Hydrothermally Synthesized Cobalt Oxide Nanowires on Nickel Foam for High-Performance Energy-Storage Applications

Abstract

In the present study, Co3O4 nanowires have been synthesized and coated uniformly on nickel foam (NF). The excellent electrochemical performance was demonstrated by the binder-free electrode material in 3 M KOH electrolytes; excellent specific capacitance of 1140 F g−1 at 1 A g−1 with 93.3% of its initial value is retained after galvanic charge-discharge (GCD) cycles of 5000. Activated carbon as negative and Co3O4 as a positive electrode is assembled in a hybrid supercapacitor device (HSC). HSC shows high capacitance retention 95 F g−1 at 1 A g−1 with maximum power density (11.80 kW kg−1 at 18.20 Wh kg−1) and high rate capability (58.26 F g−1 at 15 A g−1). The tremendous electrochemical performance could be attributed to the nanowire-like structure of Co3O4 on nickel foam which provides a high rate for ion diffusion and facilitates rapid transfer of electron and ion on the Co3O4/electrolyte interfaces. Obtained results indicate that synthesized Co3O4 nanowires with enhanced performance are potential electrode candidates for energy-storage applications.