氮掺杂多孔碳的制备及其电化学性能研究

郭坤琨 陈鹏 李柱

摘 要：利用溶剂挥发结合高温热聚合法制备了氮掺杂多孔碳（NPC）材料，并通过SEM、TEM、TG、N2吸附-脱附、XPS等表征手段对样品的微观形貌结构和元素组成进行了分析.结果表明，氮元素掺杂明显增加材料的比表面积和孔体积，当制备的氮掺杂多孔碳材料的含氮量为4.2%（原子分数）时，它的比表面积高达422.0 m2/g高于没有氮掺杂样品的301.1 m2/g.此外，采用循环伏安、恒电流充放电和交流阻抗对NPC材料的电化学性能进行了深入研究.测试结果表明氮元素掺杂能够明显增加材料的比电容量，降低材料的内阻，极大提高碳材料的电化学性能.在0.5 A/g的电流密度下，通过氮元素掺杂使得材料的比电容从83.8 F/g提高至162.8 F/g，内阻值从1.39 Ω降低至0.47 Ω；并且所得的氮掺杂多孔碳样品具有良好的倍率性能和循环稳定性.

关键词：氮掺杂；多孔碳；电化学性能；超级电容器

中图分类号：O631 文献标志码：A

Abstract：Nitrogen-doped porous carbon （NPC） was successfully prepared by solvent evaporation combined with high temperature thermal polymerization in the present study. The microstructure and element composition of the samples were characterized by SEM， TEM， Thermogravimetric analyzer （TG）， N2 adsorption-desorption and X-Ray Photoelectron Spectroscopy （XPS）. The results showed that the nitrogen content of the nitrogen-doped porous carbon was 4.2 at% and the specific surface area was as high as 422.0 m2/g higher than that of the nitrogen-free sample（301.1 m2/g）， and the specific surface area and pore volume of the samples were obviously increased by nitrogen element doped. Subsequently， the obtained NPC was also characterized with cyclic voltammetry curves， constant current charge discharge curves and AC impedance spectra.The electrochemical results showed that nitrogen doped method could significantly increase the specific capacitance of the sample， reduce the internal resistance of the porous carbon， and greatly improve the electrochemical properties of the carbon material. At the current density of 0.5 A/g， the specific capacitance of N-doped porous carbon was increased from 83.8 F/g to 162.8 F/g， and the internal resistance was reduced from 1.39 Ω to 0.47 Ω.Furthermore， nitrogen-doped porous carbon possessed good rate performance and cyclic stability.

Key words：nitrogen-doped； porous carbon； electrochemical performance； supercapacitors

超級电容器又叫电化学电容器，是一种新型储能元件，具有比电池更高的功率密度和比传统电容器更大的能量密度，因其具有功率密度高、充放电速率快、循环寿命长等优点成为当前的研究热点[1].电极材料作为超级电容器最重要的组成部分，对超级电容器的性能有着决定性影响.多孔碳材料由于其具有比表面积大、化学稳定性强、廉价易得等优点被广泛应用于双电层超级电容器的电极材料[2-3].如活性炭材料的理论双电层电容率为19 μF/cm2，比表面积为1 000 m2/g的活性炭比电容量可达近200 F/g[4].然而，Qu等通过不同……