多孔碳基超级电容器电极材料的制备与性能研究

发布时间：2017-12-27 09:16

本文关键词：多孔碳基超级电容器电极材料的制备与性能研究　出处：《浙江理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：作为新型能量储存/转换装置,超级电容器相比于其他传统的电化学储能装置,具有诸多的优点,如充放电速度极快,重复性能好,循环性优异等。超级电容器介于普通电容器和传统化学电池之间,根据储能机理分为双电层电容和赝电容两种类型。双电层电容通过电极表面和电解质液面之间形成的极薄的双电层来进行储能,相比赝电容,具有优异的稳定性、快速的充放电速率、高功率密度等优点,是目前商品化电容器的主要类型。然而当前的双电层电容器面临能量密度低的问题,而能量密度主要由电极材料的比电容决定。多孔碳是双电层电容器中常用的电极材料,其孔道根据孔径不同可分为三类:微孔,介孔和大孔。微孔容易阻碍电解质离子的传输,大孔则实现不了高的表面积,相比于这两类孔型,介孔的优势较大。本论文以多孔碳作为基础研究材料,选取不同的制备方法和不同的原材料,并且尝试通过掺杂的方式,制备出了具有高比表面积,适宜的孔径分布以及低成本简单易制的高性能的电极材料。同时采用扫描电镜(SEM)、透射电镜(TEM)、氮吸附、X射线衍射(XRD)、Raman和XPS对电极材料的结构与组成成分进行了表征,运用电化学工作站对其电化学性能进行研究。论文分为以下三个体系:1、以酚醛树脂纳米球为碳源,采用无惰性气氛无化学活化剂的空气活化法制备具有高比表面积的多孔碳纳米球(AACS)。考察活化时间对孔结构的影响,表明多孔碳中介孔比例随活化时间的延长而增多。6小时活化的样品AACS-6具有最高的比表面积(2178 m_2 g~(-1))和最大孔容(1.01 cm~3 g~(-1))。电化学测试表明,AACS-6具有最大的比电容值222 F g~(-1)(0.5A g~(-1)),优异的倍率性能(20 A g~(-1)保留87.5%)和循环性能(5000圈循环后保留97%)。组装所得对称型两电极体系具有高的能量密度(功率密度为398.7 W kg~(-1)时,能量密度为10.1Wh kg~(-1))。2、以生物质香榧壳为碳源,采用惰性氛围KOH活化法制备具有良好形貌和高比表面积的生物质多孔碳。研究结果表明,通过调节活化温度和KOH用量可调控多孔碳的孔道结构。以香榧壳/KOH质量比为1:3经800 oC活化所得样品AC-800-3具有最大的比表面积(2100.8m2 g~(-1))和微介孔分级的孔道结构。电化学测试表明,AC-800-3具有最大的比电容值290.5F g~(-1)(0.5 A g~(-1)),良好的倍率性能(20 A g~(-1)保留62.6%)。组装所得对称型两电极体系具有高的能量密度(功率密度为360.1 W kg~(-1)时,能量密度为13.5 Wh kg~(-1))和优异的循环性能(5000圈循环后保留93.1%)3、以介孔氧化硅SBA-15为硬模板,糠醇为碳源,三聚氰胺为氮源,通过模板复制和KOH化学活化制备具有发达介孔结构的多孔碳材料。当KOH/碳质量比为2:1,800 oC活化所得多孔碳ANMC-2具有发达的孔道结构,比表面积高达2277.7 m2 g-1,氮含量为3.84%。电化学测试表明,ANMC-2具有极高的比电容292.6 F g~(-1)(0.5 A g~(-1)),良好的倍率性能(20 Ag~(-1)保留82.7%)。组装所得对称型两电极体系具有高的能量密度(功率密度为359.3 W kg~(-1)时,能量密度为14.8 Wh kg~(-1))和优异的循环性能(5000圈循环后保留98.5%)。
[Abstract]:As a new energy storage / conversion device, super capacitor has many advantages compared with other traditional electrochemical energy storage devices, such as fast charge and discharge, good repeatability and excellent cycling performance. The supercapacitor is between the ordinary capacitor and the traditional chemical battery. According to the energy storage mechanism, it can be divided into two types: double layer capacitance and pseudo capacitance. The electric double layer capacitor is used to store energy between the electrode surface and the electrolyte layer. It has the advantages of excellent stability, fast charge and discharge rate and high power density compared with the pseudo capacitor. It is the main type of commercialized capacitors. However, the current double layer capacitor is faced with the problem of low energy density, and the energy density is mainly determined by the specific capacitance of the electrode material. Porous carbon is a common electrode material in double layer capacitors. The pore channel can be divided into three types according to the pore size: micropores, mesoporous and large pores. Micropores can easily impede the transmission of electrolyte ions, and large pores can not achieve high surface area. Compared to these two types of pores, the advantages of mesoporous pores are larger. In this paper, porous carbon is chosen as the basic research material, and different preparation methods and different raw materials are selected. And by doping, we have prepared high-performance electrode materials with