A facile co-electrodeposition method has been developed to fabricate reduced graphene oxide/polypyrrole (rGO/PPy) composite films, with sodium dodecyl benzene sulfonate as both a surfactant and supporting electrolyte in the precursor solution. The introduction of rGO into the PPy films forms porous structure and enhances the conductivity across the film, leading to superior electrochemical performance. By controlling the deposition time and rGO concentration, the highest area capacitance can reach 411 mF/cm2 (0.2 mA/cm2) for rGO/PPy films, whereas optimized specific capacitance is as high as 361 F/g (0.2 mA/cm2). All of the composite films exhibit excellent rate capability (at least 175 F/g at the current density of 12 mA/cm2) compared with pure PPy film (only 12 F/g at the current density of 12 mA/cm2). The rGO/PPy composite exhibits excellent cycling stability that maintains 104% of its initial capacitance after cycling for 2000 cycles and 80% for 5000 cycles. The two-electrode solid-state supercapacitor (SC) based on rGO/PPy composite electrodes demonstrates good rate performance, excellent cycling stability, as well as a high area capacitance of 222 mF/cm2. The solid-state planar SC based on the rGO/PPy composite exhibits an area capacitance of 9.4 mF/cm2, demonstrating great potential for fabrication of microsupercapacitors.
Keywords: co-electrodeposition; facile; graphene; planar supercapacitor; polypyrrole; solid-state supercapacitor.