Hierarchical chestnut-like manganese cobalt oxide (MnCo2O4) nanoneedles (NNs) are successfully grown on nickel foam using a facile and cost-eff ective hydrothermal method. High resolution TEM image further verifies that the chestnut-like structure is assembled by numerous 1D nanoneedles, which are formed by numerous interconnected MnCo2O4 nanoparticles with grain diameter of ~10 nm. The MnCo2O4 electrode exhibits high specific capacitance of 1535 F g -1 at 1 A g -1 and good rate capability (950 F g -1 at 10 A g -1 ) in a 6 M KOH electrolyte. An asymmetric supercapacitor is fabricated using MnCo2O4 NNs on Ni foam (NF) as the positive electrode and graphene/NF as the negative electrode. The device shows an operation voltage of 1.5 V and delivers a high energy density of ∼60.4 Wh kg −1 at a power density of ∼375 W kg −1 . Moreover, the device exhibits an excellent cycling stability of 94.3% capacitance retention after 12000 cycles at 30 A g -1 . This work demonstrates that hierarchical chestnut-like MnCo2O4 NNs could be a promising electrode for the high performance energy storage devices.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.