Ni Foam-Supported Carbon-Sheathed NiMoO₄ Nanowires as Integrated Electrode for High-Performance Hybrid Supercapacitors

Rational design of hierarchical nanostructure arrays as integrated electrodes with the capability of storing energy has been studied extensively. However, a low electronic/ionic transport rate and structural instability hampered their practical application. In this study, we have fabricated carbon-sheathed NiMoO₄ nanowires standing on nickel foam (NF) and employed as a free-standing electrode for supercapacitor. The unique structure revealed remarkable electrochemical behavior including a high areal capacitance, ∼70% capacitance retention at 100 mA cm^–2, and an stability during cycling (86% retention after 50,000 cycles). In addition, an NF@NiMoO₄@C//activated carbon hybrid supercapacitor presents 201.3 F g^–1 of specific capacitance along with an 72.4 W h kg^–1 of energy density. The carbon sheath, which prevents the structural pulverization of NiMoO₄ and provides another conductive path together with Ni foam, is responsible for the superior electrochemical performances. Our work demonstrates an improved step toward rational design of high-performance integrated electrodes for a supercapacitor with a new vision for theoretical and practical applications