Hybrid Supercapacitors Based on Self-Assembled Electrochemical Deposition of Reduced Graphene Oxide/Polypyrrole Composite Electrodes

Abstract

Conductive polymers (CPs) have potential application to commercial energy storage because of their high electrochemical activity and low cost. However, an obstacle in developing CP-based supercapacitors is the degradation in their capacitance during the charge-discharge process that leads to poor rate performance. This study fabricates layers of a high-performance self-assembled polypyrrole/reduced graphene oxide (PPY/RGO) composite material on a carbon cloth through electrochemical deposition. The layered graphene improved the electrochemical properties of PPY. Carbon fiber rods were coated with the PPY/RGO composite layer, the thickness of which depends on the deposition time. Adequate capacitive behaviors were achieved by using 16 layers of polypyrrole/reduced graphene oxide, with a specific capacitance of 490 F g −1 (0.6 A g −1 ) and good rate performance. The results here provide a novel means of preparing graphene-based nanocomposites films for a variety of functions. A symmetric device was subsequently assembled by using electrodes featuring 16 layers of the polypyrrole/reduced graphene oxide composite. It yielded a specific capacitance of 205 F g −1 and a high energy density of 16.4 Wh kg −1 . It also exhibited good cycle stability, with a capacitance retention rate of 85% for 5,000 cycles.