MnO2-Au Composite Electrodes for Supercapacitors

The MnO2 nanorod-Au nanoparticle composites that exhibit superior supercapacitance and long-term durability have been fabricated using a two-step procedure. The role of Au nanoparticles is not only to improve the electrical conductivity but also to enhance the structural stability. The composites have a specific capacitance of 406.8 F g(-1) at a scan rate of 50 mV s(-1), which is almost five times that of the pure MnO2 nanorods. The composites have 91.3% capacitance retention over 2000 charge-discharge cycles at 5 A g(-1), which is much better than the capacitance retention of pure MnO2 nanorods (74.6%).