭微球具有最好的比容量和循環(huán)性能,可逆比容量在199.2 mAh/g,同時在電流密度100 mA/g下循環(huán)1000次后,容量保持率達到90%以上,具有優(yōu)越的循環(huán)壽命。作為鋰離子電池負極材料時,可逆容量較高的樣品是在150℃和180℃水熱還原的炭微球,在電流密度20mA/g下,充電比容量分別為698.7 mAh/g、664.3 mAh/g,遠遠高于石墨的實際比容量。成功制備了不同復(fù)合量的錫碳復(fù)合材料,同時當錫碳質(zhì)量比為1:1時具有最好的循環(huán)性能和較好的比容量,在100 mA/g電流密度下循環(huán)220次后比容量達到550 mAh/g,容量保持率在95%以上,具有優(yōu)越的循環(huán)性能,也提升了炭材料的可逆比容量,同時具有較好的倍率性能,在大電流密度1A/g下,放電比容量達到 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，

本文編號：2191495