化学改性对碳基纳米笼超级电容器性能的影响
发布时间：2019-06-04 05:41
【摘要】：随看人类对能源的需求不断增大,环境和能源问题日益凸显,开发高效能、环境友好、廉价的储能器件具有十分重要的意义,如超级电容器。超级电容器的核心是电极材料,一般要求电极材料具有比表面积大、导电性和稳定性良好、孔道结构合适、浸润性良好等特征。碳材料因为具有理想超级电容器电极材料所要求的多种特性而被广泛应用,碳材料的表面化学性质对双电层电容器(EDLC)性能有较大影响。在我们课题组制备出的具有多尺度分级孔结构、高比表面积、良好导电性、优异超级电容器性能的新型碳纳米笼的工作基础上,本论文研究表面化学改性对碳纳米笼超级电容器性能的影响,主要研究进展包括：1.表面官能团化提高EDLC性能：CNCs为前驱体,采用硝酸氧化法在CNCs表面引入含氧官能团,硝酸氧化的CNCs表现出显著优于纯CNCs的超级电容器性能：在1 Ag-1的电流密度下,CNC-6M样品比电容达到255 Fg-1,比纯CNCs的188 F g-1增加了34%：在相同电流密度下,氧化后样品的比电容均显著高于纯CNCs。在100 A g-1的大电流密度下,硝酸氧化后CNCs均具有良好的耐大电流充放电性能,其比电容保持在111-167 F g-1。在10 Ag-1的电流密度下循环10000圈后,CNC-6M样品的比电容由196 Fg-1下降到176F g-1,仅降低约10%。CNCs优异的超级电容器性能可归因于CNCs勺分级孔结构、高比表面积、良好的导电性、表面亲水性含氧官能团化带来的浸润性提高和引入的赝电容。2.磷原子掺杂：采用CVD法制备了不同磷含量的磷掺杂碳纳米笼(PCNCs)，在磷含量较低(1.0(at.%))时,其比电容值与纯碳纳米笼相比明显增大,磷含量为0.6(at.%)的800P1CNC在1 A g-1电流密度下的电容值高达192 F g-1,与800CNC的126 F g-1相比增大了52%,磷含量为0.4(at.%)的900PCNC的电容值由900CNC的36 F g-1提升到了56 F g-1。随着磷含量的增加,它们的比电容值逐渐减小,均低于纯碳纳米笼,同时磷的引入也增加了电荷和离子的传输、扩散电阻,即高磷含量的掺杂会降低碳纳米笼的超级电容性能。这对于深入研究磷掺杂等杂原子掺杂碳基材料的超级电容器性能提供有益参考。
[Abstract]:With the increasing demand for energy, the environment and energy problems are becoming more and more prominent. It is of great significance to develop high efficiency, environment-friendly and cheap energy storage devices, such as supercapacitors. The core of supercapacitor is electrode material, which generally requires the electrode material to have the characteristics of large specific surface area, good conductivity and stability, suitable pore structure, good wettability and so on. Carbon material is widely used because of its many characteristics required by ideal supercapacitor electrode material. The surface chemical properties of carbon material have great influence on the performance of double layer capacitor (EDLC). On the basis of the work of a new type of carbon nanocage with multi-scale graded pore structure, high specific surface area, good conductivity and excellent supercapacitor performance prepared by our research group, In this paper, the effect of surface chemical modification on the properties of carbon nanocage supercapacitors is studied. the main research progress is as follows: 1. Surface functionalization improves the performance of EDLC: CNCs is the precursor and oxygen-containing functional groups are introduced on the surface of CNCs by nitric acid oxidation. The performance of CNCs oxidized by nitric acid is significantly better than that of pure CNCs supercapacitor: at the current density of 1 Ag-1, The specific capacitance of CNC-6M sample reaches 255Fg-1, which is 34% higher than that of pure CNCs 188Fg-1. At the same current density, the specific capacitance of oxidized sample is significantly higher than that of pure CNCs.. At the high current density of 100 mg 鈮，
本文编号：2492511
[Abstract]:With the increasing demand for energy, the environment and energy problems are becoming more and more prominent. It is of great significance to develop high efficiency, environment-friendly and cheap energy storage devices, such as supercapacitors. The core of supercapacitor is electrode material, which generally requires the electrode material to have the characteristics of large specific surface area, good conductivity and stability, suitable pore structure, good wettability and so on. Carbon material is widely used because of its many characteristics required by ideal supercapacitor electrode material. The surface chemical properties of carbon material have great influence on the performance of double layer capacitor (EDLC). On the basis of the work of a new type of carbon nanocage with multi-scale graded pore structure, high specific surface area, good conductivity and excellent supercapacitor performance prepared by our research group, In this paper, the effect of surface chemical modification on the properties of carbon nanocage supercapacitors is studied. the main research progress is as follows: 1. Surface functionalization improves the performance of EDLC: CNCs is the precursor and oxygen-containing functional groups are introduced on the surface of CNCs by nitric acid oxidation. The performance of CNCs oxidized by nitric acid is significantly better than that of pure CNCs supercapacitor: at the current density of 1 Ag-1, The specific capacitance of CNC-6M sample reaches 255Fg-1, which is 34% higher than that of pure CNCs 188Fg-1. At the same current density, the specific capacitance of oxidized sample is significantly higher than that of pure CNCs.. At the high current density of 100 mg 鈮，
本文编号：2492511
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