Fabrication of flexible polypyrrole/graphene oxide/manganese oxide supercapacitor

A flexible polypyrrole/graphene oxide/manganese oxide-based supercapacitor was prepared via an electrodeposition process. The polypyrrole, graphene oxide, and manganese oxide were deposited onto a flexible and highly porous nickel foam, which acted as a current collector to enhance the electrochemical performances. The good coverage of the polypyrrole, graphene oxide, and manganese oxide onto the scaffold of the nickel foam was evidenced using field emission scanning electron microscopy and X-ray diffraction. The manganese species, which were present in the oxidation states of Mn3+ and Mn4+, were shown using X-ray photoelectron spectroscopy. The presence of Mn2O3 and MnO2 polymorphs was detected using Fourier transform infrared and Raman spectroscopies. The cyclic stability of the ternary supercapacitor was consistent regardless of its geometry and curvature. In contrast, an activated carbon supercapacitor possesses limited energy storage capability compared to a ternary supercapacitor, which suppresses the electrochemical performances of activated carbon. The ternary as-fabricated supercapacitor could retain a specific capacitance of 96.58% after 1000cycles, and the as-synthesized energy storage device was able to light up a light emitting diode. Copyright (c) 2014 John Wiley & Sons, Ltd.