Optimization of Active Manganese Oxide Electrodeposits Using Graphenated Carbon Nanotube Electrodes for Supercapacitors

Graphenated carbon nanotubes (g-CNTs) were investigated as the electrode support in MnO 2 composite cathodes for aqueous asymmetric supercapacitors. The electrode performance could be tuned by optimizing the density of graphene foliates on the g-CNTs, which enabled geometric/morphologic control over the MnO 2 electrodeposits. The synergy and optimization of the g-CNT hybrid structure led to a high specific capacitance (640 F/g) at high MnO 2 specific loading (2.3 mg/cm 2 ), thus creating a unique pathway toward improved practical performance.