Pencil graphite/polypyrrole supercapacitors: The structural and chemical changes of the electrodes after capacitive measurements

Abstract

Polypyrrole (PPy) films were electropolymerized on pencil graphite electrodes (PGE). It is usual that for supercapacitor applications composite materials containing conductive polymers and low dimension carbon are being studied. PGE was employed as a substrate and also a source of carbon contributing to the capacitive effect. By this, a specific capacitance of 695 F/g, and a stability of 77% after 1000 times cycled was obtained. Moreover, a cheap, rapid and easy way to fabricate supercapacitor electrodes was found. A PGE/PPy symmetrical super -capacitor was produced. The energy and power density values were calculated as 38.76 Wh/kg and 227.99 W/ kg. The cycles showed remarkable charge/discharge capacity. Parallel connected several electrodes could enlighten an LED for a while.