Nickel-based materials electrodeposited from a deep eutectic solvent on steel for energy storage devices

摘要

Nickel film composed of agglomerated nanoparticles was electrodeposited cathodically on stainless steel current collectors from choline chloride and urea-based deep eutectic solvent for charge storage electrodes. The electrochemically modified electrodes were investigated at positive potential regions in alkaline solution. Nickel-based electrode cycled in KOH was NiOOH in the oxidized form and Ni(OH)(2) in the reduced form. Compositional, structural and morphological studies of the electrodes were characterized by means of FTIR, XRD and SEM, respectively. The porous NiOOH/Ni(OH)(2) electrode with KOH electrolyte can provide a high electrode/electrolyte interfacefor fast charge transfer reactions. The charge storage mechanism was the mixed surface-controlled and diffusional-controlled processes. The as-prepared binder-free nickel-based electrode illustrates a high specific capacity of 986 Fg(-1) at 5mVs(-1). The cycling stability test gave 86% of initial capacity retained after 550 cycles. The use of deep eutectic solvent for the growth of nickel-based nanoparticles presented herein may offer promising potential in electrodeposition for the preparation of high-performance supercapacitors.[GRAPHICS].