球形活性炭孔结构对其电化学性能的影响

Effect of pore structure on electrochemical performance of spherical activated carbon

以苯乙烯、二乙烯苯为原料,通过分散聚合法合成制备聚苯乙烯树脂球,经过磺化、炭化、KOH活化制得聚苯乙烯基球形活性炭。通过扫描电镜、氮气吸附、循环伏安、恒电流充放电及交流阻抗测试,表征活性炭形貌、孔结构及电化学性能。结果表明:所制备活性炭具有良好的球形度,比表面积在2 000～3 000 m^2/g内孔径可调,作为电极材料应用于水系超级电容器后显示出优异的电化学性能,在2 A/g的电流密度下,比电容达261 F/g,且具有良好的倍率特性及循环性能,同时球形活性炭0.7～1.5 nm的微孔含量是超级电容器比容量的决定因素。

Spherical activated carbon were prepared by sulphonation,carbonization and KOH activation of resin balls obtained by dispersion polymerization of styrene and vinylstyrene.The appearance and pore structure were analyzed by scanning electron microscope(SEM)and N2 physical adsorption-desorption instrument.Cyclic voltammogram(CV),galvanostatic charge-discharge(GCD)and electrochemical impedance spectroscopy(EIS)were used to characterize the electrochemical performance of supercapacitors.The result shows that the obtained activated carbon with good sphericity and possess high specific surface area,also the pore structure can be adjusted in the range of 2 000 m2/g to 3 000 m2/g of specific surface area.It shows excellent electrochemical performance when applied as electrode material to water supercapacitor,the spherical activated carbon electrode materials emerges a high specific capacitance of 261 F/g at a current density of 2 A/g,and presents excellent rate capacity and cycle performance.Meanwhile,the specific capacitance of spherical activated carbon is mainly contribute by the micropore(0.7-1.5 nm).