Stabilities of Flexible Electrochemical Capacitors Based on Polypyrrole/Carbon Fibers in Different Gel Electrolytes  

作　　者：ya-hui chang wen zhou 韩高义 yun-zhen chang 肖尧明 wen-hui ma 

机构地区：[1]The Institute of Molecular Science, Key Laboratory of Materials for Energy Conversion and Storage of Shanxi Province, Shanxi University, Taiyuan 030006, China

出　　处：《Chinese Journal of Polymer Science》2017年第8期961-973,共13页高分子科学（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(Nos.21574076,U1510121,21501113,61504076 and 21407100);the Science Foundation of Shanxi province(Nos.2014011016-1 and 2015021129);the Program for the Top Young and Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi(No.020352901014)

摘　　要：Flexible electrochemical capacitors（ECs） are vitally important as the emerging flexible electronics.We have prepared polypyrrole doped with counter ion of Cl-on carbon fibers（PPy-Cl/CFs） via the simple electrochemical deposition method.The flexible ECs based on PPy-Cl/CFs electrodes have been assembled by using H_3PO_4/poly（vinyl alcohol）（PVA）,H_2SO_4/PVA,LiClO_4/PVA,KCl/PVA and Li Cl/PVA as gel electrolytes.The capacitive properties of ECs have been systematically evaluated with electrochemical methods.The results show that the cells with H_3PO_4/PVA electrolyte exhibit good cyclic stability（91.5% retention after 15000 cycles） although PPy-Cl/CFs has moderate specific capacitance in H_3PO_4/PVA（41.6 m F·cm^-1 or 52.0 F·cm^-3）.However,the ECs in other electrolytes have poor cyclic stability.Further electrochemical analysis reveals that the doping/dedoping processes of PPy-Cl/CFs are different in the five electrolytes,and X-ray photoelectron spectra demonstrate that the ratios of counter anions in PPy＇s oxidized states to those in reduced states are obviously different when PPy-Cl/CFs are kept in reduced or oxidized states in the five electrolytes.The results also illustrate why the capacitors using H_3PO_4/PVA as electrolyte exhibit good cyclic stability.Furthermore,a light emitting diode（LED） with a threshold voltage of 2.5 V can be lighted by three ECs connected in series.Flexible electrochemical capacitors（ECs） are vitally important as the emerging flexible electronics.We have prepared polypyrrole doped with counter ion of Cl-on carbon fibers（PPy-Cl/CFs） via the simple electrochemical deposition method.The flexible ECs based on PPy-Cl/CFs electrodes have been assembled by using H_3PO_4/poly（vinyl alcohol）（PVA）,H_2SO_4/PVA,LiClO_4/PVA,KCl/PVA and Li Cl/PVA as gel electrolytes.The capacitive properties of ECs have been systematically evaluated with electrochemical methods.The results show that the cells with H_3PO_4/PVA electrolyte exhibit good cyclic stability（91.5% retention after 15000 cycles） although PPy-Cl/CFs has moderate specific capacitance in H_3PO_4/PVA（41.6 m F·cm^-1 or 52.0 F·cm^-3）.However,the ECs in other electrolytes have poor cyclic stability.Further electrochemical analysis reveals that the doping/dedoping processes of PPy-Cl/CFs are different in the five electrolytes,and X-ray photoelectron spectra demonstrate that the ratios of counter anions in PPy＇s oxidized states to those in reduced states are obviously different when PPy-Cl/CFs are kept in reduced or oxidized states in the five electrolytes.The results also illustrate why the capacitors using H_3PO_4/PVA as electrolyte exhibit good cyclic stability.Furthermore,a light emitting diode（LED） with a threshold voltage of 2.5 V can be lighted by three ECs connected in series.

关 键 词：oxidized electrolyte systematically assembled capacitive retention vinyl connected photoelectron capacitance 

分 类 号：O648.17[理学—物理化学] TM53[理学—化学]