Three-dimensional BiO/Ti microspheres as an advanced negative electrode for hybrid supercapacitors.

Herein, we report a novel, low-temperature solvothermal method to grow 3D-Bi2O3 flower-like microspheres on Ti substrates as a binder-free negative electrode for supercapacitor applications. The Bi2O3/Ti electrode showed an areal capacitance of 1.65 F cm-2 at 4 mA cm-2. Moreover, the 3D-NiCo2O4||3D-Bi2O3 hybrid device delivered high energy and power densities of 31.17 μW h cm-2 and 7500 μW cm-2, respectively. The more optimal energy storage performance based on the strong adhesion of the current collector and self-assembled three-dimensional nanostructures permits efficient electron and ion transportation.