锰氧化物基超级电容器电极材料的制备及性能研究

发布时间：2018-01-12 20:15

  本文关键词：锰氧化物基超级电容器电极材料的制备及性能研究　出处：《哈尔滨工业大学》2015年硕士论文　论文类型：学位论文

  更多相关文章： 超级电容器 石墨烯 炭黑 锰氧化物 电极材料

【摘要】：近些年来,超级电容器因为其诸多优势而逐渐受到越来越多的研究人员的关注,很多人都将其视为一种很具潜力的电化学储能设备。在目前研究中,碳基材料与过渡金属氧化物的复合材料因为其资源丰富、价格低廉和环境友好以及良好的电化学性能而成为研究热点。但是石墨烯材料的制备成为了该项研究的症结所在,这是因为石墨烯材料在还原的过程中容易发生团聚而使得所制得的材料丧失了石墨烯的优异性能。在本课题研究中,我们采用一定的方法来抑制石墨烯的团聚,在随后的过程中将所制得的石墨烯基材料与锰氧化物复合,并测试复合材料的电化学性能。通过在氧化石墨烯还原之前加入炭黑的方法,制得石墨烯-炭黑复合材料。通过对该材料进行SEM形貌和拉曼表征,对比氧化石墨烯还原之前加入炭黑和氧化石墨烯还原之后加入炭黑所制得的样品,发现炭黑的添加一定要在氧化石墨烯的还原之前进行,否则即便加入还原之后加入炭黑也很得到炭黑阻止石墨烯团聚的效果。而且炭黑的最佳添加比例为氧化石墨:炭黑=10:1。在KMnO_4与石墨烯-炭黑复合材料中碳原子反应制备的电极材料中,反应温度为120℃,KMnO_4与石墨烯-炭黑复合材料的添加量分别为50 mg和110 mg时制备得到的样品比电容最大,在电流密度为1 A/g和0.5 A/g时分别可以达到118F/g和146.7 F/g。该反应在120℃和150℃下不仅会生成Mn_3O_4,也会生成杂质相MnOOH和MnCO_3。并且随着KMnO_4浓度的增加,Mn_3O_4会逐渐发生团聚现象,这样会导致比电容的下降。在KMnO_4与乙二醇反应制备Mn_3O_4的样品中,最大比电容在电流密度为1A/g和0.5 A/g时分别仅为62.1 F/g和77.9 F/g。单纯Mn_3O_4由于其电导率低下,并不能使Mn_3O_4完全发挥其优良的赝电容特性。由于石墨烯-炭黑复合材料的存在,一方面提高了Mn_3O_4的电导率,另一方面使得Mn_3O_4结构细化,增加其与电解液的接触面积,进而增大比电容。但是随着石墨烯-炭黑复合材料的加入,反应中也会生成一定的杂质相。综合比较两种不同的制备方法易知,KMnO_4与石墨烯-炭黑复合材料反应的原位生长法是一种更加合理且具有实用意义的方法。
[Abstract]:In recent years, supercapacitors have attracted more and more attention from researchers because of their many advantages. Many people regard supercapacitors as a potential electrochemical energy storage equipment. Carbon based composites with transition metal oxides are rich in resources. Low cost, environment-friendly and good electrochemical performance have become the focus of research, but the preparation of graphene materials has become the crux of the study. This is because graphene materials are prone to agglomeration in the process of reduction, which results in the loss of the excellent performance of graphene. In this study, we used certain methods to suppress the agglomeration of graphene. In the subsequent process, the graphene based materials were compounded with manganese oxides, and the electrochemical properties of the composites were tested by adding carbon black before the reduction of graphene oxide. The graphene carbon black composites were prepared. The SEM morphology and Raman characterization were used to compare the samples prepared by adding carbon black and graphene oxide before reduction and adding carbon black after reduction of graphene oxide. It was found that the addition of carbon black must be carried out before the reduction of graphene oxide. Otherwise, the effect of carbon black on the agglomeration of graphene was obtained even after adding carbon black after reduction. The best addition ratio of carbon black is graphite oxide: carbon black 10:. 1. In the electrode material prepared by the reaction of KMnO_4 with carbon atom in graphene carbon black composite. The maximum specific capacitance was obtained when the reaction temperature was 120 鈩，

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