Morphology modulation of cobalt-based nano-oxides and their use as high-performance supercapacitor electrode materials

To further enhance the electrochemical performance of electrochemical supercapacitors (ESCs), we have prepared Co3O4 nanomaterials with a foam substrate using a simple one-step hydrothermal method. The morphological modulation of Co3O4 nanomaterial is accomplished by nickel atoms and fluorine ions in the feedstock. Three samples of Co3O4 porous nano microspheres (PNS), Co3O4 nanoflower (NFAS), and Co3O4 nanowire arrays (NWAS), are prepared by the controlled variable method. Their unique nanostructures effectively increase the specific surface area of the material and shorten the ion conduction path, ultimately achieving high capacity and extremely long cycle stability. The results show that the Co3O4 NWAS has the highest specific capacity (525.5 F g(-1) at a current density of 1 A g(-1)) and good cycling stability (107% capacity retention for 10,000 cycles at a current density of 10 A g(-1)). In addition, the Co3O4 NWAS provides an energy density of 21.4 W h kg(-1) at a power density of 4.87 kW kg(-1) (15 A g(-1)). These results provide ample evidence that the Co3O4 prepared in this work has the potential to become a commercial ESC electrode material.