Using chemical bath deposition to create nanosheet-like CuO electrodes for supercapacitor applications.

We report the effect of ionic liquids on chemically synthesized hierarchical-like copper oxide (CuO) thin films for supercapacitor applications. Concisely, the CuO thin films were deposited via chemical bath deposition (CBD) using 2-dimethylimidazolium chloride [HPDMIM(C1)], 1-(2',3'-dihydroxypropyl)-3-methylimidazolium chloride [DHPMIM(C1)], and N-(3-methyl-2-oxopropyl)pyridine chloride [MOCPP(C1)] ionic liquid solvents. The effects of the ionic liquid solvents on the morphological evolution of the as-prepared films were analyzed, and electrochemical properties were investigated. The highest specific capacitance was achieved for the electrode with a nanosheet-like structure produced by functionalization with the HPDMIM(C1) ionic liquid. The maximum specific capacitance achieved for the HPDMIM(C1):CuO hybrid electrode was 464 F g-1 at 5 mV s-1 in a 1 M Na2SO4 electrolyte. Thus, our findings, in addition to the stability of the HPDMIM(C1):CuO, indicate that it is a candidate for energy-storage applications.

Novel approach to synthesize NiCo2S4 composite for high-performance supercapacitor application with different molar ratio of Ni and Co.

Here, we developed a new approach to synthesize NiCo2S4 thin films for supercapacitor application using the successive ionic layer adsorption and reaction (SILAR) method on Ni mesh with different molar ratios of Ni and Co precursors. The five different NiCo2S4 electrodes affect the electrochemical performance of the supercapacitor. The NiCo2S4 thin films demonstrate superior supercapacitance performance with a significantly higher specific capacitance of 1427 F g-1 at a scan rate of 20 mV s-1. These results indicate that ternary NiCo2S4 thin films are more effective electrodes compared to binary metal oxides and metal sulfides.

Supercapacitive activities of potentiodynamically deposited nanoflakes of cobalt oxide (Co3O4) thin film electrode.

In the present work, the Co3O4 thin films are successfully prepared via potentiodynamic electrodeposition method onto inexpensive stainless steel substrate. As-deposited films were heat treated at 623K for their conversion into Co3O4. These films were characterized by means of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM) techniques. The X-ray diffraction (XRD) study revealed the formation of cobalt oxide (Co3O4) with cubic crystal structure. The FT-IR study supports the formation of Co3O4 material. The SEM image of Co3O4 film showed nanoflake-like morphology with an average thickness of 100 nm. Supercapacitive properties of Co3O4 thin film electrode were examined using cyclic voltammetry and charge-discharge techniques. The Co3O4 thin film electrode showed maximum specific capacitance of 365 Fg(-1) in 1M KOH electrolyte at the scan rate of 5 mV s(-1). The charge-discharge technique was employed to estimate the values of specific energy, power and coulombic efficiency as 64 W h kg(-1), 21.53 kW kg(-1) and 99%, respectively.