生物质碳源用作电极材料的可行性研究
发布时间：2018-11-03 19:36
【摘要】：锂离子电池因具有环境友好、工作电压高、比能量大、循环寿命长等优点在储能领域的性价比突出,已迅速成为研发的热点。当前市场上的负极材料主要是以石墨为主的传统炭材料,而石墨理论的比容量较低,这大大阻碍了高性能锂离子电池的快速发展。本文以三种不同的生物质为碳源,通过低温炭化、高温石墨化和化学活化等方法对生物质炭材料进行综合处理,改善炭材料的表面形貌和微观结构。采用了X射线衍射(XRD)、拉曼光谱(Raman)、扫描电子显微镜(SEM)等测试从而对材料的结构及形貌进行分析。并且将制备得到的炭材料作为负极材料组装成扣式电池。为研究材料的结构对电化学性能的影响,进行了恒流充放电测试、循环伏安测试和电化学交流阻抗测试。研究发现,微藻在900℃低温炭化得到的炭材料拥有适宜的多级孔结构和石墨结构,而且在充放电过程中形成的SEI膜完整性和稳定性好,因而材料表现出最优异的电化学性能。豆渣在2800℃热处理后石墨化程度明显提高,在0.1 C倍率下循环100次后容量从423 mAh g-1下降到396 mAh g-1,表现出优秀的循环性能;豆渣经过化学活化处理后电化学性能明显改善,特别是KOH处理后的样品,在0.1 C下首次充电容量高达801 mAh g-1,甚至在1 C下容量还有643 mAh g-1,循环500次后容量保持率高达94%,这优异的电化学性能取决于它高比表面积和丰富的介孔结构。同样以KOH为活化剂,茶籽壳炭化活化得到的炭材料的电化学性能优于水热活化,这也是由于它更高的比表面积和更发达的孔隙结构导致的。
[Abstract]:Li-ion battery has become a hot research and development field because of its advantages such as friendly environment, high working voltage, large specific energy, long cycle life and so on, which has outstanding performance-price ratio in the field of energy storage. At present, the anode materials in the market are mainly traditional carbon materials based on graphite, but the specific capacity of graphite theory is relatively low, which greatly hinders the rapid development of high-performance lithium ion batteries. In this paper, three kinds of biomass were used as carbon source to improve the surface morphology and microstructure of carbon materials by means of low temperature carbonization, high temperature graphitization and chemical activation. X-ray diffraction (XRD) (XRD), Raman spectroscopy (XRD),) (Raman), scanning electron microscope (SEM) was used to analyze the structure and morphology of the materials. The prepared carbon material is assembled as a negative electrode material to form a button battery. In order to study the influence of structure on electrochemical performance, constant current charge-discharge test, cyclic voltammetry test and electrochemical impedance test were carried out. It was found that the carbon material obtained from the carbonization of microalgae at 900 鈩，
本文编号：2308785
[Abstract]:Li-ion battery has become a hot research and development field because of its advantages such as friendly environment, high working voltage, large specific energy, long cycle life and so on, which has outstanding performance-price ratio in the field of energy storage. At present, the anode materials in the market are mainly traditional carbon materials based on graphite, but the specific capacity of graphite theory is relatively low, which greatly hinders the rapid development of high-performance lithium ion batteries. In this paper, three kinds of biomass were used as carbon source to improve the surface morphology and microstructure of carbon materials by means of low temperature carbonization, high temperature graphitization and chemical activation. X-ray diffraction (XRD) (XRD), Raman spectroscopy (XRD),) (Raman), scanning electron microscope (SEM) was used to analyze the structure and morphology of the materials. The prepared carbon material is assembled as a negative electrode material to form a button battery. In order to study the influence of structure on electrochemical performance, constant current charge-discharge test, cyclic voltammetry test and electrochemical impedance test were carried out. It was found that the carbon material obtained from the carbonization of microalgae at 900 鈩，
本文编号：2308785
本文链接：https://www.wllwen.com/kejilunwen/dianlidianqilunwen/2308785.html
