發(fā)布時間：2018-04-12 06:20

  本文選題：石墨烯 + 錳氧化物��； 參考：《北京交通大學》2014年碩士論文

【摘要】：進入21世紀,能源的日益枯竭和環(huán)境污染問題越來越嚴重,發(fā)展風能、太陽能等新能源和電動汽車成為全世界的共識,因此發(fā)展新型的高性能能量存儲裝置越來越迫切。超級電容器作為一種介于電池和傳統(tǒng)電容器之間的新型儲能裝置,具有高的功率密度,長的循環(huán)壽命,高的放電效率,較寬的溫度適用范圍,環(huán)境友好性,安全性,易維護等優(yōu)異性能而成為儲能領(lǐng)域的研究熱點。超級電容器能量密度較低,是限制其商業(yè)化發(fā)展的最大因素。目前超級電容器的研究,主要是探索和改善高性能電極材料,從而提高超級電容器的能量密度。本文選定高表面積、高導電性的石墨烯和廉價的錳氧化物作為超級電容器的電極材料,結(jié)合多種材料表征測試方法和電化學性能測試的研究手段,研究了合成的電極材料的相關(guān)性能。本文主要研究成果如下 (1)提出一種新的液相的沉淀法,合成了納米Mn3O4顆粒和Mn3O4／石墨烯復合材料,并對材料進行了XRD、TEM、SEM和電化學性能表征；得到的復合材料中,Mn3O4顆粒均勻分散在石墨烯片層上,使得Mn3O4贗電容得到更有效地利用,石墨烯能極大地改善體系的導電性。Mn3O4/石墨烯復合材料在表現(xiàn)出140F/g的比電容(10mV/s下),經(jīng)過1000次循環(huán)后仍保持約96%的容量,展現(xiàn)出極好的循環(huán)穩(wěn)定性。 (2)利用乙醇還原高錳酸鉀的方法,制備了納米MnO2,并且將納米Mn02與石墨烯／碳納米管體系復合。合成的MnO2/GNS/CNTs三元復合材料展現(xiàn)出優(yōu)異的電化學性能,尤其是其倍率性能和循環(huán)穩(wěn)定性。在MnO2/GNS/CNTs復合材料中的Mn02成分在5mV/s的掃描速率下最大表現(xiàn)出240F/g的比電容,遠大于純MnO2電極(192F/g)的比電容。 (3)為了進一步優(yōu)化MnO2/GNS/CNTs三元復合材料體系中,研究了不同的GNS/CNTs比例對電化學性能的影響。組裝了對稱的超級電容器,最大的能量密度為11.9Wh/kg,優(yōu)于商用活性炭超級電容器(一般小于5Wh/kg)。
[Abstract]:In the 21st century, the problem of energy depletion and environmental pollution is becoming more and more serious. The development of new energy sources such as wind energy, solar energy and electric vehicles has become a consensus all over the world. Therefore, the development of new high-performance energy storage devices is becoming more and more urgent.As a new energy storage device between batteries and conventional capacitors, supercapacitors have high power density, long cycle life, high discharge efficiency, wide temperature range, environmental friendliness and safety.Easy maintenance and other excellent performance has become a research hotspot in the field of energy storage.The low energy density of supercapacitors is the biggest factor limiting the development of their commercialization.At present, the research of supercapacitors is mainly to explore and improve the high performance electrode materials, so as to improve the energy density of supercapacitors.In this paper, graphene with high surface area and high conductivity and cheap manganese oxide are selected as electrode materials for supercapacitors.The properties of the synthesized electrode materials were studied.The main research results of this paper are as follows(1) A new liquid phase precipitation method was proposed to synthesize nano-sized Mn3O4 particles and Mn3O4/ graphene composites, which were characterized by SEM and electrochemical properties, and the particles of mn _ 3O _ 4 in the composites were uniformly dispersed on graphene lamellae.The pseudo-capacitance of Mn3O4 can be utilized more effectively, and graphene can greatly improve the conductivity of the system. Mn _ 3O _ 4 / graphene composite shows the specific capacitance of 140F/g at 10 MV / s, and maintains the capacity of about 96% after 1000 cycles.Show excellent cyclic stability.Nanocrystalline MNO _ 2 was prepared by reducing potassium permanganate by ethanol, and nanosized Mn02 and graphene / carbon nanotube system were prepared.The synthesized MnO2/GNS/CNTs ternary composites exhibit excellent electrochemical properties, especially their rate performance and cyclic stability.The Mn02 composition in the MnO2/GNS/CNTs composite exhibits the maximum specific capacitance of 240F/g at the scanning rate of 5mV/s, which is much larger than that of the pure MnO2 electrode (192F / g).In order to optimize the electrochemical properties of MnO2/GNS/CNTs ternary composites, the effects of different GNS/CNTs ratios on electrochemical properties were studied.Symmetrical supercapacitors were assembled with a maximum energy density of 11.9 Whs / kg, which is superior to commercial activated carbon supercapacitors (typically less than 5 Whs / kg 路kg ~ (-1) 路kg ~ (-1)).
【學位授予單位】：北京交通大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：TQ127.11;TM53

【參考文獻】

相關(guān)期刊論文 前1條

1 Thang Ngoc Cong;;Progress in electrical energy storage system:A critical review[J];Progress in Natural Science;2009年03期

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本文編號：1738530