High performance pseudocapacitor electrode material fabricated by pulse electro-synthesized cobalt oxide nanostructures

Abstract

High surface Co3O4 nanosheets were prepared were synthesized by a facile two-step approach, including a pulsed cathodic deposition without any surfactant and followed calcination of precursor. The as-deposited material was composed of pure β-cobalt hydroxide with sheet-like morphology. The calcined product was cubic spinel Co3O4 phase with sheet texture according to X-ray diffraction and scanning electron microscopy. The oxide formation on heating was discussed based on the thermogravimetric data. Brunauer-Emmett-Teller (BET) measurement showed the high surface area of about 164 m2 g-1 for the prepared cobalt oxide nanosheets. The pseudocapacitor capacitance of the prepared electrode was as high as 501.6 F g-1 at a current density of 2 A g-1, and the cycling stability remained about 89.9% after 2000 cycles. The fabricated electrode delivered energy and power densities of 29.43Wh/Kg and 0.33 W/g, respectively. These results confirmed the high pseudocapacitive performance of the prepared active nanomaterials.