Construction Of Nanostructured-Conductive Polymer And Its Capacitive Properties For Supercapacitor

With development of hybrid electric vehicles and portable devices,the demand for the performance of chemical power sources is higher and higher.It requires not only high specific energy to realize long time operation,but also high specific power to realize rapid discharge.However,a single chemical power supply cannot meet the above requirements.The proton exchange membrane fuel cells(PEMFC)can provide high specific energy,meanwhile,it suffer from low specific power;Spercapacitor possess high specific power,whereas it usually suffer from low specific energy.Hybrid electric power device(HEPD),with high specific power and high specific energy,can be made by integrating complementary characteristics of PEMFCs and supercapacitors.Therefor,this research focuses on the preparation and performance of the novel nano-conductive polymer as well as the resulted dual-function electrode:(1)The in-situ synthesis method was used to synthesize polyaniline nanowire arrays(PANI-0.3)and polyaniline nanowire network(PANI-9)as well as polypyrrole.Then the performance of supercapacitor based on the polyaniline or polypyrrole are tested by electrochemical workstation.(i)The PANI-0.3 shows specific capacitance of 307.3 and 253.1 F g^-1 at 0.5 and20 A g^-1,which is nearly 4.31%and 10.24%higher than PANI-9 at 0.5 A g^-1(294.6 F g^-1)and 20 A g^-1(229.6 F g^-1),respectively.(ii)The PPy-1 shows specific capacitance of 343.07 and 260.53 F g^-1 at 0.5 and20 A g^-1,which is nearly 3.19%and 12.65%higher than PPy-9 at 0.5 A g^-1(332.45 F g^-1)and 20 A g^-1(231.27 F g^-1),respectively.(iii)Through in-situ EIS test,the ohm resistance(2.2?),mass transfer resistance(0.091?)and ion diffusion resistance(0.68?)of array structure of polyaniline are lower than those of network structure of polyaniline(2.4??0.10??0.80?s^-1/2).The EIS results of polypyrrole are consistent with those of polyaniline.This indicates that the array structure can effectively reduce ohmic resistance,thus improve the specific capacitance of supercapacitor.(2)The dual-function electrode with polypyrrole is prepared and its singl cell performance is tested by the homemade cell test system.The Rs and Rct of HEPD is0.21?cm^-2 and 0.18?cm^-2,respectively,which is smller than that of conventional PEMFC(0.36?cm^-2 and 0.27?cm^-2).Further more,the power density of HEPD is up to 380.6 m W cm^-2 at intermittent pulse discharge,which is 45.4%higher than that of conventional PEMFC(261.8 m W cm^-2).