Perforated Co₃O₄ nanosheets as high-performing supercapacitor material

While cobalt oxide (Co₃O₄) is a promising material to be used in electrical energy storage systems, its full potential remains to be tapped presumably due to limited porous surface (small surface area) and high electrical resistance. In this work, the Co₃O₄ is prepared in the form of perforated nanosheets using hydrothermal synthesis method. After the detailed characterization of structure, phase purity, surface morphology, surface area and pore-size distribution, the potential of the as-prepared Co₃O₄ is evaluated as electrode materials for supercapacitor. The perforated Co₃O₄ nanosheets exhibited excellent specific capacitance performance of 1455.64 F g⁻¹ at 1.0 A g⁻¹ in 3.0 M KOH electrolyte solution. The fabricated asymmetric device showed an excellent (94.10%) retention after 2000 cycles suggesting high chemical stability because of upright standing perforated Co₃O₄ nanosheets. The Co₃O₄//Co₃O₄ symmetric device exhibited the energy density of 22.51 Wh kg⁻¹ and maximum power density of 311.68 W kg⁻¹ at the current density of 1 A g⁻¹, reflecting its industrial potential. In addition, the fabricated device showed excellent chemical and cyclic stability with 82.52% after 2000 cycles at current density of 5 A g⁻¹. The present work demonstrates the capabilities of the perforated Co₃O₄ nanosheets morphology with admirable half-cell and device performance.