high specific surface area, suitable pore size distribution, and low cost. Meanwhile, the structure and composition of electrode materials were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen adsorption, X ray diffraction (XRD), Raman and XPS. The electrochemical performance of electrode materials was studied by electrochemical workstation. The paper is divided into three systems: 1. Nano porous carbon nanospheres (AACS) with high specific surface area were prepared by air activation with phenolic resin nanospheres as carbon source and inert atmosphere without chemical activator. The effect of activation time on pore structure was investigated, which showed that the ratio of porous carbon medium pore increased with the prolongation of activation time. The 6 hour activated sample AACS-6 has the highest specific surface area (2178 m_2 g~ (-1)) and the maximum Kong Rong (1.01 cm~3 g~ (-1)). Electrochemical measurements showed that AACS-6 had the largest specific capacitance value of 222 F g~ (-1) (0.5A g~ (-1)), and the excellent rate performance (20 A g~ (-1) retained 87.5%) and cycle performance (97% after 5000 cycles). The assembled symmetric two electrode system has high energy density (the power density is 398.7 W kg~ (-1), and the energy density is 10.1Wh kg~ (-1)). 2, the biomass of Torreya grandis shell as the carbon source, using an inert atmosphere KOH activation preparation has good morphology and high surface area porous carbon biomass. The results show that the pore structure of porous carbon can be regulated by adjusting the activation temperature and the amount of KOH. In Torreya grandis shell mass ratio of /KOH was 1:3 by oC AC-800-3 800 activation samples had the largest surface area (2100.8m2 g~ (-1)) and micro mesoporous hierarchical pore structure. The electrochemical test showed that AC-800-3 had the maximum specific capacitance value 290.5F g~ (-1) (0.5 A g~ (-1)), and the good multiplier performance (20 A g~ (-1) retained 62.6%). The assembly of symmetric two electrode system has the advantages of high energy density (power density of 360.1 W kg~ (-1), the energy density of 13.5 Wh kg~ (-1)) and excellent cycling performance (93.1% retained 5000 cycles after 3), using mesoporous silica SBA-15 as hard template and furfuryl alcohol as carbon source. Melamine as nitrogen source, through the template replication and KOH activation of porous carbon materials prepared with developed mesoporous structure. When the KOH/ carbon mass ratio is 2:1800 oC activation, the porous carbon ANMC-2 has developed pore structure, and the specific surface area is 2277.7 M2 g-1, and the nitrogen content is 3.84%. The electrochemical test shows that ANMC-2 has a high specific capacitance of 292.6 F g~ (-1) (0.5 A g~ (-1)), and a good multiplier performance (20 Ag~ (-1) 82.7%). The assembled symmetrical two electrode system has high energy density (power density is 359.3 W kg~ (-1), the energy density is 14.8 Wh kg~ (-1)) and excellent cycle performance (5000 cycles after 98.5%).
【学位授予单位】：浙江理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM53;O646

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