Designed Nickel Cobalt-Layered Double Hydroxide/CuCo₂O₄ Nanorod Heterostructure for High-Performance Supercapacitors

Bimetallic oxide CuCo2O4 has captured widespread interest in the application of supercapacitors in light of its outstanding conductivity and electrochemical activity. Structural optimization is crucial for increasing the electroactive sites and accelerating the surface chemical reactions to enhance the capacitance and longevity for supercapacitors. In this study, a CuCo2O4@NiCo-layered double hydroxide heterostructure (CCO@NC-LDH) is constructed in situ on nickel foam via a hydrothermal-assisted electrodeposition strategy. CCO@NC-LDH nanorods offer a large specific surface area, rich redox reaction sites, and effective interface charge mobility through tight interfacial connections between the interface. These properties address the inherent limitations of traditional electrodes, leading to the superior specific capacitance along with outstanding cycling durability. Thanks to the high utilization of abundant electroactive sites, the optimized CCO@NC-LDH shows an impressively high specific capacitance of 4824.3 F g–1 at 1 A g–1, significantly outperforming standalone CCO and NC-LDH electrodes. Besides, the density functional theory (DFT) calculations give a rational interpretation for the heightened conductivity and accelerated charge migration dynamics at the heterointerface between CCO and NC-LDH. The asymmetric supercapacitor based on CCO@NC-LDH shows a remarkable energy density of 65.6 Wh kg–1 at a power density of 750.0 W kg–1 and a remarkable sustained stability. Furthermore, the fabricated supercapacitor successfully powers LED lights continuously, showcasing its practical application potential. These excellent performances highlight the immense promise of heterostructured nanomaterials in advanced energy storage applications.