超级电容器用炭基复合电极材料的研究

发布时间：2018-02-09 00:56

本文关键词： 超级电容器煤焦油渣四氧化三铁钼酸亚铁石墨烯铁酸钴镍碳纳米管　出处：《西南科技大学》2014年硕士论文　论文类型：学位论文

【摘要】：超级电容器是一种新型的储能元件,它具有比传统电容器更高的能量密度和比电池更高的功率密度,有望实现高倍率放电。电极材料是决定超级电容器性能的最主要因素。超级电容器电极材料主要包括碳材料、导电聚合物和金属氧化物等。碳材料具有比表面积大、导电性高、化学稳定性高等优点,但比电容较低；导电聚合物和金属氧化物具有较大的比电容,但循环稳定性较差。因此添加碳材料至导电聚合物或金属氧化物制备其复合物,从而获得高性能超级电容器电极材料,已成为目前研究的热点。本论文制备了三种碳材料与金属氧化物的复合物材料,并对其形貌、结构以及电化学性能进行研究,具体研究内容如下： (1)采用KOH化学活化煤焦油渣,再在N2保护下高温煅烧制备具有三维结构且富氧的活性炭。采用简单的化学沉淀法制备活性炭与Fe3O4的复合物,并用作超级电容器电极材料。在1.0mol dm-3的Na2SO3溶液中测试了它的电化学性能,结果表明,Fe3O4/AC复合物的比电容在电流密度3.0A g-1时达到150Fg-1,远高于单独的Fe304和AC电极材料,并且Fe3O4/AC复合物具有较好的循环稳定性,完成1000次循环充放电后几乎没有发生比电容的衰减。 (2)采用简单的水热合成法制备了FeMoO4/RGO复合物,并将其用作超级电容器电极材料。采用SEM和XRD对所制备材料的形貌和结构进行表征；通过循环伏安、计时电位和电化学阻抗法对所制备材料的电化学性能进行考察,电解液为1.0mol dm-3的Na2SO3溶液。结果表明,FeMoO4/RGO复合物的比电容在电流密度1.0Ag-1时达到135Fg-1远高于单独的FeMoO4和RGO电极材料,分别为96Fg-1和66Fg-1。而且相较FeMoO4和RGO, FeMoO4/RGO复合物具有更低的电阻和更长的循环稳定性。 (3)采用浓硝酸和浓硫酸混合液回流处理碳纳米管,对其进行改性,采用简单的水热合成法制备NiCoFe2O4/CNT复合物,并对其电化学性能进行研究,电解液为6.0mol dm-3的KOH溶液。结果表明,NiCoFe2O4/CNT复合物的比电容在电流密度0.5Ag-1时达到145Fg-1,远高于单独的NiCoFe2O4和CNT电极材料,分别为121Fg-1和35Fg-1。而且NiCoFe2O4/CNT复合物在500次循环充放电后的比电容保持率达到85.8%。
[Abstract]:Supercapacitor is a new energy storage element , which has higher energy density and higher power density than traditional capacitor . It is expected to realize high multiplying power discharge . The electrode material mainly includes carbon material , conductive polymer and metal oxide . The electrode material has the advantages of large specific surface area , high conductivity , high chemical stability and the like . The composite materials of three kinds of carbon materials and metal oxides were prepared , and their morphology , structure and electrochemical properties were studied . The results show that the specific capacitance of Fe3O4 / AC composite reaches 150fg - 1 when the current density is 3.0A g - 1 , far higher than that of the separate Fe304 and AC electrode materials , and the Fe3O4 / AC composite has good cycle stability . ( 2 ) The FeMoO4 / RGO composite was prepared by a simple hydrothermal synthesis method . The morphology and structure of the prepared materials were characterized by SEM and XRD . The results showed that the specific capacitance of FeMoO4 / RGO composite was higher than that of the single FeMoO4 and RGO electrode materials at the current density of 1.0Ag - 1 . The results showed that the specific capacitance of FeMoO4 / RGO composite was higher than that of the individual FeMoO4 and RGO electrode materials , and the phase was higher than that of FeMoO4 and RGO , and the FeMoO4 / RGO composite has lower resistance and longer cycle stability . ( 3 ) The carbon nanotubes were treated with concentrated nitric acid and concentrated sulfuric acid . The NiCoFe2O4 / CNT composite was prepared by a simple hydrothermal synthesis method . The electrochemical properties of NiCoFe2O4 / CNT composites were studied . The results showed that the specific capacitance of the NiCoFe2O4 / CNT composite reached 145 fg - 1 at the current density of 0.5Ag - 1 , which was much higher than that of the individual NiCoFe2O4 and CNT electrode materials . The ratio of the NiCoFe2O4 / CNT composite to 500 cycles was 85.8 % .

【学位授予单位】：西南科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM53;TQ317

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