Ultrathin porous hierarchically textured NiCo2O4–graphene oxide flexible nanosheets for high-performance supercapacitors†
The ultimate goal of supercapacitor research industries is to develop devices which could be used as flexible, portable, ultrathin and highly-efficient power sources. However, the bulk NiCo2O4 materials prevent the achievement of high energy density as well as immense rate performance due to the limited electroactive surface area. In this work, we proposed a new breakthrough strategy to develop highly porous hierarchical flexible nanosheets of NiCo2O4–graphene oxide (NiCo2O4–GO) on nickel foam by a facile electrochemical deposition method. The morphogenesis of the NiCo2O4–GO hybrid nanostructure-based electrode exhibits hierarchical porous flexible nanosheet-like structures. The electrochemical properties of these electrodes were investigated by cyclic voltammetry and galvanostatic charge–discharge measurements in 3 M KOH electrolyte. The obtained results exhibit that this new hybrid nanostructure has a specific capacitance of 1078 F g−1 at a discharge current of 1 mA with great cyclic stability. These excellent capacitive performances of NiCo2O4–GO can be attributed to its hierarchical porous nanosheet-like unique structure. This unique structure provides efficient ion transport that is highly desirable for superior rate capability and excellent cycling stability. Hence, our method provides a promising facile and binder-free nanostructure electrode for next generation high-performance supercapacitor applications.