A Novel Radiation Method for Preparing MnO 2 /BC Monolith Hybrids with Outstanding Supercapacitance Performance

摘要

A novel facile process for fabrication of amorphous MnO 2 /bamboo charcoal monolith hybrids (MnO 2 /BC) for potential supercapacitor applications using γ-irradiation methods is described. The structural, morphological and electrochemical properties of the MnO 2 /BC hybrids have been investigated using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), cyclic voltammetry (CV), galvanostatic charge/discharge (GCD) and electrochemical impedance spectroscopy (EIS) techniques. The combination of BC (electrical double layer charge) and MnO 2 (pseudocapacitance) created a complementary effect, which enhanced the specific capacitance and good cyclic stability of the MnO 2 /BC hybrid electrodes. The MnO 2 /BC hybrids showed a higher specific capacitance (449 F g ?1 at the constant current density of 0.5 A g ?1 over the potential range from –0.2 V to 0.8 V), compared with BC (101 F g ?1 ) in 1 M of Na 2 SO 4 aqueous electrolyte. Furthermore, the MnO 2 /BC hybrid electrodes showed superior cycling stability with 78% capacitance retention, even after 10,000 cycles. The experimental results demonstrated that the high performance of MnO 2 /BC hybrids could be a potential electrode material for supercapacitors.