Preparation and characterization of high charge density polypyrrole/graphite fiber composite electrode for supercapacitor application

Abstract

Novel polypyrrole/graphite composite electrode for pseudocapacitor is fabricated by chemical oxidation method. We investigated the morphology, cyclic voltammetry characters, ac impedance response and chage/dischage characters. The composite electrode has very good electrochemical properties including the charge capacity, reversible oxidation and reduction reaction etc. The polymer morphology affected by the chemical oxidative agent was an important fact to the electrochemical properties of composite electrodes. From CV voltagrams, we can get various capacitance of composite electrode between 250F/g and 400F/g as a experimental variables. We have fabricated supercapacitors using polypyrrole/graphite composite electrode. The charge-discharge curves obtained at various kinds of current density show very stable charge-discharge behavior over multiple cycle. The discharge capacitance of the composite electrode was about 260-300F/g between 1cycle and 100cycles, respectively, at current density of 1mA/$cm^2$. From impedance test, we can see vary low bulk and ionic transport resistance.