Facile Hydrothermal Synthesis Of Hierarchically Mesoporous Zinc-NickelCobalt (Zn0.6Ni0.8Co1.6O4) Ternary Oxide Nanowires For Asymmetric Supercapacitors

Abstract

Hierarchical mesoporous nanostructured zinc-nickel-cobalt oxide has been established as a promising electrode material due to the synergic enhancement effect of cobalt cations replacement with zinc and nickel. Zinc-nickel-cobalt oxide (ZNCO) nanowires were synthesized using a facile hydrothermal approach followed by annealing treatment. For a comparative study nickel cobalt oxide (NCO), Zinc Cobalt Oxide (ZCO) and Cobalt Oxide (CO) were also synthesized by the same method. Electrochemical analysis affirmed the developed hierarchically mesoporous ZNCO nanowires for supercapacitors. ZNCO nanowires exhibit specific capacitance of 2082.21 F g-1 at 1 A g-1 and 95.5 % specific capacitance was retained up to 5000 charge-discharge cycles. Moreover, asymmetric testing by employing ZNCO as positive electrode and MWCNTs as well as graphene nano platelets as a negative electrode. An asymmetric supercapacitor (ASC) with MWCNTs shows high energy density 37.89 Wh kg-1 and good capacitance retention of 88.50% over 1000 cycles, whereas with graphene nanoplatelets 21.21 Wh kg-1 of maximum energy density and 83% of capacitance retention up to 8000 cycles