LAUSR

Abstract Room-temperature successive ionic layer adsorption and reaction (SILAR) electroless chemical method has been proposed for synthesizing Bi2O3, MnO2 and Bi2O3@MnO2 electrode materials over graphite rod. The flake-type Bi2O3 on MnO2 granules increases active sites on preventing the agglomeration of MnO2 to easy and fast electrolyte ions percolation for higher energy storage performance. The X-ray photo-spectroscopy investigation provides the evidence for the formation of the Bi2O3@MnO2 composite matrix. The as-prepared compose electrode material tested for its electrochemical characterizations endows 350 F g−1 of specific capacitance (SC) @10 A g−1 which is better than that of an individual counterpart. Furthermore, the 28 Wh kg−1 energy density at 1395 W kg−1 power density of its symmetric electrochemical supercapatter i.e. summation of battery and supercapacitor performance of the Bi2O3@MnO2//Bi2O3@MnO2 is again superior than that of individuals and also those reported previously for Bi2O3, MnO2 and Bi2O3@MnO2-based symmetric electrochemical storage devices. This enables to light a “CNED” panel designed with 42 LEDs in full-brightness for 45 s, suggesting a commercial potential of the as-obtained electroless Bi2O3@MnO2 composite electrode material in energy storage devices.