MnO2/SWCNT buckypaper for high performance supercapacitors

Abstract

Abstract We report the supercapacitive performance of manganese oxide (MnO2)/single-walled carbon nanotube (SWCNT) buckypaper electrodes enabled via electrochemical deposition of MnO2 onto SWCNT buckypaper for the first time. The entangled SWCNT network provides electro-conductive pathways for the charge transfer. We demonstrate that the MnO2/SWCNT buckypaper supercapacitor exhibits a specific capacitance of 605 Fg−1 and gravimetric energy density of ∼120 Whkg−1. Furthermore, our MnO2/SWCNT buckypaper electrode shows excellent rate capability (85% capacity retention at 20 Ag−1) and long cycle life (1% capacity loss after 10,000 charge/discharge cycles). The excellent performance of MnO2/SWCNT buckypaper supercapacitor is attributed to the flower-like unique hierarchical porous architecture of MnO2 around SWCNTs arranged in “pearl necklace” formation, enabling large electrode/electrolyte interface and charge storage surface, better electrolyte penetration, and rapid charge transfer. The results suggest that the MnO2/SWCNT buckypaper electrode can provide excellent supercapacitive performance suitable for future generation electric vehicles.