Facile construction of a MgCo2O4@NiMoO4/NF core–shell nanocomposite for high-performance asymmetric supercapacitors†
The development of all-solid-state asymmetric supercapacitors (ASCs) is a hot topic, and the main goal of researchers is to develop better electrode materials. In this work, a double urchin-like hierarchical MgCo2O4@NiMoO4 (MCN) core–shell nanomaterial is successfully synthesized on foam nickel (NF) by a two-step simple and effective hydrothermal method. It displays good physical, chemical structure and excellent electrochemical properties, which is mainly due to the synergistic effect of both MgCo2O4 and NiMoO4 electrode materials. The MCN-2 electrode material exhibits a high specific capacitance of 1775 F g−1 at 1 A g−1 and an excellent cycling stability of 74.7% after 5000 cycles. In addition, the MCN-2//AC ASC device is assembled using the MCN-2 electrode material as the positive electrode and activated carbon (AC) as the negative electrode. Obviously, the MCN-2//AC ASC device possesses an excellent cycling stability of 71.7% after 10 000 cycles and a high energy density of 37.5 W h kg−1 at the power density of 480 W kg−1. Simultaneously, it can supply power for light emitting diodes (LEDs) and motors successfully. The above results manifest that the MCN-2//AC ASC device is a good energy storage device, and it has great potential in practical applications.