Hydrothermally synthesized CuNiS@CNTs composite electrode material for hybrid supercapacitors and non-enzymatic electrochemical glucose sensor

Advanced energy storage has driven significant research in the field of energy storage, which bridges the gap between traditional capacitors and batteries in terms of energy and power density. This study investigates the electrochemical performance of copper–nickel sulfide (CuNiS) for supercapacitor applications. Carbon nanotubes (CNTs) are doped into CuNiS mixture to improve the electrical conductivity and capacitive characteristics. The study aimed to determine whether CuNiS/CNTs nanocomposite material was suitable for supercapacitor devices through synthesis, characterization, and electrochemical analysis studies. The hydrothermal method was used to create the composite material, which then went through several characterization processes, such as scanning electron microscopy (SEM) and x-ray diffraction (XRD), to study its morphology and structural properties. The specific capacity of binary composite CuNiS shows 638 C/g; when CuNiS material is doped with 20% CNTs, the specific capacity increases to 1173.69 C/g at the same current density of 1.8 A/g. Additionally, we created a supercapattery device (CuNiS@CNTs//AC) and examined its electrochemical properties. The supercapattery device displays a high coulombic efficiency of 82.69%, an exceptional energy density of 23.51 Wh/kg and a strong power density of 1289.58 W/kg after 7000 GCD cycles. Besides, the composite electrode is used as a non-enzymatic electrochemical glucose sensor. The electrode showed high sensitivity and performance against glucose detection. The nanocomposite electrode materials provide an opportunity to design highly efficient and multifunctional devices.