Ni foam-supported Cu0.33Co0.67Se2 and modified NiCo-layered double hydroxide nanoarray composites for high-energy-density hybrid supercapacitors

Abstract

High-performance supercapacitors, valued for their extended operational lifespan and remarkable power density, have garnered significant attention as potential energy storage solutions. Nevertheless, their practical application has been impeded by the limited energy density and unsatisfied rate capability of conventional electrode materials. To address these challenges, we developed an effective approach for crafting a composite material, featuring a core-shell nanostructure comprised of dodecyl sulfate (DS) ions intercalated Cu0.33Co0.67Se2/NiCo-DS-LDH nanostructures. The synergistic inter-component effect between copious active sites of Cu–Co–Se and DS-modified NiCo-LDH readily boosts the high specific capacity as ∼488 mAh g−1 at 1 A g−1 with an enhanced capacity retention of ∼36.3%. In this material system, the Cu0.33Co0.67Se2/NiCo-DS-LDH cathode-integrated hybrid supercapacitor device, with the N, S co-doped porous carbon anode achieves an energy density of ∼54.4 Wh kg−1 at a power density of ∼801 W kg−1. These exceptional electrochemical performances can be attributed to the combinatorial effect of the high conductivity of the Ni network, the high activity of the bimetallic selenide, and the expanded interlayer spacing of the NiCo-LDH. The current work presents a newly developed strategy for the design of promising transition metal-based composites with a rational architecture, offering significant potential for next-generation energy storage systems.