Stability studies of polypyrole- derived carbon based symmetric supercapacitor via potentiostatic floating test

This work present the synthesis and electrochemical performance of mesoporous carbon material derived from the activation and carbonisation of polypyrole (PPY). Electrochemical performance of the PPY derived carbon was investigated in a two electrode cell in a 6 M KOH alkaline electrolyte. The symmetric device was subjected to floating test (voltage holding) for ∼200 h at a voltage of 1.2 V and the specific capacitance as well as the resistance of device was determined after every 10 h of floating. The device exhibited a specific capacitance of 179 F g−1 at 0.5 A g−1 and 158 F g−1 at 10 A g−1. In addition, after floating for ∼120 h the resistance was constant with a very slow decrease in capacitance. Beyond ∼120 h, a quick decrease in capacitance was observed with a corresponding increase in resistance, indicating a possible deterioration to the electrodes. Remarkably, at the end of floating, the specific capacitance calculated at 5 A g−1 was 120 F g−1 (∼25% decay in capacitance from the initial value 160.5 F g−1 at 5 A g−1) suggesting good stability of the device over a long period of time (∼8 days).