仿生石墨烯基复合材料的合成及其电性能研究

发布时间：2018-02-10 02:06

本文关键词： 生物模板石墨烯氧化镍四氧化三钴超级电容器　出处：《苏州科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着核能危机、核污染的不断扩散,清洁核聚变能源又面临技术难题短期内难以实现突破,以及石油、天然气等自然不可再生资源的开采殆尽,寻求新型能源的开发已迫在眉睫,人们也开始思考如何开发新的动力电源技术,储能技术以在实际应用中,如锂电池、超级电容器等。在目前的众多研究领域中,具有功率密度高、循环使用寿命长、成本低、环境友好等优势的超级电容器,已然成为了目前最有前途、最吸引人眼球的高效储能装置。超级电容器依据其特殊的储能原理,主要分为两种:(1)双电层电容(EDLC);(2)赝电容。为了使得制备的超级电容器电极材料具有高比电容和良好的循环寿命等特性,同时为达到所制备的材料成本低廉且环境友好,利用植物纤维大分子制备出了石墨化较好的三维多孔石墨烯。石墨烯作为当今最有前景的碳材料,当其缺陷区域极小时,拥有高电导率,较大的比表面积,优越的机械性能。但是,单纯的石墨烯产生的双电层电容并不能满足现实应用的大量的能量,不能作为最好的能量储存装置。为了有效的解决这一问题,本课题选择了将赝电容器电极材料,如某些金属氧化物(NiO、Co3O4等),作为第二相引入并负载到双电层电容,如石墨烯表面,通过其优势互补协同作用,从而有效的充分发挥石墨烯双电层电容的循环稳定性和赝电容电极材料的高能量密度,使获取的复合材料具有优异的电化学性能,也避免了导电性、稳定性差这一缺点。本论文实验主要分为三大部分,第一部分钴-铈@中空石墨烯复合材料的制备及其电化学性质的研究,以油菜花茎秆为炭源,采用高温煅烧法制备了石墨烯材料(用G表示),并使用水热法制备了以Co3O4、CeO2为负载物的复合材料,同样,实验第二、三部分,分别使用NiO、CeO2和NiO、Co3O4为负载物,以期获得比电容高、循环寿命好的石墨烯金属基复合材料。结果表明:以钴-铈为负载物最高比表面积达到364 m2/g,粒径尺寸大约在20 nm左右,电化学测试结果显示:当电解液Na2SO4溶液浓度为1 mol/L时,1 A/g的电流密度,材料纳米粒子负载量为80%时,得到的复合物拥有最高比电容,达220 F/g,经过1000次循环充放电测试仍有较高的电化学性能,比电容始终保持在90%。以镍-铈为负载物最高比表面积达到262 m2/g,粒径尺寸大约在40 nm左右,电化学测试结果显示:当电解液Na2SO4溶液浓度为1mol/L时,1 A/g的电流密度,材料纳米粒子负载量为80%时,达180 F/g,经过1000次循环充放电测试具有稍低的电化学性能,比电容始终保持在78%。而以镍-钴为负载物最高比表面积达到312 m2/g,粒径尺寸大约在10 nm左右,电化学测试结果显示:当电解液Na2SO4溶液浓度为1 mol/L时,0.5 A/g的电流密度,材料纳米粒子负载量为80%时,达320 F/g,经过1000次循环充放电测试后仍表现出较高的电化学性能,比电容始终保持在92%左右。结果表明,采用油菜花茎秆为生物模板成功制备了石墨烯材料,并且采用双负载的电极材料能远远好于单一负载0的电极材料。可以推断,对金属氧化物负载的比例和种类这两方面的调整,仍有很大的进步,从以后的研究中可以寻找更好、更多的金属氧化物来进行复合负载来提高所制备材料的电化学性能或吸附性能或催化性能。
[Abstract]:With the nuclear crisis, spread of nuclear pollution, clean nuclear fusion energy is facing technical problems in the short term is difficult to achieve a breakthrough, as well as oil, natural gas and other non renewable natural resources depleted, seeking new energy development is imminent, people begin to reflect on the development of power technology and energy storage technology in practice in the application, such as lithium batteries, super capacitors. In many research fields at present, it has high power density, long cycle life, low cost, super capacitor, environment friendly and other advantages, has become the most promising and efficient storage of the most eye-catching device. The super capacitor based on the special energy storage principle, mainly divided into two types: (1) the electric double layer capacitor (EDLC); (2) pseudocapacitor. In order to make the super capacitor electrode material prepared with high specific capacitance and good cycle life. At the same time, to achieve the preparation of low cost and environmentally friendly materials, use of plant fiber macromolecules were prepared by graphite porous graphene. Good carbon material graphene as the most promising, when the defect area isminimum, have high conductivity, large surface area, mechanical properties superior. However, pure graphene produced by electric double layer capacitor and can not meet the practical application of a large amount of energy, can not be used as the best energy storage device. In order to solve this problem, this paper chose the pseudo capacitor electrode material, such as metal oxides (NiO, Co3O4), as the second phase is introduced and the load to the electric double layer capacitor, such as graphene surface, through its complementary synergy, so as to effectively make full use of high energy density graphene electric double layer capacitor cycle stability and pseudocapacitive electrode material, The composite material obtained has excellent electrochemical performance, but also to avoid the conductivity, poor stability of the defect. This paper is mainly divided into three parts, the first part of the cobalt cerium @ hollow graphene composite preparation and electrochemical properties of the rape stem, straw as a carbon source, graphene materials prepared by high temperature calcination method (G), was prepared by hydrothermal method using Co3O4 and CeO2 as a composite material, the same load, the second, third part of experiment, using NiO, CeO2 and NiO, Co3O4 load, in order to obtain high content than electricity, graphene metal matrix composite life cycle good. The results showed that the cobalt cerium load. The highest specific surface area reached 364 m2/g, particle size of about 20 nm. The electrochemical test results showed that: when the concentration of Na2SO4 is 1 mol/L, the current density of 1 A/g, nanoparticles negative materials The load is 80%, the composite obtained has the highest specific capacitance of 220 F/g, after 1000 cycles of charge and discharge test is still higher than the electrochemical performance, the capacitance is always maintained at 90%. in nickel cerium load. The highest specific surface area reached 262 m2/g, the particle size is about 40 nm left and right. The electrochemical test results showed that: when the concentration of Na2SO4 is 1mol/L, the current density of 1 A/g materials, nanoparticles loading was 80%, up to 180 F/g, after 1000 cycles of charge and discharge test is slightly lower than the electrochemical performance of the capacitor is always maintained at 78%. in nickel cobalt load high surface area up to 312 m2/g, particle size of about 10 nm. The electrochemical test results showed that: when the concentration of Na2SO4 is 1 mol/L, the current density of 0.5 A/g materials, nanoparticles loading was 80%, up to 320 F/g, after 1000 cycles of charge and discharge test Continue to show high electrochemical performance, the specific capacitance remained at about 92%. The results show that the preparation of graphene materials were successfully used as bio templates and the rape stem stalk, electrode material of double load can far better than a single load. 0 electrode materials can be inferred, and the proportion of the load of the metal oxide species the two aspects of the adjustment, there is still a great progress from future research for a better, more complex metal oxide to the load to improve the electrochemical performance of the prepared materials or adsorption and catalytic properties.

【学位授予单位】：苏州科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ127.11;TB33

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