Facile growth of nickel foam-supported MnCo 2 O 4.5 porous nanowires as binder-free electrodes for high-performance hybrid supercapacitors

In this work, porous MnCo 2 O 4.5 nanowires (NWs) were directly grown on nickel foam (NF) via an initial hydrothermal route with an extra annealing treatment of precursor. Another comparative experiment was conducted with a lower amount of urea to obtain particle-based MnCo 2 O 4.5 films. These binder-free MnCo 2 O 4.5 @NF electrodes exhibited battery-type electro-chemical response with superior electro-chemical performance. Especially, the MnCo 2 O 4.5 -NWs@NF delivered a huge capacity of 288.47 C g −1 at 1 A g −1 and 78.07% of capacity retention at 10 A g −1. Moreover, a hybrid supercapacitor (HSC) that was assembled using activated carbon (AC) as an anode could operate over a voltage of 1.7 V. The MnCo 2 O 4.5 -NWs@NF//AC HSC delivered an energy density of up to 29.57 W h kg −1 at the power density of 914.28 W kg −1, and it could still hold 20.82 W h kg −1 since the power density was improved to 8.24 kW kg −1. In addition, both these MnCo 2 O 4.5 NWs- and films-based HSCs showed an impressive cyclic stability over continuous 6000 cycles at a high current density of 6 A g −1, but only a little capacity decay was observed. Such extraordinary electro-chemical performance makes the binder-free MnCo 2 O 4.5 -NWs@NF electrode material promising and very feasible to be applied for electro-chemical energy storage devices such as batteries, supercapacitors, and so on.