Electrochemical in situ polymerization of reduced graphene oxide/polypyrrole composite with high power density

We demonstrate a novel method of in situ galvanostatic polymerization to prepare reduced graphene oxide (RGO)/polypyrrole composite (RGO-PPy) for supercapacitors electrode. The PPy and the RGO interact closely and form the composite with porous structure. The BET specific surface area of RGO-PPy reaches 108 m(2) g(-1). The RGO-PPy composites show the high protonation level on polypyrrole (PPy) ring (41.1%), which can be related to the doping of PPy by oxygen-containing groups in RGO sheet. The RGO-PPy electrodes exhibit good electrochemical performance. The specific capacitance of RGO-PPy electrodes still reaches 224 F g(-1) at charge/discharge current density of 240 A g(-1) within an electrochemical windows of 0.8 V in 3 M KCl aqueous solution. The specific power of RGO-PPy electrodes reaches 38.6 kW kg(-1) when its specific energy reaches 2.5 Wh kg(-1) in two-electrode cell. The RGO-PPy electrodes have good cycle stability and show less than 17% specific capacitance decay at a charge/discharge current of 30 A g(-1) within an electrochemical windows of 0.8 V after 5000 cycles. (C) 2012 Elsevier B.V. All rights reserved.