氧化钌复合电极材料的制备及其电化学性能研究

发布时间：2018-06-01 06:18

本文选题：RuO2/SiC-NWs + RuO2/nano-C　；参考：《浙江理工大学》2015年硕士论文

【摘要】：新型电化学储能装置超级电容器的电极材料是该装置发挥优异性能的关键，目前较受关注的电极材料有碳、过渡金属氧化物和导电聚合物三大类。其中以过渡金属氧化物RuO2为电极材料的法拉第准电容器因具有高比电容量、低电阻率等优良特性而受到极大的关注，但各类材料各自的缺陷又限制了它们的应用。因此，研究多针对氧化钌与碳、其它过渡金属氧化物、导电聚合物以及其他材料的复合，以达到协同作用来提高材料电化学性能，，这已经成为超级电容器电极材料的重要发展方向。本论文采用醇盐水解法，制备了两种体系的氧化钌复合电极材料。一是将乙醇钌水解制得的RuO2与纳米石墨复合，制备新型纳米RuO2/nano-C复合电极材料；二是将乙醇钌水解制得的RuO2与碳化硅纳米线复合，制备RuO2/SiC-NWs复合电极材料。在此基础上，深入研究了这两种复合电极材料的制备工艺、组织形貌以及不同钌含量对电化学性能的影响规律。主要的研究结论如下：（1）通过有机物高温分解法，将酚醛树脂进行碳化处理制备纳米石墨。经过XRD和SAED分析表明所制备的纳米石墨包括结晶部分和非结晶部分。而通过TEM分析表明纳米石墨粒子的直径非常小，呈圆球状，尺寸在20~50nm之间且分布均匀。（2）采用溶胶凝胶法和碳热还原法，以正硅酸乙酯和活性炭分别作为硅源和碳源制备碳化硅纳米线。通过XRD和SEM分析表明所制备的碳化硅纳米线主要是念珠状碳化硅纳米线，念珠状碳化硅纳米线长度在150μm左右，由两部分组成，中间是直杆形的结晶碳化硅纳米线，直径在20nm左右，在其表面上包裹着非晶的念珠状小球，小球的直径在100nm左右。（3）RuO2/nano-C和RuO2/SiC-NWs两种复合材料的SEM和TEM显示，在乙醇钌的水解反应过程中，生成的氧化钌沉积在纳米石墨和碳化硅纳米线的表面，并且是以非晶态的形式存在。并且随着两种复合材料中钌含量的增加，氧化钌在纳米石墨和碳化硅纳米线表面上的分散量逐渐增多。在钌含量为12.0wt.%的复合材料中，有大量的氧化钌均匀地沉积在纳米石墨和碳化硅纳米线的表面上。FTIR的分析则表明RuO2/SiC-NWs复合材料中的Si-Ru之间相互作用成键，提高了RuO2/SiC-NWs复合材料的稳定性。（4）RuO2/nano-C和RuO2/SiC-NWs两种复合材料均有较好的电容性能。随着钌含量的增加，复合电极材料的循环伏安曲线峰面积增大，即电容量增大，当钌含量为12.0wt.%时，制得的RuO2/nano-C和RuO2/SiC-NWs复合材料的比电容量分别达到了314F·g-1和393F·g-1。阻抗曲线则表明RuO2/nano-C和RuO2/SiC-NWs复合材料包括碳双电层电容和氧化钌准电容两种电化学行为，并且具有优良的阻抗特性，其等效串联电阻（ESR）值随着两种复合材料中钌含量的增加，等效串联电阻呈减小趋势。钌含量为12.0wt.%的RuO2/nano-C和RuO2/SiC-NWs复合材料经过1000次充放电循环的比电容损失分别为0.81%和0.76%，具有较高的电化学稳定性。
[Abstract]:The electrode material of the new electrochemical energy storage device supercapacitor is the key to the performance of the device. At present, there are three major categories of carbon, transition metal oxide and conductive polymer. The Faraday quasi capacitor with transition metal oxide RuO2 as the electrode material has high specific capacitance, low resistivity and so on. Great attention has been paid to the excellent properties, but their applications are limited by the defects of various materials. Therefore, the research is aimed at the combination of ruthenium oxide and carbon, other transition metal oxides, conductive polymers and other materials to achieve synergism to improve the electrochemical properties of materials. This has become a supercapacitor electrode material. The important direction of development.
In this paper, two kinds of ruthenium oxide composite electrode materials are prepared by the solution of alcohol and brine. One is to compounded the RuO2 and nano graphite prepared by the hydrolysis of ruthenium ethanol, and to prepare a new nano RuO2/nano-C composite electrode material. The two is to compounded the RuO2 and the silicon carbide nanowires prepared by the hydrolysis of ruthenium ethanol, and to prepare the RuO2/SiC-NWs composite electrode material. On this basis, the preparation process of the two composite electrode materials, the microstructure and the influence of different ruthenium content on the electrochemical properties are studied. The main conclusions are as follows:
(1) the nanoscale graphite was prepared by carbonization by high temperature decomposition of organic matter. The results of XRD and SAED analysis showed that the prepared nanoscale graphite included crystalline and non crystalline parts. By TEM analysis, the diameter of the graphite nanoparticles was very small, and the size of the particles was evenly distributed between 20~50nm and 20~50nm.
(2) the sol-gel method and carbon thermal reduction method were used to prepare silicon carbide nanowires using ethyl orthosilicate and activated carbon as silicon source and carbon source respectively. By XRD and SEM analysis, the silicon carbide nanowires were mainly beads like SiC nanowires, and the length of the Candida SiC nanowires was about 150 m, consisting of two parts, and the middle was straight. The crystalline silicon carbide nanowires with a diameter of 20nm are coated with amorphous beads, and the diameter of the spheres is about 100nm.
(3) SEM and TEM of two composite materials of RuO2/nano-C and RuO2/SiC-NWs show that ruthenium oxide deposited on the surface of nano graphite and silicon carbide nanowires in the process of hydrolysis of ruthenium, and exists in the form of amorphous state. And with the increase of ruthenium content in the two composite materials, ruthenium oxide is in nanoscale graphite and silicon carbide. A large amount of ruthenium oxide is deposited on the surface of nano graphite and silicon carbide nanowires on the surface of Ru content 12.0wt.%. The analysis of.FTIR on the surface of nano graphite and SiC nanowires shows that the interaction of Si-Ru in the RuO2/SiC-NWs composites is a bond, which improves the stability of the RuO2/SiC-NWs composites.
(4) the two composite materials of RuO2/nano-C and RuO2/SiC-NWs have good capacitive performance. With the increase of ruthenium content, the peak area of cyclic volt ampere curve of the composite electrode increases, that is, the electric capacity increases. When the ruthenium content is 12.0wt.%, the specific capacity of the prepared RuO2/nano-C and RuO2/SiC-NWs composites reaches 314F g-1 and 393F. G-1, respectively. The impedance curve shows that the RuO2/nano-C and RuO2/SiC-NWs composites include two electrochemical behaviors of carbon double layer capacitance and ruthenium oxide quasi capacitance, and have excellent impedance characteristics. The equivalent series resistance (ESR) value decreases with the increase of ruthenium content in the two composites, and the ruthenium content is 12.0wt.% RuO2/n. The specific capacitance losses of ano-C and RuO2/SiC-NWs composites after 1000 charge discharge cycles were 0.81% and 0.76% respectively, and the electrochemical stability was high.
【学位授予单位】：浙江理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB33;TM53

【参考文献】