超级电容器是一种新型储能装置，电极材料作为其关键部件一直备受关注，其中电极材料的改性处理对于高性能超级电容器的研究至关重要。以河北无烟煤为前驱体，KOH为活化剂，碱与煤的质量比为2∶1，活化温度为800 ℃制备具有高比表面积的煤基电容炭(2 586 m2/g)。以煤基电容炭为原料，考察了电容炭在不同温度(600～1 000℃)氢热还原过程中微观结构与表面化学性质的演变及其对电化学性能的影响。结果表明，随着氢热还原温度的升高，样品的比表面积先略微升高后逐渐降低，中孔率较原煤基电容炭相比均有不同程度的提高。其中，700 ℃氢热还原处理得到的样品具有较低的氧含量(0.35%)、较强的导电性、与有机电解液之间较好的润湿性以及较高的缺陷程度，电化学性能得到显著的提高，具有较高的比电容(0.5 A/g电流密度下为179 F/g)、能量密度(33.36 Wh/kg)、功率密度(1 014.75 W/kg)、倍率性能(电流密度为5 A/g时的电容保持率为58.7%)和循环稳定性(5 000次循环电容保持率为82%)。对于煤基电容炭而言，氢热还原是一种良好的改性处理方法。

Supercapacitor is a new type of energy storage device,and electrode material as its key component has been attracting much attention,among which the modification treatment of electrode material is crucial for the research of high-performance supercapacitor.Coal-based capacitive carbon with high specific surface area (2 586 m2/g) was prepared with using Hebei anthracite coal as the precursor,KOH as the activator,alkali to coal mass ratio of 2∶1 and activation temperature of 800 ℃. The evolution of microstructure and surface chemistry of the capacitance carbon during hydrothermal reduction at different temperatures (600-1 000 ℃) and their effects on electrochemical properties were investigated by using coal-based capacitance carbon as raw material. The results show that with the increase of hydrothermal reduction temperature,the specific surface area of the samples first slightly increases and then gradually decreases,and the mesoporosity increases to different degrees compared with the original coal-based capacitive carbon. Among them,the samples obtained by hydrothermal reduction treatment at 700 ℃ have lower oxygen content (0.35%),stronger electrical conductivity,better wettability with organic electrolyte and higher degree of defects,and the electrochemical properties has been significantly improved:higher specific capacitance (179 F/g at 0.5 A/g current density),energy density (33.36 Wh/kg),power density (1 014.75 W/kg),multiplicative performance (58.7% capacitance retention at 5 A/g current density),and cycling stability (82% capacitance retention at 5 000 cycles). For coal-based capacitive carbon,hydrothermal reduction is a good modification treatment.

0 引言

1 试验

   1.1 试验原料

   1.2 样品制备

   1.3 材料表征

   1.4 电容炭电极制作及电容器组装

   1.5 电化学性能测试

2 结果与讨论

   2.1 电容炭的孔结构

   2.2 活性炭的微观结构

   2.3 活性炭的表面性质

   2.4 电化学性能

3 结论