Effect of different electrolytes and deposition time on the supercapacitor properties of nanoflake-like Co(OH)2 electrodes

The effect of ultrasonic treatment and deposition time on nanoflake-like Co(OH)2 thin films were prepared using the potentiostatic mode of electrodeposition method on stainless steel substrates by a nitrate reduction reaction. After ultrasonic treatment, we used stainless steel substrates for deposition of the nanoflakes like Co(OH)2 thin films. The effect of deposition times and electrolytes on different physico-chemical properties of Co(OH)2 was investigated in detail, such as X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDS), and electrochemical testing. After ultrasonic treatment Co(OH)2 thin films had devolvement of the uniform and interconnected formation of nanoflakes nanostructures. Supercapacitor performance of the Co(OH)2 electrodes suggest that, specific capacitance are depends on the surface morphology, and Co(OH)2 electrodes after ultrasonic treatment exhibited higher performance than without ultrasonication. The maximum specific capacitance of the 30 min. deposited Co(OH)2 nanoflakes exceeded 276 Fg−1 in 0.5M KOH electrolyte at 5 mVs−1 scan rate.