以菌丝为模板合成铈锰氧化物—石墨烯复合材料及其超级电容性能研究

发布时间：2018-04-01 20:33

  本文选题：石墨烯　切入点：超级电容器　出处：《苏州科技学院》2015年硕士论文

【摘要】：随着社会的发展,日益普及的各种便携式电子设备和电动汽车等对储能设备的要求日益提高。超级电容器是介于普通电容器和充电电池之间的一种储能设备,可广泛应用于电动车辆、消费电子类、医学仪器等需要快速充电的产品,其具有更高的能量存储密度、更长的循环使用寿命、更低的维护成本和更快的充放电能力等特点。目前三种电极材料在超级电容器中用得比较多,分别有碳基材料、导电聚合物和金属氧化物,碳基材料更是超级电容器的核心材料。传统的碳材料自身存在较多的封闭孔道,内阻较大,电容量偏低等缺点,远不能满足需求;碳纳米管的应用成本昂贵,使得没法在实际生活中批量生产。石墨烯的出现,打破了这一难题,而且具有卷曲结构的石墨烯能够更好的储存电荷。本文尝试通过培养具有长管结构的菌丝,以极简单的方式制备品质较高的多壁石墨烯管。利用晶格类型相异的MnO2与CeO2同时生长,既为了提高石墨烯电极的储能密度,也有利于MnO2的晶粒纳米化可避免电极因长期电化学反应产生大块晶体导致的性能丧失,降低金属氧化物在反复充放电过程中循环寿命的不稳定性。采用XRD、SEM、Raman、FT-IR、AFM、TEM,氮气吸脱附等方法进行表征,通过使用循环伏安法、恒流充放电法分析复合电极材料的电化学性能。结果表明,利用特殊模板——菌丝,在氮气保护下的管式炉中700℃保温100 min就可以制备出高性能多壁石墨烯管,制备方法简单廉价。所制备出的石墨烯管材料的比表面积高达385.4 m2/g,而且所制备的材料缺陷少,层数大约4-5层。向石墨烯基体中加入MnO2后,比电容为295 F·g-1,相对于纯石墨烯管材料和普通商业碳粉电极材料的电容,电性能明显有了提高。CeO2掺杂入MnO2中,生成超细纳米颗粒,粒径只有10 nm以下,均匀负载到石墨烯管,能够制备石墨烯 铈锰氧化物复合材料。通过CV和CP测试,这种材料显示出远超普通商业碳粉电极材料的比电容性能,比电容有400 F·g-1,而碳粉电极仅26 F·g-1。试验结果表明所研究的石墨烯-铈锰氧化物复合材料能用于制备高性能超级电容器。
[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，

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