%A YANG Hong-Sheng; ZHOU Xiao; ZHANG Qing-Wu
%T Electrochemical Performances of Supercapacitor with Polyaniline Particles with Hierarchy as Active Electrode Material
%0 Journal Article
%D 2005
%J Acta Phys. -Chim. Sin.
%R 10.3866/PKU.WHXB20050414
%P 414-418
%V 21
%N 04
%U {http://www.whxb.pku.edu.cn/CN/abstract/article_25279.shtml}
%8 2005-04-15
%X Polyaniline (PANi) particles with hierarchy are prepared by adding (NH_{4})_{2}S_{2}O_{8} dropwise into aqueous solution containing aniline monomer and HCl acid at 0 ℃ under nitrogen atmosphere with stirring. SEM images show that the resulted PANi particles are composed of their primary particles, which are composed of multi-layer flakes. Symmetric redox supercapacitor (prototype) is assembled with the PANi particles as active electrode materials and 2 mol•L^{-1} H_{2}SO_{4} aqueous solution as electrolyte. The electrochemical performances of the supercapacitor are tested with cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy. When the charge-discharge current is 7 mA, the specific energy and specific power of the supercapacitor can reach 6.35 Wh•kg^{-1} and 132 W•kg^{-1} (based on the mass of PANi), respectively；the capacitance of PANi electrode is about 408 F•g^{-1} . When the charge-discharge current is 20 mA, the specific energy and specific power of the super-capacitor can reach 4.39 Wh•kg^{-1} and 328 W•kg^{-1} (based on the weight of PANi), respectively; the capacitance of PANi electrode is about 324 F•g^{-1} . During 100 charge-discharge cycles, the discharge capacity of the supercapacitor is constant, and the charge-discharge efficiency is 95%. The results show that the PANi supercapacitor with hierarchial particles as active electrode material can store a great deal of charge and energy in H_{2}SO_{4} solution.