An integrated electrode of hierarchical ZnCo2O4@ZnCo2O4 core–shell nanosheet arrays/nickel foam has been successfully synthesized, via a one-step hydrothermal method followed by calcination treatment. The hierarchical ZnCo2O4@ZnCo2O4 nanosheet arrays seem to possess mesoporous characteristics with ultrathin thickness. Due to its novel, hybrid nanoarchitecture, such an electrode system has exhibited remarkable areal specific capacitance along with excellent cycling life, even under fairly high current density conditions.
