Electrochemical Performance of α-MnO2 Nanorods/Activated Carbon Hybrid Supercapacitor

Hollondite type alpha-MnO2 nanorods are prepared by hydrothermal route at 160 degrees C for 8 h. The structural and morphological properties are examined by X-ray diffraction, BET surface area, scanning electron microscopy and high resolution transmission electron microscopy. Half-cells (Li/alpha-MnO2) are fabricated to study the Li-cycling behavior in both galvanostaic and potentiostatic modes. The alpha-MnO2 delivers a stable reversible capacity of similar to 80 mA h g(-1) at constant current 50 mA g(-1) up to 50 cycles when cycled between 1.5-3.8 V versus Li. The hybrid electrochemical capacitor is fabricated using alpha-MnO2 nanorods (as anode) and activated carbon (as cathode) in non-aqueous medium and cycled between 0-3 V. The hybrid electrochemical capacitor exhibited a stable specific discharge capacitance of 28 F g(-1) at high current (60 mA g(-1)). Further, hybrid electrochemical capacitor displayed a maximum energy and power densities of 9 W h kg(-1) and 87 W kg(-1), respectively.