Dumbbell-shaped nanorod assembly of a NiO/CuO composite for high-performance redox-active battery-type supercapacitor electrodes

Abstract

Engineering nano-/microstructured electrode architectures with enhanced redox properties plays a pivotal role in boosting the electrochemical performance of battery-type hybrid supercapacitors. Herein, we report the synthesis of a dumbbell-shaped NiO/CuO nanorod composite via a one-step hydrothermal approach and comprehensive characterization techniques were employed to gain in-depth insights into the physicochemical properties of the composite. The unique nanorod-assembled dumbbell-like morphology, coupled with the synergistic interaction between the NiO and CuO phases, imparts a high surface area of 120.5 m² g⁻¹ and enhanced charge transport kinetics compared to pristine NiO. Electrochemical analysis reveals the battery-type characteristics of the NiO/CuO electrode, which exhibits a remarkable specific capacity of 1005.2 C g⁻¹—nearly twice that of pristine NiO (498 C g⁻¹)—along with exceptional cycling stability, retaining 98% of its initial capacity over 5000 cycles. These findings highlight the structural and compositional merits of the NiO/CuO composite, positioning it as a promising redox-active electrode for next-generation hybrid supercapacitors.