超级电容器用碳基电极材料研究

【作者】 谭强；

【导师】 秦川丽；

【作者基本信息】 黑龙江大学 ， 高分子化学与物理， 2009， 硕士

【摘要】 本论文采用SEM、XPS、激光粒度分析法、循环伏安法、恒流充放电法研究了活性碳、碳纳米管、碳气凝胶三种碳材料以及三聚氰胺树脂基含氮碳材料、三聚氰胺树脂基含氮碳/碳气凝胶、三聚氰胺树脂基含氮碳/氧化石墨三种含氮碳材料作为超级电容器负极材料的结构特点以及电化学性能,并通过纯化,活化等手段提高材料有效比表面积,以期得到高比容量的超级电容器用负极材料。研究结果表明,论文所研究的碳材料和含氮碳材料及其复合材料在储能方式上均为双电层静电吸附形式,所有材料经过KOH活化后比容量都有所提高。三种碳材料中,活性碳具有最高的比容量,循环伏安法测试其比容量由活化前的161.9F/g变为活化后的202.8F/g,恒流充放电测试其比容量由活化前的92.4F/g变为活化后的118.0F/g。活化后三聚氰胺甲醛树脂基含氮碳材料比纯碳材料具有更高的比容量,循环伏安法测得比容量为230.7 F/g,恒流充放电测得比容量为122.3 F/g,这是由于氮原子的引入增加了材料亲水的极性活性点位置,提高了电解质溶液对材料的浸润性,从而提高了材料储存电荷的能力。论文还考察了不同复合比例的三聚氰胺树脂基含氮碳/碳气凝胶复合材料做负极,Ni(OH)2/Co(OH)2材料作为正极材料组装的不对称型单体超级电容器的电化学性能及测试电流密度对其电化学性能的影响。测试结果表明:此单体电容器既有双电层电容性质又有赝电容性质;当复合材料中三聚氰胺树脂基含氮碳质量与碳气凝胶质量为12:1时单体电容器具有最高的比容量值,循环伏安法测得比容量为312.8F/g恒流充放电测得比容量为99.8F/g;组装的不对称型单体超级电容器具有大电流快速充放电性能,三聚氰胺树脂基含氮碳/碳气凝胶复合材料具有优良的循环稳定性,适宜做超级电容器负极材料。更多还原

【Abstract】 In this paper, three kinds of carbon materials including the activative carbon, carbon nanotubes, carbon aerogel and three kinds of nitrogen-enriched carbon materials including nitrogen-enriched carbon preprared by carbonization of melamine-formaldehyde resin, nitrogen-enriched carbon/carbon aerogel composites,nitrogen-enriched carbon/graphite oxide composites were studied as cathode materials of supercapacitors by SEM, XPS, laser grain size analysis, cyclic voltammetry and galvanostatic charge/discharge techniques. The structure and the electrochemical properties were detected. The methods of purification and activation were used in order to improve the effective specific surface areas of materials and obtain cathode materials of supercapacitors with high Cp.The results showed that carbon materials and nitrogen-enriched carbon studied in our paper stored the energy in the style of double layer adsorption and Cp of all the material was improved by KOH activation. In the three kinds of carbon materials, active carbon had the highest Cp. The Cp of active carbon is improved from 161.9 F/g to 202.8F/g tested by the cyclic voltammetry technique and was improved from 92.4 F/g to 118.0F/g tested by the galvanostatic charge/discharge technique. The Cp of activated nitrogen-enriched carbon based on melamine resin was 230.7 F/g tested by the cyclic voltammetry technique and is 122.3 F/g tested by the galvanostatic charge/discharge technique which were higher than those of carbon materials. It was due to that the introduction of nitrogen atoms increased the hydrophilic polarity location and improved wetting ability of materials, thereby improved the capability of storage charges.The electrichemical properties of asymmetrical unit supercapacitors, which were assembled by nitrogen-enriched carbon/carbon aerogel composites with different ratios of nitrogen-enriched carbon and carbon aerogels as cathode and Ni (OH)2/Co(OH)2 composites as anode, and the influence of current density on the electrichemical properties of the asymmetrical supercapacitors were studied. The results showed that the asymmetrical supercapacitors showed the double layercapacitance and and paeudo capacitance.The asymmetrical supercapacitor 12:1 showed the highest Cp when the mass ratio of nitrogen-enriched carbon and carbon aerogels is 12:1.The Cp was 312.8 F/g tested by the cyclic voltammetry technique and was 99.8F/g tested by the galvanostatic charge/discharge technique. The asymmetrical supercapacitors can quickly charge and discharge at high current density And the nitrogen-enriched carbon/carbon aerogel composites had excellent cycling stability which was suitable cathode materials of supercapacitors.更多还原