以煤焦油沥青为炭前驱体,硫酸铵为发泡剂和氮源,KOH为活化剂,采用化学发泡耦合KOH活化制备氮掺杂三维结构多孔炭,通过调节碱炭比实现调控煤焦油沥青基多孔炭的微观结构和杂原子含量,研究了碱炭比和杂原子含量对多孔炭性能的影响。通过SEM、XPS、N2吸脱附等表征材料的结构和组成,采用恒流充放电、循环伏安、交流阻抗测试手段评估材料的电化学性能。结果表明化学发泡耦合KOH活化不仅优化了内部孔隙形成层次孔结构并在碳骨架中掺杂适量杂原子,双重作用下有效提高了多孔炭的电化学性能。优化后的NPC-2显示较高的比表面积(1636m2/g)、丰富的氮元素(5.27%)和相互交联的氮掺杂炭骨架。在三电极体系中,NPC-2电极材料获得较高的质量比电容,在电流密度为0.5A/g时,其质量比电容为374.2F/g;当电流密度高达100A/g时,其质量比电容仍可达249.5F/g,电容保持率可达66.7%,表现出优异的电化学性能。这种优异性能源于其发达的三维分级孔隙结构、较高的氮含量和优良的炭导电网络。

Using the coal tar pitch as the carbon precursor, ammonium sulfate as the foaming agent and nitrogen source, and KOH as theactivator.Nitrogen-doped three-dimensional structured porous carbon was prepared by chemical foaming coupled with KOH activation.The microstructure and heteroatom content of coal tar pitch based porous carbon were controlled by adjusting the alkali carbon ratio and theeffects of alkali carbon ratio and heteroatom content on the performance of porous carbon were investigated. The structure and compositionof the materials were characterized by SEM, XPS, and N2 adsorption and desorption, and the electrochemical properties of the materialswere evaluated with Galvanostatic Charge-Discharge, Cyclic Voltammetry, and Electrochemical Impedance Spectroscopy. The results showthat chemical foaming coupled with KOH activation not only optimizes the internal pores to form a hierarchical pore structure and dopesthe carbon skeleton with an appropriate amount of heteroatoms, but also effectively improves the electrochemical performance of the por⁃ous carbon under the dual effect. The optimized NPC-2 shows a high specific surface area (1 636 m2 / g), abundant nitrogen (5.27%),and mutually cross-linked nitrogen - doped carbon skeleton. In the three - electrode system, the NPC - 2 electrode material obtains ahigh mass specific capacitance with a mass specific capacitance of 374.2 F/ g at a current density of 0.5 A/ g; when the current density isas high as 100 A/ g, its mass specific capacitance can still reach 249.5 F/ g and the capacitance retention rate can reach 66.7%, showingexcellent electrochemical performance. This excellent performance is derived from the well-developed graded pore structure and excel⁃lent carbon conductive network.

0 引言

1 试验

   1.1 原料试剂及材料表征

   1.2 氮掺杂煤焦油沥青基多孔炭的制备 

   1.3 工作电极的制备与电化学性能测试

2 结果与分析

   2.1 微观形貌和结构分析

   2.2 电化学性能分析

3 结论