【作者】 戴春岭；

【导师】 王先友；

【作者基本信息】 湘潭大学 ， 物理化学， 2008， 硕士

【摘要】 超级电容器是一种新型的能量储存装置,又称电化学电容器或双电层电容器,其容量可达到法拉级甚至数万法拉,比能量是传统电容器的20-200倍。此外还兼有功率密度大、温度范围宽（-20-60℃）、无污染、长寿命等优良特性,在介于可充电电池和传统电容器的应用领域逐渐崭露头角。由于超级电容器具有广阔的应用前景,开展超级电容器电极材料、电解液等的基础研究,在民用和国防领域均具有重要意义。本文以廉价碳化钙为前驱体,实验室自制高活性氯气为刻蚀剂,通过一步合成法制备了碳化钙骨架碳材料。用X-射线衍射（XRD）,扫描电镜（SEM）,透射电镜（TEM）等对制备的碳化钙骨架碳样品的物理性能进行表征。研究结果表明:碳化钙骨架碳具有纳米多孔结构,孔洞相互连通,其XRD谱图显示碳化钙骨架碳是由两个宽化的衍射峰组成,说明碳化钙骨架碳为非晶态结构。随着反应温度升高至600℃,（002）衍射峰变窄,表明骨架碳材料有部分石墨化倾向。表面积及孔径分析显示,100℃所制备的骨架碳具有较大的比表面积,其值达800 m²g^-1。随着反应温度的升高,比表面积逐渐下降,所得的碳化钙骨架碳具有窄孔径分布,范围为1.4-17 nm,平均孔径与制备温度密切相关。随着制备温度从100℃升高至600℃,平均直径从1.9 nm增加至3.8 nm。将不同温度下制备的碳化钙骨架碳材料用作超级电容器的电极材料,6molL^-1 KOH溶液作为电解液,组装了对称型扣式电容器,采用一系列的电化学方法研究了不同温度下制备的碳化钙骨架碳的电化学性能。结果表明:碳化钙骨架碳作为超级电容器的电极材料具有较大的比电容,400℃制备的碳化钙骨架碳单电极的比电容达174.6 Fg^-1;且用骨架碳材料作电极的超级电容器具有较好的可逆性、较高的充放电效率、稳定的循环寿命,特别是用400℃制备的骨架碳材料作电极的电容器循环10000次容量衰减仅为5%。活化处理是提高碳材料性能的一个有效方法。将200℃,400℃和600℃制备的碳化钙骨架碳在70℃浓硝酸中活化处理,用红外光谱仪研究其表面含氧官能的变化,用电化学方法研究活化对碳化钙骨架碳电极性能的影响。结果显示:硝酸活化可以使骨架碳材料的表面含氧官能团含量增加,从而增加了电极材料的亲水性,与电解液的接触更加充分,使骨架碳电极的比电容有所增加。更多还原

【Abstract】 The supercapacitor is a new type of electrochemical energy storage devices, which also called electrochemical capacitor （EC） or electrical double layer capacitor （EDLC）. The capacitance of supercapacitor can reach the order of Farad （F） even ten thousand Farads （F）. At the same time its specific energy density is 20-200 times of traditional capacitor. Environment-friendly Supercapacitor can work in wide temperature range of -20℃-60℃. Besides, it has much higher power density, much longer cycle life. Supercapacitor has begun filling the niche between electrochemical batteries and dielectric capacitors. Because of their wide application foreground, it’s of great importance to conduct a series of experimental studies on electrode materials and electrolytes for the application of supercapacitor, which can promote the development in the the civil and military field.In this study, a new type of one-step preparation technique for the calcium carbide-derived- carbon （CCDC） was developed. CCDC was synthesized from CaC₂ in a freshly prepared chlorine environment in the temperature range of 100-600℃. The structure and morphology of CCDCs were studied by x-ray diffraction （XRD）, scanning electron microscopy （SEM） and transmission electron microscopy （TEM）. The results showed that CCDCs were amorphous nanoscaled materials, which pores were interlaced. XRD indicated they consisted of two broad peaks and the CCDCs structures depended on the synthesis temperature. When reaction temperature was at 600℃, the （002） diffraction peak of CCDCs became more narrow, which was due to the beginning of graphitization tendency. Porosity measurements demonstrated that the CCDCs had narrow pore size distribution （1.4-17 nm） and specific surface area close to 800 m²g^-1 at a synthesized temperature of 100℃. The average pore size increased from1.9 nm to 3.8 nm with reaction temperature increasing from 100℃to 600℃.Coin cell supercapacitors were assembled by CCDCs as electrode materials and 6 molL^-1 KOH as electrolyte. The coin cells were studied by a series of electrochemical measurements. The results showed that the CCDCs electrodes exhibitated good electrochemical performances, high reversibility and high charge-discharge efficiency in KOH electrolyte. The specific capacitance of electrode with the CDCC prepared at 400℃had maximum capacitance of 174.6 Fg^-1. The coin cell was cycled for 10000 cycles, and specific capacitance had only a decrease of 5%.Activation is a good method to improve the electrochemical performances of electrode materials. The CCDCs synthesized at 200°C, 400°C, 600°C were treated in nitric acid （HNO₃） at 70°C. Oxygenous functions on the surface of CCDCs were studied by infrared spectrometer （IR）. The capacitive properties of treated CCDCs were studied by a series of electrochemical tests. It was found that the moderate content of oxygenous functions on the surface of CDCCs could result in a higher specific capacitance.更多还原