Facile synthesis of porous CuCo₂O₄ composite sheets and their supercapacitive performance

The synthesis of metal oxide composites with porous structures for supercapacitor application has drawn much attention owing to their high surface area and easy access of the electrolyte ions to the electrode surface through the pores of the active materials. A facile hydrothermal approach is suggested for the synthesis of porous CuCo₂O₄ composite sheets and their application as an active electrode material for supercapacitor application. Field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) measurements show the formation of porous CuCo₂O₄ composite sheets. BET surface area measurements show that the porous CuCo₂O₄ composite sheet has 69.44 m² g⁻¹ surface area, which is 4.7 times higher than quasi-spherical CuCo₂O₄ nanoparticles. The porous CuCo₂O₄ composite sheet delivered 1037 C g⁻¹ specific capacity at 5 mV s⁻¹. Additionally, the porous CuCo₂O₄ composite sheet retained 94% of its initial specific capacity after 5000 charge-discharge cycles at 10 A g⁻¹ indicating an excellent cyclic stability. This excellent supercapacitive performance is attributed to the high surface area and enhanced ion transport through the pores of the CuCo₂O₄ sheets. This high specific capacity and excellent cyclic stability of the porous CuCo₂O₄ composite sheets prove to be a promising candidate for supercapacitor application.