Performance of High Energy Density Symmetric Supercapacitor Based on Sputtered MnO2 Nanorods

Here, we demonstrate the fabrication of binder free and very efficient supercapacitor electrodes based on MnO2 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 MnO2 up to similar to 796 F/g. A symmetric supercapacitor device in form of alpha-MnO2 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 (similar to 36 kW/kg at 6 Wh/kg) in a voltage range of 1.3 V. These observed excellent electrochemical performances of the present MnO2 nanorods based device, suggest it tremendous potential as supercapacitor electrodes in energy storage applications.