3D-C-Fe4N@NiCu/Metallic macroporous frameworks for binder-free compact hybrid supercapacitors with high areal capacities

Abstract

In the present research work, binder-free three-dimensional nickel-copper (3D-NiCu) over various substrates copper (Cu), stainless steel (SS) and titanium (Ti) were synthesized via dynamic hydrogen bubble template (DHBT) method and further deposited by carbon-doped iron nitride (C@Fe4N) electroactive material via vapor phase growth method to form 3D-C-Fe4N@NiCu/Cu, 3D-C-Fe4N@NiCu/SS, and 3D-C-Fe4N@NiCu/Ti electrodes, respectively. Unveiling the maximum performance among the three electrodes, 3D-C-Fe4N@NiCu/Cu delivered a high areal capacity value of 2118 mC/cm2 at 3 mA/cm2 current density along with 92% capacity retention. Further, the assembled hybrid supercapacitor(HSC) based on 3D-Co3O4/Ni‖3D-C-Fe4N@NiCu/Cu HSC delivered the best electrochemical performance including wide potential window (1.5 V), specific capacity and cycling stability (89%) among the three HSCs. The results conclude that the novel synthesis strategy of vapor phase growth over 3D bi-metallic templates, opens up a new avenue, towards the formation of reliable and competitive HSC negative electrodes over a range of metal substrates, divergent from conventional carbon-based negative electrodes, which is extendable to other metals and applications.