Facile synthesis of Ni-Co LDH /Cu۲SnO۴ nanostructure for highperformance supercapacitors

Supercapacitors have attracted significant attention due to the fast charge-discharge ability,excellent rate capability and long-time stability. In this study, a nanoarray electrode composed of Cu۲SnO۴ and Ni-Co layerd double hydroxide (Ni-Co LDH) supported on Ni foam (NF) is successfully constructed by in situ growth route. Firstly , Copper (II) - Tin (IV) oxide arrays were fabricated by a mild hydrothermal reaction as the core. Afterwards, the as-prepared electrode wasutilized as a skeleton to immobilize Ni-Co LDH with an electrochemical deposition method. The electrochemical performance of prepared Ni-Co LDH/Cu۲SnO۴ to achieve high specific capacitance and long-term life for supercapacitor electrode applications. The electrochemicalproperties of the Ni-Co LDH/Cu۲SnO۴ as a binder-free electrode for a supercapacitor were examined using cyclic voltammetry (CV), galvanostatic charge-discharge analysis (GCD), electrochemical impedance spectroscopy (EIS), and cycle life measurements in ۲ M KOHelectrolyte. The GCD analysis exhibited a specific capacitance as high as ۲۷۹۱ F g−۱ at ۱ A g−۱.This capacitor electrode has exellent cyclic stability with ۹۶.۹۲% capacitance retention after ۳۰۰۰cycles at ۲۰ A g−۱. These results demonstrate that Ni-Co LDH/Cu۲SnO۴ could be a promisingelectrode for high-performance energy storage devices. Moreover, an asymmetric supercapacitor was fabricated using Ni-Co LDH/Cu۲SnO۴ as the positive electrode, and activated carbon on Nifoam (AC/NF) as the negative electrode displayed an excellent electrochemical behavior with ahigh specific capacitance of ۱۷۷.۳۳ F g–۱ at ۱ A g–۱.

Keywords:

Cu۲SnO۴ nanostructure , Ni-Co LDH , Supercapacitor , Hydrothermal method , Energy storage.