石墨烯基不对称超级电容器的研究

发布时间：2018-07-18 11:14

【摘要】：不对称型超级电容器,一般也常被称之为混合型超级电容器,这类超级电容器的得名主要是其结构即两个电极分别由不同的材料组成。由于其充分结合利用了两种储存电容的机理,所以具有比能量高、比功率大和循环性能良好、无污染等优点,具有很高的实际应用价值,可以应用在新能源蓄电池、移动式电子设备、大型导弹军事装备、车辆、野外作业、空间飞行物等领域。而对超级电容器的性能有十分重要影响的关键之一为电极材料的选择,这也是目前不对称超级电容器的研究热点,目前,常用的电极材料有碳材料、金属氧化物和导电聚合物。石墨烯因比表面积大、强的力学性能、优异的导热性能及导电性能,因此它在电子器件器皿、电池电容器、生物材料以及力学增强等很多领域具有非常大的应用前景。特别是石墨烯的大比表面积和优异的电导特性,这些特点使他在超级电容器的研究制备方面具有很好的应用前景。本文以石墨烯(采用改进的Hummers法制备)为基体,使其分别与共沉淀法制备的橄榄石LiFePO_4、微波反应制备的无定形MnO_2以及水热法制备的Fe_2O_3颗粒复合成为正极材料与石墨烯负极材料组成不对称电容器。所制备的磷酸铁锂/石墨烯||石墨烯不对称超级电容器工作窗口电压为3V,在能量密度为42.8Wh/kg时,其功率密度为1284W/kg;二氧化锰/石墨烯|石墨烯不对称超级电容器的工作窗口电压为1.4V,其能量密度为23.59Wh/kg时,其功率密度为7018W/kg;三氧化二铁/石墨烯||石墨烯不对称超级电容器的工作窗口电压为1V,其能量密度为11.8Wh/kg时,其功率密度为786.43W/kg。
[Abstract]:Asymmetrical supercapacitors are often referred to as hybrid supercapacitors. The name of these supercapacitors is the structure of which two electrodes are composed of different materials. Because it combines the two kinds of storage capacitance fully, it has the advantages of high specific energy, high specific power, good cycle performance, no pollution and so on. It has high practical application value and can be used in new energy storage battery. Mobile electronic equipment, large-scale missile military equipment, vehicles, field operations, space flying objects and other fields. The selection of electrode materials is one of the most important factors affecting the performance of supercapacitors, which is the research hotspot of asymmetric supercapacitors. At present, the commonly used electrode materials are carbon materials, metal oxides and conductive polymers. Because of its large specific surface area, strong mechanical properties, excellent thermal conductivity and conductive properties, graphene has great application prospects in many fields, such as electronic devices, battery capacitors, biomaterials and mechanical enhancement. Especially the large specific surface area and excellent electrical conductivity of graphene make it have a good application prospect in the research and preparation of supercapacitors. In this paper, graphene (prepared by improved Hummers method) was used as the matrix. The composite of them with olivine LiFePO4 prepared by coprecipitation method, amorphous MnO _ 2 prepared by microwave reaction and Fe _ S _ 2O _ 3 prepared by hydrothermal method is composed of cathode material and graphene negative electrode material. The working window voltage of the prepared lithium iron phosphate / graphene asymmetric supercapacitor is 3V, and the energy density is 42.8 Wh.kg. The power density is 1284 W / kg; the working window voltage of the manganese dioxide / graphene asymmetric supercapacitor is 1.4 V, and its energy density is 23.59 Wh-1 / kg. Its power density is 7018W / kg, and the working window voltage is 1V and the energy density is 11.8Wh/ kg, and the power density is 786.43W / kg.
【学位授予单位】：武汉工程大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ127.11;TM53

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