Performance of High Energy Density Symmetric Supercapacitor Based on Sputtered MnO 2 Nanorods

Here, we demonstrate the fabrication of binder free and very efficient supercapacitor electrodes based on MnO 2 nanorods on silver (Ag) coated porous anodic aluminum oxide (AAO) substrate in a very simple way by DC magnetron sputtering. The Ag coated porous AAO substrate acts as excellent current collector and also enhances high specific capacitance of MnO 2 up to ∼796 F/g. A symmetric supercapacitor device in form of α ‐MnO 2 nanorods/Ag/AAO electrode has been fabricated, characterized and its performance has been investigated in detail. The binder free supercapacitor device delivered a high capacitance (132 F/g), good cycling ability (95.52 % capacitance retention after 3000 cycles), high energy density (26.4 Wh/kg), and also a high power density (∼36 kW/kg at 6 Wh/kg) in a voltage range of 1.3 V. These observed excellent electrochemical performances of the present MnO 2 nanorods based device, suggest it tremendous potential as supercapacitor electrodes in energy storage applications.