化学活化和化学-物理联合活化制备石油焦基活性炭

Petroleum coke based activated carbon prepared from chemical activation and chemical-physical activation

以石油焦为原料,采用化学活化和化学-物理联合活化2种活化工艺分别制备超级电容器用活性炭材料CA和CB。采用N2吸附法表征活性炭材料的BET比表面积及孔隙结构;通过恒电流充放电、循环伏安、交流阻抗等电化学测试方法,对2种活性炭在有机电解液中的电化学特性进行研究。研究结果表明,CA具有较高的收率、振实密度以及BET比表面积,分别可达61.28%,0.35g/cm3和2760m2/g;CB具有较高的中孔率和平均孔径,分别为24.1%和2.3nm;在充放电电流密度为1A/g时,CA的质量比电容量为137.8F/g;而CB表现出较好的功率特性,在20A/g时,质量比容量仅比1A/g时的质量比容量衰减4.7%。

Taking petroleum cokes as raw material, activated carbons CA and CB were prepared by chemical activation and chemical-physical activation. The BET specific surface area and the pore structure of activated carbons were analyzed by N2 adsorption method. Electrochemical properties of both samples, such as constant-current charge-discharge measurement, cyclic voltammogram, and electrochemical impedance spectroscopy were investigated in non-aqueous electrolytes. It can be found that CA shows higher yield, tap density and BET specific surface area, which are 61.28%, 0.35 g/cm3 and 2 760 m2/g, respectively. However, CB has higher mesopore ratio of 24.1% and pore diameter of 2.3 nm. At the current density of 1 A/g, CA attains the highest specific capacitance of 137.8 F/g. CB shows good power discharge behavior with the capacitance loss of 4.7% at the current density of 20 A/g than that at 1 A/g.