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 108m2g−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 224Fg−1 at charge/discharge current density of 240Ag−1 within an electrochemical windows of 0.8V in 3M KCl aqueous solution. The specific power of RGO–PPy electrodes reaches 38.6kWkg−1 when its specific energy reaches 2.5Whkg−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 30Ag−1 within an electrochemical windows of 0.8V after 5000 cycles.