Carbon-supported, nano-structured, manganese oxide composite electrode for electrochemical supercapacitor

Carbon-supported MnO2 nanorods are synthesized using a microemulsion process and a manganese oxide/carbon (MnO2/C) composite is investigated for use in a supercapacitor. As shown by high-resolution transmission electron microscopy the 2 nm × 10 nm MnO2 nanorods are uniformly dispersed on the carbon surface. Cyclic voltammograms recorded for the MnO2/C composite electrode display ideal capacitive behaviour between −0.1 and 0.8 V (vs. saturated calomel electrode) with high reversibility. The specific capacitance of the MnO2/C composite electrode found to be 165 F g−1 and is estimated to be as high as 458 F g−1 for the MnO2. Based on cyclic voltammetric life-cycle tests, the MnO2/C composite electrode gives a highly stable and reversible performance for up to 10,000 cycles.