3D marigold flowers of copper-nickel oxide composite materials as a positive electrode for high-performance hybrid supercapacitors

• Published in: New journal of chemistry Vol. 48; no. 27; pp. 12275 - 12287
• Main Authors: Jadhav, Amar L, Jadhav, Sharad L, Mali, Sawanta, Hong, C. K, Kadam, Anamika V
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 08.07.2024
• Subjects: Capacitance; Composite materials; Copper; Cycles; Electrical resistivity; Electrodes; Graphene; Marigolds; Metal oxides; Morphology; Nanomaterials; Nickel; Nickel oxides; Stability; Supercapacitors; Three dimensional composites; Three dimensional flow
• ISSN: 1144-0546; 1369-9261
• DOI: 10.1039/d4nj01796j

Despite their high specific capacitances, metal oxide-based electrodes still do not meet the commercial standard for cycling stability owing to their inherent poor electronic conductivity and morphological structural changes during charging and discharging. A superior specific capacitance, accompanied with long-term cycling durability, is pivotal for supercapacitor application. In this research article, different precursor volume ratios of copper-nickel solution were used for the construction of binder-free 3D marigold flower-like copper-nickel oxide (3D-MCuNi oxide) electrodes via a hydrothermal method. XPS, EDAX, and TEM studies reveal that the increased amount of O-vacancies in the marigold flowers of the copper-nickel oxide composite is caused by a significant number of imperfections in the structure and might enhance their electrical conductivity. The marigold flower-like morphological structure exhibits electrode-electrolyte ions with significantly high hydrophilicity and better electrochemical diffusion performance. The optimized volume ratio of Cu : Ni = 1 : 1 for 3D-MCuNi oxide composite nanomaterials demonstrates an excellent specific capacitance of 2387.15 F g −1 at a current density of 0.6 mA cm −2 and 93% cycling capacitive retention performance up to 10 000 cycles. Additionally, a flexible hybrid supercapacitor device (HSD) was assembled using reduced graphene oxide (rGO) and 3D-MCuNi oxide as the negative and positive electrode, respectively, which revealed excellent electrochemical charge storage performance with a high energy density of 120.9 W h kg −1 , power density of 34.82 kW kg −1 , and superior cycling stability of 87% retention. Thus, the 3D-MCuNi oxide composite potential materials are more attractive for charge storage supercapacitor applications. 3D marigold flowers of copper-nickel oxide via hydrothermal method as positive electrode for high-performance hybrid supercapacitor with specific capacitance of 2387.15 F g −1 and 93% cycling capacitive retention performance up to 10 000 cycles.