Synthesis of a novel hybrid anode nanoarchitecture of Bi2O3/porous-RGO nanosheets for high-performance asymmetric supercapacitor

Novel bismuth oxide (Bi2O3) nanoparticles dispersed on porous reduced graphene oxide nanosheets is prepared using the facile hydrothermal reaction followed by a calcination process in the air atmosphere. At electrochemical study, the electrode materials of Bi2O3/porous-RGO display the capacitance retention to be 81.1% at a current density of 0.5 Ag-1 and alpha-MnO2-NRs exhibit about 80.7% at a scan rate of 10 mVs(-1) for 3000 cycles in 6 M KOH electrolytes of three-electrode configuration. Moreover, the outstanding capacitance retention of anode and cathode materials mainly due to the porosity (porous-RGO), thermal stability with maximal weight loss rate temperature T-(mwlr) reach of 623 degrees C, a smaller size of Bi2O3 (similar to 7.5 +/- 0.5 nm), and aspect ratio of alpha-MnO2 nanorods for 5.1 +/- 0.9 nm. The assembled asymmetric supercapacitor (ASC) achieves the specific capacitance of 84 Fg(-1) at a scan rate of 5 mVs(-1) and capacitance retention of 91.4% at a current density of 1 Ag-1 by the Bi2O3/porous-RGO//alpha-MnO2-NRs in PVA/KOH gel electrolyte of two-electrode configuration. Notably, the ASC delivers an energy density of 86 Wh kg(-1) (787 mF cm(-2)) at a power density of 9000 W kg(-1). As a result, Bi2O3/porous-RGO and alpha-MnO2-NRs is considered as a promising candidate for future anode/cathode material in ASC energy storage device.