發(fā)布時間：2018-04-01 20:33

  本文選題：石墨烯　切入點：超級電容器　出處：《蘇州科技學(xué)院》2015年碩士論文

【摘要】：隨著社會的發(fā)展,日益普及的各種便攜式電子設(shè)備和電動汽車等對儲能設(shè)備的要求日益提高。超級電容器是介于普通電容器和充電電池之間的一種儲能設(shè)備,可廣泛應(yīng)用于電動車輛、消費電子類、醫(yī)學(xué)儀器等需要快速充電的產(chǎn)品,其具有更高的能量存儲密度、更長的循環(huán)使用壽命、更低的維護成本和更快的充放電能力等特點。目前三種電極材料在超級電容器中用得比較多,分別有碳基材料、導(dǎo)電聚合物和金屬氧化物,碳基材料更是超級電容器的核心材料。傳統(tǒng)的碳材料自身存在較多的封閉孔道,內(nèi)阻較大,電容量偏低等缺點,遠(yuǎn)不能滿足需求;碳納米管的應(yīng)用成本昂貴,使得沒法在實際生活中批量生產(chǎn)。石墨烯的出現(xiàn),打破了這一難題,而且具有卷曲結(jié)構(gòu)的石墨烯能夠更好的儲存電荷。本文嘗試通過培養(yǎng)具有長管結(jié)構(gòu)的菌絲,以極簡單的方式制備品質(zhì)較高的多壁石墨烯管。利用晶格類型相異的MnO2與CeO2同時生長,既為了提高石墨烯電極的儲能密度,也有利于MnO2的晶粒納米化可避免電極因長期電化學(xué)反應(yīng)產(chǎn)生大塊晶體導(dǎo)致的性能喪失,降低金屬氧化物在反復(fù)充放電過程中循環(huán)壽命的不穩(wěn)定性。采用XRD、SEM、Raman、FT-IR、AFM、TEM,氮氣吸脫附等方法進行表征,通過使用循環(huán)伏安法、恒流充放電法分析復(fù)合電極材料的電化學(xué)性能。結(jié)果表明,利用特殊模板——菌絲,在氮氣保護下的管式爐中700℃保溫100 min就可以制備出高性能多壁石墨烯管,制備方法簡單廉價。所制備出的石墨烯管材料的比表面積高達(dá)385.4 m2/g,而且所制備的材料缺陷少,層數(shù)大約4-5層。向石墨烯基體中加入MnO2后,比電容為295 F·g-1,相對于純石墨烯管材料和普通商業(yè)碳粉電極材料的電容,電性能明顯有了提高。CeO2摻雜入MnO2中,生成超細(xì)納米顆粒,粒徑只有10 nm以下,均勻負(fù)載到石墨烯管,能夠制備石墨烯 鈰錳氧化物復(fù)合材料。通過CV和CP測試,這種材料顯示出遠(yuǎn)超普通商業(yè)碳粉電極材料的比電容性能,比電容有400 F·g-1,而碳粉電極僅26 F·g-1。試驗結(jié)果表明所研究的石墨烯-鈰錳氧化物復(fù)合材料能用于制備高性能超級電容器。
[Abstract]:With the development of society, more and more portable electronic devices and electric vehicles are increasingly required for energy storage. Supercapacitors are a kind of energy storage equipment between ordinary capacitors and rechargeable batteries. Can be widely used in electric vehicles, consumer electronics, medical instruments and other products requiring rapid charging, with a higher energy storage density, longer cycle life, At present, three kinds of electrode materials are used in supercapacitors, such as carbon-based materials, conductive polymers and metal oxides. Carbon-based materials are also the core materials of supercapacitors. Traditional carbon materials have many defects such as large internal resistance, low capacitance and so on, which can not meet the demand. The application cost of carbon nanotubes is expensive. The appearance of graphene breaks this problem, and graphene with curl structure can store electric charge better. In this paper, we try to culture mycelium with long tube structure. Multiwalled graphene tubes of high quality were prepared in a very simple way. The MnO2 with different lattice types was used to grow simultaneously with CeO2 in order to increase the energy storage density of graphene electrodes. It is also beneficial to the nanocrystalline MnO2 to avoid the loss of the properties of the electrode due to the large crystals produced by the electrochemical reaction for a long time. In order to reduce the instability of cyclic life of metal oxides during repeated charge and discharge, the cyclic life of metal oxides was characterized by means of XRDX SEMU Ramanan FT-IRT-AFMTEM, nitrogen adsorption and desorption, and cyclic voltammetry was used. The electrochemical properties of composite electrode materials were analyzed by constant current charge-discharge method. The results showed that high performance multiwalled graphene tubes could be prepared by using a special form-mycelium under nitrogen protection at 700 鈩，

本文編號：1697211