多孔碳材料以及碳复合物负极材料的制备及锂离子电池性能的研究

发布时间：2018-06-24 21:19

本文选题：锂离子电池负极材料 + 三维多孔碳　；参考：《江西师范大学》2015年硕士论文

【摘要】：锂离子电池作为当今社会急需的一种环境友好的新型二次能源,引起了社会的广泛关注。而社会的不断发展,对锂离子的要求也就日益增加。提高循环性能和容量的一个很重要的途径就是提高锂离子电池的负极材料的性能和容量。碳材料是稳定、环保的一种常用的锂离子负极材料。然而,当前的商业化的石墨的理论容量较低(仅为372 mAh/g),在实际应用中受到了一定的限制。因此科学家们投入了大量的精力在研究新的高容量的碳材料,或是碳材料与其他高容量材料的复合材料,来代替石墨碳负极材料。而高容量的其他负极材料中的典型代表便是硅和金属氧化物负极材料。本论文的工作主要围绕了多孔碳材料以及多孔碳与纳米硅和金属氧化物的复合材料的制备、表征及其在锂离子电池负极材料中的应用,具体研究工作如下三个方面:1.以金属有机框架为前驱体合成制备了三维多孔碳材料,制备方法简单,形貌独特,性能良好。接着对此三维多孔碳材料进行了扫描电子显微镜,X射线衍射光谱,X射线光电子能谱,电池性能等表征。发现该材料的具有1880 m2/g的高的比表面积,应用于锂电循环100圈后仍有1015 mAh/g的容量。性能远远优于传统石墨。2.为了制备高容量的锂离子电池负极材料,在纳米硅表面原位生长沸石咪唑框架(ZIFs),形成了ZIFs框架结构/纳米硅复合物,形貌均一,应用于锂电,循环100圈仍有1168 mAh/g的容量,性能优越,大大高于纯硅以及一些硅/碳复合材料。为复合材料的制备提供了一个多元化的方式。3.先通过煅烧植物竹篙草杆,形成多孔碳支撑材料。然后通过水热反应在该多孔碳上生长了10 nm大小的四氧化三钴制成多孔碳/四氧化三钴复合材料。用扫描电子显微镜观察了它的形貌并对其作为锂离子电池的负极材料的性能做了进一步的探讨,发现循环100圈仍有1215 mAh/g的容量,大大高于纯四氧化硅材料以及一些四氧化硅/碳复合材料优于很多相似材料。此方法合成灵活简单,成本低,可大规模生产。
[Abstract]:Lithium-ion battery (Li-ion battery), as a new kind of environmental friendly secondary energy, has attracted wide attention. With the development of society, the demand for lithium ion is increasing day by day. One of the most important ways to improve the cycle performance and capacity is to improve the performance and capacity of cathode materials for lithium ion batteries. Carbon material is a kind of commonly used lithium ion anode material, which is stable and environmentally friendly. However, the theoretical capacity of commercial graphite is relatively low (372 mAh/g), which is limited in practical application. So scientists are devoting a lot of energy to studying new high-capacity carbon materials, or composites of carbon materials with other high-capacity materials, to replace graphite carbon anode materials. High capacity of other anode materials are typical of silicon and metal oxide anode materials. The main work of this thesis is focused on the preparation, characterization and application of porous carbon materials and composite materials of porous carbon with nano-silicon and metal oxides. The specific research work is as follows: 1. Three dimensional porous carbon materials were synthesized using organometallic framework as precursor. The method is simple, the morphology is unique, and the properties are good. Then the three-dimensional porous carbon material was characterized by scanning electron microscope (SEM) X-ray diffraction spectrum X-ray photoelectron spectroscopy (XPS) and battery performance. It is found that the material has a high specific surface area of 1880 m2 / g, and still has a capacity of 1015 mAh/g after being used in lithium electric cycling for 100 cycles. The properties of graphite are much better than that of traditional graphite. In order to prepare high capacity cathode materials for lithium ion batteries, zeolites imidazole frames (ZIFs) were grown in situ on the surface of nanocrystalline silicon. ZIFs / nano-Si composites were formed. The structure of ZIFs / nano-Si composites was uniform and used in lithium. The capacity of ZIFs was still 1168 mAh/g in 100 cycles. Superior performance, much higher than pure silicon and some silicon / carbon composites. For the preparation of composite materials to provide a diversified way. 3. Firstly, the porous carbon support material is formed by calcining the plant Penny's straw. The porous carbon / cobalt tetroxide composite was prepared by hydrothermal reaction on the porous carbon. Its morphology was observed by scanning electron microscope (SEM) and its performance as a cathode material for lithium ion batteries was further discussed. It was found that the cycle 100th cycle still had a capacity of 1215 mAh/g. It is much higher than pure silicon oxide and some silica / carbon composites are superior to many similar materials. This method is flexible and simple, low cost and can be produced in large scale.
【学位授予单位】：江西师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM912

【参考文献】