Preparation And Electrochemical Properties Of Polyaniline Based Composites

Polyaniline(PANI)has good application prospect as the supercapacitor electrode material,Its advantages of high theoretical specific capacitance,simple preparation process,cheap raw materials,and environmental protection have attracted more and more attention,However,its actual specific capacity is relatively small,the electrochemical stability is poor,and the yield is low,which has limited its practical application.To this end,the subject has done in three aspects:(1)HCl,HNO3 and H2SO4 doped PANI were prepared by chemical oxidation with high productivity.The effects of the amount of oxidant,type of acid,concentration of acid,synthesis temperature and synthesis time on the conductivity of PANI were studied.(2)In-situ composites of reduced-graphene oxide(RGO)and high-conductivity PANI were used to study the capacitance and cycling stability of PANI/RGO with different ratios.(3)Mn O2 was prepared by liquid-phase precipitation method,and PANI/Mn O2 composites were prepared by in-situ synthesis method.The capacitance performance and cycling stability of PANI/Mn O2 with different proportions were studied.The research shows that:(1)the PANI prepared by using HCl as the doped acid is superior to HNO3 and H2SO4 doped PANI in the crystallization performance,and it is easier to prepare fiber PANI.Meanwhile,by testing conductivity,it is found that when the molar ratio of oxidant to aniline monomer is 1,the concentration of doped acid is 2 mol/L,the synthesis temperature is 0?,and the synthesis time is 8h,the result of highest conductivity of PANI is 10.23 S/cm.(2)The specific capacitance and electrochemical stability of the PANI and RGO composites have been greatly improved,The compound of the mass ratio of aniline monomer to 1:8 has the highest specific capacity,Using 1 mol/L H2SO4 as electrolyte solution,the specific capacitance at 1 A/g current density can reach 546.75 F/g,and it can retain 78.65% of initial capacity after 1000 cycles,which is much higher than specific capacitance(326.27 F/g)and cycle stability(42.31%)of pure PANI.(3)Mn O2 prepared by liquid-phase precipitation method belongs to ?-Mn O2,which can be well dispersed in PANI nanofibers.,impedance of two kinds of single material are relatively high,the impedance of PANI/Mn O2 is greatly reduced.When the molar ratio of Mn O2 to aniline monomer is 1:5,using 1 mol/L H2SO4 as the electrolyte solution,the specific capacitance of PANI/Mn O2 can reach as high as 483.39 F/g under the current density of 1 A/g,The cycle stability is good,and 75.32% of the initial capacity can still be maintained after 1000 times of charge and discharge.