Abstract
Hierarchical structures of metal oxides are extremely crucial for the advancement of energy storage materials. Herein, we report a simple template free method for the synthesis of hierarchical superstructure consisting of hollow mesoporous Co3O4 nanostructures
decorated by nanoflakes. Each hollow particle is outfitted with dual-faced nanoscale thin walls with a uniform thickness of 50-80 nm and the outer surface is covered by flake like nanostructures with a thickness of 10 nm. In addition, the method yields gram quantities with highly reproducible
structures. The as-obtained Co3O4 electrodes with distinct hollow superstructures are applied into an electrode for electrochemical capacitors (ECs), revealing high specific capacitance of about 302 F · g−1 at 1 A · g−1.
Capacitive performances of hollow mesoporous Co3O4 such as cycle life and rate capability are evaluated to compare with those of control sample and previous results. A symmetric EC device is fabricated, exhibiting prominent cycle performance with less than 8% capacitance
loss after 5000 charge-discharge cycles.