Facile sonochemical synthesis of 2D porous Co3O4 nanoflake for supercapattery

Two dimensional (2D) porous cobalt oxide (Co3O4) nanoflake (CONF) arrays are prepared by a facile sonochemical synthesis followed by calcination at 300 °C for 3 h. The successful synthesis and phase purity of CONFs were confirmed using X-ray diffraction (XRD) and Raman spectroscopy. Field emission scanning electron microscopy (FESEM) and high resolution transmission electron microscopy (HRTEM) analyses confirmed the porous flake-like structure of Co3O4. The performance of the CONFs is evaluated for energy storage application. The electrochemical performance in standard three electrode cell system revealed a high redox behaviour of CONFs which reveals its battery grade behaviour. In order to fabricate the supercapattery, CONFs-based electrode is employed as a positive electrode while activated carbon based electrode is used as negative electrode. Supercapattery device showed an excellent performance in terms of specific capacity (108.8C/g), energy density (23.7 Wh/kg) and power density (307 W/kg). The enhanced electrochemical performance was attributed to the unique 2D porous structure of Co3O4. Additionally, supercapattery showed excellent cyclic stability over 2500 cycles by maintaining 88.5% of its initial specific capacity value. [Display omitted] •Porous Co3O4 nanflakes were prepared by sonochemical method.•Structural and morphological characterizations were done.•Electrochemical performance of Co3O4 nanoflakes was done for energy storage.•Co3O4 nanoflakes based supercapattery gave enhanced electrochemical performance.