A honeycomb-like ZnO/SnO2 nanocomposite on nickel foam for high-performance asymmetric supercapacitors

In this work, a honeycomb-like ZnO/SnO2 nanocomposite was synthesized on nickel foam (NF) using a single-step hydrothermal route for achieving good electrochemical performance. The as-prepared electrode showed an excellent electrochemical performance in 3 M KOH electrolyte, a superior specific capacitance (C-s) of 2307 F g(-1) and good stability, 78.8% retention of its initial value after 7000 galvanic charge-discharge (GCD) cycles in a three electrode system. An asymmetric supercapacitor (ASC, ZnO/SnO2@NF//AC@NF) exhibited a maximum C-s of 133 F g(-1) with 92.8% retention after 4000 GCD cycles. The calculated energy and power density were 47.28 W h kg(-1) and 10.4 kW kg(-1) respectively. Our investigations demonstrate that the as-synthesized ZnO/SnO2 nanocomposite could be a good competitor as an electrode material in high-performance electrochemical energy storage applications.