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  • In-situ growth of Ni–Co LDH...
    Shoghi, Zeinab; Arvand, Majid; Farahpour, Mona

    Journal of solid state electrochemistry, 02/2024, Letnik: 28, Številka: 2
    Journal Article

    In this work, a nanoarray electrode consisting of ZnCu 2 O 4 nanoparticles (ZnCu 2 O 4 NPs) and Ni–Co layered double hydroxide (Ni–Co LDH) nanoparticles supported on Ni foam (NF) is successfully achieved by an in situ growth route. The pre-formed ZnCu 2 O 4 nanoparticles on Ni foam operate as a substrate and then guide the Ni–Co LDH nanoparticles on their surface by facile hydrothermal method. Electrochemical performances of the Ni–Co LDH/ZnCu 2 O 4 nanoparticles are evaluated by cyclic voltammetry (CV), galvanostatic charge-discharge techniques (GCD), electrochemical impedance spectroscopy (EIS), and cycle life measurements in 2 mol L –1 KOH electrolyte. The Ni–Co LDH/ZnCu 2 O 4 electrode achieves a maximum capacity of 3511.77 F g –1 at 1 A g –1 with raising cycling stability of 99.84% capacitance retention after 5000 cycles at 8 A g –1 , together with ~ 100% Coulombic efficiency. In addition, an asymmetric supercapacitor is fabricated using Ni–Co LDH/ZnCu 2 O 4 NPs on Ni foam (Ni–Co LDH/ZnCu 2 O 4 NPs/NF) as the positive electrode, and activated carbon on Ni foam (AC/NF) as the negative electrode, which shows an operation voltage of 1.15 V, and high specific energy of 103.16 Wh kg –1 at a specific power of 824.97 W kg –1 with good cycling stability of 97.88% capacitance retention after 5000 cycles at 2 A g –1 . Moreover, the asymmetric device displays improved low self-discharge behavior by charging it at an optimal current density and time, and the self-discharge is severely suppressed due to the presence of a 3D network of Ni–Co LDH/ZnCu 2 O 4 NPs grown on nickel foam. The unique core-shell configuration of Ni–Co LDH/ZnCu 2 O 4 can make full use of the synergistic effects of two components, provide sufficient electroactive sites, as well as facilitate the charge transport process because of their considerable electrochemical properties, making it a potential choice for electrochemical energy storage.