Multilayered architecture of graphene nanosheets and MnO2 nanowires as an electrode material for high-performance supercapacitors

Multilayered graphene/MnO2 nanocomposite electrode prepared by anodic electrodeposition and electrophoresis exhibited superior capacitive behavior compared to the bare MnO2 and graphene electrodes. The multilayered architecture provided both the horizontal and vertical channels for electrolyte access during fast charging and discharging. The graphene layer turned out to play an important role in enhancing the electron conduction in the multilayered architecture. Therefore, the improved electrochemical behavior might result from the significantly improved ion transport and electron conduction in the multilayered architecture of the graphene/MnO2 composite electrode. Furthermore, the MnO2 nanowire layer coated on the graphene layer could significantly suppress the oxygen evolution reaction, broadening the potential window of water stability.

► Multilayered architecture of the graphene/MnO2 electrode is fabricated. ► The composite provides horizontal and vertical channels for electrolyte access. ► Graphene (GN) layer provides fast electron conduction in the composite. ► MnO2 nanowire layer on the GN layer suppresses the oxygen evolution reaction. ► Capacitance behavior is enhanced by the multilayered architecture of GN/MnO2.