碳纳米管在HQ/H_2SO_4电解质体系中的超级电容器性能研究

The supercapacitor properties of carbon nanotubes in hydroquinone/H_2SO_4 electrolyte

以自组装法合成的聚苯胺为前驱体,将其碳化活化后得到活性碳纳米管,分别研究了活性碳纳米管在H2SO4和氢醌(hydroquinone,HQ)/H2SO4电解质溶液里的超级电容器性能。通过扫描电子显微镜(SEM)、透射电子显微镜(TEM)和比表面及孔径分析等方法对材料的形貌和孔径分布进行表征。采用循环伏安法、恒电流充放电和交流阻抗法分别研究了超级电容器在1mol/L H2SO4、0.4mol/L HQ/H2SO4电解质溶液中的电化学性能。在扫描速率为2mV/s时,碳纳米管电极在H2SO4和HQ/H2SO4电解液中的比电容分别为188和380F/g。研究表明,在HQ/H2SO4电解质溶液中可以为超级电容器提供氧化还原赝电容,其比电容量提高了192F/g。

Actived carbon nanotubes are prepared by carbonizing and activating polyaniline nanotubes,which are synthesized by polymerization of aniline with a template-free self-assembly method in aqueous media.The mor-phology and surface area of the activated carbon nanotubes were investigated by scanning electron microscopy, transmission electron microscopy and Brunauer-Emmett-Teller measurement (BET),respectively.The electro-chemical properties of the supercapacitor in H2 SO4 and hydroquinone/H2 SO4 electrolyte were evaluated by cy-clic voltammetry (CV),galvanostatic charge-discharge (GCD),and electrochemical impedance spectroscopy (EIS)techniques.It was found that the supercapacitor exhibited an outstanding specific capacitance value of 380 F/g in the HQ/H2 SO4 electrolyte at a sweep rate of 2 mV/s,which was significantly higher than that of the original supercapacitor (188 F/g)using 1 mol/L H2 SO4 as electrolyte.The result showed that the capaci-tance of the as-prepared materials was heightened by 192 F/g,reaching 380 F/g,which was due to the HQ/H2 SO4 electrolyte could provide pseudocapacitance.