可快速充放电聚吡咯/碳纳米管复合材料电化学聚合与表征

Electropolymerization and Characterization of Fast Charge-Discharge PPy/F-SWNTs Composite Materials

采用恒电流法制备了具有可快速充放电性能的对甲基苯磺酸根(TOS-)掺杂聚吡咯/功能化单壁碳纳米管(PPy-TOS/F-SWNTs)复合材料,扫描电镜(SEM)结果表明该复合材料呈纳米棒状构成的多孔结构,棒径约为70nm;比表面积(BET)测试分析表明该复合材料有着较高的比表面积(12.64m2.g-1)和大的介孔孔隙率(20-40nm).循环伏安(CV)、电化学阻抗谱(EIS)和恒电流充放电(GC)电化学分析表明该材料具有优异的快速充放电性能,在800mV的电位窗和2.5A.g-1(功率密度为2kW.kg-1)的电流密度下该材料具有211F.g-1的比容量(能量密度为18.7Wh.kg-1),而当充放电电流高达80A.g-1(功率密度为60kW.kg-1)时比容量仍可达141.8F.g-1(能量密度为12.6Wh.kg-1),同时该材料还表现出优异的稳定性,在10A.g-1大电流下经历10000圈循环后容量仍保持95.2%.

Fast charge-discharge composite materials of conducting polypyrrole and functionalized single-walled carbon nanotubes doped with p-toluenesulfonate （PPy-TOS/F-SWNTs） were prepared by galvanostatic electrochemical polymerization. Scanning Electron Microscope （SEM） images showed that the composite had a nano-rod structure with a diameter of about 70 nm. Nitrogen adsorption-desorption experinents were used to characterize the specific surface area （BET） （up to 12.64 m2. g-1） and pore sizes of the composite. Electrochemical properties of the composites were studied by cyclic voltammetry （CV）, electrochemical impedance spectroscopy （EIS）, and galvanostatic charge-discharge （GC） measurements. The specific capacitance of this composite is about 211 F. g-1 （energy density： 18.7 Who kg-1） at a current density of 2.5 A- g-l, and 141.8 F. g-1 （energy density： 12.6 Wh- kg-1） at large current density of 80 A. g-1. The composite had excellent cyclability with a capacity retention of about 95.2% after 10000 cycles at a current density of 10 A. g-1. All these results indicate that this new composite material has a very rapidly charge-discharge ability.