A binder-free wet chemical synthesis approach to decorate nanoflowers of bismuth oxide on Ni-foam for fabricating laboratory scale potential pencil-type asymmetric supercapacitor device
The present work deals with the synthesis of bismuth oxide (Bi2O3) electrode consisting of an arranged nano-platelets for evolving a flower-type surface appearance on nickel-foam (Bi2O3-Ni-F) by a simple, inexpensive, binder-free and one-step chemical bath deposition (CBD) method, popularly known as a wet chemical method. As-prepared Bi2O3 on Ni-foam as an electrode material demonstrates 557 F.g-1 specific capacitance (SC, at 1 mA.cm-2) which remains about 85 % even after 2000 cycles. With specific power density of 500 kW.kg-1, the Bi2O3-Ni-F electrode documents a specific energy density of 80 Wh. kg-1. Furthermore, a portable asymmetric supercapacitor device i.e. pencil-type cell consisting of Bi2O3-Ni-F as an anode and graphite as a cathode in 6 M KOH aqueous electrolyte solution corroborates 11 Wh.kg-1 and 720 kW.kg-1 specific energy and specific power densities, respectively. An easy and a simple synthesis approach for manufacturing portable laboratory scale pencil-type supercapacitor device is a major outcome of this study which also can be applied for ternary and quaternary metal oxides for recording an enhanced performance. In addition, we also have presented a demonstration of lighting the light emitting diode (LED) using home-made pencil-type supercapacitor device which, finally, has confirmed the scaling and technical potentiality of Bi2O3-Ni-F in energy storage devices.