Study On The Electrochemical Performance Of Polypyrrole-based Composites

Conductive polymer refers to a kind of macromolecular material with the conjugated principal electron system,which can reach the conductive state through doping and the conductivity is above 1000 S/cm.Due to its unique properties,conductive polymers have potential applications in energy,optoelectronic devices,sensors,molecular wires and many other fields.In this paper,the electrochemical properties of responsive hydrogels and electrode composites in supercapacitors are studied by combining conductive polypyrrole with poly(acrylic acid)and trypan blue.(1)The conductive polymer and its preparation method are briefly reviewed.The classification,preparation method and application of conductive hydrogels in sensors are introduced.In addition,the classification and preparation of supercapacitors are briefly reviewed.(2)Using multifunctional trypan blue(TB)as a crosslinking agent for poly(acrylic acid)(PAA)and polypyrrole(PPy),a flexible and self-healing PAA-TB-PPy hydrogel was prepared.The introduction of TB not only improves the water retention capacity of the hydrogel,but also helps to form a highly interconnected conductive network,giving the hydrogel higher conductivity(15 S/m,which is almost equivalent to pure PPy hydrogel).Due to the high stability of the interpenetrating network structure,the hydrogel exhibits super-stretchability(elongation at break greater than 750%),high mechanical strength and strong adhesion to various solid surfaces.In addition,the hydrogels show high strain and pressure sensitivity as well as significant linear relationship,which makes them have potential application value in intelligent materials and detection.(3)In the presence of TB and modified GO,by in-situ polymerization of pyrrole,polypyrrole/trypan blue/graphene oxide composite material(PPy-TB-GO)was prepared.TB not only acts as a dopant for PPy,but also adsorbs Py structural unit.Cyclic voltammetry(CV),constant current charge-discharge(GCD)and electrochemical impedance spectroscopy(EIS)tests show that at a scan rate of 5 mv/s,the specific capacitance of PPy-TB-GO is 590 F/g.The capacity retention rate after 1000 cycles at a scan rate of 100 mv/s is 81%.Based on these characteristics,PPy-TB-GO composite material may become a promising material in supercapacitor applications.