Design of open-porous three-dimensional starfish-like Co3O4/Ni forest electrode for efficient energy storage devices

A binder-free positive electrode material of 3D starfish-like Co3O4/Ni forest is fabricated via a novel and facile hydrothermal process followed by thermal treatment. The morphological studies clearly showed the construction of starfish-like micro-flowers of Co3O4 nanostructure forest densely covered on the entire Ni current collector. The 3D-Co3O4/Ni electrode displayed an areal capacity as high as 143.28 mC cm−2 at 0.5 mA cm−2 and higher stability of 88.4% after 5000 cycles. Moreover, the fabricated 3D-Co3O4/Ni||3D-Bi2O3/Ti supercapattery delivered a maximum areal capacitance of 24.73 mF cm−2, the energy density of 6.73 μWh cm−2 and power density of 5250 μW cm−2 with good cycling stability> 71% capacity retention after 5000 cycles. The higher electrochemical performance of the electrode is delivered due to the availability of abundant electrochemically active sites in the 3D starfish-like Co3O4 microflower, which facilitates a higher electrochemical reaction. The starfish-like forest architectures allow rapid ion diffusion, and the binder-free electrode reduces the contact resistance, which fasten the electron transport. These tolerable results prompt the as-prepared electrode with 3D starfish-like Co3O4 microflower morphology as an auspicious positive electrode material for electrochemical energy storage devices.