Fabrication and electrochemical characterization of two-dimensional ordered nanoporous manganese oxide for supercapacitor applications

A nanoporous manganese oxide (MnO2) film was fabricated via a polystyrene templated electrodeposition in the solution containing MnSO4. The nanoporous MnO2 film obtained has been characterized by field emission scanning electron microscopy, cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic charge/discharge methods. The specific capacitance of 1018 F g−1 was observed at a low current density of 500 mA g−1. When the current density increased to 30.0 A g−1, the specific capacitance of 277 F g−1 remained. The high capacitance retention at high rates makes the prepared MnO2 a promising candidate for supercapacitor applications.

► An array of manganese oxide (MnO2) nanowall-spheres was fabricated using template via potentiodynamic electrodeposition.
► High specific capacitance of 1018 F g−1 was obtained at a low current density of 500 mA g−1.
► The maximum specific energy of sample reached 90.5 Wh kg−1, and almost 30% remained as stable value.