两种用作超级电容材料的石墨烯复合材料制备及性能研究

发布时间：2018-05-12 07:52

本文选题：氮化硼 + 石墨烯　；参考：《湖南大学》2015年硕士论文

【摘要】：超级电容器,通常称为电化学电容器,在电子设备上的能量储存和传输上有重要作用。超级电容器有很多优良的性质,如高功率密度、循环寿命长、充放电时间快。碳材料由于其优良的性质如低成本、无毒、环境友好和稳定性,因而其被广泛用于超级电容器研究。在碳材料家族中,石墨烯具有高的比表面积、良好的导电性、较高的理论电容容量等优良性质被认为是非常具有希望的下一代储能材料。石墨烯的理论电容为550 F g~(-1),然而目前大部分石墨烯类超级电容器的电容都远远低于这个数值。尤其在大电流充放电时更小,在电流密度为10 A g~(-1)时其电容仅有40 F g~(-1)。本文以氧化石墨烯(GO)为基本原料,将它分别与氮化硼、液相剥离的石墨烯(LG)进行组装制备了氮化硼/石墨烯(BN/RGO)、折叠石墨烯(FTG)复合材料。并将它们应用于超级电容储能研究。这些无机复合材料,有效的减少了石墨烯的团聚、有利于电解质溶液与电极材料的接触。这些无机复合材料的研究为石墨烯在储能领域的应用做出了前期准备,具有重要的科学意义。因此,石墨烯二元无机复合材料的研究在能源化工领域有重要的潜在的应用价值。本文的研究工作主要有以下两点:1.简便合成了BN/RGO。这种复合材料用于超级电容研究,在电流密度为2 A g~(-1)时它的电容比较大,达140 F g~(-1);它的倍率性能非常好,在电流密度为50 A g~(-1)电容仍然有71.5 F g~(-1);它的循环性能非常好,在扫描速度为200 m V s~(-1)时循环1000圈后,电容反而增加了5.5%。这些良好的电容性能说明BN/RGO在超级电容领域有很大的潜在应用价值。2.将氧化石墨和液相剥离制备的石墨烯进行组装,然后经过超声和还原反应,制备了FTG。FTG由少层石墨烯片层组成。它具有很好的结晶性、三维立体结构和非常均一的介孔。基于FTG制备的超级电容显示出增强的电化学性能。在扫描速度为1 m V s~(-1)时,FTG的电容为195.4 F g~(-1);在扫描速度为500 m V s~(-1)时循环8000圈,其电容仍然保持93.9%。这些结果说明FTG是一种具有较好电容性能超级电容电极材料。论文的创新点就在于制备了无金属、环境友好的石墨烯复合材料并用于超级电容储能研究。这些复合材料的储能效果理想,制备方法比较简单、便于工业化,在能源化工领域有潜在的工业应用价值。
[Abstract]:Supercapacitors, commonly known as electrochemical capacitors, play an important role in energy storage and transmission in electronic devices. Supercapacitors have many excellent properties, such as high power density, long cycle life and fast charge / discharge time. Carbon materials are widely used in supercapacitors because of their excellent properties such as low cost, non-toxic, environmentally friendly and stable. In the carbon materials family, graphene has high specific surface area, good conductivity, high theoretical capacitance capacity and other excellent properties are considered to be very promising for the next generation of energy storage materials. The theoretical capacitance of graphene is 550 F / g ~ (-1). However, the capacitance of most graphene supercapacitors is far below this value. Especially in the case of high current charge and discharge, the capacitance is only 40 F / g ~ (-1) when the current density is 10 A / g ~ (-1). In this paper, boron nitride / graphene oxide (BN / RGOG) composite was prepared by assembling it with boron nitride (BN) and liquid phase exfoliated graphene (LGG) with graphene oxide (GOO) as the basic raw material. They are applied to the study of super capacitor energy storage. These inorganic composites can effectively reduce the agglomeration of graphene and facilitate the contact between electrolyte solution and electrode material. The research of these inorganic composite materials is of great scientific significance for the application of graphene in the field of energy storage. Therefore, the study of graphene binary inorganic composites has important potential application value in the field of energy and chemical industry. The research work of this paper mainly has the following two points: 1. BN / RGO was synthesized conveniently. This composite is used in the study of super capacitances, its capacitance is relatively large when the current density is 2 A g ~ (-1), it reaches 140 F / g ~ (-1), its rate performance is very good, and it still has a capacitance of 71.5 F / g ~ (-1) when the current density is 50 A / g ~ (-1), and its cycle performance is very good. After 1000 cycles at a scanning speed of 200mV / s ~ (-1), the capacitance increased by 5.5 times. These good capacitive properties show that BN/RGO has great potential application value in the field of super capacitor. Graphite oxide and graphene prepared by liquid phase stripping were assembled, and then FTG.FTG was prepared by ultrasonic and reduction reaction. It has good crystallization, three-dimensional structure and very uniform mesoporous. Supercapacitors based on FTG show enhanced electrochemical performance. The capacitance of FTG is 195.4 F / g ~ (-1) when the scanning speed is 1 MV / s ~ (-1) and 8000 cycles at the scanning speed of 500 MV / s ~ (-1). These results indicate that FTG is a super capacitor electrode material with good capacitance performance. The innovation of this paper lies in the preparation of metal-free and environmentally friendly graphene composites and their application in energy storage of super capacitors. These composite materials have the advantages of ideal energy storage effect, simple preparation method and convenient industrialization, so they have potential industrial application value in the field of energy and chemical industry.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB332;TM53

【相似文献】